Financing Receivables - Credit Quality Indicators (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Major Markets | Lease receivables
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	$ 5,173	$ 5,492
Major Markets | Lease receivables | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	449	535
Major Markets | Lease receivables | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,205	1,318
Major Markets | Lease receivables | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,444	1,486
Major Markets | Lease receivables | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,171	1,208
Major Markets | Lease receivables | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	520	510
Major Markets | Lease receivables | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	352	401
Major Markets | Lease receivables | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	32	33
Major Markets | Loan receivables
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	8,588	9,656
Major Markets | Loan receivables | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	745	941
Major Markets | Loan receivables | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	2,000	2,318
Major Markets | Loan receivables | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	2,398	2,613
Major Markets | Loan receivables | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,944	2,125
Major Markets | Loan receivables | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	864	897
Major Markets | Loan receivables | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	585	705
Major Markets | Loan receivables | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	53	58
Growth Markets | Lease receivables
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	1,439	1,336
Growth Markets | Lease receivables | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	29	34
Growth Markets | Lease receivables | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	123	142
Growth Markets | Lease receivables | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	181	343
Growth Markets | Lease receivables | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	409	309
Growth Markets | Lease receivables | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	403	243
Growth Markets | Lease receivables | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	196	189
Growth Markets | Lease receivables | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	99	76
Growth Markets | Loan receivables
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	2,199	2,872
Growth Markets | Loan receivables | Aaa - Aa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	44	73
Growth Markets | Loan receivables | A1 - A3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	188	305
Growth Markets | Loan receivables | Baa1 - Baa3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	276	738
Growth Markets | Loan receivables | Ba1 - Ba2
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	624	664
Growth Markets | Loan receivables | Ba3 - B1
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	615	522
Growth Markets | Loan receivables | B2 - B3
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	299	406
Growth Markets | Loan receivables | Caa - D
Net recorded investment for each class of receivables, by credit quality indicator
Financing receivables, net recorded investment	$ 151	$ 164