Summary of Significant Accounting Policies - Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowance	$ 62,223				$ 44,089				$ 62,223	$ 44,089
Other accrued liabilities	32,442				33,257				32,442	33,257
Accumulated deficit	(574,529)				(446,375)				(574,529)	(446,375)
Total revenues	66,965	$ 65,280	$ 63,069	$ 62,340	52,050	$ 55,910	$ 52,283	$ 49,382	257,654	209,625	$ 212,512
Loss from operations									(114,628)	(135,341)	(101,050)
Net loss	$ (31,841)	$ (29,616)	$ (33,824)	$ (32,873)	$ (47,217)	$ (27,865)	$ (29,066)	$ (33,480)	$ (128,154)	$ (137,628)	$ (100,327)
Net loss per share (Note 13):
Basic (in dollars per share)	$ (0.51)	$ (0.49)	$ (0.62)	$ (0.61)	$ (0.88)	$ (0.52)	$ (0.55)	$ (0.63)	$ (2.22)	$ (2.58)	$ (1.95)
Diluted (in dollars per share)	$ (0.51)	$ (0.49)	$ (0.62)	$ (0.61)	$ (0.90)	$ (0.52)	$ (0.55)	$ (0.65)	$ (2.22)	$ (2.59)	$ (1.95)
Operating activities
Net loss									$ (128,154)	$ (137,628)	$ (100,327)
Changes in operating assets and liabilities:
Accounts receivable									(18,093)	6,315	(3,956)
Net cash (used in) provided by operating activities									(70,581)	(97,825)	(74,052)
Cash, cash equivalents and restricted cash, beginning of period				$ 13,021				$ 16,690	13,021	16,690	30,531
Cash, cash equivalents and restricted cash, end of period	$ 51,004				$ 13,021				51,004	13,021	16,690
Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues									240,366	203,777	209,406
Licensing and other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues									17,288	5,848	3,106
Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loss from operations									10,200
Accounting Standards Update 2016-18
Changes in operating assets and liabilities:
Net cash (used in) provided by operating activities										(1,033)	(150)
Cash, cash equivalents and restricted cash, beginning of period				401				1,434	401	1,434	1,584
Cash, cash equivalents and restricted cash, end of period					401					401	1,434
As Previously Reported
Operating activities
Net loss										(136,314)	(95,765)
Changes in operating assets and liabilities:
Accounts receivable										5,001	(8,518)
Net cash (used in) provided by operating activities										(96,792)	(73,902)
Cash, cash equivalents and restricted cash, beginning of period				$ 12,620				$ 15,256	$ 12,620	15,256	28,947
Cash, cash equivalents and restricted cash, end of period					12,620					12,620	15,256
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					8,252
Other accrued liabilities					33,207					33,207
Accumulated deficit					(482,162)					(482,162)
Total revenues										210,939	217,074
Loss from operations										(134,027)	(96,488)
Net loss										$ (136,314)	$ (95,765)
Net loss per share (Note 13):
Basic (in dollars per share)										$ (2.56)	$ (1.86)
Diluted (in dollars per share)										$ (2.56)	$ (1.86)
As Previously Reported | Accounting Standards Update 2014-09 | Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues										$ 205,489	$ 213,968
As Previously Reported | Accounting Standards Update 2014-09 | Licensing and other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues										5,450	3,106
Adoption of ASC 606
Operating activities
Net loss										(1,314)	(4,562)
Changes in operating assets and liabilities:
Accounts receivable										1,314	4,562
Adoption of ASC 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowance					35,837					35,837
Other accrued liabilities					50					50
Accumulated deficit					$ 35,787					35,787
Total revenues										(1,314)	(4,562)
Loss from operations										(1,314)	(4,562)
Net loss										$ (1,314)	$ (4,562)
Net loss per share (Note 13):
Basic (in dollars per share)										$ (0.02)	$ (0.09)
Diluted (in dollars per share)										$ (0.03)	$ (0.09)
Adoption of ASC 606 | Accounting Standards Update 2014-09 | Product
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues										$ (1,712)	$ (4,562)
Adoption of ASC 606 | Accounting Standards Update 2014-09 | Licensing and other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues										398
Adoption of ASC 606 | Accounting Standards Update 2014-09 | Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment												$ 41,700
Total revenues										$ (1,300)	$ (4,600)