Acquisition of Si En (Narrative) (Details) (USD $)			12 Months Ended		1 Months Ended	20 Months Ended				12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Minimum	Sep. 30, 2012 Maximum	Sep. 30, 2012 Si En	Sep. 30, 2012 Si En	Sep. 30, 2011 Si En	Jan. 31, 2011 Si En	Apr. 27, 2009 Si En	Sep. 30, 2012 Developed technology Si En	Sep. 30, 2012 Customer relationships Si En	Sep. 30, 2012 Other Si En Minimum	Sep. 30, 2012 Other Si En Maximum
Business Acquisition [Line Items]
Percentage of equity acquired									100.00%
Total purchase price									$ 27,400,000
Acquisition related liability	4,200,000	0			4,200,000	4,200,000	4,200,000	4,200,000
Holdback provision period (years)						2 years
Estimated useful lives of purchased definite lived intangible assets			6 months	8 years						8 years	5 years	3 years	4 years
Weighted average useful life for intangibles (years)												3 years	6 months
Goodwill and intangibles aquired asset impairment					13,100,000
Legal fees related to acquistion							$ 300,000