Financing Receivables - Credit Quality Indicators (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Net recorded investment for each class of receivables, by credit quality indicator
Troubled debt restructurings of financing receivables
Lease receivables | Americas
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	3,676	3,847
Lease receivables | Americas | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	390	422
Lease receivables | Americas | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	808	855
Lease receivables | Americas | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	857	980
Lease receivables | Americas | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	784	730
Lease receivables | Americas | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	479	443
Lease receivables | Americas | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	320	367
Lease receivables | Americas | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	39	51
Lease receivables | EMEA
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,292	1,340
Lease receivables | EMEA | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	51	49
Lease receivables | EMEA | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	156	190
Lease receivables | EMEA | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	397	371
Lease receivables | EMEA | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	401	448
Lease receivables | EMEA | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	177	192
Lease receivables | EMEA | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	102	77
Lease receivables | EMEA | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	9	13
Lease receivables | Asia Pacific
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,233	1,302
Lease receivables | Asia Pacific | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	101	68
Lease receivables | Asia Pacific | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	477	544
Lease receivables | Asia Pacific | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	320	337
Lease receivables | Asia Pacific | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	188	184
Lease receivables | Asia Pacific | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	85	89
Lease receivables | Asia Pacific | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	54	64
Lease receivables | Asia Pacific | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	9	18
Loan receivables | Americas
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	6,206	6,607
Loan receivables | Americas | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	658	724
Loan receivables | Americas | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,364	1,469
Loan receivables | Americas | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,446	1,683
Loan receivables | Americas | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,323	1,253
Loan receivables | Americas | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	808	760
Loan receivables | Americas | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	540	630
Loan receivables | Americas | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	67	88
Loan receivables | EMEA
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	3,487	3,545
Loan receivables | EMEA | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	137	129
Loan receivables | EMEA | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	420	502
Loan receivables | EMEA | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,072	982
Loan receivables | EMEA | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,082	1,186
Loan receivables | EMEA | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	477	508
Loan receivables | EMEA | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	274	204
Loan receivables | EMEA | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	24	34
Loan receivables | Asia Pacific
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	2,362	2,303
Loan receivables | Asia Pacific | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	194	120
Loan receivables | Asia Pacific | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	913	961
Loan receivables | Asia Pacific | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	613	596
Loan receivables | Asia Pacific | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	359	325
Loan receivables | Asia Pacific | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	162	157
Loan receivables | Asia Pacific | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	103	113
Loan receivables | Asia Pacific | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	$ 17	$ 31