Fair Value Measurements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 25, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assumptions, Risk Free Interest Rate	2.00%	1.70%
Assets, Fair Value Disclosure [Abstract]
Convertible note hedge fair value	$ 53,683,000	$ 0
Liabilities, Fair Value Disclosure [Abstract]
Note conversion obligation fair value	54,359,000	0
Warrant liability	211,136,000	89,441,000
Fair value warrants issued	$ 14.24	$ 8.09
Fair Value Assumptions, Expected Volatility Rate	34.00%	37.50%
Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents - money market	$ 1,326,000	$ 482,000
Derivative Asset	1,840,000	547,000
Convertible note hedge fair value	53,683,000
Total Assets	56,849,000	1,029,000
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap		(77,000)
Note conversion obligation fair value	(54,359,000)
Warrant liability	(211,136,000)	(89,441,000)
Total Liabilities	(265,495,000)	(89,518,000)
Carrying value, debt	515,800,000	458,700,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents - money market	0	0
Derivative Asset	0	0
Convertible note hedge fair value	0
Total Assets	0	0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap		0
Note conversion obligation fair value	0
Warrant liability	0	0
Total Liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents - money market	1,326,000	482,000
Derivative Asset	1,840,000	547,000
Convertible note hedge fair value	53,683,000		$ 56,097,000
Total Assets	56,849,000	1,029,000
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap		(77,000)
Note conversion obligation fair value	(54,359,000)		$ 57,369,000
Warrant liability	(211,136,000)	(89,441,000)
Total Liabilities	(265,495,000)	(89,518,000)
Difference between fair value and carrying value, debt	9,100,000	200,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents - money market	0	0
Derivative Asset	0	0
Convertible note hedge fair value	0
Total Assets	0	0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap		0
Note conversion obligation fair value	0
Warrant liability	0	0
Total Liabilities	$ 0	$ 0
Convertible Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assumptions, Risk Free Interest Rate	2.30%
Liabilities, Fair Value Disclosure [Abstract]
Fair Value Assumptions, Expected Volatility Rate	34.00%