Note 21 - Parent Company Only Financial Information (Detail) - Condensed Statements of Financial Condition for the Holding Company: (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets:
Cash and due from banks	$ 40,425	$ 55,721
Other securities ($2,359 and $2,410 at fair value pursuant to the fair value option at December 31, 2012 and 2011, respectively)	229,453	65,242
Goodwill (in Dollars)	16,127	16,127
Other assets	47,502	48,016
Total assets	4,451,416	4,287,949
Borrowings (at fair value pursuant to the fair value option at December 31, 2012 and 2011)	23,922	26,311
Other liabilities	45,453	39,654
Total liabilities	4,009,051	3,871,038
Stockholders' Equity:
Common stock	315	315
Treasury stock, at average cost (787,266 shares and 626,418 at December 31, 2012 and 2011, respectively)	10,257	7,355
Retained earnings	241,856	223,510
Accumulated other comprehensive income, net of taxes	12,137	4,813
Total equity	442,365	416,911	390,045
Total liabilities and equity	4,451,416	4,287,949
Holding Company [Member]
Assets:
Cash and due from banks	21,041	18,798
Other securities ($2,359 and $2,410 at fair value pursuant to the fair value option at December 31, 2012 and 2011, respectively)	3,165	3,180
Interest receivable	13	12
Investment in subsidiaries	451,190	429,353
Goodwill (in Dollars)	2,185	2,185
Other assets	4,418	4,521
Total assets	482,012	458,049
Borrowings (at fair value pursuant to the fair value option at December 31, 2012 and 2011)	23,923	26,311
Other liabilities	15,724	14,827
Total liabilities	39,647	41,138
Stockholders' Equity:
Common stock	315	315
Additional paid-in capital	198,314	195,628
Treasury stock, at average cost (787,266 shares and 626,418 at December 31, 2012 and 2011, respectively)	(10,257)	(7,355)
Retained earnings	241,856	223,510
Accumulated other comprehensive income, net of taxes	12,137	4,813
Total equity	442,365	416,911
Total liabilities and equity	$ 482,012	$ 458,049