Consolidated Sponsored Investment Products - Schedule of Net Gain (Loss) Related to Consolidated VIEs (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Nonoperating net gain (loss) on consolidated VIEs	$ 972	$ 342	$ 1
Net income (loss) attributable to noncontrolling interests	354	50	(3)
Consolidated Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Nonoperating net gain (loss) on consolidated VIEs	477	210	(105)
Net income (loss) attributable to noncontrolling interests	$ 348	$ 42	$ (6)

Amount of Net Income (Loss) attributable to noncontrolling interest.

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