Credit Facilities (Deerfield Revolver) (Details) - USD ($)				3 Months Ended		9 Months Ended
	Mar. 31, 2019	Aug. 09, 2018	Jan. 12, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Apr. 03, 2017
Line of Credit Facility [Line Items]
Cash paid for debt extinguishment						$ 0	$ 1,310,000
Gain (loss) on extinguishment of debt				$ 0	$ 0	(11,756,000)	$ (2,270,000)
Commitment fee amount		$ 500,000
Revolving loan facility				0		0		$ 0
Revolving loan facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 24,000,000.0
Debt instrument, stated interest rate	5.50%
Debt issuance costs, noncurrent				600,000.0		600,000.0
Deferred financing cost				400,000.0		400,000.0
Deerfield ELGX Revolver, LLC | Revolving loan facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity									$ 50,000,000
Debt issuance costs, gross									$ 1,200,000.0
Cash paid for debt extinguishment			$ 1,300,000.0
Write off of deferred debt issuance cost			1,000,000.0
Gain (loss) on extinguishment of debt			(2,300,000.0)
Debt instrument face amount	$ 120,000,000.0
Global liquidity requirement	$ 17,500,000.0	22,500,000.0
Credit Agreement
Line of Credit Facility [Line Items]
Debt instrument face amount			$ 50,000,000
Global liquidity requirement						17,500,000.0
ABL Facility
Line of Credit Facility [Line Items]
Deferred financing cost				800,000.0		800,000.0
Revolving loan facility				0		0
Remaining borrowing capacity				$ 18,900,000.0		$ 18,900,000.0
London Interbank Offered Rate (LIBOR) | Revolving loan facility
Line of Credit Facility [Line Items]
Variable rate, floor	1.00%
Interest accrued	$ 9,750,000
Closing
Line of Credit Facility [Line Items]
Commitment fee amount		200,000
First Anniversary
Line of Credit Facility [Line Items]
Commitment fee amount		200,000
Termination fee	2.50%
Second Anniversary
Line of Credit Facility [Line Items]
Commitment fee amount		100,000
Termination fee	1.50%
Expiration
Line of Credit Facility [Line Items]
Commitment fee amount		$ 1,000,000
Third Anniversary
Line of Credit Facility [Line Items]
Termination fee	0.50%
Thereafter, Fee
Line of Credit Facility [Line Items]
Termination fee	0.00%