Comprehensive Income And Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accounting Standards Update [Extensible List]					us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 612
Ending balance	$ 1,041		1,041		$ 612
Pension and Other Retirement Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(92)	$ (69)	(92)	$ (53)	(53)
Other comprehensive income/(loss) before reclassifications	7	(2)	6	(1)
Amounts reclassified from AOCI	1	1	2	1
Other comprehensive income/(loss)	8	(1)	8	(17)
Ending balance	(84)	(70)	(84)	(70)	(92)	$ (53)
Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(35)	0	0	0	0
Other comprehensive income/(loss) before reclassifications	(14)	0	(50)	0
Amounts reclassified from AOCI	0	0	1	0
Other comprehensive income/(loss)	(14)	0	(49)	0
Ending balance	(49)	0	(49)	0	0	0
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(570)	(440)	(401)	(406)	(406)
Other comprehensive income/(loss) before reclassifications	91	39	(78)	5
Amounts reclassified from AOCI	0	0	0	0
Other comprehensive income/(loss)	91	39	(78)	5
Ending balance	(479)	(401)	(479)	(401)	(401)	(406)
Net Investment Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	143	54	54	33	33
Other comprehensive income/(loss) before reclassifications	(73)	(29)	16	(5)
Amounts reclassified from AOCI	0	0	0	0
Other comprehensive income/(loss)	(73)	(29)	16	(8)
Ending balance	70	25	70	25	54	33
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(554)	(455)	(439)	(426)	(426)
Other comprehensive income/(loss) before reclassifications	11	8	(106)	(1)
Amounts reclassified from AOCI	1	1	3	1
Other comprehensive income/(loss)	12	9	(103)	(20)
Ending balance	$ (542)	$ (446)	$ (542)	(446)	(439)	(426)
Cumulative Effect, Period of Adoption, Adjustment | Pension and Other Retirement Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance				(17)	(17)
Ending balance						(17)
Cumulative Effect, Period of Adoption, Adjustment | Net Investment Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance				(3)	(3)
Ending balance						(3)
Cumulative Effect, Period of Adoption, Adjustment | Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance				$ (20)	$ (20)
Ending balance						$ (20)