Contingently Issuable Common Stock (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended		0 Months Ended		3 Months Ended				9 Months Ended			0 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 10, 2010 Nelix Milestones	Jun. 17, 2014 OUS Milestone	Sep. 30, 2014 OUS Milestone	Sep. 30, 2014 OUS Milestone Common Stock	Jun. 16, 2014 OUS Milestone Common Stock Minimum	Jun. 16, 2014 OUS Milestone Common Stock Maximum	Sep. 30, 2014 PMA Milestone	Dec. 10, 2010 PMA Milestone	Dec. 10, 2010 PMA Milestone Maximum	Dec. 10, 2010 Nellix	Sep. 30, 2014 Nellix	Sep. 30, 2014 Nellix
Business Acquisition [Line Items]
Purchase price common shares						2.7								3.2
Common shares value												$ 15,000,000		$ 19,400,000
Number of Shares, Contingently Issuable					10.2						1.1
Estimated fair value of Contingent payment					28,200,000
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, Low								10,000,000
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High							24,000,000
Business Acquisition, Share Price									$ 3.50	$ 7.50			$ 4.50
Closing stock price											$ 10.60
Contingent consideration, at fair value hypothetical value											11,700,000
Fair Value of Contingently Issuable Common Stock [Roll Forward]
December 31, 2013																60,900,000
Fair Value of OUS Milestone Shares	(200,000)	7,600,000	(8,228,000)	5,200,000											(8,228,000)	(38,372,000)
September 30, 2014															$ 14,300,000	$ 14,300,000