Commitments and Contingent Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Guarantees
Related recorded liability	$ 1
Guarantees, maximum potential amount of future payments	43	$ 39
SPC's assets in Consolidated Statements of Financial Position	1,090	1,210
SPC's liabilities in Consolidated Statements of Financial Position	1,090	1,210
Unused commitments and lines of credit for dealers	12,970	13,120
Unused commitments and lines of credit for customers	$ 3,340	3,570
Maximum
Guarantees
Related recorded liability		$ 1