CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net income	$ 78,691	$ 77,420
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,026	10,742
Amortization of intangible assets	11,980	4,204
Net accretion on securities, loans and borrowings	(4,412)	(3,261)
Stock-based compensation	3,985	3,392
Provision for loan losses	5,603	5,436
Amortization of mortgage servicing rights	374	386
Income from bank-owned life insurance policies	(1,170)	(1,124)
Net loss (gain) on sale of loans and other assets	155	(624)
Change in other assets and other liabilities	31,624	7,257
Net cash provided by operating activities	138,856	103,828
Investing activities:
Proceeds from maturities of available-for-sale investment securities	110,160	86,885
Proceeds from maturities of other investment securities	28,580	9,050
Purchases of available-for-sale investment securities	(59,425)	(40,463)
Purchases of other securities	(12,434)	(4,612)
Net change in loans	120,029	(148,384)
Cash paid for acquisitions, net of cash acquired of $51,793 and $0, respectively	(105,402)	(575)
Settlement of bank-owned life insurance policies	1,779	2,481
Purchases of premises and equipment, net	(7,701)	(7,832)
Net cash provided by/(used in) investing activities	75,586	(103,450)
Financing activities:
Net increase in deposits	81,630	203,945
Net change in borrowings	(193,602)	(167,400)
Issuance of common stock	3,740	7,556
Purchases of treasury stock	(3,226)	(716)
Sales of treasury stock	7,861	6,925
Increase in deferred compensation arrangements	3,226	0
Cash dividends paid	(45,059)	(40,883)
Withholding taxes paid on share-based compensation	(1,389)	(1,473)
Net cash (used in)/provided by financing activities	(146,819)	7,954
Change in cash and cash equivalents	67,623	8,332
Cash and cash equivalents at beginning of period	173,857	153,210
Cash and cash equivalents at end of period	241,480	161,542
Supplemental disclosures of cash flow information:
Cash paid for interest	10,092	8,557
Cash paid for income taxes	33,187	23,717
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	17,412	14,220
Transfers from loans to other real estate	2,470	2,137
Acquisitions:
Common stock issued	340,737	0
Fair value of assets acquired, excluding acquired cash and intangibles	1,961,722	0
Fair value of liabilities assumed	$ 1,871,074	$ 0