CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Cash Flows [Abstract]
Net income	$ 403	$ 364
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion, net	63	65
Deferred income tax benefit	38	36
Share-based compensation	31	34
Net realized investment losses (gains)	(19)	12
Net trading gains	(1)	(2)
Loss from equity method investments	12	9
Other-than-temporary impairments and provision for loan losses	1	0
Net losses of consolidated investment entities	3	4
Changes in operating assets and liabilities:
Restricted and segregated investments	25	50
Deferred acquisition costs	5	28
Other investments, net	(98)	(4)
Policyholder account balances, future policy benefits and claims, net	(434)	669
Derivatives, net of collateral	304	(382)
Receivables	(59)	(62)
Brokerage deposits	77	(108)
Accounts payable and accrued expenses	(259)	(295)
Other operating assets and liabilities of consolidated investment entities, net	0	(12)
Other, net	(86)	210
Net cash provided by operating activities	6	616
Available-for-Sale securities:
Proceeds from sales	46	154
Maturities, sinking fund payments and calls	1,274	956
Purchases	(1,135)	(1,366)
Proceeds from sales, maturities and repayments of mortgage loans	117	410
Funding of mortgage loans	(112)	(119)
Proceeds from sales and collections of other investments	90	32
Purchase of other investments	(54)	(46)
Purchase of investments by consolidated investment entities	(285)	(158)
Proceeds from sales, maturities and repayments of investments by consolidated investment entities	296	182
Purchase of land, buildings, equipment and software	(33)	(28)
Other, net	7	(16)
Net cash provided by investing activities	211	1
Investment certificates:
Proceeds from additions	1,284	1,159
Maturities, withdrawals and cash surrenders	(1,083)	(807)
Policyholder account balances:
Deposits and other additions	502	481
Net transfers from (to) separate accounts	(23)	33
Surrenders and other benefits	(507)	(497)
Cash paid for purchased options with deferred premiums	(58)	(85)
Cash received from purchased options with deferred premiums	0	33
Repayments of long-term debt	(2)	(19)
Dividends paid to shareholders	(117)	(115)
Repurchase of common shares	(436)	(481)
Exercise of stock options	6	2
Repayments of debt by consolidated investment entities	0	(26)
Net cash used in financing activities	(434)	(322)
Effect of exchange rate changes on cash	5	(12)
Net increase (decrease) in cash, cash equivalents and restricted cash	(212)	283
Cash, Cash Equivalents and Restricted Cash, Beginning Balance	5,392	5,407
Cash Divested from Deconsolidation	0	(346)
Cash, Cash Equivalents and Restricted Cash, Ending Balance	$ 5,180	$ 5,344