Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Statement of Cash Flows [Abstract]
Net cash provided by (used in) operating activities	$ 1,322	$ 1,496
Cash flows from investing activities
Sales, maturities and repayments of fixed maturity securities	11,888	11,680
Sales, maturities and repayments of equity securities	29	15
Sales, maturities and repayments of mortgage loans	933	446
Sales, maturities and repayments of real estate limited partnerships and limited liability companies	2	87
Sales, maturities and repayments of other limited partnership interests	203	137
Purchases of fixed maturity securities	(13,412)	(12,005)
Purchases of equity securities	(3)	(1)
Purchases of mortgage loans	(2,625)	(2,771)
Purchases of real estate limited partnerships and limited liability companies	(13)	(31)
Purchases of other limited partnership interests	(308)	(194)
Cash received in connection with freestanding derivatives	1,179	1,142
Cash paid in connection with freestanding derivatives	(1,705)	(2,286)
Net change in policy loans	89	81
Net change in short-term investments	(1,977)	196
Net change in other invested assets	21	35
Net cash provided by (used in) investing activities	(5,699)	(3,469)
Cash flows from financing activities
Policyholder account balances: Deposits	5,689	4,704
Policyholder account balances: Withdrawals	(2,021)	(2,199)
Net change in payables for collateral under securities loaned and other transactions	234	(126)
Long-term debt issued	1,000	375
Long-term debt repaid	(601)	(9)
Preferred stock issued, net of issuance costs	412	0
Dividends on preferred stock	(14)	0
Treasury stock acquired in connection with share repurchases	(314)	(42)
Financing element on certain derivative instruments and other derivative related transactions, net	179	(386)
Other, net	(43)	(57)
Net cash provided by (used in) financing activities	4,521	2,260
Change in cash, cash equivalents and restricted cash	144	287
Cash, cash equivalents and restricted cash, beginning of period	4,145	1,857
Cash, cash equivalents and restricted cash, end of period	4,289	2,144
Supplemental disclosures of cash flow information
Net cash paid (received) for interest	108	83
Net cash paid (received) for income tax	$ 8	$ 3