Related Party Transactions - Summary of Amounts Included in Condensed Consolidated Statements of Operations Related to Fee for Service Arrangement (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Related Party Transaction [Line Items]
Equity in earnings (losses) from unconsolidated affiliates	$ 1	$ (1)	$ 7	$ 3
BRE Ace LLC
Related Party Transaction [Line Items]
Equity in earnings (losses) from unconsolidated affiliates	1	(1)	7	3
Commissions and other fees	$ 33	$ 16	$ 70	$ 43

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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