Basis of Presentation - Out of Period Correction (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Correction related to defined benefit plans
Out-of-period correction
Out-of-period correction	$ 29
Correction related to performance fees
Out-of-period correction
Out-of-period correction		$ 19

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