Fair Values of Assets and Liabilities (Recurring) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2020		Dec. 31, 2019
Assets
Available-for-Sale securities		$ 19,742		$ 20,902
Separate account assets at NAV		70,842		82,425
Liabilities
Individual contracts in a liability position	[1]	7,436		5,168
Individual contracts in an asset position	[2]	5,690		4,283
Cumulative increase (decrease) in embedded derivatives of adjustment for nonperformance risk		(2,700)		(502)
GMWB and GMAB embedded derivatives [Member]
Liabilities
Individual contracts in a liability position		3,300		981
Individual contracts in an asset position		12		218
Recurring basis [Member]
Assets
Available-for-Sale securities		19,742		20,902
Cash equivalents		5,020		1,256
Other assets		5,690		4,283
Separate account assets at NAV	[3]	70,842		82,425
Total assets at fair value		101,294		108,866
Liabilities
Policyholder account balances, future policy benefits and claims		4,027	[4]	1,690	[5]
Other liabilities		3,409		3,478
Total liabilities at fair value		7,436		5,168
Recurring basis [Member] | Interest rate derivative contracts [Member]
Assets
Other assets		3,097		1,451
Liabilities
Other liabilities		1,238		418
Recurring basis [Member] | Equity derivative contracts [Member]
Assets
Other assets		2,543		2,812
Liabilities
Other liabilities		2,157		3,054
Recurring basis [Member] | Foreign exchange derivative contracts [Member]
Assets
Other assets		37		16
Liabilities
Other liabilities		14		6
Recurring basis [Member] | Credit derivative contracts [Member]
Assets
Other assets		13		4
Recurring basis [Member] | Fixed deferred indexed annuity embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		35		46
Recurring basis [Member] | IUL embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		725		881
Recurring basis [Member] | GMWB and GMAB embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		3,276	[6]	763	[7]
Recurring basis [Member] | Structured annuity embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		(9)
Recurring basis [Member] | Corporate debt securities [Member]
Assets
Available-for-Sale securities		10,443		11,522
Recurring basis [Member] | Residential mortgage backed securities [Member]
Assets
Available-for-Sale securities		3,178		3,108
Recurring basis [Member] | Commercial mortgage backed securities [Member]
Assets
Available-for-Sale securities		3,638		3,618
Recurring basis [Member] | State and municipal obligations [Member]
Assets
Available-for-Sale securities		1,272		1,306
Recurring basis [Member] | Asset backed securities [Member]
Assets
Available-for-Sale securities		963		1,080
Recurring basis [Member] | Foreign government bonds and obligations [Member]
Assets
Available-for-Sale securities		247		267
Recurring basis [Member] | U.S. government and agencies obligations [Member]
Assets
Available-for-Sale securities		1		1
Level 1 [Member] | Recurring basis [Member]
Assets
Available-for-Sale securities		1		1
Cash equivalents		1,920
Other assets		662		163
Total assets at fair value		2,583		164
Liabilities
Other liabilities		296		37
Total liabilities at fair value		296		37
Level 1 [Member] | Recurring basis [Member] | Interest rate derivative contracts [Member]
Assets
Other assets		1
Level 1 [Member] | Recurring basis [Member] | Equity derivative contracts [Member]
Assets
Other assets		661		162
Liabilities
Other liabilities		293		36
Level 1 [Member] | Recurring basis [Member] | Foreign exchange derivative contracts [Member]
Assets
Other assets				1
Liabilities
Other liabilities		3		1
Level 1 [Member] | Recurring basis [Member] | U.S. government and agencies obligations [Member]
Assets
Available-for-Sale securities		1		1
Level 2 [Member] | Recurring basis [Member]
Assets
Available-for-Sale securities		18,703		19,760
Cash equivalents		3,100		1,256
Other assets		5,028		4,120
Total assets at fair value		26,831		25,136
Liabilities
Policyholder account balances, future policy benefits and claims		2		3
Other liabilities		3,113		3,441
Total liabilities at fair value		3,115		3,444
Level 2 [Member] | Recurring basis [Member] | Interest rate derivative contracts [Member]
Assets
Other assets		3,096		1,451
Liabilities
Other liabilities		1,238		418
Level 2 [Member] | Recurring basis [Member] | Equity derivative contracts [Member]
Assets
Other assets		1,882		2,650
Liabilities
Other liabilities		1,864		3,018
Level 2 [Member] | Recurring basis [Member] | Foreign exchange derivative contracts [Member]
Assets
Other assets		37		15
Liabilities
Other liabilities		11		5
Level 2 [Member] | Recurring basis [Member] | Credit derivative contracts [Member]
Assets
Other assets		13		4
Level 2 [Member] | Recurring basis [Member] | Fixed deferred indexed annuity embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		2		3
Level 2 [Member] | Recurring basis [Member] | Corporate debt securities [Member]
Assets
Available-for-Sale securities		9,722		10,787
Level 2 [Member] | Recurring basis [Member] | Residential mortgage backed securities [Member]
Assets
Available-for-Sale securities		3,161		3,091
Level 2 [Member] | Recurring basis [Member] | Commercial mortgage backed securities [Member]
Assets
Available-for-Sale securities		3,638		3,618
Level 2 [Member] | Recurring basis [Member] | State and municipal obligations [Member]
Assets
Available-for-Sale securities		1,272		1,306
Level 2 [Member] | Recurring basis [Member] | Asset backed securities [Member]
Assets
Available-for-Sale securities		663		691
Level 2 [Member] | Recurring basis [Member] | Foreign government bonds and obligations [Member]
Assets
Available-for-Sale securities		247		267
Level 3 [Member] | Recurring basis [Member]
Assets
Available-for-Sale securities		1,038		1,141
Total assets at fair value		1,038		1,141
Liabilities
Policyholder account balances, future policy benefits and claims		4,025		1,687
Total liabilities at fair value		4,025		1,687
Level 3 [Member] | Recurring basis [Member] | Fixed deferred indexed annuity embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		33		43
Level 3 [Member] | Recurring basis [Member] | IUL embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		725		881
Level 3 [Member] | Recurring basis [Member] | GMWB and GMAB embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		3,276		763
Level 3 [Member] | Recurring basis [Member] | Structured annuity embedded derivatives [Member]
Liabilities
Policyholder account balances, future policy benefits and claims		(9)
Level 3 [Member] | Recurring basis [Member] | Corporate debt securities [Member]
Assets
Available-for-Sale securities		721		735
Level 3 [Member] | Recurring basis [Member] | Residential mortgage backed securities [Member]
Assets
Available-for-Sale securities		17		17
Level 3 [Member] | Recurring basis [Member] | Asset backed securities [Member]
Assets
Available-for-Sale securities		$ 300		$ 389

[1] The fair value of freestanding derivative liabilities is included in Other liabilities on the Consolidated Balance Sheets. The fair value of GMWB and GMAB, IUL, indexed annuity and structured annuity embedded derivatives is included in Policyholder account balances, future policy benefits and claims on the Consolidated Balance Sheets.

[2] The fair value of freestanding derivative assets is included in Other assets on the Consolidated Balance Sheets.

[3] Amounts are comprised of certain financial instruments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient and have not been classified in the fair value hierarchy.

[4] The Company’s adjustment for nonperformance risk resulted in a $(2.7) billion cumulative increase (decrease) to the embedded derivatives as of March 31, 2020.

[5] The Company’s adjustment for nonperformance risk resulted in a $(502) million cumulative increase (decrease) to the embedded derivatives as of December 31, 2019.

[6] The fair value of the GMWB and GMAB embedded derivatives included $3.3 billion of individual contracts in a liability position and $12 million of individual contracts in an asset position as of March 31, 2020.

[7] The fair value of the GMWB and GMAB embedded derivatives included $981 million of individual contracts in a liability position and $218 million of individual contracts in an asset position as of December 31, 2019.