Note 21 - Parent Company Only Financial Information (Detail) - Condensed Statements of Income for the Holding Company: (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
Interest income									$ 31,306	$ 32,121	$ 31,252
Interest expense	14,498	15,610	16,097	17,070	17,920	19,228	19,704	19,871	63,275	76,723	91,767
Net gain from fair value adjustments									55	1,960	47
Other operating expenses									11,450	10,485	9,136
Income tax (expense) benefit	5,782	5,988	5,519	4,558	5,664	6,756	5,991	5,058	21,847	23,469	15,941
Net income	9,200	9,365	8,637	7,129	8,171	10,150	9,074	7,953	34,331	35,348	38,835
Holding Company [Member]
Dividends from the Bank									20,000	20,000	10,000
Interest income									694	753	750
Interest expense									(2,957)	(4,325)	(4,324)
Net gain from fair value adjustments									1,991	5,725	2,253
Other operating expenses									(730)	(746)	(737)
Income before taxes and equity in undistributed earnings of subsidiary									18,998	21,407	7,942
Income tax (expense) benefit									498	(585)	972
Income before equity in undistributed earnings of subsidiary									19,496	20,822	8,914
Equity in undistributed earnings of the Bank									14,835	14,526	29,921
Net income									$ 34,331	$ 35,348	$ 38,835