Goodwill and Acquired Intangible Assets (Schedule Of Movements of Goodwill by Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Goodwill [Roll Forward]
Balance, beginning of period	$ 610,347	$ 613,394
Foreign currency translation and other adjustments	4,568	(2,097)
Balance, end of period	769,095	610,347
Software Products [Member]
Goodwill [Roll Forward]
Balance, beginning of period	585,469	588,443
Foreign currency translation and other adjustments	4,476	(2,024)
Balance, end of period	720,548	585,469
Services [Member]
Goodwill [Roll Forward]
Balance, beginning of period	24,878	24,951
Foreign currency translation and other adjustments	92	(73)
Balance, end of period	48,547	24,878
4CS [Member]
Goodwill [Roll Forward]
Acquisitions		(950)
4CS [Member] | Software Products [Member]
Goodwill [Roll Forward]
Acquisitions		(950)
4CS [Member] | Services [Member]
Goodwill [Roll Forward]
Acquisitions		0
Servigistics [Member]
Goodwill [Roll Forward]
Acquisitions	139,833
Balance, end of period	139,833
Servigistics [Member] | Software Products [Member]
Goodwill [Roll Forward]
Acquisitions	127,033
Servigistics [Member] | Services [Member]
Goodwill [Roll Forward]
Acquisitions	12,800
NetIDEAS [Member]
Goodwill [Roll Forward]
Acquisitions	10,196
NetIDEAS [Member] | Software Products [Member]
Goodwill [Roll Forward]
Acquisitions	0
NetIDEAS [Member] | Services [Member]
Goodwill [Roll Forward]
Acquisitions	10,196
Enigma [Member]
Goodwill [Roll Forward]
Acquisitions	4,151
Enigma [Member] | Software Products [Member]
Goodwill [Roll Forward]
Acquisitions	3,570
Enigma [Member] | Services [Member]
Goodwill [Roll Forward]
Acquisitions	$ 581