Financing Arrangements (Details) - USD ($)			3 Months Ended		6 Months Ended		12 Months Ended
	May 09, 2016	Apr. 04, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Interest Expense, Debt, Excluding Amortization			$ 2,032,000	$ 2,031,000	$ 4,064,000	$ 2,031,000
Convertible Debt, Fair Value Disclosures			$ 246,100,000		$ 246,100,000
Debt Instrument, Convertible, Remaining Discount Amortization Period			4 years 9 months
Share Price			$ 3.84		$ 3.84
Hedging Activity, Shares Covered	46,300,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities			46,300,000
Convertible Note Hedge, Strike Price	$ 5.40
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 8.50		$ 8.50
Debt Instrument, Face Amount			$ 250,000,000		$ 250,000,000		$ 250,000,000
Debt Instrument, Unamortized Discount			(65,763,000)		(65,763,000)		(71,005,000)
Convertible Notes Payable, Noncurrent			184,237,000		184,237,000		178,995,000
Proceeds from Debt, Net of Issuance Costs			$ 243,200,000
Debt Instrument, Interest Rate, Stated Percentage		3.25%
Debt Conversion, Converted Instrument, Amount		$ 1,000
Debt Conversion, Converted Instrument, Shares Issued		185.1852
Debt Instrument, Convertible, Conversion Price		$ 5.40
Proceeds from Issuance of Warrants					$ 0	35,495,000
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger		150.00%
Debt Instrument, Convertible, Threshold Trading Days		20
Debt Instrument, Interest Rate, Effective Percentage			9.75%		9.75%
Debt Issuance Cost			$ 6,800,000
Deferred Finance Costs, Net			4,800,000		$ 4,800,000
Amortization of Debt Discount (Premium)			2,655,000	2,396,000	5,242,000	2,396,000
Interest Expense, Debt			4,687,000	$ 4,427,000	9,306,000	$ 4,427,000
Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Debt		$ 250,000,000
Additional Paid-in Capital [Member]
Debt Instrument [Line Items]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt					67,014,000		$ 67,014,000
Transaction Costs [Member]
Debt Instrument [Line Items]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt			$ 2,000,000
Excluding Transaction Costs [Member]
Debt Instrument [Line Items]
Payments for Derivative Instrument, Financing Activities					$ 59,100,000