Shareholders' Equity (Deficiency) (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ 9			$ (1,746)	$ 9	$ (1,746)
Other Comprehensive Income							(72)	35
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax								8
Other Comprehensive Income	$ (6)	$ 29	(95)	$ (20)	$ 30	33	(72)	43
Ending balance	(63)			(1,703)			(63)	(1,703)
Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			7			(1,724)	7	(1,724)
Other Comprehensive Income							(72)	35
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax								0
Other Comprehensive Income								35
Ending balance	(65)			(1,689)			(65)	(1,689)
Defined Benefit Pension
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			2			(14)	2	(14)
Other Comprehensive Income							0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax								0
Other Comprehensive Income								0
Ending balance	2			(14)			2	(14)
Deferred Loss on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ 0			$ (8)	0	(8)
Other Comprehensive Income							0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax								8
Other Comprehensive Income								8
Ending balance	$ 0			$ 0			$ 0	$ 0