Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Line Items]
Impairment loss	$ 0	$ 398	$ 1,960
Amortization expense for intangible assets	$ 12,900	10,600	9,800
CeligoCell Cytometer product line
Goodwill and Intangible Assets Disclosure [Line Items]
Impairment loss		$ 400	$ 2,000