Revenue - Summary of Revenues Disaggregated by Product Classification and Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Research, development and other	$ 2,857	$ 1,944	$ 5,251	$ 3,793
Total Revenue	22,676	19,058	44,917	36,071
Royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue	9,932	8,428	20,028	15,504
Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	22,676	19,058	44,917	36,071
Operating Segments [Member] | Medical Device [Member]
Disaggregation Of Revenue [Line Items]
Research, development and other	2,811	1,937	5,195	3,785
Total Revenue	17,301	14,052	34,559	26,826
Operating Segments [Member] | Medical Device [Member] | Product Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,558	3,687	9,336	7,537
Operating Segments [Member] | Medical Device [Member] | Royalties [Member]
Disaggregation Of Revenue [Line Items]
Revenue	8,313	7,891	15,998	14,933
Operating Segments [Member] | Medical Device [Member] | License Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,619	537	4,030	571
Operating Segments [Member] | In Vitro Diagnostics [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	5,375	5,006	10,358	9,245
Operating Segments [Member] | In Vitro Diagnostics [Member] | Product Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue	5,329	4,999	10,302	9,237
Operating Segments [Member] | In Vitro Diagnostics [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 46	$ 7	$ 56	$ 8