CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Net income	$ 22,297	$ 22,173
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	3,247	3,286
Amortization of intangible assets	919	1,141
Net accretion/amortization of premiums and discounts on securities, loans, and borrowings	(595)	(654)
Stock-based compensation	1,151	1,182
Provision for loan losses	623	1,000
Amortization of mortgage servicing rights	104	117
Income from bank-owned life insurance policies	(273)	(289)
Net (gain) loss from sale of loans and other assets	176	(128)
Net change in loans originated for sale	(189)	(7)
Change in other assets and liabilities	(5,446)	105
Net cash provided by operating activities	22,014	27,926
Investing activities:
Proceeds from maturities of available-for-sale investment securities	36,670	19,231
Proceeds from maturities of other investment securities	6,404	11
Purchases of available-for-sale investment securities	(153,211)	(260,923)
Purchases of other securities	0	(3,384)
Net decrease in loans	70,013	10,389
Cash paid for acquisition, net of cash acquired of $0	0	(924)
Purchases of premises and equipment, net	(3,321)	(1,395)
Net cash used in investing activities	(43,445)	(236,995)
Financing activities:
Net increase in deposits	191,283	142,844
Net change in borrowings, net of payments of $0 and $3	(142,300)	75,197
Issuance of common stock	2,941	4,844
Purchase of treasury stock	(9,125)	0
Issuance of treasury stock	2,247	0
Cash dividends paid	(12,174)	(11,291)
Tax benefits from share-based payment arrangements	696	1,245
Net cash provided by financing activities	33,568	212,839
Change in cash and cash equivalents	12,137	3,770
Cash and cash equivalents at beginning of period	138,396	149,647
Cash and cash equivalents at end of period	150,533	153,417
Supplemental disclosures of cash flow information:
Cash paid for interest	2,642	3,182
Cash paid for income taxes	5,707	164
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	12,306	11,355
Transfers from loans to other real estate	$ 521	$ 763