Revenue - Contract Balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Contract assets	$ 67,594	$ 60,621
Contract liabilities	(328,888)	(279,796)
Net contract liability	(261,294)	(219,175)
Revenue recognized related to contract liabilities	103,500
Retention amounts included in accounts receivable	7,300	$ 7,400
Retained amount expected to be collected in the next twelve months	7,100
Retained amount expected to be collected	$ 200