Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operations
Net income (loss)	$ 468.2	$ (848.0)	$ 1,034.1
Adjustments to reconcile net income (loss) to net cash flows from operations:
Provision for credit losses	114.6	210.3	160.5
Net depreciation, amortization and (accretion)	392.6	700.0	783.9
Net (gains) losses on asset sales and impairments of assets held for sale and other	(283.4)	152.0	5.1
Loss on debt extinguishment and deposit redemption	259.0	20.8	0.0
(Benefit) provision for deferred income taxes	(39.7)	978.5	(572.9)
(Increase) decrease in loans held for sale	(96.2)	336.7	(251.3)
Goodwill and intangible assets impairment	255.6	358.4	15.0
Net (payment) reimbursement of expenses from FDIC	(5.5)	1.8	7.2
Decrease in other assets	170.2	230.1	53.3
(Decrease) increase in other liabilities	(715.6)	258.6	(45.1)
Net cash flows provided by operations	519.8	2,399.2	1,189.8
Cash Flows From Investing Activities
Change in loans, net	65.7	831.9	(1,759.2)
Purchases of investment securities	(6,990.4)	(4,939.2)	(8,316.3)
Proceeds from sales and maturities of investment securities	4,741.9	3,585.5	9,226.6
Proceeds from asset and receivable sales	909.9	1,753.9	2,252.4
Proceeds from sale of commercial air	10,026.0	0.0	0.0
Purchases of assets to be leased and other equipment	(793.3)	(1,866.8)	(3,088.7)
Net (increase) decrease in short-term factoring receivables	(260.5)	(170.6)	124.7
Purchases of restricted stock	(32.4)	(1.7)	(128.9)
Proceeds from redemption of restricted stock	10.6	25.5	20.3
Payments to the FDIC under loss share agreements	(0.2)	(2.9)	(18.1)
Proceeds from FDIC under loss share agreements and participation agreements	63.8	147.8	33.7
Proceeds from the sale of OREO, net of repurchases	107.3	129.2	60.8
Purchase of bank owned life insurance	(781.0)	0.0	0.0
Acquisition, net of cash received	0.0	0.0	2,521.2
Net change in restricted cash	687.8	12.1	156.7
Net cash flows provided by (used in) investing activities	7,755.2	(495.3)	1,085.2
Cash Flows From Financing Activities
Proceeds from the issuance of term debt	15.3	781.1	1,626.9
Repayments of term debt and net settlements	(8,427.3)	(2,619.0)	(4,325.3)
Proceeds from FHLB advances	2,450.0	1,645.5	5,964.1
Repayments of FHLB debt	(1,165.4)	(2,352.3)	(6,070.2)
Net (decrease) increase in deposits	(2,729.1)	(459.1)	2,419.2
Collection of security deposits and maintenance funds	70.9	341.7	330.9
Use of security deposits and maintenance funds	(37.6)	(149.3)	(147.5)
Repurchase of common stock	(3,431.9)	0.0	(531.8)
Net proceeds from issuance of preferred stock	318.0	0.0	0.0
Dividends paid	(113.7)	(123.0)	(114.9)
Taxes paid through withholding of common stock under employee stock plans	(21.0)	(21.9)	(22.2)
Purchase of noncontrolling interest	0.0	0.0	(20.5)
Payments on affordable housing investment credits	0.0	(8.4)	(4.8)
Net cash flows used in financing activities	(13,071.8)	(2,964.7)	(896.1)
Effect of exchange rate changes on cash and cash equivalents	15.6	(34.6)	(63.8)
(Decrease) increase in unrestricted cash and cash equivalents	(4,781.2)	(1,095.4)	1,315.1
Unrestricted cash and cash equivalents, beginning of period	6,375.2	7,470.6	6,155.5
Unrestricted cash and cash equivalents, end of period	1,594.0	6,375.2	7,470.6
Supplementary Cash Flow Disclosure
Interest paid	(915.2)	(1,149.7)	(1,112.0)
Federal, foreign, state and local income taxes (paid) refunded, net	(40.5)	61.2	(9.5)
Supplementary Non Cash Flow Disclosure
Transfer of assets from held for investment to held for sale	2,109.6	2,093.6	3,039.4
Transfer of assets from held for investment to held for sale	174.0	124.4	208.7
Deposits on flight equipment purchases applied to acquisition of flight equipment purchases, and origination of finance leases, capitalized interest and buyer furnished equipment	91.2	286.6	554.2
Transfers of assets from held for investment to OREO	99.0	90.2	65.8
Capital lease unexercised bargain purchase options	17.5	7.1	0.0
Unfunded payments on affordable housing investments credits committed during the period	60.1	55.0	0.0
Issuance of common stock as consideration	$ 0.0	$ 0.0	$ 1,462.0