Derivatives and Hedging Activities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Net of tax effect on unrealized loss on derivatives	$ (1,000)	$ (300)	$ (1,900)	$ (300)
Percentage of option to prepay in equity offerings			40.00%
Period of option to prepay using proceeds from equity offering			180 days
Percentage of principal amount outstanding			50.00%
Redemption price percentage			108.25%
Other Noncurrent Liabilities
Derivative [Line Items]
Fair value of embedded derivative liability	0		$ 0		$ 13,200
Other Operating Income (Expense)
Derivative [Line Items]
Change in fair value in amount included as other income (expense)	0	100	13,200	100
Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Notional foreign exchange contract outstanding	88,000		88,000		88,000
Loss recognized in other comprehensive income (loss)	1,600		0
Net of tax effect on unrealized loss on derivatives	1,000	(300)	1,900	(300)
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion		700		700
Ineffective portion of loss	111		205
Derivative Instruments, Gain Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing		$ 48		$ 48
Designated as Hedging Instrument | Foreign Exchange Contract | Other Noncurrent Liabilities
Derivative [Line Items]
Fair value asset of derivative instrument	$ 2,700		$ 2,700
Designated as Hedging Instrument | Foreign Exchange Contract | Other Noncurrent Assets
Derivative [Line Items]
Fair value asset of derivative instrument					$ 2,400
Senior Secured Notes Due 2021
Derivative [Line Items]
Percentage of option to prepay principal amount (equal to)			100.00%
Senior Notes | Senior Secured Notes Due 2021
Derivative [Line Items]
Periodic payment			$ 575,000