Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jul. 31, 2013
Income tax expense	$ 36,000,000	$ 33,000,000	$ 67,000,000	$ 67,000,000
US federal statutory income tax rate	35.00%	35.00%	35.00%	35.00%
Effective income tax rate			33.00%	35.00%
Tax expense related to repatriation of foreign earnings	$ 2,000,000	$ 2,000,000	$ 3,000,000	$ 3,000,000
Tax expense related to other adjustments	6,000,000	1,000,000	6,000,000	$ 5,000,000
Deferred tax asset valuation allowance reasonably likely to reverse in next twelve months	$ 500,000,000		$ 500,000,000
Senior Notes Sold In 2013 [Member]
Senior notes issued					$ 750,000,000
ITALY
Tax expense related to settlements of outstanding tax matters		$ 2,000,000