Quarterly Financial Data (Unaudited) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Quarterly Financial Data [Line Items]
Acquisition related costs including due diligence and integration expenses								$ 3,187
Royalty and license fee								33,203	$ 31,763	$ 30,277
Royalty catch-up payment		$ 2,900				$ 600
Income tax provision								6,963	6,294	6,265
Claim settlement					$ 2,500				2,500
Impairment losses on strategic investments					1,500				1,500	1,184
Contingent royalties					$ 800
Gain on sale of strategic investment							$ 500	$ 514	$ 492	$ 842
ASU 2016-09 [Member]
Quarterly Financial Data [Line Items]
Income tax provision	$ 500
Out of Period Royalty Adjustment [Member]
Quarterly Financial Data [Line Items]
Royalty and license fee			$ 1,100
Previously Reported [Member]
Quarterly Financial Data [Line Items]
Royalty and license fee			$ 1,000
Creagh Medical and NorMedix [Member]
Quarterly Financial Data [Line Items]
Acquisition related costs including due diligence and integration expenses				$ 2,500