CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 110,247	$ 96,035	$ 226,168	$ 207,347
Other comprehensive income, net of tax
Reclassifications of losses to net income on derivatives designated as hedging instruments, net of tax of $(80), $(80), $(159) and $(159), respectively	264	263	527	527
Adjustment to postemployment benefit obligation, net of tax of $(13), $(232), $(25) and $(465), respectively	41	768	82	1,534
Other comprehensive income, net of tax	305	1,031	609	2,061
Comprehensive income	$ 110,552	$ 97,066	$ 226,777	$ 209,408