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Investments (Real Estate and Real Estate Joint Ventures) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Real Estate [Line Items]
Leased real estate investments, Carrying Value	$ 4,519		$ 4,519		$ 5,146
Other real estate investments, Carrying Value	478		478		474
Real estate joint ventures, Carrying Value	7,379		7,379		6,596
Real Estate Investments, Net	12,376		12,376		$ 12,216
Income (Loss) from Equity Method Investments	386	$ 1,000	1,500	$ 2,300
Real Estate and Real Estate Joint Ventures
Real Estate [Line Items]
Gross Investment Income, Operating	379	205	707	381
Leased real estate
Real Estate [Line Items]
Operating Lease, Lease Income	98	108	204	219
Other real estate
Real Estate [Line Items]
Operating Lease, Lease Income	68	44	100	86
Real estate joint ventures
Real Estate [Line Items]
Income (Loss) from Equity Method Investments	$ 213	$ 53	$ 403	$ 76