Investments (Other Invested Assets) (Details) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019
Other Invested Assets [Line Items]
Other invested assets	[2]	$ 18,071	[1]	$ 15,606
LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		11,288		11,157
Real estate held through direct ownership
Other Invested Assets [Line Items]
Other invested assets		2,410		2,388
Derivative instruments
Other Invested Assets [Line Items]
Other invested assets		3,188		877
Other
Other Invested Assets [Line Items]
Other invested assets		1,185		1,184
Mortgage Debt | Real estate-related
Other Invested Assets [Line Items]
Other invested assets		548		537
Equity method | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		7,157		6,944
Equity method | Private equity | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		3,889		3,625
Equity method | Hedge funds | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		1,864		1,947
Equity method | Real estate-related | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		1,404		1,372
Fair Value
Other Invested Assets [Line Items]
Other invested assets		196		36
Fair Value | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		4,131		4,213
Fair Value | Private equity | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		1,769		1,705
Fair Value | Hedge funds | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		2,018		2,172
Fair Value | Real estate-related | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets		$ 344		$ 336

[1] March 31, 2020 amounts include the impacts of the January 1, 2020 adoption of ASU 2016-13. See Note 2 for details.

[2] See Note 4 for details of balances associated with variable interest entities.