CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income/(loss)		$ 452,373	$ 556,507	$ 176,980
Adjustments to reconcile net income/(loss) to net cash provided/(used) by operating activities:
Provision/(provision credit) for loan losses		47,000	7,000	0
Provision/(benefit) for deferred income taxes		14,357	103,557	121,001
Depreciation and amortization of premises and equipment		43,785	47,232	34,703
Amortization of intangible assets		24,834	25,855	8,728
Net other amortization and accretion		(3,380)	(13,962)	27,493
Net (increase)/decrease in derivatives		(134,009)	41,687	(26,662)
Fair value adjustment on interest-only strips		4,725	398	(1,021)
Repurchase and foreclosure provision/(provision credit)		0	0	(20,000)
(Gains)/losses and write-downs on OREO, net		624	(626)	(61)
Litigation and regulatory matters		(8,443)	(836)	40,250
Stock-based compensation expense		22,730	23,171	20,627
Gain on sale and pay down of held-to-maturity loans		(1,105)	(3,777)	0
Equity securities (gains)/losses, net		(441)	(212,896)	(109)
Debt securities (gains)/losses, net		267	(52)	(483)
(Gain)/loss on extinguishment of debt		(58)	15	14,329
Net (gains)/losses on sale/disposal of fixed assets		22,172	(1,320)	6,657
Qualified pension plan contributions		(509)	(353)	(5,100)
(Gain)/loss on BOLI		(4,978)	(4,217)	(9,012)
Loans held-for-sale:
Purchases and originations		(2,075,042)	(2,345,030)	(2,001,708)
Gross proceeds from settlements and sales		817,863	919,187	1,780,047
(Gain)/loss due to fair value adjustments and other	[1]	(7,196)	19,932	(6,624)
Net (increase)/decrease in:
Trading securities		1,422,617	1,356,797	(381,057)
Fixed income receivables		(1,253)	29,832	(11,282)
Interest receivable		4,546	(15,372)	(34,352)
Other assets		(116,888)	32,950	240,629
Net increase/(decrease) in:
Trading liabilities		170,201	(303,135)	76,667
Fixed income payables		39,963	(39,424)	(68,495)
Interest payable		339	15,165	5,934
Other liabilities		95,200	(3,980)	(16,877)
Total adjustments		377,921	(322,202)	(205,778)
Net cash provided/(used) by operating activities		830,294	234,305	(28,798)
Available-for-sale securities:
Sales		191,681	20,751
Sales				936,958
Maturities		800,147	675,526	583,014
Purchases		(629,649)	(473,205)
Purchases				(1,558,990)
Proceeds from sale of equity investment		1,440	0	0
Held-to-maturity securities:
Prepayments and maturities		0	0	4,740
Premises and equipment:
Sales		20,058	30,464	3,416
Purchases		(49,159)	(47,986)	(53,046)
Proceeds from sale of Visa Class B shares		0	240,206	0
Proceeds from sales of OREO		15,824	30,824	13,468
Proceeds from sales and pay down of loans classified as held-to-maturity		20,100	50,498	0
Proceeds from BOLI		14,407	12,860	11,440
Net (increase)/decrease in:
Loans		(3,570,386)	105,267	(808,399)
Interests retained from securitizations classified as trading securities		489	800	865
Interest-bearing cash		795,206	(92,011)	(121,434)
Cash paid related to divestitures		0	(27,599)	0
Cash (paid)/received for acquisitions, net		0	(46,023)	(336,634)
Net cash provided/(used) by investing activities		(2,389,842)	480,372	(1,324,602)
Common stock:
Stock options exercised		9,665	4,482	6,132
Cash dividends paid		(171,076)	(138,706)	(79,904)
Repurchase of shares		(134,813)	(104,768)	(5,554)
Cash dividends paid - preferred stock - noncontrolling interest		(11,465)	(11,465)	(11,434)
Cash dividends paid - Series A preferred stock		(6,200)	(6,200)	(6,200)
Term borrowings:
Issuance		0	0	121,184
Payments/maturities		(405,562)	(69,025)	(147,413)
Increases in restricted and secured term borrowings		9,635	20,477	7,960
Net increase/(decrease) in:
Deposits		(253,459)	2,092,519	(197,158)
Short-term borrowings		2,384,391	(2,548,712)	2,080,039
Net cash provided/(used) by financing activities		1,421,116	(761,398)	1,767,652
Net increase/(decrease) in cash and cash equivalents		(138,432)	(46,721)	414,252
Cash and cash equivalents at beginning of period		1,405,325	1,452,046	1,037,794
Cash and cash equivalents at end of period		1,266,893	1,405,325	1,452,046
Supplemental Disclosures
Total interest paid		410,883	307,578	140,373
Total taxes paid		70,505	42,817	54,417
Total taxes refunded		27,889	48,455	8,285
Transfer from loans to OREO		8,996	12,106	6,624
Transfer from loans HFS to trading securities		1,321,145	1,389,420	1,004,416
Transfer from loans to loans HFS		$ 31,465	$ 0	$ 0

[1] 2018 includes $107.4 million related to the sale of approximately $120 million UPB of subprime auto loans. See Note 2 - Acquisitions and Divestitures for additional information.