Income Taxes (Schedule Of Provision For (Benefit From) Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Federal	$ 2,423	$ 2,417	$ 3,907
State	340	571	599
Foreign	17,881	28,467	23,823
Current provision for income taxes	20,644	31,455	28,329
Federal	4,911	965	(20,809)
State	877	515	(566)
Foreign	(34,077)	(45,662)	(27,986)
Deferred provision for (benefit from) income taxes	(28,289)	(44,182)	(49,361)
Benefit from income taxes	$ (7,645)	$ (12,727)	$ (21,032)