Purchased Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended				12 Months Ended					3 Months Ended	12 Months Ended			3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2012 Developed technology	Sep. 30, 2012 Customer relationships	Sep. 30, 2012 Other	Sep. 30, 2012 Chingis	Sep. 14, 2012 Chingis	Sep. 30, 2012 Si En	Sep. 30, 2012 Si En	Sep. 30, 2011 Si En	Jan. 31, 2011 Si En	Sep. 30, 2012 Cost of sales Si En	Sep. 30, 2012 Operating expenses Si En
Acquired Indefinite-lived Intangible Assets [Line Items]
Additions to purchased intangible assets								$ 7,900,000				$ 11,600,000
Impairment of intangible assets	8,887,000	145,000	0							8,900,000				5,400,000	3,500,000
Weighted average useful life for intangibles (years)					5 years 6 months 11 days	5 years 11 months 16 days	2 years 11 months 16 days
In process research and developement transfered to developed technology	1,000,000
Goodwill	9,178,000	9,463,000	1,301,000	1,251,000					3,976,000	3,900,000	3,900,000		8,162,000
Impairment	$ 4,261,000	$ 0	$ 0								$ 4,300,000