CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net Income	$ 59,590	$ 50,143	$ 44,453
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	18,480	14,948	11,196
Deferred Income Taxes and Tax Credits	5,713	12,653	4,862
Depreciation and amortization	7,116	7,640	13,721
Net (gains) losses on securities and other assets	(5,257)	(729)	2,832
Net amortization of premiums and discounts on securities	4,524	2,793	2,233
Net amortization of premiums and discounts on long-term debt	0	0	(37)
Income from increase in cash surrender value of bank owned life insurance	(5,325)	(5,412)	(5,275)
Payments for Origination of Mortgage Loans Held-for-sale	(133,278)	(86,576)	(17,697)
Proceeds from Sale of Mortgage Loans Held-for-sale	136,037	85,718	15,598
(Increase) decrease in interest receivable	(577)	(41)	542
Decrease in interest payable	(272)	(103)	(404)
(Increase) decrease in income taxes payable	(589)	(354)	1,860
Other—net	3,111	(7,929)	8,253
Net cash provided by operating activities	89,273	72,751	82,137
Transactions with securities held to maturity:
Proceeds from maturities and redemptions	54,057	9,358	0
Purchases	(45,188)	(380,877)	0
Transactions with securities available for sale:
Proceeds from sales	55,744	88,054	132,868
Proceeds from maturities and redemptions	168,237	373,228	242,895
Purchases	(128,916)	(24,150)	(339,649)
Purchases of FHLB stock	(37,326)	(65,605)	(40,920)
Proceeds from the redemption of FHLB stock	63,780	48,029	31,819
Proceeds from bank owned life insurance	467	378	2,080
Proceeds from the sale of loans	18,612	3,018	3,112
Proceeds from sales of other assets	7,765	6,407	12,882
Acquisition, net of cash acquired	479,469	(3,533)	(3,042)
Net increase in loans	(135,436)	(191,853)	(195,120)
Payments for Purchase of Other Assets	(430)	0	0
Purchases of premises and equipment	(7,061)	(4,887)	(10,980)
Net cash provided by (used in) investing activities	493,774	(142,433)	(164,055)
Financing Activities
Net decrease in federal funds purchased	(4,000)	(5,000)	(7,000)
Net (decrease) increase in other short-term borrowings	(638,882)	409,949	486,261
Net increase (decrease) in deposits	132,180	(209,928)	(288,352)
Repayments of other long-term debt	(565)	(80,145)	(59,889)
Proceeds from issuance of long-term debt	0	0	5,000
Discount on dividend reinvestment plan purchases	0	0	(65)
Dividends paid	(24,907)	(25,089)	(26,174)
Proceeds from reissuance of treasury stock	216	192	192
Purchase of treasury stock	(864)	(25,383)	(30,956)
Net cash (used in) provided by financing activities	(536,822)	64,596	79,017
Net increase (decrease) in cash and cash equivalents	46,225	(5,086)	(2,901)
Cash and cash equivalents at January 1	69,452	74,538	77,439
Cash and cash equivalents at December 31	$ 115,677	$ 69,452	$ 74,538