Acquisition of Si En (Narrative) (Details) (USD $)			12 Months Ended		0 Months Ended	1 Months Ended			12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Minimum	Sep. 30, 2013 Maximum	Jan. 31, 2011 Si En	Sep. 30, 2012 Si En	Sep. 30, 2011 Si En	Apr. 27, 2009 Si En	Sep. 30, 2013 Developed technology Si En	Sep. 30, 2013 Customer relationships Si En	Sep. 30, 2013 Other Si En Minimum	Sep. 30, 2013 Other Si En Maximum
Business Acquisition [Line Items]
Percentage of equity acquired								100.00%
Total purchase price					$ 27,400,000
Acquisition related liability	0	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 acquired asset impairment						13,100,000
Legal fees related to acquisition							$ 300,000