Acquisition and Divestitures - Restore Flow Allografts - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Nov. 10, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	May 31, 2018
Business Acquisition [Line Items]
Net revenue		$ 24,165,000	$ 24,822,000	$ 77,179,000	$ 74,714,000
Weighted average useful life				9 years 4 months 24 days
Restore Flow Allografts [Member]
Business Acquisition [Line Items]
Initial purchase price	$ 12,000,000
Acquisition-related contingent consideration	$ 900,000					$ 2,000,000
Additional payment description				One payment of $2 million was due not later than 15 days following the expiration of the 18 month period following the closing date, subject to reductions as specified in the agreement for each calendar month that certain retained employees were not employed by us due to resignation without good reason, or termination for cause, both as defined in the agreement. The portion of this payment that was to be paid to retained employees and that was contingent on their continued employment, estimated at $0.9 million, was being accounted for as post-combination compensation expense rather than purchase consideration. The remaining $1.1 million that was payable to non-employee investors but that was also contingent on the continued employment of the retained employees had been accounted for as contingent purchase consideration, at an acquisition-date fair value of $0.9 million. In May 2018 we paid this $2 million liability as the contingency was met.There were also two potential earn-out payments under the agreement. The first earn-out was to be calculated at 50% of the amount by which net revenue in the first 12 months following the closing exceeded $6 million, with such payout not to exceed $2 million. The second earn-out was to be calculated at 50% of the amount by which net revenue in the second 12 months following the closing exceeds $9 million, with such payout not to exceed $2 million.
Estimated weighted average cost of capital	14.10%
Maximum goodwill deductible for tax purposes				15 years
Weighted average useful life				10 years 3 months 18 days
Restore Flow Allografts [Member] | Non-employee Investors [Member]
Business Acquisition [Line Items]
Acquisition-related contingent consideration	$ 1,100,000
Acquisition-date fair value	900,000
Restore Flow Allografts [Member] | Maximum [Member]
Business Acquisition [Line Items]
Acquisition-related contingent consideration	6,000,000
Restore Flow Allografts [Member] | Contingency One [Member]
Business Acquisition [Line Items]
Acquisition-related contingent consideration	2,000,000
Restore Flow Allografts [Member] | Earn - Outs Payment One [Member] | Maximum [Member]
Business Acquisition [Line Items]
Acquisition-related contingent consideration	2,000,000
Restore Flow Allografts [Member] | Earn - Outs Payment One [Member] | Minimum [Member]
Business Acquisition [Line Items]
Net revenue	6,000,000
Restore Flow Allografts [Member] | Earn - Outs Payment Two [Member] | Maximum [Member]
Business Acquisition [Line Items]
Acquisition-related contingent consideration	2,000,000
Restore Flow Allografts [Member] | Earn - Outs Payment Two [Member] | Minimum [Member]
Business Acquisition [Line Items]
Net revenue	9,000,000
Restore Flow Allografts [Member] | Combined Earn-out Payment [Member]
Business Acquisition [Line Items]
Acquisition-date fair value	$ 100,000