CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 57,330	$ 52,084	$ 46,367
Adjustments to reconcile net income to net cash from operating activities:
Depreciation	5,119	4,229	3,758
Provision for loan losses	3,000	1,150	0
(Gain) Loss on sale and write down of other real estate owned	12	17	(48)
Amortization of loan servicing rights	599	598	553
Loans originated for sale	(54,188)	(69,998)	(64,346)
Net gain on sales of loans	(1,749)	(2,047)	(1,650)
Proceeds from sale of loans	57,621	68,692	63,601
Net loss on sale of premises and equipment	79	160	7
Net (gain) loss on sales and calls of securities available for sale	(32)	(66)	(42)
Net securities amortization	3,114	2,860	4,464
Stock based compensation expense	5,698	4,210	2,535
Earnings on life insurance	(1,768)	(1,392)	(1,338)
Tax benefit of stock option exercises	(964)	(669)	(148)
Net change:
Interest receivable and other assets	787	(1,386)	(398)
Interest payable and other liabilities	2,584	3,757	2,466
Total adjustments	19,912	10,115	9,414
Net cash from operating activities	77,242	62,199	55,781
Cash flows from investing activities:
Proceeds from sale of securities available for sale	40,877	12,095	7,787
Proceeds from maturities, calls and principal paydowns of securities available for sale	61,745	69,343	74,679
Purchases of securities available for sale	(139,252)	(116,196)	(91,810)
Purchase of life insurance	(580)	(3,390)	(2,629)
Net increase in total loans	(347,217)	(391,145)	(322,114)
Proceeds from sales of land, premises and equipment	10	28	701
Purchases of land, premises and equipment	(9,582)	(9,825)	(9,167)
Proceeds from redemption of Federal Home Loan Bank Stock	0	0	1,745
Purchase of Federal Home Loan Bank Stock	(2,250)	(3,854)	0
Proceeds from sales of other real estate owned	199	136	963
Proceeds from life insurance	0	360	738
Net cash from investing activities	(396,050)	(442,448)	(339,107)
Cash flows from financing activities
Net increase in total deposits	430,743	394,491	310,301
Net increase/(decrease) in short-term borrowings	100,607	(19,577)	(55,785)
Proceeds on long-term borrowings	95,000	180,000	70,000
Payments on long-term borrowings	(275,002)	(70,002)	(35,001)
Common dividends paid	(21,396)	(18,200)	(15,697)
Preferred dividends paid	(13)	(13)	(13)
Proceeds (Payments) related to equity incentive plans	(1,736)	614	12
Purchase of treasury stock	(495)	(458)	(455)
Net cash from financing activities	327,708	466,855	273,362
Net change in cash and cash equivalents	8,900	86,606	(9,964)
Cash and cash equivalents at beginning of the year	167,280	80,674	90,638
Cash and cash equivalents at end of the year	176,180	167,280	80,674
Cash paid during the year for:
Interest	29,171	18,567	15,786
Income taxes	29,120	21,613	21,566
Supplemental non-cash disclosures:
Loans transferred to other real estate owned	88	105	853
Security purchased not settled	$ 0	$ 1,459	$ 0