Significant Accounting Policies - Additional Information (Detail)		3 Months Ended								6 Months Ended	12 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) Asset	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Net sales		$ 116,896,000	$ 105,247,000	$ 108,942,000	$ 102,738,000	$ 108,537,000	$ 98,497,000	$ 104,075,000	$ 98,679,000		$ 433,823,000	$ 409,788,000	$ 396,489,000
Cumulative-effect adjustment to retained earnings												604,000
Number of assets transferred | Asset										2
Prepaid income taxes										$ 8,600,000
Increase (decrease) in net cash from operating activities											53,341,000	44,707,000	43,610,000
ASU 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to retained earnings	$ 5,000,000
ASU 2016-16, as Amended [Member] | Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to retained earnings	$ 2,100,000
ASU 2016-18 [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in net cash from operating activities											(14,400,000)	14,400,000
Musculoskeletal Transplant Foundation ("MTF") [Member]
Summary Of Significant Accounting Policies [Line Items]
Expenditures for other research and development											900,000	1,300,000	0
Customers and Distributors Based in Europe [Member]
Summary Of Significant Accounting Policies [Line Items]
Net sales											57,000,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Transactional foreign currency gains and (losses), including those generated from intercompany operations											$ 1,900,000	$ (100,000)	$ (3,500,000)