Note 16 - Stockholders' Equity (Detail) - Accumulated Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Beginning balance, net of tax	$ 465
Reclassification adjustment for net securities gains included in net income	(6,292)
Reclassification adjustment for net securities gains included in net income	(2,645)
Reclassification adjustment for net securities gains included in net income	(3,647)	(1,284)
Net unrealized gains arising from transferring securities held-to-maturity to available-for-sale	38,052
Net unrealized gains arising from transferring securities held-to-maturity to available-for-sale	15,997
Net unrealized gains arising from transferring securities held-to-maturity to available-for-sale	22,055
Total other comprehensive income	39,707
Total other comprehensive income	16,695
Total other comprehensive income	23,012	4,195
Ending balance, net of tax	23,477
Net unrealized gains arising during the period	7,947
Net unrealized gains arising during the period	3,343
Net unrealized gains arising during the period	$ 4,604