CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 480,711	$ 161,930
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses (benefit)	(99,241)	252,180
Amortization of intangibles	2,306	4,269
Depreciation and amortization of premises and equipment	28,408	28,901
Net accretion of discounts and amortization of premiums and deferred fees	(17,234)	(42,087)
Interest capitalized on loans subject to the temporary payment moratorium or loss mitigation alternatives	(8,330)	(8,496)
Share-based compensation	14,609	7,164
Impairment losses on long-lived assets	303	0
Fair value adjustments on mortgage servicing rights	5,727	12,869
Adjustments to indemnity reserves on loans sold	(970)	5,953
Earnings from investments under the equity method, net of dividends or distributions	(21,689)	(6,425)
Deferred income tax expense (benefit)	125,228	(7,824)
Gain on:
Disposition of premises and equipment and other productive assets	(8,674)	(7,939)
Proceeds from insurance claims	0	(366)
Sale of loans, including valuation adjustments on loans held-for-sale and mortgage banking activities	(10,106)	(12,652)
Sale of foreclosed assets, including write-downs	(16,126)	(5,754)
Acquisitions of loans held-for-sale	(122,806)	(82,812)
Proceeds from sale of loans held-for-sale	54,262	24,897
Net originations on loans held-for-sale	(284,298)	(100,408)
Net decrease (increase) in:
Trading debt securities	369,194	176,054
Equity securities	(5,191)	(3,731)
Accrued income receivable	5,818	(46,377)
Other assets	(7,729)	30,513
Net (decrease) increase in:
Interest payable	(3,878)	(3,422)
Pension and other postretirement benefits obligation	(1,954)	2,771
Other liabilities	930	(71,684)
Total adjustments	(1,441)	145,594
Net cash provided by operating activities	479,270	307,524
Cash flows from investing activities:
Net increase in money market investments	(6,161,953)	(6,362,958)
Purchases of investment securities:
Available-for-sale	(7,568,621)	(10,313,044)
Equity	(10,590)	(20,282)
Proceeds from calls, paydowns, maturities and redemptions of investment securities:
Available-for-sale	5,672,695	8,106,422
Held-to-maturity	4,999	3,102
Proceeds from sale of investment securities:
Equity	2,500	17,424
Net repayments (disbursements) on loans	422,509	(1,159,732)
Proceeds from sale of loans	51,032	26,070
Acquisition of loan portfolios	(150,116)	(123,738)
Payments to acquire other intangible	(1,185)	0
Return of capital from equity method investments	2,438	131
Payments to acquire equity method investments	0	(440)
Acquisition of premises and equipment	(36,481)	(24,057)
Proceeds from insurance claims	0	366
Proceeds from sale of:
Premises and equipment and other productive assets	8,185	14,714
Foreclosed assets	49,271	32,805
Net cash used in investing activities	(7,715,317)	(9,803,217)
Net increase (decrease) in:
Deposits	7,778,119	10,090,333
Assets sold under agreements to repurchase	(30,377)	(40,313)
Payment of notes payable	(49,009)	(66,989)
Principal payments of finance leases	(1,692)	(1,047)
Proceeds from issuance of notes payable	0	151,009
Proceeds from issuance of common stock	2,226	6,585
Payments for repurchase of redeemable preferred stock	0	(28,017)
Dividends paid	(68,161)	(65,584)
Net payments for repurchase of common stock	(350,409)	(500,282)
Payments related to tax witholding for share-based compensation	(4,898)	(3,200)
Net cash provided by financing activities	7,275,799	9,542,495
Net increase in cash and due from banks, and restricted cash	39,752	46,802
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	$ 536,846	$ 441,125