Amortization, net
Accretion (Amortization) of Discounts and Premiums, Investments
Amortization, net
Additional paid-in capital
Depreciation
CONSOLIDATED BALANCE SHEETS [Abstract]
Unrealized holding gains arising during the period
Net unrealized gains on other securities before tax expense
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax
Cash and due from banks
Beginning
Ending
Cash and Due from Banks
Interest
Increase (decrease) in accrued expenses and other liabilities
Change in assets and liabilities:
Commitments, Contingencies and Concentrations of Credit Risk
Commitments and Contingencies Disclosure [Text Block]
Authorized (in shares)
Issued (in shares)
Outstanding (in shares)
Common stock, $2 par value, authorized 18,000,000 shares; 9,432,915 shares issued and outstanding
Common stock, $2 par value, authorized 18,000,000 shares; issued 9,432,915 shares; outstanding 9,310,913 shares as of December 31, 2011 and 9,432,915 shares as of December 31, 2010
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Ames National Corporation (Parent Company Only) Financial Statements
Condensed Financial Information of Parent Company Only Disclosure [Text Block]
Borrowings
Debt Disclosure [Text Block]
Provision for deferred income taxes
Deferred Income Tax Expense (Benefit)
Deferred income taxes
Deposits
Deposit Liabilities Disclosures [Text Block]
Total deposits
Deposits
Deposits
Deposits [Abstract]
Time, $100,000 and over
Other time
Demand, noninterest bearing
NOW accounts
Regulatory Matters
Regulatory Capital Requirements under Banking Regulations [Text Block]
Basic and diluted earnings per share
Other-than-temporary impairment of investment securities
Federal funds purchased and securities sold under agreements to repurchase
Federal funds sold
Federal Home Loan Bank (FHLB) advances
Long-term Federal Home Loan Bank Advances
Loss on disposal of equipment
Gain (Loss) on Sale of Property Plant Equipment
Loss on disposal of equipment
Impairment of other real estate owned
CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Income Taxes
Income Tax Disclosure [Text Block]
Income taxes
Decrease (increase) in other assets
Increase (Decrease) in Other Operating Assets
Decrease (increase) in other assets
Interest bearing deposits in financial institutions
Total interest expense
Interest Expense
Interest expense:
Other borrowed funds
Deposits
Interest Expense, Deposits
Net interest income after provision for loan losses
Interest Income (Expense), after Provision for Loan Loss
Tax-exempt
Taxable
Securities:
Accrued income receivable
Debt and Equity Securities
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Salaries and employee benefits
Total liabilities
Liabilities
LIABILITIES
Liabilities [Abstract]
Total liabilities and stockholders ' equity
Liabilities and Equity
LIABILITIES AND STOCKHOLDERS ' EQUITY
LIABILITIES AND STOCKHOLDERS' EQUITY
Loans held for sale
Loans, including fees
Other long-term borrowings
Long-term Debt
Securities available-for-sale
Net cash provided by financing activities
Net Cash Provided by (Used in) Financing Activities
CASH FLOWS FROM FINANCING ACTIVITIES
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
CASH FLOWS FROM OPERATING ACTIVITIES
Increase in deposits
Increase (decrease) in federal funds purchased and securities sold under agreements to repurchase
Net decrease (increase) in federal funds sold
Decrease (increase) in accrued income receivable
Increase (Decrease) in Interest and Dividends Receivable
Decrease (increase) in accrued income receivable
Decrease (increase) in loans held for sale
Increase (Decrease) in Loans Held-for-sale
Decrease (increase) in loans held for sale
Net income
Net income
Net income
Net increase (decrease) in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease)
Net interest income
Interest Income (Expense), Net
Loans receivable, net
FDIC insurance assessments
Occupancy expenses
Other operating expenses, net
Noninterest Income
Total noninterest income
Noninterest Income [Abstract]
Noninteest income:
Trust services income
Gain on sale of other real estate owned
Gains (Losses) on Sales of Other Real Estate
Gain on sale of other real estate owned
Securities gains, net
Securities gains, net
Gain (Loss) on Sale of Securities, Net
Gain on sale of loans held for sale
Noninterest Income, Other
Other noninterest income
Service fees
Foreclosed Real Estate Expense
Other real estate owned, net
Interest and Dividend Income, Operating
Total interest income
Interest and Dividend Income, Operating [Abstract]
Interest income:
Net unrealized gains (losses) on securities with other than temporary impairment before tax expense
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax
Securities for which a portion of an other than temporary impairment has been recorded in earnings:
Less: reclassification adjustment for gains (losses) realized in net income
Unrealized holding gains (losses) arising during the period
Other real estate owned
Other short-term borrowings
Other Short-term Borrowings
Dividends paid
Payments of Dividends
Dividends paid
Employee Benefit Plans
Pension and Other Postretirement Benefits Disclosure [Text Block]
Proceeds from issuance of stock
Proceeds from FHLB and other long-term borrowings
Proceeds from maturities and calls of securities available-for-sale
Proceeds from sale of securities available-for-sale
Net proceeds from the sale of other real estate owned
Bank premises and equipment, net
Bank Premises and Equipment [Abstract]
Provision for loan losses
Purchase of securities available-for-sale
Payments to Acquire Available-for-sale Securities
Purchase of securities available-for-sale
Purchase of bank premises and equipment, net
Payments to Acquire Property, Plant, and Equipment
Purchase of bank premises and equipment, net
Other Real Estate Owned
Real Estate Owned [Text Block]
Loans Receivable and Credit Disclosures
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]
Payments on FHLB and other long-term borrwings
Repayments of Long-term Debt
Payments on FHLB and other long-term borrowings
Proceeds (payments) from other short-term borrowings, net
Repayments of Other Short-term Debt
Proceeds (payments) from other short-term borrowings
Payments for the purchase of common stock
Purchase of treasury stock
Retained earnings
Summary of Significant Accounting Policies
Significant Accounting Policies [Text Block]
CONSOLIDATED STATEMENTS OF CASH FLOWS [Abstract]
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY [Abstract]
STOCKHOLDERS' EQUITY
Stockholders' Equity Attributable to Parent [Abstract]
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Total noninterest expense
Noninterest Expense
Total noninterest expense
Noninterest expense:
Common Stock [Member]
Bank Premises and Equipment
Property, Plant and Equipment Disclosure [Text Block]
Total assets
Assets
Cash dividends declared per share
Statement [Table]
ASSETS
Assets [Abstract]
Statement [Line Items]
Fair Value Measurements
Fair Value Disclosures [Text Block]
Selected Quarterly Financial Data (Unaudited)
Quarterly Financial Information [Text Block]
Accumulated other comprehensive income-net unrealized gain on securities available-for-sale
Income before income taxes
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest
Par Value (in dollars per share)
Total stockholders ' equity
Beginning balance
Ending balance
Stockholders' Equity Attributable to Parent
Provision for income taxes
Statement, Equity Components [Axis]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income (loss) net of taxes [Member]
Equity Component [Domain]
CASH AND DUE FROM BANKS
Data processing
Sale of common stock
Stock Issued During Period, Value, New Issues
Sale of common stock (in shares)
Purchase of common stock (in shares)
Comprehensive Income [Member]
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING ACTIVITIES
Purchase of common stock
Cash dividends declared
Dividends, Common Stock, Cash
Adjustments to reconcile net income to net cash provided by operating activities:
Accrued expenses and other liabilities
Dividend payable
Other comprehensive income (loss), before tax:
Other comprehensive income before tax
Tax expense related to other comprehensive income
Other comprehensive income, net of tax:
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Other assets
Debt and Equity Securities [Abstract]
Loans Receivable and Credit Disclosures [Abstract]
Commitments, Contingencies and Concentrations of Credit Risk [Abstract]
Income Taxes [Abstract]
Ames National Corporation (Parent Company Only) Financial Statements [Abstract]
Fair Value Measurements [Abstract]
Subsequent Events
Subsequent Events [Text Block]
Borrowings [Abstract]
Employee Benefit Plans [Abstract]
Fair Value of Financial Instruments
Financial Instruments Disclosure [Text Block]
Selected Quarterly Financial Data (Unaudited) [Abstract]
Summary of Significant Accounting Policies [Abstract]
Subsequent Events [Abstract]
Regulatory Matters [Abstract]
Other Real Estate Owned [Abstract]
Transfer of loans to other real estate owned
Other-than-temporary impairment of investment securities
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net
Plus: reclassification adjustment for impairment losses realized in net income
Less: reclassification adjustment for gains realized in net income
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments
Amendment Flag
Current Fiscal Year End Date
Document Period End Date
Entity [Text Block]
Entity Well-known Seasoned Issuer
Entity Voluntary Filers
Entity Current Reporting Status
Entity Filer Category
Entity Public Float
Entity Registrant Name
Entity Central Index Key
Entity Common Stock, Shares Outstanding
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Type
Savings and money market
Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs), combined with the amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.
Savings and money market
Net (increase) decrease in loans
The net change during the reporting period in the value of loans or securitized loans that are held in portfolio.
Net decrease (increase) in loans
Improvements in other real estate owned
The cash outflow for capital improvements to real estate properties held for sale.
Other changes in other real estate owned
Cash payments for [Abstract]
Cash payments for:
Interest Bearing Deposits And Federal Funds Sold
Interest income derived from funds deposited with both domestic and foreign financial institutions including funds in money market and other accounts. And, interest income on federal funds sold. Federal funds sold represent the excess federal funds held by one commercial bank which it lends to another commercial bank, usually at an agreed-upon (federal funds) rate of interest. Such loans are made for legal reserve requirement purposes of the borrowing bank and generally are of short-duration (overnight).
Interest bearing deposits and federal funds sold
Merchant and ATM fees
Fee income from merchant transactions and ATM operations.
Provision for off-balance sheet commitments
Provision for off-balance sheet commitments.
Provision (credit) for off-balance sheet commitments
Net decrease (increase) in interest bearing deposits in financial institutions
Net decrease (increase) in interest bearing deposits in financial institutions.
Net decrease (increase) in interest bearing deposits in financial institutions
Fair Value of Financial Instruments [Abstract]
Restrictions on Cash and Due from Banks [Abstract]
Restrictions on Cash and Due from Banks [Text Block]
Disclosure of the cash and cash items which are restricted as to withdrawal or usage per Federal Reserve Bank requirements.
Restrictions on Cash and Due from Banks
Unrealized gains (losses) on securities without other than temporary impairment before tax: [Abstract]
Unrealized gains (losses) on securities without other than temporary impairment before tax:
Deferred income taxes
Deferred Income Taxes
Treasury stock, at cost: 122,002 shares and no shares at December 31, 2011 adn 2010, respectively
Treasury stock, at cost: 122,002 shares and no shares at December 31, 2011 and 2010, respectively
Other comprehensive income
Treasury Stock [Member]