Summary of Significant Accounting Policies - Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended	15 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowance	$ 50,326		$ 44,089	$ 50,326
Other accrued liabilities	31,523		33,257	31,523
Accumulated deficit	(479,248)		(446,375)	(479,248)
Total revenues	62,340	$ 49,382	49,382
Loss from operations	(30,517)	(34,550)
Net loss	$ (32,873)	$ (33,480)
Net loss per share (Note 12):
Basic (in dollars per share)	$ (0.61)	$ (0.63)
Diluted (in dollars per share)	$ (0.61)	$ (0.65)
Operating activities
Net loss	$ (32,873)	$ (33,480)
Changes in operating assets and liabilities:
Accounts receivable	(6,284)	3,538
Net cash (used in) provided by operating activities	1,046	(24,620)
Cash, cash equivalents and restricted cash, beginning of period	13,021	16,690	16,690	16,690
Cash, cash equivalents and restricted cash, end of period	39,690	10,203	13,021	39,690
Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	54,269	48,394	48,394
Licensing and other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	$ 8,071	988	988
Accounting Standards Update 2016-18
Changes in operating assets and liabilities:
Net cash (used in) provided by operating activities		(317)
Cash, cash equivalents and restricted cash, beginning of period		1,434	1,434	1,434
Cash, cash equivalents and restricted cash, end of period		1,117
As Previously Reported
Operating activities
Net loss		(35,961)
Changes in operating assets and liabilities:
Accounts receivable		6,019
Net cash (used in) provided by operating activities		(24,303)
Cash, cash equivalents and restricted cash, beginning of period		15,256	15,256	$ 15,256
Cash, cash equivalents and restricted cash, end of period		9,086
As Previously Reported | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowance			8,252
Other accrued liabilities			33,207
Accumulated deficit			(482,162)
Total revenues		46,901
Loss from operations		(37,031)
Net loss		$ (35,961)
Net loss per share (Note 12):
Basic (in dollars per share)		$ (0.68)
Diluted (in dollars per share)		$ (0.70)
As Previously Reported | Accounting Standards Update 2014-09 | Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		$ 45,913
As Previously Reported | Accounting Standards Update 2014-09 | Licensing and other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		988
Adoption of ASC 606
Operating activities
Net loss		2,481
Changes in operating assets and liabilities:
Accounts receivable		(2,481)
Adoption of ASC 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment			41,600
Accounts receivable, net of allowance			35,837
Other accrued liabilities			50
Accumulated deficit			$ 35,787
Total revenues		2,481
Loss from operations		2,481
Net loss		$ 2,481
Net loss per share (Note 12):
Basic (in dollars per share)		$ 0.05
Diluted (in dollars per share)		$ 0.05
Adoption of ASC 606 | Accounting Standards Update 2014-09 | Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		$ 2,481