Revenue - Contract Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Contract assets	$ 56,148	$ 88,351
Contract liabilities	(225,767)	(79,857)
Net contract asset (liability)	(169,619)	8,494
Revenue recognized related to contract liabilities	68,100
Retention amounts included in accounts receivable	7,000	$ 6,900
Retained amount expected to be collected in the next twelve months	6,800
Retained amount expected to be collected	$ 200