Closed Block (Liabilities and Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Closed Block Liabilities
Future policy benefits	$ 41,367	$ 41,667
Other policy-related balances	283	265
Policyholder dividends payable	485	461
Policyholder dividend obligation	2,328	3,155	$ 1,771
Current income tax payable	4	1
Other liabilities	570	646
Total closed block liabilities	45,037	46,195
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	27,799	29,199
Equity securities available-for-sale, at estimated fair value	120	91
Mortgage loans	6,202	6,076
Policy loans	4,645	4,646
Real estate and real estate joint ventures	649	666
Other invested assets	1,061	1,065
Total investments	40,476	41,743
Cash and cash equivalents	395	227
Accrued investment income	464	477
Premiums, reinsurance and other receivables	93	67
Deferred income tax assets	269	289
Total assets designated to the closed block	41,697	42,803
Excess of closed block liabilities over assets designated to the closed block	3,340	3,392
Amounts included in accumulated other comprehensive income (loss) (“AOCI”)
Unrealized investment gains (losses), net of income tax	1,720	2,291
Unrealized gains (losses) on derivatives, net of income tax	45	28
Allocated to policyholder dividend obligation, net of income tax	(1,513)	(2,051)
Total amounts included in AOCI	252	268
Maximum future earnings to be recognized from closed block assets and liabilities	$ 3,592	$ 3,660