Notes Receivable and Other Long-term Receivables (Narrative) (Detail) (USD $)	9 Months Ended			0 Months Ended		3 Months Ended		0 Months Ended		1 Months Ended				1 Months Ended	3 Months Ended		0 Months Ended	1 Months Ended		9 Months Ended			0 Months Ended					1 Months Ended	3 Months Ended	9 Months Ended		58 Months Ended	0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Aug. 15, 2013 Wellstat Diagnostics [Member]	Sep. 24, 2013 Merus Labs [Member]	Jul. 31, 2012 Merus Labs [Member]	Sep. 30, 2013 Merus Labs [Member]	Dec. 31, 2012 Merus Labs [Member]	Sep. 30, 2013 AxoGen [Member]	Aug. 14, 2013 AxoGen [Member]	Mar. 31, 2012 Notes Receivable [Member] Wellstat Diagnostics [Member]	Sep. 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]	Aug. 15, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Feb. 28, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Jan. 31, 2013 Credit Agreement [Member] Wellstat Diagnostics [Member]	Sep. 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]	Aug. 15, 2013 Initial Loan [Member] Wellstat Diagnostics [Member]	Sep. 30, 2013 Initial Loan [Member] Merus Labs [Member]	Jun. 28, 2013 Additional Loan [Member] Wellstat Diagnostics [Member]	Sep. 30, 2013 Additional Loan [Member] Merus Labs [Member]	Apr. 18, 2013 Additional Loan [Member] Avinger [Member]	Oct. 31, 2012 Royalty Agreement [Member] AxoGen [Member]	Sep. 30, 2013 Royalty Agreement [Member] AxoGen [Member]	Sep. 30, 2013 Royalty Agreement [Member] AxoGen [Member]	Dec. 31, 2012 Royalty Agreement [Member] AxoGen [Member]	Apr. 30, 2018 Royalty Agreement [Member] Avinger [Member]	Aug. 15, 2013 Term loan and interest [Member] Wellstat Diagnostics [Member]	Aug. 15, 2013 Forbearance principal and interest [Member] Wellstat Diagnostics [Member]
Accounts Notes And Loans Receivable [Line Items]
Financing receivable, gross										$ 7,500,000	$ 45,300,000	$ 10,000,000	$ 35,000,000			$ 20,000,000					$ 40,000,000				$ 1,300,000
Financing Receivable, Modifications, Pre-Modification Recorded Investment																							33,700,000										1,300,000	9,100,000
Fair value of collateral supporting note receivable																				76,600,000
Financing receivable, modification, cost as a component of interest and other income, net			2,500,000
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)			5.00%							10.00%		12.00%				12.00%								13.50%		14.00%	14.00%
Reduction in royalty rate (in percent)																																50.00%
Repayment of notes receivable	58,134,000	0		43,300,000		7,500,000	5,000,000
Financing receivable, prepayment fee				0.01
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					55,000,000									40,000,000				7,900,000		8,700,000
Financing Receivable, Modifications, Post-Modification Recorded Investment																	44,100,000
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	1,000,000	600,000
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net																													0	400,000
Investment Owned, Balance, Shares									1,166,666
Share Price									$ 3.00
Investment Owned, at Cost									3,500,000
Investment Owned, at Fair Value								5,200,000
Unrealized Gain (Loss) on Investments								1,700,000
Minimum amount of additional funds, upon attainment of milestones															10,000,000
Maximum amount of additional funds, upon attainment of milestones															$ 20,000,000