Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities
Net income (loss)	$ 752	$ 846
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	(3)	30
Trading securities purchases, sales and maturities, net	133	60
Change in premiums and fees receivable	(91)	65
Change in accrued investment income	(17)	(20)
Change in future contract benefits and other contract holder funds	(848)	(864)
Change in reinsurance related assets and liabilities	664	(92)
Change in accrued expenses	(90)	(96)
Change in federal income tax accruals	44	162
Realized (gain) loss	(5)	49
Amortization of deferred gain on business sold through reinsurance		(22)
Other	93	84
Net cash provided by (used in) operating activities	632	202
Cash Flows from Investing Activities
Purchases of available-for-sale securities and equity securities	(4,836)	(5,513)
Sales of available-for-sale securities and equity securities	870	842
Maturities of available-for-sale securities	3,351	2,840
Purchase of common stock in acquisition, net of cash acquired	(1,404)
Sale of business, net	(12)
Purchases of alternative investments	(146)	(124)
Sales and repayments of alternative investments	69	100
Issuance of mortgage loans on real estate	(1,310)	(705)
Repayment and maturities of mortgage loans on real estate	513	571
Issuance and repayment of policy loans, net	23	34
Net change in collateral on investments, derivatives and related settlements	588	(12)
Other	(79)	(37)
Net cash provided by (used in) investing activities	(2,373)	(2,004)
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(537)
Issuance of long-term debt, net of issuance costs	1,094
Payment related to early extinguishment of debt	(23)
Proceeds from sales leaseback transaction	51	45
Deposits of fixed account values, including the fixed portion of variable	5,916	5,216
Withdrawals of fixed account values, including the fixed portion of variable	(3,007)	(2,934)
Transfers to and from separate accounts, net	(1,353)	(770)
Common stock issued for benefit plans	(8)	33
Repurchase of common stock	(100)	(400)
Dividends paid to common stockholders	(145)	(132)
Net cash provided by (used in) financing activities	1,888	1,058
Net increase (decrease) in cash, invested cash and restricted cash	147	(744)
Cash, invested cash and restricted cash as of beginning-of-year	1,628	2,722
Cash, invested cash and restricted cash as of end-of-period	$ 1,775	$ 1,978