PARENT ONLY CONDENSED FINANCIAL STATEMENTS - Parent Only Condensed Statement Of Cash Flows - (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 9,108	$ 9,111	$ 9,660	$ 7,663	$ 6,560	$ 8,457	$ 7,754	$ 6,225	$ 35,542	$ 28,996	$ 26,345
Change in other assets and liabilities									1,402	4,172	5,091
Net cash provided by operating activities									53,392	43,358	60,083
Investing Activities
Proceeds from sales of securities available for sale									147,109	27,131	80,151
Purchases of equipment									(7,794)	(5,593)	(7,631)
Net cash (used) by investing activities									(171,539)	(48,972)	(141,392)
Financing Activities
Repurchase of preferred shares											(15,100)
Purchase of treasury shares									(3,527)	(319)	(204)
Repayment of subordinated debentures, net										(5,000)	(4,000)
Cash dividends on preferred stock											(470)
Cash dividends on common stock									(11,680)	(8,726)	(5,709)
Net cash provided by financing activities									123,240	6,779	76,979
Net change in cash and cash equivalents									5,093	1,165	(4,330)
Cash and cash equivalents, beginning of year				62,485				61,320	62,485	61,320	65,650
Cash and cash equivalents, end of period	67,578				62,485				67,578	62,485	61,320
Parent Company
Operating Activities
Net income									35,542	28,996	26,345
Undistributed (income)/loss of subsidiaries									(12,010)	(10,636)	2,398
Change in other assets and liabilities									1,896	3,862	1,833
Net cash provided by operating activities									25,428	22,222	30,576
Investing Activities
Capital contributed to subsidiary, net											(250)
Proceeds from sales of securities available for sale										750
Cash paid for bank acquisitions, net										(13,935)
Purchases of equipment									(1,991)	(403)	(667)
Net cash (used) by investing activities									(1,991)	(13,588)	(917)
Financing Activities
Proceeds from exercise of stock options									294	66	389
Repurchase of preferred shares											(15,100)
Purchase of treasury shares									(3,527)	(319)	(204)
Repayment of subordinated debentures, net										(5,000)	(4,000)
Cash dividends on preferred stock											(470)
Cash dividends on common stock									(11,680)	(8,726)	(5,709)
Net cash provided by financing activities									(14,913)	(13,979)	(25,094)
Net change in cash and cash equivalents									8,524	(5,345)	4,565
Cash and cash equivalents, beginning of year				$ 6,322				$ 11,667	6,322	11,667	7,102
Cash and cash equivalents, end of period	$ 14,846				$ 6,322				$ 14,846	$ 6,322	$ 11,667