Adoption Of New Accounting Standard - Additional Information (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction in deferred acquisition costs due to adoption of accounting standard			$ 568,000,000	$ 537,000,000
Reduction in Equity due to Adoption of Accounting Standard			369,000,000	349,000,000
Adjustment to earnings for the adoption of the new accounting standard		12,000,000
Adjustment to per share earnings for the adoption of the new accounting standard		$ 100,000
Direct Response advertising costs charged to earnings during the period	8,200,000	7,300,000
Capitalized advertising costs	$ 1,020,000,000		$ 1,000,000,000