Net Investments in Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Net Investment in Operating Leases, Length of Lease	60 months or less
Net investment in operating lease, term and payment extension	12 months
Investment In Operating Leases, Net	$ 27,606		$ 27,449
Property Subject to or Available for Operating Lease, Gross	33,585		33,593
Property Subject to or Available for Operating Lease, Accumulated Depreciation	5,979		6,144
Allowance for credit losses	(513)	$ (600)	(589)	$ (597)
Provision for Loan and Lease Losses	(33)	(94)
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	924	1,053
Net Investment in Operating Leases [Member]
Continuing Involvement with Continued to be Recognized Transferred Financial Assets, Amount Outstanding	$ 16,000		16,300
Adjustments for New Accounting Pronouncement [Member]
Property Subject to or Available for Operating Lease, Accumulated Depreciation			78
Allowance for credit losses			$ (78)
Provision for Loan and Lease Losses		(25)
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease		$ 25
Maximum [Member]
Net investment in operating lease, payment extension	6 months