CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 84,712	$ 43,448
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,959	7,775
Amortization of intangible assets	9,353	7,031
Net accretion on securities, loans and borrowings	(4,784)	(2,345)
Stock-based compensation	3,396	2,730
Provision for loan losses	6,127	3,289
Amortization of mortgage servicing rights	229	248
Income from bank-owned life insurance policies	(784)	(746)
Net (gain) loss on sale of loans and other assets	(146)	257
Change in other assets and other liabilities	5,558	30,397
Net cash provided by operating activities	111,620	92,084
Investing activities:
Proceeds from maturities of available-for-sale investment securities	69,637	73,770
Proceeds from maturities of other investment securities	7,408	10,006
Purchases of available-for-sale investment securities	(31,669)	(34,842)
Purchases of other securities	(21)	(1,447)
Net change in loans	13,647	70,094
Cash paid for acquisitions, net of cash acquired of $16 and $51,793, respectively	(1,737)	(105,402)
Settlement of bank-owned life insurance policies	0	1,779
Purchases of premises and equipment, net	(5,298)	(5,390)
Net cash provided by investing activities	51,967	8,568
Financing activities:
Net increase in deposits	69,573	101,243
Net change in borrowings	(179,297)	(134,838)
Issuance of common stock	4,644	2,829
Purchases of treasury stock	(150)	(3,078)
Sales of treasury stock	6,174	6,169
Increase in deferred compensation arrangements	150	3,078
Cash dividends paid	(34,611)	(28,849)
Withholding taxes paid on share-based compensation	(954)	(1,368)
Net cash used in financing activities	(134,471)	(54,814)
Change in cash and cash equivalents	29,116	45,838
Cash and cash equivalents at beginning of period	221,038	173,857
Cash and cash equivalents at end of period	250,154	219,695
Supplemental disclosures of cash flow information:
Cash paid for interest	7,896	6,010
Cash paid for income taxes	12,681	20,154
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	17,547	16,331
Transfers from loans to other real estate	1,845	2,048
Acquisitions:
Common stock issued	0	340,737
Fair value of assets acquired, excluding acquired cash and intangibles	115	1,960,935
Fair value of liabilities assumed	$ 31	$ 1,869,876