Debt - Schedule of percentage of principal amount at which the entity may redeem the notes (Details)	12 Months Ended
	Dec. 31, 2015
Senior notes due 2020 | 2015
Debt Instrument [Line Items]
Redemption percentage	104.25%
Senior notes due 2020 | 2016
Debt Instrument [Line Items]
Redemption percentage	102.833%
Senior notes due 2020 | 2018 and thereafter
Debt Instrument [Line Items]
Redemption percentage	100.00%
Senior notes due 2020 | 2017
Debt Instrument [Line Items]
Redemption percentage	101.417%
Senior Notes, Due 2022 | 2017
Debt Instrument [Line Items]
Redemption percentage	102.938%
Senior Notes, Due 2022 | 2018
Debt Instrument [Line Items]
Redemption percentage	101.958%
Senior Notes, Due 2022 | 2019
Debt Instrument [Line Items]
Redemption percentage	100.979%
Senior Notes, Due 2022 | 2020 and thereafter
Debt Instrument [Line Items]
Redemption percentage	100.00%