Fair Value Measurement - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Carrying Amount | 2022 Notes | Senior notes
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	$ 500,000	$ 500,000
Carrying Amount | 2023 Notes | Senior notes
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	250,000
Carrying Amount | Revolving credit facility | Revolver | Line of credit
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	110,000	360,000
Level 3 | Nonrecurring | Fair Value | Revolving credit facility | Revolver | Line of credit
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	110,000	360,000
Level 1 | Nonrecurring | Fair Value | 2022 Notes | Senior notes
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	260,000	$ 384,375
Level 2 | Nonrecurring | Fair Value | 2023 Notes | Senior notes
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Debt	$ 153,283