Segment Information (Revenue By Geographic Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Revenue	$ 1,241,824	$ 1,164,039	$ 1,140,533
Total long-lived intangible assets	80,613	63,600	67,113
Americas [Member]
Revenue	511,237	500,879	487,594
Total long-lived intangible assets	67,704	47,055	48,281
Europe [Member]
Revenue	485,851	435,183	424,268
Total long-lived intangible assets	5,303	6,284	6,915
Asia Pacific [Member]
Revenue	244,736	227,977	228,671
Total long-lived intangible assets	7,606	10,261	11,917
United States [Member]
Revenue	487,300	475,500	463,100
Germany [Member]
Revenue	$ 193,300	$ 164,700	$ 167,200