Commitments and Contingencies - Guarantees (Details) $ in Millions	Jun. 30, 2018 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	$ 367
Recorded Liability for Guarantees	188
Debt service
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	128
Recorded Liability for Guarantees	76
Operating profit
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	229
Recorded Liability for Guarantees	110
Other
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	10
Recorded Liability for Guarantees	$ 2