CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Cash Flows from Operating Activities
Net income	$ 10,626	$ 9,109	$ 28,323	$ 25,181
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based and non-cash compensation			1,001	835
Depreciation			4,267	4,238
Amortization of intangible assets	807	701	2,384	2,181
Provision for loan losses			600	2,000
Provision for deferred income taxes			(1,986)	11,999
Amortization of security premiums and discounts, net			6,336	5,525
Accretion of premiums and discounts on loans, net			(1,222)
Net security losses (gains)			21	(40)
Gain on sales of loans	(1,549)	(1,339)	(4,843)	(3,554)
Net loss on disposition of premises and equipment			145	4
Premises and equipment impairment			670
Increase in cash surrender value of bank owned life Insurance			(1,090)	(436)
Change in assets and liabilities:
Decrease (increase) in other assets			2,028	(2,427)
Decrease in other liabilities			(2,937)	(4,209)
Decrease in interest payable			(98)	(146)
Decrease (increase) in income taxes receivable			3,742	(426)
Net cash provided by operating activities before activities for loans originated for sale			37,341	40,725
Loans originated for sale			(228,307)	(164,570)
Proceeds from sales of loans			229,604	169,874
Net cash provided by operating activities			38,638	46,029
Cash Flows from Investing Activities
Proceeds from sales of securities classified available for sale			15,302	65,906
Proceeds from maturities of securities classified available for sale			152,165	137,943
Proceeds from maturities of securities classified held to maturity			408	6
Purchase of securities classified available for sale			(235,905)	(169,560)
Purchase of securities classified held to maturity			(16,025)	(1,026)
Net increase in loans			(54,656)	(89,514)
Proceeds from disposition of premises and equipment			311	8
Proceeds from sale of other real estate owned ("OREO") properties			927	2,655	$ 2,739
Purchases of premises and equipment			(3,265)	(2,792)
Net cash received in acquisitions			12,114
Net cash used in investing activities			(128,624)	(56,374)
Cash Flows from Financing Activities
Net decrease in certificates of deposit			(66,625)	(65,691)
Net increase in demand, money market and savings deposits			34,406	21,947
Cash dividends paid			(13,586)	(12,699)
Value of shares surrendered upon vesting of restricted stock units to cover tax obligations			(269)	(25)
Proceeds from long-term debt				30,000
Net decrease in securities sold under agreements to repurchase			(21,932)	(15,066)
Cash payment for fractional shares related to reverse stock split			(5)
Purchase of treasury stock			(6,296)
Net cash used in financing activities			(74,307)	(41,534)
Net decrease in cash and due from banks			(164,293)	(51,879)
Cash and due from banks, beginning			339,438	231,603	231,603
Cash and due from banks, ending	$ 175,145	$ 179,724	175,145	179,724	339,438
Cash Payments for:
Interest			4,751	5,075
Income taxes			9,570	2,686
Non-cash investing and financing activities:
Other real estate acquired in settlement of loans			$ 399	$ 596	$ 660