SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Cash Flows Statement) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows from Operating Activities
Net income (loss)	$ 1,313	$ 221	$ 902
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Equity in (income) loss of subsidiaries greater than distributions	751	(529)	379
Realized gain (loss)	(190)	(148)	(180)
Change in federal income tax accruals	192	318	394
(Gain) loss on early extinguishment of debt	(5)	(8)	(5)
Other	31	(114)	(23)
Net cash provided by (used in) operating activities	1,269	1,276	1,720
Cash Flows from Investing Activities
Proceeds from sale of subsidiaries/businesses, net of cash disposed	0	0	321
Increase (decrease) in payables for collateral on investments	448	2,074	(248)
Net cash provided by (used in) investing activities	(3,857)	(2,125)	(5,630)
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(320)	(525)	(405)
Issuance of long-term debt, net of issuance costs	300	298	749
Increase (decrease) in commercial paper, net	0	(100)	1
Issuance (redemption) of Series B preferred stock and issuance (repurchase and cancellation) of associated common stock warrants	0	0	(998)
Issuance of common stock	0	0	368
Repurchase of common stock	(492)	(575)	(25)
Dividends paid to common and preferred stockholders	(91)	(61)	(42)
Net cash provided by (used in) financing activities	2,308	2,618	2,467
Net increase (decrease) in cash and invested cash	(280)	1,769	(1,443)
Cash and invested cash at beginning-of-year	4,510
Cash and invested cash as of end-of-year	4,230	4,510
Parent Company [Member]
Cash Flows from Operating Activities
Net income (loss)	1,313	221	902
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Realized gain (loss)	(6)	(3)	(4)
Change in federal income tax accruals	(170)	(32)	190
(Gain) loss on early extinguishment of debt	5	8	5
Other	(13)	(21)	(22)
Change in legal accruals	0	(70)	70
Net cash provided by (used in) operating activities	730	702	390
Cash Flows from Investing Activities
Sales or maturities of investments	0	105	0
Capital contribution to subsidiaries	0	(17)	(125)
Proceeds from sale of subsidiaries/businesses, net of cash disposed	0	0	459
Increase (decrease) in payables for collateral on investments	73	0	0
Net cash provided by (used in) investing activities	73	88	334
Cash Flows from Financing Activities
Payment of long-term debt, including current maturities	(320)	(525)	(405)
Issuance of long-term debt, net of issuance costs	300	300	749
Increase (decrease) in commercial paper, net	0	(100)	1
Increase (decrease) in loans from subsidiaries, net	(3)	58	(97)
Increase (decrease) in loans to subsidiaries, net	20	154	(683)
Common stock issued for benefit plans and excess tax benefits	5	1	0
Issuance (redemption) of Series B preferred stock and issuance (repurchase and cancellation) of associated common stock warrants	0	0	(998)
Issuance of common stock	0	0	368
Repurchase of common stock	(493)	(576)	(25)
Dividends paid to common and preferred stockholders	(90)	(62)	(42)
Net cash provided by (used in) financing activities	(581)	(750)	(1,132)
Net increase (decrease) in cash and invested cash	222	40	(408)
Cash and invested cash at beginning-of-year	622	582	990
Cash and invested cash as of end-of-year	$ 844	$ 622	$ 582