Income Tax Expense - Components Of Income From Continuing Operations Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Expense
United States	$ 70,214	$ 23,951	$ 87,150
Foreign	10,457	12,455	10,727
Total income before income taxes	$ 80,671	$ 36,406	$ 97,877