Contingently Issuable Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		3 Months Ended		6 Months Ended
	Dec. 10, 2010	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value of Contingently Issuable Common Stock
Beginning balance				$ 12,200
Fair Value Adjustment of Contingent Payment for the six months ended June 30, 2017		$ (3,800)	$ 100	(2,600)	$ 100
Ending balance		9,600		9,600
Nelix Milestones
Business Acquisition [Line Items]
Number of shares contingently issuable (in shares)	10.2
Estimated fair value of contingent payment	$ 28,200
PMA Milestone
Business Acquisition [Line Items]
Common shares value		$ 15,000		$ 15,000
Number of shares contingently issuable (in shares)				3.0
Share price (in dollars per share)		$ 4.5		$ 4.5
Closing stock price (in dollars per share)		$ 4.86		$ 4.86
Average daily closing stock price				30 days
Days prior to milestone achievement announcement				5 days
Contingent consideration, at fair value hypothetical value		$ 14,500		$ 14,500
Nellix
Business Acquisition [Line Items]
Purchase price common shares (in shares)	3.2
Common shares value	$ 19,400