Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ 1,641	$ 2,079	$ 1,192
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred acquisition costs, value of business acquired, deferred sales inducements and deferred front-end loads deferrals and interest, net of amortization	(81)	16	143
Trading securities purchases, sales and maturities, net	(118)	121	168
Change in premiums and fees receivable	(87)	34	(54)
Change in accrued investment income	(17)	(16)	8
Change in future contract benefits and other contract holder funds	(105)	(1,720)	(1,024)
Change in reinsurance related assets and liabilities	718	128	226
Change in accrued expenses	(101)	113	(27)
Change in federal income tax accruals	154	(1,119)	69
Realized (gain) loss	(141)	170	339
Amortization of deferred gain on business sold through reinsurance	(9)	(23)	(73)
Impairment of intangibles		905
Other	89	100	305
Net cash provided by (used in) operating activities	1,943	788	1,272
Cash Flows from Investing Activities
Purchases of available-for-sale securities and equity securities	(12,650)	(10,148)	(11,113)
Sales of available-for-sale securities and equity securities	3,668	1,612	2,959
Maturities of available-for-sale securities	6,004	5,886	5,364
Purchase of common stock in acquisition, net of cash acquired	(1,410)
Sale of business, net	(12)
Purchases of alternative investments	(314)	(357)	(302)
Sales and repayments of alternative investments	178	184	238
Issuance of mortgage loans on real estate	(2,927)	(2,058)	(2,155)
Repayment and maturities of mortgage loans on real estate	1,085	1,184	942
Issuance and repayment of policy loans, net	21	51	92
Net change in collateral on investments, derivatives and related settlements	735	(429)	415
Other	(193)	(113)	(106)
Net cash provided by (used in) investing activities	(5,815)	(4,188)	(3,666)
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(537)		(600)
Issuance of long-term debt, net of issuance costs	1,094		395
Payment related to early extinguishment of debt	(23)		(59)
Proceeds from sales leaseback transaction	88	62	85
Deposits of fixed account values, including the fixed portion of variable	13,638	10,797	10,053
Withdrawals of fixed account values, including the fixed portion of variable	(6,007)	(5,825)	(5,505)
Transfers to and from separate accounts, net	(2,469)	(1,787)	(1,308)
Common stock issued for benefit plans	(6)	46	26
Repurchase of common stock	(900)	(725)	(879)
Dividends paid to common stockholders	(289)	(262)	(238)
Net cash provided by (used in) financing activities	4,589	2,306	1,970
Net increase (decrease) in cash, invested cash and restricted cash	717	(1,094)	(424)
Cash, invested cash and restricted cash as of beginning-of-year	1,628	2,722	3,146
Cash, invested cash and restricted cash as of end-of-year	$ 2,345	$ 1,628	$ 2,722