Derivatives (Effects on the Consolidated Statement of Operations and Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	$ 4,284	$ 5,314
Net investment gains (losses)	(518)	134
Derivative, Gain (Loss) on Derivative, Net	(859)	(2,235)
Policyholder Benefits and Claims Incurred, Net	(11,193)	(10,523)
Policyholder Account Balance, Interest Expense	(630)	(1,351)
Operating Expenses	3,020	3,150
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	11	(15)
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	(1,136)	(3,160)
Policyholder Benefits and Claims Incurred, Net	(52)	(148)
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	2	1
Net investment gains (losses)	32	(7)
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	(17)	(29)
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	17	15
Net investment gains (losses)	16	21
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	1	1
Other Comprehensive Income (Loss), before Tax	(200)	(1,268)
Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	62	56
Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net	(14)	(43)
Foreign Exchange Forward [Member] | Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax		29
Designated as Hedging Instrument [Member] | Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	43
Interest Rate Contract | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	15	12
Net investment gains (losses)	18	29
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	1	1
Other Comprehensive Income (Loss), before Tax	(34)	(42)
Credit forwards [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Other Comprehensive Income (Loss), before Tax	0	0
Currency Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	2	3
Net investment gains (losses)	(148)	(219)
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Other Comprehensive Income (Loss), before Tax	146	216
Derivative [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	33	(2)
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Derivative [Member] | Interest rate swaps | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	4	3
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	452	602
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Derivative [Member] | Currency Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	32	13
Net investment gains (losses)	(81)	(128)
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Debt Securities [Member] | Interest rate swaps | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	(4)	(3)
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	435	573
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Debt Securities [Member] | Currency Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	(30)	(12)
Net investment gains (losses)	80	123
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Non-derivative [Domain] [Member] | Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	19	27
Foreign Currency Gain (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	146	211
Derivative, Gain (Loss) on Derivative, Net	0	0
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Other Comprehensive Income (Loss), before Tax	0	0
Accumulated Other Comprehensive Income (Loss) | Credit forwards [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	0	(68)
Accumulated Other Comprehensive Income (Loss) | Currency Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	452	(153)
Accumulated Other Comprehensive Income (Loss) | Interest rate swaps | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	(764)	(1,221)
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	1	0
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	(74)	(483)
Policyholder Benefits and Claims Incurred, Net	(1)	3
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Credit derivatives — purchased | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	46	19
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Credit derivatives — written | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	(50)	5
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Equity Market Risk [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	9	(17)
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	161	(676)
Policyholder Benefits and Claims Incurred, Net	(82)	(104)
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Interest Rate Risk [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	1	2
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	(1,337)	(2,250)
Policyholder Benefits and Claims Incurred, Net	29	47
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Foreign Currency Gain (Loss) [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	0	0
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	118	225
Policyholder Benefits and Claims Incurred, Net	0	0
Policyholder Account Balance, Interest Expense	0	0
Operating Expenses	0	0
Net Derivative Gain (Loss) [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	83	39
Net investment gains (losses)	0	0
Derivative, Gain (Loss) on Derivative, Net	235	252
Policyholder Benefits and Claims Incurred, Net	(52)	(53)
Policyholder Account Balance, Interest Expense	(35)	(39)
Operating Expenses	0	0
Other Comprehensive Income (Loss), before Tax	0	0
Net Embedded Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	42	673
Policyholder Benefits and Claims Incurred, Net	0	0
Effects of Derivatives on Consolidated Statements of Operations and Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income	113	40
Net investment gains (losses)	48	14
Policyholder Benefits and Claims Incurred, Net	(87)	124
Policyholder Account Balance, Interest Expense	35	39
Operating Expenses	1	1
Other Comprehensive Income (Loss), before Tax	$ (138)	$ (1,212)