Acquisitions Acquisitions (Purchase Price Allocation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended				12 Months Ended	0 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Dec. 30, 2013	Sep. 30, 2014 Axeda [Member]	Jun. 30, 2014 Atego [Member]	Sep. 30, 2014 Atego [Member]	Sep. 30, 2014 ThingWorx [Member]	Sep. 30, 2014 ThingWorx, Inc. [Member]	Jun. 28, 2014 ThingWorx, Inc. [Member]	Sep. 30, 2013 Servigistics [Member]	Sep. 30, 2013 Servigistics [Member]	Sep. 30, 2014 Customer Relationships [Member] Axeda [Member]	Sep. 30, 2014 Customer Relationships [Member] Atego [Member]	Sep. 30, 2014 Customer Relationships [Member] ThingWorx, Inc. [Member]	Sep. 30, 2014 Trademarks [Member]	Sep. 30, 2014 Trademarks [Member] Axeda [Member]	Sep. 30, 2014 Trademarks [Member] Atego [Member]	Sep. 30, 2014 Trademarks [Member] ThingWorx, Inc. [Member]	Sep. 30, 2014 Other Intangible Assets [Member]	Sep. 30, 2014 Other Intangible Assets [Member] Axeda [Member]	Sep. 30, 2014 Other Intangible Assets [Member] Atego [Member]	Sep. 30, 2014 Other Intangible Assets [Member] ThingWorx [Member]	Sep. 30, 2014 Computer Software, Intangible Asset [Member]	Sep. 30, 2014 Computer Software, Intangible Asset [Member] Axeda [Member]	Sep. 30, 2014 Computer Software, Intangible Asset [Member] Atego [Member]	Sep. 30, 2014 Computer Software, Intangible Asset [Member] ThingWorx, Inc. [Member]
Business Acquisition [Line Items]
Goodwill, Acquired During Period					$ 130,443		$ 27,256	$ 102,190	$ 102,190			$ 139,833
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue	(18,242)						(6,058)		(900)
Deferred Tax Liabilities, Net	(136,196)	(120,796)			(9,145)		(3,476)		(8,934)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	3,674						634		(309)
Cash Acquired from Acquisition	(9,575)				(9,575)		(3,550)		(133)		(1,400)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	175,475						49,656		124,700
Payments to Acquire Businesses, Net of Cash Acquired	323,525	245,843	220		165,900	46,015	46,106		111,519		220,818
Finite-lived Intangible Assets Acquired	59,170						27,750		32,520				36,600	19,400	8,800		2,800	150	2,300		70	0	420		19,700	8,200	21,000
Weighted average useful lives of acquired intangible assets													11 years	9 years	9 years	9 years	12 years	3 years	12 years	3 years	2 years		3 years	9 years	9 years	11 years	11 years
Business Combination, Consideration Transferred									124,567
Business Combination, Contingent Consideration, Liability	$ (13,048)			$ (13,048)	$ 0		$ 0			$ (13,048)