CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities:
Net income	$ 86,961	$ 84,712
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,680	7,959
Amortization of intangible assets	8,034	9,353
Net accretion on securities, loans and borrowings	(3,462)	(4,784)
Stock-based compensation	2,757	3,396
Provision for loan losses	3,822	6,127
Amortization of mortgage servicing rights	188	229
Gain on sale of investment securities, net	(4,882)	0
Unrealized (gain) loss on equity securities	(18)	21
Income from bank-owned life insurance policies	(769)	(784)
Net loss (gain) on sale of loans and other assets	19	(146)
Change in other assets and other liabilities	(10,406)	6,734
Net cash provided by operating activities	89,924	112,817
Investing activities:
Proceeds from sales of available-for-sale investment securities	590,179	0
Proceeds from maturities, calls, and paydowns of available-for-sale investment securities	99,105	69,637
Proceeds from maturities and redemptions of equity and other investment securities	2,537	7,408
Purchases of available-for-sale investment securities	(60,826)	(31,669)
Purchases of equity and other securities	(144)	(21)
Net (increase) decrease in loans	(8,457)	13,647
Cash paid for acquisitions, net of cash acquired of $0 and $16, respectively	(1,200)	(1,737)
Purchases of premises and equipment, net	(3,963)	(5,298)
Real estate limited partnership investments	(564)	(1,197)
Net cash provided by investing activities	616,667	50,770
Financing activities:
Net increase in deposits	165,834	69,573
Net decrease in borrowings	(171,453)	(179,297)
Issuance of common stock	1,221	4,644
Purchases of treasury stock	(145)	(150)
Sales of treasury stock	3,340	6,174
Increase in deferred compensation arrangements	145	150
Cash dividends paid	(39,381)	(34,611)
Withholding taxes paid on share-based compensation	(3,150)	(954)
Net cash used in financing activities	(43,589)	(134,471)
Change in cash and cash equivalents	663,002	29,116
Cash and cash equivalents at beginning of period	211,834	221,038
Cash and cash equivalents at end of period	874,836	250,154
Supplemental disclosures of cash flow information:
Cash paid for interest	11,725	7,896
Cash paid for income taxes	21,775	12,681
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	19,663	17,547
Transfers from loans to other real estate	1,179	1,845
Acquisitions:
Fair value of assets acquired, excluding acquired cash and intangibles	0	115
Fair value of liabilities assumed	$ 0	$ 31