Leases - Contractual Future Lease Payments to be Received (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Sales-type and direct finance leases, One Year or Less	$ 4,547
Sales-type and direct finance leases, Over One Through Two Years	3,833
Sales-type and direct finance leases, Over Two Through Three Years	2,567
Sales-type and direct finance leases, Over Three Through Four Years	1,270
Sales-type and direct finance leases, Over Four Through Five Years	388
Sales-type and direct finance leases, thereafter	522
Sales-type and direct finance leases, lease payments	13,127
Sales-type and direct finance leases, amounts representing interest	(1,032)
Sales-type and direct finance leases, lease receivables	12,095	$ 12,207
Operating leases, One Year or Less	180
Operating leases, Over One Through Two Years	142
Operating leases, Over Two Through Three Years	104
Operating leases, Over Three Through Four Years	68
Operating leases, Over Four Through Five Years	51
Operating leases, thereafter	64
Operating leases, lease payments	$ 609