Debt - Additional Information (Details) (USD $)	1 Months Ended	9 Months Ended				0 Months Ended	1 Months Ended			9 Months Ended			9 Months Ended		0 Months Ended	9 Months Ended			0 Months Ended	1 Months Ended	9 Months Ended			0 Months Ended
	Feb. 28, 2013	Sep. 30, 2014	Sep. 30, 2013	Mar. 17, 2014	Dec. 31, 2013	Aug. 30, 2013 Amended Credit Facilty with MidCap [Member]	Sep. 30, 2013 Amended Credit Facilty with MidCap [Member]	Sep. 30, 2014 Amended Credit Facilty with MidCap [Member]	Jul. 30, 2013 Amended Credit Facilty with MidCap [Member]	Sep. 30, 2014 Amended Credit Facilty with MidCap [Member] Term Loan [Member]	Aug. 30, 2013 Amended Credit Facilty with MidCap [Member] Term Loan Drawn On Closing [Member]	Aug. 30, 2013 Amended Credit Facilty with MidCap [Member] Term Loan. Delayed Draw [Member]	Sep. 30, 2014 Amended Credit Facilty with MidCap [Member] Credit Facility [Member]	Aug. 30, 2013 Amended Credit Facilty with MidCap [Member] Credit Facility [Member]	Mar. 20, 2014 Deerfield [Member]	Sep. 30, 2014 Deerfield [Member] payment	Mar. 17, 2014 Deerfield [Member]	Mar. 17, 2014 Maximum [Member] Deerfield [Member]	Apr. 10, 2014 Orthotec LLC, Litigation Settlement [Member]	Mar. 31, 2014 Orthotec LLC, Litigation Settlement [Member]	Sep. 30, 2014 Orthotec LLC, Litigation Settlement [Member]	Sep. 30, 2014 Beginning October 2013 [Member] Amended Credit Facilty with MidCap [Member]	Sep. 30, 2014 Beginning October 2014 [Member] Amended Credit Facilty with MidCap [Member]	Oct. 01, 2014 Subsequent Event [Member] Orthotec LLC, Litigation Settlement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 73,000,000			$ 50,000,000		$ 33,000,000	$ 5,000,000		$ 40,000,000			$ 50,000,000
Repayments of Lines of Credit		115,068,000	130,017,000			28,000,000
Interest rate description										( "LIBOR") plus 8.0%			LIBOR plus 6.0%
Debt, spread on variable rate										8.00%			6.00%
Floor on interest rate										9.50%
Interest rate of revolving line of credit										9.50%			6.20%
Term loan payments																						300,000	500,000
Unamortized debt issuance and debt discount costs		6,613,000						500,000
Debt issuance costs							400,000
Additional interest rate to be charged in the event of default		5.00%
Amendment fee	100,000
Aggregate amount of draw down for working capital																	15,000,000
Increment amount of draw down for general corporate purposes																	2,500,000.0
Transaction fee as percentage of principal amount																	2.50%
Debt instrument, stated interest rate																	8.75%
Number of securities called by warrants																	6,250,000
Number of securities called by warrants associated with each disbursement borrowing																		10,000,000
Amount of initial draw-down under Facility Agreement													31,800,000		20,000,000
Net Proceeds from Initial Draw Under Facility Agreement															19,500,000
Transaction fee															500,000
Number of warrants issued															4,000,000
Warrants value				5,700,000											4,700,000
Warrant amount reclassified as debt discount															2,300,000
Litigation settlement expense																			15,750,000	1,750,000	17,500,000			1,100,000
Restricted cash		$ 2,001,000			$ 0
Number of Equal Annual Payments to Make Under Facility Agreement																3