Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities:
Net income	$ 84,471	$ 170,612
Adjustments to reconcile net income to net cash (used for) provided by operating activities
Provision for credit losses	188,014	35,204
Depreciation, amortization and accretion, net	47,138	43,322
Stock-based compensation expense	(2,278)	6,283
Net amortization of premium on securities	4,694	2,971
Accretion of discount and deferred fees on loans, net	(41,304)	(11,746)
Mortgage servicing rights fair value change, net	35,509	19,122
Originations and purchases of mortgage loans held-for-sale	(3,426,911)	(1,832,264)
Proceeds from sales of mortgage loans held-for-sale	3,035,641	1,736,063
Bank owned life insurance (BOLI) income	(666)	(2,740)
Decrease (increase) in trading securities, net	178	(738)
Net decrease (increase) in brokerage customer receivables	1,950	(960)
Gains on mortgage loans sold	(155,108)	(51,086)
Losses (gains) on investment securities, net	3,551	(2,228)
Losses on sales of premises and equipment, net	3	37
Net (gains) losses on sales and fair value adjustments of other real estate owned	(694)	1,115
Increase in accrued interest receivable and other assets, net	(171,099)	(139,971)
Increase in accrued interest payable and other liabilities, net	27,244	49,233
Net Cash (Used for) Provided by Operating Activities	(369,667)	22,229
Investing Activities:
Proceeds from maturities and calls of available-for-sale securities	549,981	231,198
Proceeds from maturities and calls of held-to-maturity securities	529,974	51,393
Proceeds from sales of available-for-sale securities	502,676	667,918
Proceeds from sales of equity securities with readily determinable fair value	4,030	11,000
Proceeds from sales and capital distributions of equity securities without readily determinable fair value	444	609
Purchases of available-for-sale securities	(1,048,539)	(871,269)
Purchases of held-to-maturity securities	(124,802)	(178,331)
Purchases of equity securities with readily determinable fair value	(7,659)	(18,677)
Purchases of equity securities without readily determinable fair value	(3,166)	(1,072)
Purchases of Federal Home Loan Bank and Federal Reserve Bank stock, net	(34,832)	(672)
(Purchases of) distributions from investments in partnerships, net	(355)	772
Net cash received (paid) in business combinations	0	748
Proceeds from sales of other real estate owned	5,405	5,155
Net increase in interest bearing deposits with banks	(1,852,194)	(337,581)
Net increase in loans	(4,460,325)	(1,340,204)
Purchases of premises and equipment, net	(38,132)	(31,297)
Net Cash Used for Investing Activities	(5,977,494)	(1,810,310)
Financing Activities:
Increase in deposit accounts, net	5,545,133	1,262,941
Increase in other borrowings, net	98,974	16,243
Increase in Federal Home Loan Bank advances, net	553,500	148,441
Proceeds from the issuance of subordinated notes, net	0	296,741
Proceeds from the issuance of preferred stock, net	277,375	0
Cash payments to settle contingent consideration liabilities recognized in business combinations	(1,276)	(66)
Issuance of common shares resulting from the exercise of stock options, employee stock purchase plan and conversion of common stock warrants	6,332	5,978
Common stock repurchases authorized	(37,116)	0
Common stock repurchases for tax withholdings related to stock-based compensation	(844)	(1,016)
Dividends paid	(36,336)	(32,389)
Net Cash Provided by Financing Activities	6,405,742	1,696,873
Net Increase (Decrease) in Cash and Cash Equivalents	58,581	(91,208)
Cash and Cash Equivalents at Beginning of Period	286,476	392,200
Cash and Cash Equivalents at End of Period	$ 345,057	$ 300,992