Amounts Reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income taxes	$ 66	$ 69	$ 185	$ 195
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)	(3)	(2)
Gain (Loss) on Derivative Instruments, Net, Pretax	(1)	(1)	(4)	(3)
Income taxes	$ 0	$ 0	$ (1)	$ (1)

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