Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities:
Net income	$ 269,733	$ 263,509
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	46,038	24,431
Depreciation, amortization and accretion, net	64,838	48,908
Stock-based compensation expense	8,278	10,346
Net amortization of premium on securities	4,501	5,998
Accretion of discount on loans	(17,335)	(15,510)
Mortgage servicing rights fair value change, net	30,417	(3,660)
Originations and purchases of mortgage loans held-for-sale	(3,252,539)	(3,027,658)
Proceeds from sales of mortgage loans held-for-sale	3,118,102	3,060,577
Bank owned life insurance (BOLI) income	(3,469)	(5,448)
(Increase) decrease in trading securities, net	(1,512)	307
Net (increase) decrease in brokerage customer receivables	(2,334)	10,782
Gains on mortgage loans sold	(96,631)	(80,826)
(Gains) losses on investment securities, net	(2,938)	249
Losses (gains) on sales of premises and equipment, net	43	(34)
Net losses on sales and fair value adjustments of other real estate owned	1,823	3,808
Increase in accrued interest receivable and other assets, net	(181,144)	(97,844)
(Decrease) increase in accrued interest payable and other liabilities, net	(8,826)	63,166
Net Cash (Used for) Provided by Operating Activities	(22,955)	261,101
Investing Activities:
Proceeds from maturities and calls of available-for-sale securities	391,434	222,387
Proceeds from maturities and calls of held-to-maturity securities	341,912	8,061
Proceeds from sales of available-for-sale securities	905,926	209,640
Proceeds from sales of equity securities with readily determinable fair value	16,200	1,895
Proceeds from sales and capital distributions of equity securities without readily determinable fair value	1,461	680
Purchases of available-for-sale securities	(1,098,566)	(777,324)
Purchases of held-to-maturity securities	(373,394)	(148,865)
Purchases of equity securities with readily determinable fair value	(25,677)	0
Purchases of equity securities without readily determinable fair value	(1,847)	(3,779)
Purchases of Federal Home Loan Bank and Federal Reserve Bank stock, net	(1,360)	(10,009)
Distributions from investments in partnerships, net	1,532	3,181
Net cash received (paid) in business combinations	748	(13,749)
Proceeds from sales of other real estate owned	9,656	16,892
Net increase in interest bearing deposits with banks	(1,161,452)	(75,636)
Net increase in loans	(1,744,613)	(1,304,555)
Redemption of BOLI	326	8,134
Purchases of premises and equipment, net	(51,450)	(52,639)
Net Cash Used for Investing Activities	(2,789,164)	(1,915,686)
Financing Activities:
Increase in deposit accounts	2,454,510	1,520,270
Increase in other borrowings, net	10,950	109,112
Increase in Federal Home Loan Bank advances, net	148,442	52,000
Proceeds from the issuance of subordinated notes, net	296,617	0
Cash payments to settle contingent consideration liabilities recognized in business combinations	(66)	0
Issuance of common shares resulting from the exercise of stock options, employee stock purchase plan and conversion of common stock warrants	8,056	14,390
Common stock repurchases for tax withholdings related to stock-based compensation	(1,165)	(561)
Dividends paid	(48,611)	(38,224)
Net Cash Provided by Financing Activities	2,868,733	1,656,987
Net Increase in Cash and Cash Equivalents	56,614	2,402
Cash and Cash Equivalents at Beginning of Period	392,200	277,591
Cash and Cash Equivalents at End of Period	$ 448,814	$ 279,993