Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current [Abstract]
Federal	$ (6)	$ (41)	$ (454)
Non-U.S.	241	222	161
State and local	(9)	(15)	(26)
Total current	226	166	(319)
Deferred [Abstract]
Federal	(1,016)	284	893
Non-U.S.	30	1	93
State and local	63	55	56
Total deferred	(923)	340	1,042
Provision for income taxes	$ (697)	$ 506	$ 723
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
U.S. statutory tax rate	35.00%	35.00%	35.00%
Non-U.S. tax rates under U.S. rate	(4.00%)	(3.80%)	(3.00%)
State and local income taxes	1.50%	1.30%	1.00%
Effective Income Tax Rate Reconciliation Foreign Operations Taxed in United States	15.60%	(4.90%)	0.20%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(78.10%)	0.00%	0.00%
Other	(0.20%)	(0.70%)	(0.20%)
Valuation allowance	0.00%	0.00%	1.70%
Effective tax rate	(30.20%)	26.90%	34.70%
Future Effective Federal Income Tax Rate, Percent	21.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ 1,800
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount	375
Undistributed Foreign Earnings, Deferred Taxes Not Provided	2,400
Potential Deferred Tax Liability Undistributed Foreign Earnings	60
Deferred tax assets [Abstract]
Net operating loss carryforwards	1,310	$ 1,207
Provision for credit losses	204	191
Other foreign	79	83
Employee benefit plans	33	34
Foreign tax credits	1,244	803
Other	51	89
Total gross deferred tax assets	2,921	2,407
Less: valuation allowance	(68)	(42)
Total net deferred tax assets	2,853	2,365
Deferred tax liabilities [Abstract]
Leasing transactions	4,017	4,479
Finance receivables	523	594
Other foreign	391	303
Other	61	14
Total deferred tax liabilities	4,992	5,390
Net deferred tax liability	2,139	3,025
Amount of valuation allowance released	68
Operating Loss Carryforwards	4,900
Net operating loss carryforwards	1,310	1,207
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at January 1	80	91	$ 111
Increase - tax positions in prior years	18	2	9
Increases - tax positions in current year	1	0	1
Decrease - tax positions in prior years	(2)	(1)	(22)
Settlements	(7)	(12)	(8)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	(7)	0	0
Unrecognized Tax Benefits, Increase Resulting from Foreign Currency Translation	7	0	0
Balance at December 31	90	80	91
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	85	69	76
Unrecognized Tax Benefits Interest Income	5	8	3
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	5	11
Income Taxes Paid	$ 220	$ 107	$ 74