Recent Accounting Pronouncements (Schedule Of Adjustment Made To Consolidated Assets, Liabilities And Equity By Transition Method Of Consolidation) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Consolidated Assets, Liabilities [Line Items]
Total assets	$ 26,873		$ 32,279	$ 25,701
Unearned premium revenue
Total liabilities	25,150		29,433
Retained earnings	805		2,124
Accumulated other comprehensive income (loss)	(176)		(406)
Total equity	1,723		2,846
Variable Interest Entities [Member]
Consolidated Assets, Liabilities [Line Items]
Other assets	1		38
Cash	160		764
Investments held-to-maturity	3,843		4,039
Fixed-maturity securities at fair value	2,884		5,241
Loans receivable at fair value	2,046		2,183
Loan repurchase commitments	1,077		835
Derivative assets	450		699
Total assets	10,900		14,100
Long-term debt	360		360
Derivative liabilities	825		2,104
Other liabilities	1		1
Variable interest entity notes	8,697	[1]	10,590
Total liabilities	9,900		13,100
Fair Value Option [Member]
Consolidated Assets, Liabilities [Line Items]
Total investments				(593)
Accrued investment income				(3)
Premiums receivable				(23)
Deferred acquisition costs				(7)
Insurance loss recoverable				(594)
Deferred income taxes, net				10
Other assets				(484)
Total assets				6,638
Unearned premium revenue				(46)
Loss and loss adjustment expense reserves				(364)
Payable for investments purchased				(1)
Derivative liabilities				(33)
Other liabilities				(8)
Total liabilities				6,670
Retained earnings				(296)
Accumulated other comprehensive income (loss)				264
Total equity				(32)
Fair Value Option [Member] | Variable Interest Entities [Member]
Consolidated Assets, Liabilities [Line Items]
Other assets				37
Cash				320
Fixed-maturity securities at fair value				5,507
Loans receivable at fair value				2,002
Loan repurchase commitments				436
Derivative assets				30
Derivative liabilities				764
Variable interest entity notes				6,358
Unpaid Principal Balance [Member]
Consolidated Assets, Liabilities [Line Items]
Total investments				(3,058)
Accrued investment income				(3)
Premiums receivable				(127)
Current income taxes				14
Deferred income taxes, net				(3)
Other assets				5
Total assets				1,642
Unearned premium revenue				(92)
Medium-term notes				(1,429)
Long-term debt				(433)
Derivative liabilities				(9)
Other liabilities				(2)
Total liabilities				1,665
Retained earnings				(23)
Total equity				(23)
Unpaid Principal Balance [Member] | Variable Interest Entities [Member]
Consolidated Assets, Liabilities [Line Items]
Other assets				16
Investments held-to-maturity				4,798
Long-term debt				433
Derivative liabilities				9
Other liabilities				18
Variable interest entity notes				3,170
Deconsolidated VIEs [Member]
Consolidated Assets, Liabilities [Line Items]
Total investments				(172)
Deferred income taxes, net				2
Total assets				(170)
Total liabilities				(252)
Retained earnings				(3)
Accumulated other comprehensive income (loss)				85
Total equity				82
Deconsolidated VIEs [Member] | Variable Interest Entities [Member]
Consolidated Assets, Liabilities [Line Items]
Variable interest entity notes				(252)
Increase (Decrease) [Member]
Consolidated Assets, Liabilities [Line Items]
Total investments				(3,823)
Accrued investment income				(6)
Premiums receivable				(150)
Deferred acquisition costs				(7)
Insurance loss recoverable				(594)
Current income taxes				14
Deferred income taxes, net				9
Other assets				(479)
Total assets				8,110
Unearned premium revenue				(138)
Loss and loss adjustment expense reserves				(364)
Medium-term notes				(1,429)
Long-term debt				(433)
Payable for investments purchased				(1)
Derivative liabilities				(42)
Other liabilities				(10)
Total liabilities				8,083
Retained earnings				(322)
Accumulated other comprehensive income (loss)				349
Total equity				27
Increase (Decrease) [Member] | Variable Interest Entities [Member]
Consolidated Assets, Liabilities [Line Items]
Other assets				53
Cash				320
Investments held-to-maturity				4,798
Fixed-maturity securities at fair value				5,507
Loans receivable at fair value				2,002
Loan repurchase commitments				436
Derivative assets				30
Long-term debt				433
Derivative liabilities				773
Other liabilities				18
Variable interest entity notes				$ 9,276

[1] Includes $4.8 billion of VIE notes accounted for at fair value as of December 31, 2011.