Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 46,432	$ 43,251	$ 45,172
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,932	4,314	4,562
Deferred taxes	115	(1,048)	582
Stock-based compensation	783	852	698
Excess tax benefits of stock-based compensation	104	760	572
Provision for loan losses	8,650	8,755	8,568
Write-downs of other real estate owned and other repossessed assets	1,656	1,730	2,480
Gains on sale of mortgage loans held for sale	(1,978)	(1,468)	(3,098)
Securities losses	106	211	45
Gains on sale of assets, net	(321)	(73)	(19)
Proceeds from sale of mortgage loans held for sale	80,571	51,181	134,695
Funding of mortgage loans held for sale	(77,501)	(51,149)	(109,939)
Amortization of securities premiums and discounts, net	3,098	2,661	3,976
Change in cash surrender value of bank owned life insurance	(1,638)	(1,506)	(1,488)
Mortgage servicing rights:
Fair value adjustments	289	830	(206)
New servicing assets created	(557)	(374)	(854)
Changes in:
Other assets	(6,274)	(60)	4,647
Other liabilities	(2,488)	(1,339)	323
Net cash provided by operating activities	54,979	57,528	90,716
Certificates of deposit in other banks:
Purchase of certificates of deposit	0	(245)	(4,472)
Maturity of certificates of deposit	4,365	1,616	240
Securities available-for-sale (AFS):
Purchase of AFS securities	(81,456)	(217,949)	(197,264)
Proceeds from sales of AFS securities	44,198	135,411	42,936
Proceeds from prepayments, calls, and maturities of AFS securities	79,068	63,023	112,412
Securities held-to-maturity (HTM):
Proceeds from prepayments and maturities of HTM securities	1	0	0
Change in loans, net	(161,702)	(132,906)	(76,442)
Purchase of premises and equipment	(2,246)	(2,081)	(2,105)
Proceeds from sale of premises and equipment	239	82	48
Redemption of stock by FHLB	0	7,746	0
Additional investment in Federal Reserve Bank stock	(18)	(1)	(1)
Cancellation of Federal Reserve Bank stock	0	18	0
Proceeds from sale of other real estate owned and repossessed assets	9,287	6,714	9,914
Additional investment in other real estate owned and repossessed assets	(85)	0	(6)
Additional investment in bank owned life insurance	0	(5,504)	(7,306)
Net cash used in investing activities	(108,349)	(144,076)	(122,046)
Cash flows from financing activities:
Change in deposits, net	106,525	19,183	(48,774)
Change in repurchase agreements, federal funds purchased, and other short-term borrowings, net	8,594	25,695	(1,902)
Advances from Federal Home Loan Bank	170,000	60,000	30,000
Payments on advances from Federal Home Loan Bank	(130,114)	(116)	(30,143)
Issuance of common stock	2,082	1,992	6,348
Netting of common stock	(189)	0	0
Excess tax benefits of stock-based compensation	(104)	(760)	(572)
Dividends paid	(21,330)	(20,570)	(24,546)
Net cash provided by (used in) financing activities	135,464	85,424	(69,589)
Net increase (decrease) in cash and cash equivalents	82,094	(1,124)	(100,919)
Cash and cash equivalents at beginning of year	105,517	106,641	207,560
Cash and cash equivalents at end of year	187,611	105,517	106,641
Supplemental disclosures:
Income taxes paid	20,527	15,818	20,827
Interest paid	11,609	11,922	13,717
Non-cash activities:
Loans to facilitate the sale of other real estate owned and repossessed assets	4,343	6,168	3,528
Common stock dividends accrued, paid in subsequent quarter	239	216	167
Real estate acquired in settlement of loans	$ 18,557	$ 12,199	$ 7,384