Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Current:
Federal	$ 17,872	$ 81,127	$ 23,923
State	1,379	6,067	3,108
Foreign	15,118	9,689	18,343
Deferred:
Federal	16,907	(40,801)	19,236
State	(2,561)	(9,054)	751
Foreign	3,525	(1,380)	(5,864)
Income tax expense	$ 52,240	$ 45,648	$ 59,497