Income Taxes - Additional Information (Details) (USD $)	3 Months Ended					9 Months Ended				3 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013 Subsidiary	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Group Eight [Member]	Jul. 31, 2013 Senior Notes Sold In 2013 [Member]	Jun. 30, 2014 ITALY	Mar. 31, 2013 UNITED KINGDOM Valuation Allowance [Member]
Income tax expense	$ 29,000,000			$ 34,000,000		$ 96,000,000	$ 96,000,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%			35.00%		35.00%	35.00%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	2,000,000			1,000,000		5,000,000	5,000,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		1,000,000	4,000,000
Tax Adjustments, Settlements, and Unusual Provisions										2,000,000
Number of subsidiaries in which Noncontrolling Interests were purchased					3
Valuation allowance released											2,000,000
Senior notes issued									750,000,000
Deferred Tax Asset Valuation Allowance Reasonably Likely To Reverse In Next Twelve Months								$ 625,000,000