Note 22 - Parent Company Only Financial Information (Details) - Condensed Statements of Financial Condition for the Holding Company: (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets:
Cash and due from banks	$ 34,265	$ 33,485
Other securities ($864 and $2,562 at fair value pursuant to the fair value option at December 31, 2014 and 2013, respectively)	268,377	261,634
Goodwill	16,127	16,127
Other assets	69,335	57,915
Total assets	5,077,013	4,721,501
Borrowings (at fair value pursuant to the fair value option at December 31, 2014 and 2013)	28,771	29,570
Other liabilities	55,676	44,067
Total liabilities	4,620,766	4,288,969
Stockholders' Equity:
Common stock	315	315
Treasury stock, at average cost (2,126,772 shares and 1,407,343 at December 31, 2014 and 2013, respectively)	37,221	22,053
Retained earnings	289,623	263,743
Accumulated other comprehensive loss, net of taxes	(2,907)	(11,375)	12,137
Total equity	456,247	432,532	442,365
Total liabilities and equity	5,077,013	4,721,501
Holding Company [Member]
Assets:
Cash and due from banks	7,749	16,525
Other securities ($864 and $2,562 at fair value pursuant to the fair value option at December 31, 2014 and 2013, respectively)	1,156	2,849
Interest receivable	4	4
Investment in subsidiaries	482,996	449,580
Goodwill	2,185	2,185
Other assets	4,402	4,354
Total assets	498,492	475,497
Borrowings (at fair value pursuant to the fair value option at December 31, 2014 and 2013)	28,770	29,570
Other liabilities	13,475	13,395
Total liabilities	42,245	42,965
Stockholders' Equity:
Common stock	315	315
Additional paid-in capital	206,437	201,902
Treasury stock, at average cost (2,126,772 shares and 1,407,343 at December 31, 2014 and 2013, respectively)	(37,221)	(22,053)
Retained earnings	289,623	263,743
Accumulated other comprehensive loss, net of taxes	(2,907)	(11,375)
Total equity	456,247	432,532
Total liabilities and equity	$ 498,492	$ 475,497