CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income	$ 38,323	$ 35,542	$ 28,996
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,705	1,625	1,500
Depreciation expense	7,289	6,410	5,886
Amortization of mortgage servicing rights	1,510	1,313	1,004
(Recovery)/additional impairment of valuation allowance on mortgage servicing rights		(200)	25
Securities amortization, net	4,901	3,386	1,973
Amortization of purchased intangible assets	1,342	1,640	1,690
Earnings on cash surrender value of life insurance policies	(1,513)	(1,236)	(1,298)
Gain on life insurance benefit		(307)
Securities gains, net	(170)	(386)	(24)
Gain on loans sold	(7,311)	(5,553)	(4,730)
Loans originated for sale	(254,581)	(236,928)	(165,827)
Proceeds from loan sales	256,946	243,230	168,832
Stock based compensation expense	1,001	843	647
Stock portion of director retainer fee expense	382	315	359
Gain/(Loss) on sale and write-down of OREO	268	68	(153)
Prepayment penalty on FHLB advance		2,364
Change in other assets and liabilities	(2,294)	1,402	4,172
Net cash provided by operating activities	47,262	53,392	43,358
Investing Activities
Net change in short term investments		(45)	(1,915)
Purchases of securities available for sale	(242,730)	(345,783)	(61,756)
Proceeds from calls, maturities, and payments on securities available for sale	142,543	136,799	106,268
Proceeds from sales of securities available for sale	88,203	147,109	27,131
Loan originations and payments, net	(144,129)	(176,184)	(110,124)
Purchases of premises and equipment	(14,068)	(7,794)	(5,593)
Proceeds from sale of OREO	3,985	2,272	3,864
Proceeds from redemption of restricted stock	3,789	2,785	3,251
Purchase of restricted stock	(5,531)	(231)
Proceeds from sale of portfolio loans		11,356
Proceeds from life insurance benefit		1,094	588
Cash received/(paid) from bank/branch acquisitions, net	(11,289)	57,083	(10,686)
Net cash used by investing activities	(179,227)	(171,539)	(48,972)
Financing Activities
Net change in deposits	15,401	83,428	83,796
Net change in other borrowings	162,976	2,014	(13,293)
Proceeds from FHLB advances	420,000	700,000	825,000
Repayment of FHLB advances	(451,986)	(647,289)	(874,745)
Proceeds from term debt	30,000
Cash dividends on common stock	(14,296)	(11,680)	(8,726)
Purchase of treasury shares	(1,045)	(3,527)	(319)
Repayment on term debt	(11,667)
Repayment of subordinated debentures, net			(5,000)
Proceeds from exercise of stock options, including tax benefit	1,556	294	66
Net cash provided by financing activities	150,939	123,240	6,779
Net change in cash and cash equivalents	18,974	5,093	1,165
Cash and cash equivalents, beginning of year	67,578	62,485	61,320
Cash and cash equivalents, end of period	86,552	67,578	62,485
Supplemental cash flow information
Interest paid	10,420	8,424	8,807
Income taxes paid	5,365	4,985	4,725
Supplemental non cash disclosure
Loan balances transferred to foreclosed real estate	$ 1,965	1,475	$ 2,585
Loan balances transferred to loans held for sale		$ 11,356