Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Significant Accounting Policies [Line Items]
Assets of managed investment entities	$ 4,669		$ 4,484
Liabilities of managed investment entities	4,468		4,307
Operating lease liability	$ 204		$ 198
Operating lease liability, current, Statement of Financial Position	Other Liabilities		Other Liabilities
Operating lease right-of-use asset	$ 181		$ 176
Operating lease, right-of-use asset, Statement of Financial Position	Other Assets		Other Assets
Weighted average common shares adjustment related to stock-based compensation (shares)	100,000	200,000
Anti-dilutive potential common shares related to stock-based compensation plans (shares)	0	0
Maturities of short term investments	3 months
New collateralized loan obligation temporary warehousing entities
Significant Accounting Policies [Line Items]
Assets of managed investment entities	$ 164
Liabilities of managed investment entities	$ 134