Notes Receivable and Other Long-term Receivables (Narrative) (Detail) (USD $)	6 Months Ended		3 Months Ended		1 Months Ended				1 Months Ended	3 Months Ended		1 Months Ended		6 Months Ended								1 Months Ended	6 Months Ended		58 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Merus Labs [Member]	Dec. 31, 2012 Merus Labs [Member]	Mar. 31, 2012 Notes Receivable [Member] Wellstat Diagnostics [Member]	Jun. 30, 2013 Notes Receivable [Member] Wellstat Diagnostics [Member]	Aug. 31, 2012 Notes Receivable [Member] Wellstat Diagnostics [Member]	Jul. 31, 2012 Notes Receivable [Member] Merus Labs [Member]	Apr. 30, 2013 Notes Receivable [Member] Avinger [Member]	Jun. 30, 2014 Notes Receivable [Member] Avinger [Member]	Apr. 18, 2013 Notes Receivable [Member] Avinger [Member]	Feb. 28, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Jan. 31, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Jun. 30, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Nov. 02, 2012 Credit Agreement [Member] Wellstat Diagnostics [Member]	Jul. 31, 2012 Credit Agreement [Member] Merus Labs [Member]	Jun. 30, 2013 Initial Loan [Member] Merus Labs [Member]	Jun. 30, 2013 Additional Loan [Member] Wellstat Diagnostics [Member]	Jun. 28, 2013 Additional Loan [Member] Wellstat Diagnostics [Member]	Jun. 30, 2013 Additional Loan [Member] Merus Labs [Member]	Apr. 18, 2013 Additional Loan [Member] Avinger [Member]	Oct. 31, 2012 Royalty Agreement [Member] AxoGen [Member]	Jun. 30, 2013 Royalty Agreement [Member] AxoGen [Member]	Dec. 31, 2012 Royalty Agreement [Member] AxoGen [Member]	Apr. 30, 2018 Royalty Agreement [Member] Avinger [Member]	Apr. 18, 2013 Royalty Agreement [Member] Avinger [Member]	Jun. 30, 2013 Prepaid and other current assets [Member] Notes Receivable [Member] Wellstat Diagnostics [Member]	Jun. 30, 2013 Notes Receivable [Member] Wellstat Diagnostics [Member]
Accounts Notes And Loans Receivable [Line Items]
Financing receivable, gross					$ 7,500,000	$ 44,700,000	$ 10,000,000	$ 35,000,000			$ 20,000,000				$ 40,000,000				$ 1,300,000								$ 1,100,000	$ 43,600,000
Additional expected funding																		2,100,000
Maximum exposure for total amount due to Company						46,800,000
Fair value of collateral supporting note receivable						76,600,000
Term of receivable (in Duration)					2 years																	8 years
Royalty rate on AxoGen net revenues (in percent)																						9.95%
Guaranteed quarterly minimum payment-low																						1.3
Guaranteed quarterly minimum payment-high																						2,300,000
Interest rate of note receivable (in Percent)					10.00%		12.00%				12.00%						13.50%			14.00%	14.00%
Reduction in royalty rate (in percent)																									50.00%
Repayment of notes receivable	15,634,000	0	7,500,000	5,000,000
Credit agreement, stated interest rate (in Percent)															5.00%
Proceeds received under remedies available for borrower's breach of terms credit agreement													8,100,000
Amount company has agreed to advance under agreement									40,000,000			7,900,000		7,300,000
Forbearance period under terms of credit agreement (in Duration)												120 days
Letter of credit extended																20,000,000
Term of royalty agreement (in Duration)																						8 years
Total consideration paid to AxoGen for the royalty rights																						20,800,000
Initial interim funding for royalty rights																						1,800,000
Internal rate of return (in percent)																						32.50%
fair value change of control																							1,000,000	600,000
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net																							400,000
Minimum amount of additional funds, upon attainment of milestones										10,000,000
Maximum amount of additional funds, upon attainment of milestones										20,000,000
Initial estimated fair value intangible																										$ 3,000,000