Reportable Segments and Major Concentration Data - Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net revenues	$ 64,153	$ 84,797	$ 57,296	$ 47,421	$ 50,846	$ 48,440	$ 50,248	$ 51,480	$ 253,667	$ 201,014	$ 213,571
Operating income									61,324	32,699	31,584
Depreciation and amortization									13,567	9,964	8,688
Capital expenditures									3,299	3,797	4,201
Goodwill	114,186				89,241				114,186	89,241	54,637
Other intangible assets	83,197				60,243				83,197	60,243	23,113
Total assets	405,261				325,478				405,261	325,478	251,377
Restructuring and litigation costs									2,080	2,596	7,779
Diagnostics [Member]
Segment Reporting Information [Line Items]
Net revenues									121,132	136,682	150,454
Life Science [Member]
Segment Reporting Information [Line Items]
Net revenues									132,535	64,332	63,117
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income									(11,437)	(10,373)	(15,076)
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating income										101	292
Total assets	(34)				(83)				(34)	(83)	58
Net revenues									(587)	(823)	(789)
Operating Segments [Member] | Diagnostics [Member]
Segment Reporting Information [Line Items]
Net revenues									121,132	136,682	150,454
Operating income									3,885	25,390	34,603
Depreciation and amortization									11,451	7,676	6,557
Capital expenditures									1,850	2,049	2,477
Goodwill	94,855				70,395				94,855	70,395	35,213
Other intangible assets	83,179				59,807				83,179	59,807	22,068
Total assets	306,812				255,169				306,812	255,169	180,978
Net revenues									326	462	392
Operating Segments [Member] | Life Science [Member]
Segment Reporting Information [Line Items]
Net revenues									132,535	64,332	63,117
Operating income									68,826	17,581	11,765
Depreciation and amortization									2,116	2,288	2,131
Capital expenditures									1,449	1,748	1,724
Goodwill	19,331				18,846				19,331	18,846	19,424
Other intangible assets	18				436				18	436	1,045
Total assets	$ 98,483				$ 70,392				98,483	70,392	70,341
Net revenues									$ 261	$ 361	$ 397