Stockholders' Equity - Changes in Each Component of Accumulated Other Comprehensive Income of the Parent (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		$ (1,362)
Other comprehensive income (loss):
Ending Balance		(987)	$ (1,362)
Accounting Standards Update 2016-01 [Member]
Other comprehensive income (loss):
Adoption of new accounting standard, January 1				$ 0
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(721)	(670)	(646)
Other comprehensive income (loss):
Currency translation adjustments		8	(48)	(22)
Holding loss on net investment hedge			(3)	(2)
Tax (expense) benefit		(1)
Other comprehensive income (loss) attributable to the parent company		7	(51)	(24)
Ending Balance		(714)	(721)	(670)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(54)	(64)	(34)
Other comprehensive income (loss):
Holding gains and losses		58	66	(162)
Reclassification of amount to net income	[1]	(33)	(56)	128
Tax (expense) benefit		(1)		4
Other comprehensive income (loss) attributable to the parent company		24	10	(30)
Ending Balance		(30)	(54)	(64)
Accumulated Net Gain (Loss) from Investments Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		0	2	0
Other comprehensive income (loss):
Holding gains and losses				1
Reclassification of amount to net income	[1]
Tax (expense) benefit				1
Other comprehensive income (loss) attributable to the parent company		0	0	2
Ending Balance		0	0	2
Accumulated Net Gain (Loss) from Investments Attributable to Parent [Member] | Accounting Standards Update 2016-01 [Member]
Other comprehensive income (loss):
Adoption of new accounting standard, January 1				(2)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(587)	(610)	(604)
Other comprehensive income (loss):
Net actuarial gains (losses)		71	(8)	(28)
Reclassification adjustment for net actuarial losses included in net periodic benefit cost	[2]	286	34	31
Other			2
Tax (expense) benefit		(13)	(5)	(9)
Other comprehensive income (loss) attributable to the parent company		344	23	(6)
Ending Balance		(243)	(587)	(610)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(1,362)	(1,342)	(1,284)
Other comprehensive income (loss):
Currency translation adjustments		8	(48)	(22)
Holding loss on net investment hedge			(3)	(2)
Holding gains and losses		58	66	(161)
Reclassification of amount to net income	[1]	(33)	(56)	128
Net actuarial gains (losses)		71	(8)	(28)
Reclassification adjustment for net actuarial losses included in net periodic benefit cost	[2]	286	34	31
Other			2
Tax (expense) benefit		(15)	(5)	(4)
Other comprehensive income (loss) attributable to the parent company		375	(18)	(58)
Ending Balance		$ (987)	$ (1,362)	(1,342)
AOCI Attributable to Parent [Member] | Accounting Standards Update 2016-01 [Member]
Other comprehensive income (loss):
Adoption of new accounting standard, January 1				$ (2)

[1] reclassifications from AOCI were included in other expense, net.

[2] See Note 13 for additional details.