Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Current:
Federal	$ 15,109	$ 15,976	$ 40,173
State	853	1,383	2,402
Foreign	34,354	22,588	34,660
Deferred:
Federal	(8,369)	10,784	(2,015)
State	(2,658)	(547)	(2,948)
Foreign	(2,139)	(8,698)	(11,262)
Income tax expense	$ 37,150	$ 41,486	$ 61,010