CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net income	$ 57,786	$ 57,486	$ 58,069
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	5,833	2,160	3,733
Depreciation of premises and equipment	5,245	4,780	4,748
Depreciation of equipment owned and leased to others	21,678	18,280	13,893
Stock-based compensation	2,884	3,843	3,179
Amortization of investment securities premiums and accretion of discounts, net	5,861	4,652	4,351
Amortization of mortgage servicing rights	1,478	1,424	1,278
Deferred income taxes	2,856	1,620	4,341
Gains on investment securities available-for-sale	(1,796)	(4)	(963)
Originations of loans held for sale, net of principal collected	(119,134)	(113,029)	(121,440)
Proceeds from the sales of loans held for sale	116,397	120,138	117,447
Net gain on sale of loans held for sale	(3,287)	(3,330)	(3,532)
Net gain on sale of other real estate and repossessions	(228)	(814)	(1,624)
Change in trading account securities	0	205	(13)
Change in interest receivable	(1,326)	(549)	(603)
Change in interest payable	570	798	(917)
Change in other assets	2,145	(8,230)	(9,848)
Change in other liabilities	648	8,010	(2,481)
Other	450	3,168	2,733
Net change in operating activities	98,060	100,608	72,351
Investing activities:
Proceeds from sales of investment securities available-for-sale	23,784	1,299	1,236
Proceeds from maturities and paydowns of investment securities available-for-sale	217,613	136,649	190,323
Purchases of investment securities available-for-sale	(313,074)	(147,771)	(148,841)
Proceeds from liquidation of partnership investment	2,903	423	570
Net change in other investments	(485)	(1,172)	1,599
Loans sold or participated to others	5,926	1,962	16,889
Net change in loans and leases	(209,668)	(315,938)	(165,463)
Net change in equipment owned under operating leases	(30,100)	(54,508)	(27,069)
Purchases of premises and equipment	(8,935)	(9,498)	(8,489)
Proceeds from sales of other real estate and repossessions	2,189	6,941	10,418
Net change in investing activities	(309,847)	(381,613)	(128,827)
Financing activities:
Net change in demand deposits and savings accounts	278,666	173,508	102,130
Net change in time deposits	(84,092)	162,818	47,080
Net change in short-term borrowings	58,714	(12,593)	(68,309)
Proceeds from issuance of long-term debt	20,837	0	7,161
Payments on long-term debt	(6,429)	(1,250)	(11,660)
Stock issued under stock purchase plans	120	149	197
Acquisition of treasury stock	(8,030)	(9,970)	(16,342)
Cash dividends paid on common stock	(19,416)	(18,126)	(17,643)
Net change in financing activities	240,370	294,536	42,614
Net change in cash and cash equivalents	28,583	13,531	(13,862)
Cash and cash equivalents, beginning of year	79,721	66,190	80,052
Cash and cash equivalents, end of year	108,304	79,721	66,190
Non-cash transactions:
Loans transferred to other real estate and repossessions	4,961	8,742	7,154
Common stock matching contribution to Employee Stock Ownership and Profit Sharing Plan	800	500	0
Stock dividend paid on common stock	0	90,003	0
Cash paid for:
Interest	21,531	17,364	19,143
Income taxes	$ 19,866	$ 30,429	$ 29,211