Fair Value of Assets and Liabilities (Financial Instruments where Carrying Amounts and Fair Values May Differ) (Details) - USD ($) $ in Millions		Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Assets
Mortgage loans on real estate (net of valuation allowances)		$ 6,481	$ 5,787
Policy loans		1,254	1,258
Funds withheld at interest		7,049	5,432
Cash and cash equivalents		3,254	3,408	$ 4,313	$ 1,449
Short-term investments		184	227
Other invested assets		2,924	2,829
Accrued investment income		525	511
Liabilities
Interest-sensitive contract liabilities		26,161	23,276
Long-term debt		3,173	3,573
Reported Value Measurement [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)	[1]	6,481	5,787
Policy loans	[1]	1,254	1,258
Funds withheld at interest	[1]	6,825	5,292
Cash and cash equivalents	[1]	2,087	1,930
Short-term investments	[1]	18	30
Other invested assets	[1]	1,133	1,482
Accrued investment income	[1]	525	511
Liabilities
Interest-sensitive contract liabilities	[1]	21,274	18,106
Long-term debt	[1]	3,173
Debt, Long-term and Short-term, Combined Amount	[1]		3,573
Collateral finance and securitization notes	[1]	323	388
Estimate of Fair Value Measurement [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)		6,744	6,167
Policy loans		1,254	1,258
Funds withheld at interest		7,169	5,676
Cash and cash equivalents		2,087	1,930
Short-term investments		18	30
Other invested assets		1,141	1,601
Accrued investment income		525	511
Liabilities
Interest-sensitive contract liabilities		22,983	19,683
Long-term Debt, Fair Value		3,455
Debt, Long-term and Short-term, Combined Amount			3,901
Collateral finance and securitization notes		292	351
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 1 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		0	0
Funds withheld at interest		0	0
Cash and cash equivalents		2,087	1,930
Short-term investments		18	30
Other invested assets		6	5
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 2 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		1,254	1,258
Funds withheld at interest		0	0
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		84	89
Accrued investment income		525	511
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 3 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		6,744	6,167
Policy loans		0	0
Funds withheld at interest		7,169	5,676
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		1,051	1,018
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		22,983	19,683
Long-term Debt, Fair Value		3,455
Debt, Long-term and Short-term, Combined Amount			3,901
Collateral finance and securitization notes		292	351
Estimate of Fair Value Measurement [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		0	0
Funds withheld at interest		0	0
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		0	489
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		$ 0	$ 0

[1] Carrying values presented herein may differ from those in the Company’s condensed consolidated balance sheets because certain items within the respective financial statement captions may be measured at fair value on a recurring basis.