Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net income (loss)	$ (2,195,481)	$ 484,112
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	264,207	194,040
Goodwill impairment	2,185,000	0
Securities impairment	0	113
Amortization (accretion) of discount, loan fees and purchase market adjustments, net	48,741	(26,732)
Provision for credit losses	1,047,427	477,939
Net change in trading account assets	(452,521)	(326,344)
Net change in trading account liabilities	72,623	(5,891)
Originations and purchases of mortgage loans held for sale	(1,064,535)	(554,488)
Sale of mortgage loans held for sale	975,048	509,685
Deferred tax benefit	(180,700)	(11,611)
Investment securities gains, net	(22,616)	(29,961)
Net gain on sale of premises and equipment	(273)	(7,077)
Gain on sale of loans	0	(925)
Gain on sale of mortgage loans held for sale	(51,909)	(20,745)
Net (gain) loss on sale of other real estate and other assets	(198)	1,436
(Increase) decrease in other assets	(297,558)	95,117
Increase (decrease) in other liabilities	752,674	(14,147)
Net cash provided by operating activities	1,079,929	764,521
Investing Activities:
Proceeds from sales of debt securities available for sale	863,712	2,442,176
Proceeds from prepayments, maturities and calls of debt securities available for sale	3,360,970	3,556,157
Purchases of debt securities available for sale	(2,928,381)	(2,454,096)
Proceeds from prepayments, maturities and calls of debt securities held to maturity	778,938	234,157
Purchases of debt securities held to maturity	(3,474,536)	(3,688,706)
Proceeds from sales of equity securities	82,362	180,375
Purchases of equity securities	(10,043)	(182,504)
Net change in loan portfolio	(2,625,679)	93,914
Proceeds from sales of loans	0	1,353,379
Purchases of premises and equipment	(113,044)	(88,647)
Proceeds from sales of premises and equipment	2,370	12,812
Proceeds from settlement of BOLI policies	6,575	3,331
Cash payments for premiums of BOLI policies	0	(26)
Proceeds from sales of other real estate owned	13,358	21,569
Net cash (used in) provided by investing activities	(4,043,398)	1,483,891
Financing Activities:
Net increase in total deposits	11,391,671	1,414,158
Net increase in federal funds purchased and securities sold under agreements to repurchase	16,446	15,146
Net increase in other short-term borrowings	0	45
Proceeds from FHLB and other borrowings	1,000	4,436,995
Repayment of FHLB and other borrowings	(228,939)	(4,790,177)
Capital contribution for non-controlling interest	66	144
Vesting of restricted stock	0	(2,914)
Issuance of common stock	0	802
Common dividends paid	0	(170,000)
Preferred dividends paid	(12,443)	(14,808)
Net cash provided by financing activities	11,167,801	889,391
Net increase in cash, cash equivalents and restricted cash	8,204,332	3,137,803
Cash, cash equivalents and restricted cash at beginning of year	7,156,689	3,501,380
Cash, cash equivalents and restricted cash at end of period	$ 15,361,021	$ 6,639,183