Investments (Leased Real Estate Investments - Operating Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 4,446	$ 4,523
Office
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 2,221	$ 2,206
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Retail
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 753	$ 804
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Apartment
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 641	$ 625
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Land
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 564	$ 562
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Industrial
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 200	$ 254
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Hotel
Schedule of Operating Leases by Property Type [Line Items]
Leased real estate investments, Carrying Value	$ 67	$ 72
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Leased real estate
Schedule of Operating Leases by Property Type [Line Items]
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues
Other real estate
Schedule of Operating Leases by Property Type [Line Items]
Operating Lease, Lease Income	Total revenues	Total revenues	Total revenues