Derivative Financial Instruments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]
Loss after tax was reclassified from AOCI into Discontinued operations, net of income taxes			$ (3)
Market-to-market losses after tax recognized on derivatives			2
Gains (losses) from changes in fair value of derivatives included in Investment gains (losses)	1	(5)	1	(3)
Gains (losses) from changes in fair value of derivatives held for trading included in Net investment income	(3)	(3)	5	(16)
Amount of gain (losses) recognized in OCI	5	(2)	8	(7)
Amount of gains (losses) reclassified from AOCI into income	4	1	3	2
Estimated amount of net unrealized gains associated with cash flow hedges that will be reclassified from AOCI into earnings during next twelve months			3
Maximum [Member]
Derivative [Line Items]
Net amounts recognized due to ineffectiveness	$ 1	$ 1	$ 1	$ 1