Reportable Segments and Major Customers - Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Segment Reporting Information [Line Items]
NET REVENUES	$ 54,125	$ 51,259	$ 100,934	$ 98,419
Operating income	14,186	15,156	24,271	28,742
Goodwill	60,836		60,836		$ 61,982
Other intangible assets, net	28,457		28,457		29,855
Total assets	251,902		251,902		251,823
Operating Segments [Member] | Diagnostics [Member]
Segment Reporting Information [Line Items]
NET REVENUES	37,772	37,354	71,580	72,655
Operating income	9,595	11,196	16,238	21,526
Goodwill	41,841		41,841		42,608
Other intangible assets, net	26,516		26,516		27,534
Total assets	185,094		185,094		185,241
Net revenues	128	84	207	155
Operating Segments [Member] | Life Science [Member]
Segment Reporting Information [Line Items]
NET REVENUES	16,353	13,905	29,354	25,764
Operating income	4,571	4,154	7,838	7,390
Goodwill	18,995		18,995		19,374
Other intangible assets, net	1,941		1,941		2,321
Total assets	66,894		66,894		66,624
Net revenues	107	387	232	754
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating income	20	(194)	195	(174)
Total assets	(86)		(86)		$ (42)
Net revenues	$ (235)	$ (471)	$ (439)	$ (909)