Amounts Reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income taxes	$ 58	$ 56	$ 119	$ 126
Interest Rate Contract [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member] \| AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, Current Period, Tax	(1)	(1)	(2)	(1)
Gain (Loss) on Derivative Instruments, Net, Pretax	(2)	(1)	(4)	(2)
Income taxes	$ (1)	$ 0	$ (2)	$ (1)

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No definition available.

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