Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	$ 3,793	$ 3,765
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	3,781	3,753
Additions/adjustments	114	211
Foreign currency translation adjustments	(10)	(183)
Disposition of MAKS	(163)
Ending balance, Goodwill gross	3,734	3,793
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	3,722	3,781
MIS
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	258	285
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	258	285
Additions/adjustments	53	0
Foreign currency translation adjustments	4	(27)
Disposition of MAKS	0
Ending balance, Goodwill gross	315	258
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	315	258
MA
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	3,535	3,480
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	3,523	3,468
Additions/adjustments	61	211
Foreign currency translation adjustments	(14)	(156)
Disposition of MAKS	(163)
Ending balance, Goodwill gross	3,419	3,535
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	$ 3,407	$ 3,523

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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