Acquisitions - Amounts of Assets and Liabilities at Fair Value as of Acquisition Date (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Apr. 20, 2018	Apr. 06, 2018	Oct. 05, 2017	Sep. 30, 2017	Aug. 22, 2017	Jul. 05, 2017	Nov. 28, 2016	Sep. 30, 2016	Nov. 30, 2015
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill	$ 255,876				$ 207,154				$ 175,654
Tec-Sem Group AG
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable			$ 988
Inventories			4,297
Prepaid expenses and other current assets			4,038
Property, plant and equipment			85
Intangible assets, finite-lived			10,694
Goodwill			7,665
Accounts payable			(1,049)
Accrued liabilities			(6,962)
Deferred tax liabilities			(1,391)
Accrued pension liability			(2,800)
Total purchase price			$ 15,565
4titude Limited
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable				$ 1,581
Inventories				2,667
Prepaid expenses and other current assets				140
Property, plant and equipment				1,555
Intangible assets, finite-lived				27,212
Goodwill				38,185
Accounts payable				(286)
Accrued liabilities				(845)
Deferred tax liabilities				(5,090)
Total purchase price				$ 65,119
BioSpeciMan Corporation
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable		$ 300
Intangible assets, finite-lived		2,600
Goodwill		2,700
Assumed liabilities		700
Total purchase price		$ 5,200
PBMMI and Novare
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable							$ 2,800
Prepaid expenses and other current assets							267
Property, plant and equipment							2,887
Intangible assets, finite-lived							8,600
Goodwill							21,434
Accounts payable							(699)
Accrued liabilities							(673)
Deferred revenue							(385)
Other liabilities							(103)
Total purchase price							$ 34,128
Cool Lab, LLC
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Inventories								$ 1,283
Intangible assets, finite-lived								6,100
Goodwill								8,527
Accrued liabilities								(30)
Other liabilities								(686)
Total purchase price								$ 15,194
RURO, Inc.
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable						$ 100
Intangible assets, finite-lived						4,000
Goodwill						1,600
Deferred revenue						(200)
Total purchase price						$ 5,500
BioStorage Technologies, Inc.
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable										$ 16,942
Prepaid expenses and other current assets										321
Property, plant and equipment										14,345
Intangible assets, finite-lived										41,460
Goodwill										79,639
Other assets										53
Debt assumed										(385)
Accounts payable										(1,708)
Accrued liabilities										(9,423)
Deferred revenue										(1,766)
Long-term deferred tax liabilities										(14,169)
Other liabilities										(61)
Total purchase price										$ 125,248