Goodwill and Acquired Intangible Assets (Amortization Of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquired intangible assets	$ 36,129	$ 32,127	$ 26,486
Cost of license and subscription	19,402	18,112	18,586
Total amortization expense	$ 55,531	$ 50,239	$ 45,072