Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended								12 Months Ended
	Aug. 01, 2016 shares	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jan. 01, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | segment										1
Sales returns reserve		$ 600				$ 400				$ 600	$ 400
Sales returns expense										600	900	$ 700
Reserve for wholesaler chargebacks and rebates		200				100				200	100
Wholesaler chargebacks and rebates expense										300	500	1,000
Estimated rebates earned but unpaid		300				400				300	400
Rebates expense										700	800	1,200
Freight charges										100	200	300
Transaction gains (loss)										(25)	9	124
Research and development expense		10,499	$ 11,775	$ 10,056	$ 8,447	8,539	$ 9,631	$ 8,587	$ 9,083	40,777	35,840	33,558
Allowance for doubtful accounts		700				700				700	700
Adjustments to allowance for doubtful accounts										3	6	5
Total investment balance		3,500				11,100				3,500	11,100
Impairment of intangible assets												31,300
Impairment to goodwill										0	0	0
Capitalized lease obligations										208	230	$ 20
Unamortized portion of capital leases		270				191				270	191
Accumulated deficit		237,397				155,705				$ 237,397	155,705
ASU 2016-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock compensation expense						800					$ 2,000
Options [Member]
Summary Of Significant Accounting Policies [Line Items]
Dividend yield										0.00%	0.00%	0.00%
Foreign [Member] | Geographic Concentration Risk [Member] | Net Sales [Member]
Summary Of Significant Accounting Policies [Line Items]
Revenue percentage										26.90%	8.60%	10.00%
New York [Member] | Secured Letter of Credit [Member]
Summary Of Significant Accounting Policies [Line Items]
Secured letter of credit		2,000				$ 2,000				$ 2,000	$ 2,000
Massachusetts [Member] | Secured Letter of Credit [Member]
Summary Of Significant Accounting Policies [Line Items]
Secured letter of credit		$ 91								$ 91
2015 Second-Lien Convertible Debt [Member]
Summary Of Significant Accounting Policies [Line Items]
Shares converted | shares	19,034,467
Subsequent Event [Member] | ASU 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred Revenue													$ 24,000
Accumulated deficit													$ 24,000