Note 10 - Income Taxes (Detail) - Components of the income taxes attributable to income from operations and changes in equity: (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income from operations	$ 21,847	$ 23,469	$ 15,941
Equity:
Change in fair value of securities available for sale	5,577	8,398	2,714
Current year actuarial losses of postretirement plans	(340)	(1,932)	(513)
Amortization of net actuarial losses and prior service credits	436	223	120
Compensation expense for tax purposes in (excess) or less than that recognized for financial reporting purposes	303	(292)	(12)
Total income taxes	$ 27,823	$ 29,866	$ 18,250

The tax effects of employee stock option transactions that are recognized differently for financial reporting and tax purposes, occurring during the period and charged or credited directly to shareholders' equity.

+ References+ Details

The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to pretax Income or Loss from continuing operations; income tax expense or benefit may include interest and penalties on tax uncertainties based on the entity's accounting policy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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+ Details

- Definition

Tax effect of the income statement impact of the reclassification adjustment for prior service costs recognized as a component of net period benefit cost.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details