Acquisitions - Summary of Recording of Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Apr. 28, 2017	Jul. 31, 2015	Mar. 31, 2018	Sep. 30, 2017	Mar. 25, 2017
Business Acquisition [Line Items]
Goodwill			$ 268,243	$ 256,275	$ 230,385
K&H Manufacturing
Business Acquisition [Line Items]
Current assets, net of cash and cash equivalents acquired		$ 6,052
Land, buildings, improvements and equipment - net		315
Goodwill		11,968
Other assets		0
Other intangible assets - net		29,200
Current liabilities		(757)
Net assets acquired, less cash and cash equivalents		46,778
Measurement Period Adjustments
Current assets, net of cash and cash equivalents acquired		613
Land, buildings, improvements and equipment - net		0
Goodwill	$ 12,000	11,968
Other assets		(41,781)
Other intangible assets - net	$ 29,200	29,200
Current liabilities		0
Net assets acquired, less cash and cash equivalents		0
Amounts Previously Recognized as of Acquisition Date | K&H Manufacturing
Business Acquisition [Line Items]
Current assets, net of cash and cash equivalents acquired		5,439
Land, buildings, improvements and equipment - net		315
Goodwill		0
Other assets		41,781
Other intangible assets - net		0
Current liabilities		(757)
Net assets acquired, less cash and cash equivalents		$ 46,778