Fair Value Measurements (Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Valuation Technique	Actuarial model	[1]
Minimum
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Inputs Lapse rate	1.00%	[1]
Annuitization rate	0.00%	[1]
Maximum
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Inputs Lapse rate	30.00%	[1]
Annuitization rate	55.00%	[1]
Guaranteed Living Benefits [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
GLB liability	663		$ 427		$ 1,400		$ 1,500
Guaranteed Minimum Death Benefit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
GLB liability	111		100
Guaranteed Minimum Income Benefit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	406	[1]
Balance - beginning of year, liabilities	193	[2],[3]	1,119	[3],[4]	1,319	[4]
Transfers Into Level 3, liabilities			0	[3]	0	[4]
Transfers out of Level 3, liabilities			0	[3]	0	[4]
Change in Net Unrealized Gains (Losses) included in OCI, Liabilities			0	[3]
Net Realized Gains/Losses, Liabilities	213	[2]	(926)	[3]	(200)	[4]
Purchased, liabilities			0	[3]	0	[4]
Sales, liabilities			0	[3]	0	[4]
Settlements, liabilities			0	[3]	0	[4]
Balance - end of year, liabilities	406	[2]	193	[2],[3]	1,119	[3],[4]
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Liabilities	213	[2]	(926)	[3]	(200)	[4]
Equity securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	4		3		13
Transfers into Level 3, assets			8		2
Transfers out of Level 3, assets	(2)		(1)		(11)
Change in Net Unrealized Gains (Losses) included in OCI, Assets			(6)
Net Realized Gains/Losses, Assets			4
Purchased, assets	2		2		4
Sales, assets	(2)		(6)		(5)
Balance, end of year, assets	2		4		3
Short-term investments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	7
Transfers into Level 3, assets			8
Transfers out of Level 3, assets	(7)		(2)
Purchased, assets			3
Sales, assets			(1)
Settlements, assets			(1)
Balance, end of year, assets			7
Other Long-term Investments [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	2,440		2,252		1,877
Transfers into Level 3, assets					53
Change in Net Unrealized Gains (Losses) included in OCI, Assets	39		(45)		55
Net Realized Gains/Losses, Assets	(3)		(2)		(7)
Purchased, assets	719		551		520
Sales, assets	(8)		(10)		(9)
Settlements, assets	(468)		(396)		(237)
Balance, end of year, assets	2,719		2,440		2,252
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	(3)		(2)		(7)
Other Derivative Instruments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets					3
Transfers into Level 3, assets					0
Transfers Into Level 3, liabilities	2
Net Realized Gains/Losses, Assets					(4)
Net Realized Gains/Losses, Liabilities	2
Purchased, assets					3
Settlements, assets					(2)
Balance - end of year, liabilities	4
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Liabilities	2
Fixed maturities available for sale | U.S. Treasury and agency
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets					5
Transfers out of Level 3, assets					(4)
Settlements, assets					(1)
Fixed maturities available for sale | Foreign Government Debt Securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	44		60		33
Transfers into Level 3, assets	10		36		49
Transfers out of Level 3, assets	(34)		(54)		(13)
Change in Net Unrealized Gains (Losses) included in OCI, Assets	(1)				(1)
Net Realized Gains/Losses, Assets	(3)		1		0
Purchased, assets	15		24		46
Sales, assets	(4)		(21)		(53)
Settlements, assets	(5)		(2)		(1)
Balance, end of year, assets	22		44		60
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	(4)				0
Fixed maturities available for sale | Corporate securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	166		102		134
Transfers into Level 3, assets	37		47		37
Transfers out of Level 3, assets	(23)		(31)		(46)
Change in Net Unrealized Gains (Losses) included in OCI, Assets	(1)				6
Net Realized Gains/Losses, Assets	(5)		(2)		(1)
Purchased, assets	73		75		24
Sales, assets	(38)		(7)		(19)
Settlements, assets	(22)		(18)		(33)
Balance, end of year, assets	187		166		102
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	(5)		(2)		0
Fixed maturities available for sale | Mortgage backed-securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets	8		13		28
Transfers into Level 3, assets					22
Transfers out of Level 3, assets					(35)
Purchased, assets	8				9
Sales, assets			(3)		(7)
Settlements, assets	(1)		(2)		(4)
Balance, end of year, assets	15		8		13
Fixed maturities available for sale | States, municipalities, and political subdivisions
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of year, assets					1
Transfers into Level 3, assets					1
Transfers out of Level 3, assets					(1)
Purchased, assets					0
Settlements, assets					$ (1)

[1] Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.

[2] Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.

[3] Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $427 million at December 31, 2013 and $1.4 billion at December 31, 2012, which includes a fair value derivative adjustment of $193 million and $1.1 billion, respectively.

[4] Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.4 billion at December 31, 2012 and $1.5 billion at December 31, 2011, which includes a fair value derivative adjustment of $1.1 billion and $1.3 billion, respectively.