Note 22 - Parent Company Only Financial Information - Condensed Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income									$ 25,141	$ 24,827	$ 25,969
Interest expense	$ (13,668)	$ (13,811)	$ (13,202)	$ (13,230)	$ (13,052)	$ (12,603)	$ (12,082)	$ (11,989)	(53,911)	(49,726)	(49,554)
Fair Value, Option, Changes in Fair Value, Gain (Loss)									(3,434)	(1,841)	(2,568)
Other operating expenses									(16,740)	(15,118)	(11,809)
Income tax benefit	8,116	6,655	20,717	5,615	5,439	6,661	9,521	5,546	41,103	27,167	28,573
Net income, as reported	$ 14,286	$ 10,634	$ 30,435	$ 9,561	$ 11,634	$ 11,008	$ 14,834	$ 8,733	64,916	46,209	44,239
Other comprehensive (loss) income, net of tax									(2,800)	(2,655)	8,468
Comprehensive income									62,116	43,554	52,707
Holding Company [Member]
Dividends from the Bank									24,000	26,000	20,000
Interest income									247	242	512
Interest expense									(1,324)	(1,075)	(1,039)
Fair Value, Option, Changes in Fair Value, Gain (Loss)									(4,761)	(231)	779
Other operating expenses									(1,611)	(1,298)	(786)
Income before taxes and equity in undistributed earnings of subsidiary									16,551	23,638	19,466
Income tax benefit									3,198	687	668
Income before equity in undistributed earnings of subsidiary									19,749	24,325	20,134
Equity in undistributed earnings of the Bank									45,167	21,884	24,105
Net income, as reported									64,916	46,209	44,239
Other comprehensive (loss) income, net of tax									(2,800)	(2,655)	8,468
Comprehensive income									$ 62,116	$ 43,554	$ 52,707