Significant Non-cash Transactions (Tables)

12 Months Ended

Sep. 30, 2021

Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]

Schedule of Significant Noncash Transactions

The Company engaged in the following significant non-cash investing and financing activities during the years ended September 30, 2021, 2020, and 2019:

	Year ended September 30,
	2021		2020		2019
Restricted Class A common stock issued as part of acquisition purchase consideration (Note 4)	$	35,245	$	—	$	225
Acquisition date fair value of contingent consideration in connection with business combinations	$	22,577	$	4,748	$	13,032
Replacement of the 2017 Senior Secured Credit Facility with the Senior Secured Credit Facility	$	—	$	—	$	100,229
Debt issuance costs and accrued interest financed with proceeds from the 2019 Senior Secured Credit Facility	$	—	$	—	$	1,271
Right-of-use assets obtained in exchange for operating lease obligations	$	16,879	$	—	$	—