CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 111,312	$ 81,045
Other comprehensive income, net of tax
Reclassifications of losses to net income on derivatives designated as hedging instruments, net of tax of $(79) and $(112), respectively	264	231
Adjustment to postemployment benefit obligation, net of tax of $(233) and $(245), respectively	766	812
Other comprehensive income	1,030	1,043
Comprehensive income	$ 112,342	$ 82,088