CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating activities:
Net income	$ 50,260	$ 46,137
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,150	6,533
Amortization of intangible assets	2,845	1,799
Net accretion on securities, loans and borrowings	(2,240)	(1,505)
Stock-based compensation	2,220	2,150
Provision for loan losses	3,646	1,214
Amortization of mortgage servicing rights	257	206
Income from bank-owned life insurance policies	(736)	(515)
Net (gain) loss on sale of loans and other assets	(318)	21
Change in other assets and liabilities	4,648	(2,060)
Net cash provided by operating activities	67,732	53,980
Investing activities:
Proceeds from maturities of available-for-sale investment securities	49,500	89,631
Proceeds from maturities of other investment securities	3,001	172
Purchases of available-for-sale investment securities	(28,237)	(448,747)
Purchases of other securities	(4,612)	(10,312)
Net change in loans	(108,983)	(31,173)
Cash paid for acquisition, net of cash acquired of $0 and $0, respectively	(575)	0
Expenditure for intangible asset	0	(100)
Settlement of bank-owned life insurance policies	2,481	0
Purchases of premises and equipment, net	(5,569)	(5,810)
Net cash used in investing activities	(92,994)	(406,339)
Financing activities:
Net increase in deposits	84,380	151,556
Net change in borrowings	(33,700)	228,200
Issuance of common stock	3,882	5,613
Purchases of treasury stock	(716)	(9,125)
Sales of treasury stock	6,128	4,063
Cash dividends paid	(27,216)	(24,360)
Tax benefits from share-based payment arrangements	928	1,063
Net cash provided by financing activities	33,686	357,010
Change in cash and cash equivalents	8,424	4,651
Cash and cash equivalents at beginning of period	153,210	138,396
Cash and cash equivalents at end of period	161,634	143,047
Supplemental disclosures of cash flow information:
Cash paid for interest	5,689	5,321
Cash paid for income taxes	14,174	13,291
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	13,681	12,247
Transfers from loans to other real estate	1,071	1,830
Purchase of intangible asset	$ 0	$ 241