Acquisition of Magellan - Schedule of Amounts of Identifiable Assets Acquired and Liabilities Assumed in Acquisition (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016	Mar. 24, 2016
Fair value of assets acquired -
Goodwill	$ 54,612	$ 61,982
Magellan [Member]
Fair value of assets acquired -
Cash and equivalents			$ 3,400
Accounts receivable			1,700
Inventories			1,400
Other current assets			300
Property, plant and equipment			2,600
Goodwill	$ 33,963		40,591
Other intangible assets:
Fair value of assets acquired net			77,500
Fair value of liabilities assumed -
Accounts payable and accrued expenses			1,700
Deferred income tax liabilities			7,900
Total consideration			67,900
Magellan [Member] | As Initially Reported [Member]
Fair value of assets acquired -
Cash and equivalents			3,400
Accounts receivable			1,700
Inventories			1,400
Other current assets			300
Property, plant and equipment			2,800
Goodwill			42,800
Other intangible assets:
Fair value of assets acquired net			80,000
Fair value of liabilities assumed -
Accounts payable and accrued expenses			1,600
Deferred income tax liabilities			10,600
Total consideration			67,800
Magellan [Member] | Measurement Period Adjustments [Member]
Fair value of assets acquired -
Property, plant and equipment			(200)
Goodwill			(2,200)
Other intangible assets:
Fair value of assets acquired net			(2,500)
Fair value of liabilities assumed -
Accounts payable and accrued expenses			100
Deferred income tax liabilities			(2,700)
Total consideration			100
Magellan [Member] | Customer Relationships [Member]
Other intangible assets:
Other intangible assets			12,900
Magellan [Member] | Customer Relationships [Member] | As Initially Reported [Member]
Other intangible assets:
Other intangible assets			12,600
Magellan [Member] | Customer Relationships [Member] | Measurement Period Adjustments [Member]
Other intangible assets:
Other intangible assets			300
Magellan [Member] | Technology [Member]
Other intangible assets:
Other intangible assets			10,900
Magellan [Member] | Technology [Member] | As Initially Reported [Member]
Other intangible assets:
Other intangible assets			10,600
Magellan [Member] | Technology [Member] | Measurement Period Adjustments [Member]
Other intangible assets:
Other intangible assets			300
Magellan [Member] | Non-Compete Agreements [Member]
Other intangible assets:
Other intangible assets			700
Magellan [Member] | Non-Compete Agreements [Member] | As Initially Reported [Member]
Other intangible assets:
Other intangible assets			700
Magellan [Member] | Trade Names [Member]
Other intangible assets:
Other intangible assets			3,000
Magellan [Member] | Trade Names [Member] | As Initially Reported [Member]
Other intangible assets:
Other intangible assets			3,700
Magellan [Member] | Trade Names [Member] | Measurement Period Adjustments [Member]
Other intangible assets:
Other intangible assets			$ (700)