Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net income	$ 191,786	$ 269,733
Adjustments to reconcile net income to net cash used for operating activities
Provision for credit losses	213,040	46,038
Depreciation, amortization and accretion, net	71,295	64,838
Stock-based compensation expense	(1,023)	8,278
Net amortization of premium on securities	8,079	4,501
Accretion of discount and deferred fees on loans, net	(60,451)	(17,335)
Mortgage servicing rights fair value change, net	48,497	30,417
Originations and purchases of mortgage loans held-for-sale	(5,653,486)	(3,252,539)
Proceeds from sales of mortgage loans held-for-sale	5,208,962	3,118,102
Bank owned life insurance (BOLI) income	(1,884)	(3,469)
Increase in trading securities, net	(652)	(1,512)
Net increase in brokerage customer receivables	(245)	(2,334)
Gains on mortgage loans sold	(260,622)	(96,631)
Losses (gains) on investment securities, net	3,140	(2,938)
Losses on sales of premises and equipment, net	192	43
Net (gains) losses on sales and fair value adjustments of other real estate owned	(933)	1,823
Increase in accrued interest receivable and other assets, net	(154,912)	(181,144)
Decrease in accrued interest payable and other liabilities, net	(33,935)	(8,826)
Net Cash Used for Operating Activities	(423,152)	(22,955)
Investing Activities:
Proceeds from maturities and calls of available-for-sale securities	1,005,968	391,434
Proceeds from maturities and calls of held-to-maturity securities	698,305	341,912
Proceeds from sales of available-for-sale securities	502,676	905,926
Proceeds from sales of equity securities with readily determinable fair value	6,530	16,200
Proceeds from sales and capital distributions of equity securities without readily determinable fair value	1,691	1,461
Purchases of available-for-sale securities	(1,273,798)	(1,098,566)
Purchases of held-to-maturity securities	(125,220)	(373,394)
Purchases of equity securities with readily determinable fair value	(11,367)	(25,677)
Purchases of equity securities without readily determinable fair value	(3,666)	(1,847)
Purchases of Federal Home Loan Bank and Federal Reserve Bank stock, net	(34,829)	(1,360)
(Purchases of) distributions from investments in partnerships, net	(606)	1,532
Net cash received in business combinations	0	748
Proceeds from sales of other real estate owned	6,937	9,656
Net increase in interest-bearing deposits with banks	(1,662,172)	(1,161,452)
Net increase in loans	(5,174,163)	(1,744,613)
Redemption of BOLI	0	326
Purchases of premises and equipment, net	(54,392)	(51,450)
Net Cash Used for Investing Activities	(6,118,106)	(2,789,164)
Financing Activities:
Increase in deposit accounts, net	5,737,721	2,454,510
Increase in other borrowings, net	91,823	10,950
Increase in Federal Home Loan Bank advances, net	553,500	148,442
Proceeds from the issuance of subordinated notes, net	0	296,617
Proceeds from the issuance of preferred stock, net	277,643	0
Cash payments to settle contingent consideration liabilities recognized in business combinations	(4,523)	(66)
Issuance of common shares resulting from the exercise of stock options, employee stock purchase plan and conversion of common stock warrants	8,023	8,056
Common stock repurchases under authorized program	(37,116)	0
Common stock repurchases for tax withholdings related to stock-based compensation	(844)	(1,165)
Dividends paid	(62,750)	(48,611)
Net Cash Provided by Financing Activities	6,563,477	2,868,733
Net Increase in Cash and Cash Equivalents	22,219	56,614
Cash and Cash Equivalents at Beginning of Period	286,476	392,200
Cash and Cash Equivalents at End of Period	$ 308,695	$ 448,814