Note 12 - Income Taxes (Detail) - Components of Income Tax Expense (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
Federal									$ 44,263	$ 26,548	$ 16,496
State									17,081	10,905	7,379
									61,344	37,453	23,875
Deferred:
Federal									3,755	10,133	(28,600)
State									1,029	3,675	(9,904)
									4,784	13,808	(38,504)
Total income tax expense/(benefit	$ 15,276	$ 17,686	$ 16,619	$ 16,547	$ 14,459	$ 14,162	$ 10,906	$ 11,734	$ 66,128	$ 51,261	$ (14,629)