Business Combinations and Divestitures (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Business Combinations [Abstract]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest	$ 92,463
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	36,348
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	11,965
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	837
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	59,648
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	38,632
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	(29,149)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities	(723)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Current	(3,282)
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 20,741
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 4 months 24 days
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 179,628	$ 21,836
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual	6,508	812
Business Acquisition, Pro Forma Revenue	1,631,057	1,441,933
Business Acquisition, Pro Forma Net Income (Loss)	69,928	49,257
Escrow Deposit	10,916
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	4,500
Noncontrolling Interest, Increase from Business Combination	(21,813)
Cash received (paid) in conjunction with business combinations	$ 92,463	$ 28,952	$ 50