Subsidiary Guarantors - Senior Notes (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Senior Notes [Line Items]
Carrying value of senior notes	$ 550,000,000	$ 550,000,000
Event of default for senior notes - failure of other debt payment at maturity in excess of this amount	50,000,000
Our ownership percentage of subsidiary guarantors of senior notes	100.00%
Event of default for senior notes - not discharged, bonded or insured judgment in excess of this amount	50,000,000
Senior Notes Due 2020 [Member]
Senior Notes [Line Items]
Carrying value of senior notes	300,000,000
Interest rate of senior notes	6.625%
Portion of proceeds from senior notes used to repay outstanding term debt	200,000,000
Percentage of original aggregate principle amount of senior notes included in repurchase price at change of control	101.00%
Senior Notes Due 2020 [Member] | Senior Notes, Redemption, Period One [Member]
Senior Notes [Line Items]
Senior notes, redemption price, percentage	103.313%
Senior Notes Due 2020 [Member] | Senior Notes, Redemption, Period Four [Member]
Senior Notes [Line Items]
Senior notes, redemption price, percentage	100.00%
Senior Notes Due 2021 [Member]
Senior Notes [Line Items]
Carrying value of senior notes	250,000,000
Interest rate of senior notes	4.75%
Portion of proceeds from senior notes used to repurchase shares of common stock	$ 200,000,000
Percentage of original aggregate principle amount of senior notes included in repurchase price at change of control	101.00%
Senior Notes Due 2021 [Member] | Senior Notes, Redemption, Period One [Member]
Senior Notes [Line Items]
Senior notes, redemption price, percentage	103.563%
Senior Notes Due 2021 [Member] | Senior Notes, Redemption, Period Four [Member]
Senior Notes [Line Items]
Senior notes, redemption price, percentage	100.00%