Leasing Activity, Leasing Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Line Items]
Interest income on lease financing	$ 211	$ 223
Variable revenues on lease financing	27	24
Fixed revenues on operating leases	314	373
Variable revenues on operating leases	13	18
Lease income	352	443
Total leasing revenue	563	666
Assets leased to others [Member]
Leases [Line Items]
Other lease-related revenues	$ (2)	$ 28