Closed Block (Liabilities and Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Closed Block Liabilities
Future policy benefits	$ 41,481	$ 41,667
Other policy-related balances	309	265
Policyholder dividends payable	479	461
Policyholder dividend obligation	3,483	3,155	1,771
Current income tax payable	3	1
Other liabilities	482	646
Total closed block liabilities	46,237	46,195
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	29,093	29,199
Equity securities available-for-sale, at estimated fair value	98	91
Mortgage loans	6,103	6,076
Policy loans	4,643	4,646
Real estate and real estate joint ventures	651	666
Other invested assets	1,123	1,065
Total investments	41,711	41,743
Cash and cash equivalents	323	227
Accrued investment income	483	477
Premiums, reinsurance and other receivables	78	67
Deferred income tax assets	277	289
Total assets designated to the closed block	42,872	42,803
Excess of closed block liabilities over assets designated to the closed block	3,365	3,392
Amounts included in accumulated other comprehensive income (loss) (“AOCI”)
Unrealized investment gains (losses), net of income tax	2,441	2,291
Unrealized gains (losses) on derivatives, net of income tax	63	28
Allocated to policyholder dividend obligation, net of income tax	(2,264)	(2,051)
Total amounts included in AOCI	240	268
Maximum future earnings to be recognized from closed block assets and liabilities	$ 3,605	$ 3,660