CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 728,825	$ 330,346
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses (benefit)	(160,414)	271,318
Amortization of intangibles	3,089	5,345
Depreciation and amortization of premises and equipment	41,416	43,419
Net accretion of discounts and amortization of premiums and deferred fees	(21,773)	(56,134)
Interest capitalized on loans subject to the temporary payment moratorium or loss mitigation alternatives	(12,735)	(17,625)
Share-based compensation	16,186	8,308
Impairment losses on right-of-use and long-lived assets	303	0
Fair value adjustments on mortgage servicing rights	11,706	33,360
Adjustments to indemnity reserves on loans sold	(3,008)	1,770
Earnings from investments under the equity method, net of dividends or distributions	(39,135)	(19,160)
Deferred income tax expense	198,110	26,742
Gain on:
Disposition of premises and equipment and other productive assets	(18,292)	(10,286)
Proceeds from insurance claims	0	(366)
Sale of debt securities	(23)	(41)
Sale of loans, including valuation adjustments on loans held-for-sale and mortgage banking activities	(16,183)	(21,370)
Sale of foreclosed assets, including write-downs	(23,622)	(13,676)
Acquisitions of loans held-for-sale	(191,591)	(151,916)
Proceeds from sale of loans held-for-sale	73,362	51,077
Net originations on loans held-for-sale	(413,258)	(243,954)
Net decrease (increase) in:
Trading debt securities	535,835	287,764
Equity securities	(1,621)	(5,390)
Accrued income receivable	8,584	(30,832)
Other assets	2,379	75,243
Net (decrease) increase in:
Interest payable	(10,483)	(11,308)
Pension and other postretirement benefits obligation	(3,078)	4,225
Other liabilities	(6,605)	(65,269)
Total adjustments	(30,851)	161,244
Net cash provided by operating activities	697,974	491,590
Cash flows from investing activities:
Net increase in money market investments	(5,884,981)	(8,597,704)
Purchases of investment securities:
Available-for-sale	(12,117,969)	(15,997,778)
Equity	(11,648)	(28,885)
Proceeds from calls, paydowns, maturities and redemptions of investment securities:
Available-for-sale	7,903,982	14,386,967
Held-to-maturity	8,869	5,770
Proceeds from sale of investment securities:
Available-for-sale	235,992	5,103
Equity	2,688	20,169
Net repayments (disbursements) on loans	680,937	(965,465)
Proceeds from sale of loans	99,680	64,917
Acquisition of loan portfolios	(213,804)	(994,908)
Payments to acquire other intangible assets	(1,185)	(83)
Return of capital from equity method investments	3,616	812
Payments to acquire equity method investments	0	(443)
Acquisition of premises and equipment	(50,809)	(39,121)
Proceeds from insurance claims	0	366
Proceeds from sale of:
Premises and equipment and other productive assets	19,874	20,816
Foreclosed assets	69,456	53,872
Net cash used in investing activities	(9,255,302)	(12,065,595)
Net increase (decrease) in:
Deposits	9,148,635	12,264,323
Assets sold under agreements to repurchase	(34,833)	(87,350)
Other short-term borrowings	0	100,000
Payment of notes payable	(49,009)	(127,989)
Principal payments of finance leases	(2,262)	(1,608)
Proceeds from issuance of notes payable	0	226,807
Proceeds from issuance of common stock	3,461	7,931
Payments for repurchase of redeemable preferred stock	0	(28,017)
Dividends paid	(104,808)	(99,600)
Net payments for repurchase of common stock	(350,521)	(500,325)
Payments related to tax witholding for share-based compensation	(5,050)	(3,342)
Net cash provided by financing activities	8,605,613	11,750,830
Net increase in cash and due from banks, and restricted cash	48,285	176,825
Cash and due from banks and restricted cash at beginning of period	497,094	394,323
Cash and due from banks and restricted cash at end of period	$ 545,379	$ 571,148