Business Combinations - Schedule of Recognized Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Oct. 01, 2019	Dec. 31, 2021	Dec. 31, 2020
Liabilities assumed:
Goodwill recognized from BlueMountain acquisition		$ 117	$ 117
BlueMountain Capital Management, LLC
Business Acquisition [Line Items]
Cash purchase price	$ 157
Identifiable assets acquired:
Investment portfolio	3
Cash	12
Intangible assets	79
Other assets	59
Total assets	153
Liabilities assumed:
Compensation payables	61
Other liabilities	52
Total liabilities	113
Net identifiable assets acquired	40
Goodwill recognized from BlueMountain acquisition	$ 117