SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Cash Flows Statement) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash Flows from Operating Activities
Net income (loss)	$ 1,515		$ 1,244		$ 1,313
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
(Gain) loss on early extinguishment of debt					(5)
Other	200		(117)		31
Net cash provided by (used in) operating activities	2,526		799		1,269
Cash Flows from Investing Activities
Increase (decrease) in payables for collateral on investments	1,019		(943)		448
Net cash provided by (used in) investing activities	(1,805)		(4,710)		(3,857)
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(500)				(320)
Issuance of long-term debt, net of issuance costs			393		300
Repurchase of common stock	(650)		(450)		(492)
Dividends paid to common and preferred stockholders	(170)		(128)		(91)
Net cash provided by (used in) financing activities	834		2,045		2,308
Net increase (decrease) in cash and invested cash	1,555		(1,866)		(280)
Cash and invested cash, including discontinued operations, as of beginning-of-year	2,364		4,230		4,510
Cash and invested cash, including discontinued operations, as of end-of-year	3,919		2,364		4,230
Parent Company [Member]
Cash Flows from Operating Activities
Net income (loss)	1,515		1,244		1,313
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in (income) loss of subsidiaries greater than distributions	(845)	[1]	(655)	[1]	(751)	[1]
Realized (gain) loss	(1)		9		6
Change in federal income tax accruals	(32)		63		170
(Gain) loss on early extinguishment of debt					5
Other	(1)		(10)		(13)
Net cash provided by (used in) operating activities	636		651		730
Cash Flows from Investing Activities
Sales or maturities of investments	50
Investment acquisition			(25)
Capital contribution to subsidiaries	(5)	[1]	(75)	[1]
Increase (decrease) in payables for collateral on investments	(278)		315		73
Net cash provided by (used in) investing activities	(233)		215		73
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(500)				(320)
Issuance of long-term debt, net of issuance costs			400		300
Increase (decrease) in loans from subsidiaries, net	(7)	[1]	405	[1]	(3)	[1]
Increase (decrease) in loans to subsidiaries, net			(410)	[1]	20	[1]
Common stock issued for benefit plans and excess tax benefits	32		32		5
Repurchase of common stock	(650)		(450)		(493)
Dividends paid to common and preferred stockholders	(170)		(129)		(90)
Net cash provided by (used in) financing activities	(1,295)		(152)		(581)
Net increase (decrease) in cash and invested cash	(892)		714		222
Cash and invested cash, including discontinued operations, as of beginning-of-year	1,558		844		622
Cash and invested cash, including discontinued operations, as of end-of-year	$ 666		$ 1,558		$ 844

[1] Eliminated in consolidation.