Acquisition of Chingis (Narrative) (Details) (USD $)	3 Months Ended										12 Months Ended			0 Months Ended	12 Months Ended			12 Months Ended
	Sep. 30, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2012 Chingis	Sep. 30, 2012 Chingis	Sep. 14, 2012 Chingis	Sep. 30, 2012 Chingis Selling, general and administrative	Sep. 30, 2012 Developed technology Chingis	Sep. 30, 2012 Customer relationships Chingis	Sep. 30, 2012 Other intangibles Chingis
Business Acquisition [Line Items]
Percentage of equity acquired																94.10%
Total purchase price																$ 31,800,000
Investment in consolidated subsidiaries, net of cash and cash equivalents acquired											13,210,000	15,960,000	50,000		13,200,000
Cash on acquired entity's balance sheet															18,600,000
Estimated useful lives of purchased definite lived intangible assets																		6 years	6 years	3 years
Costs related to acquistion																	400,000
Revenue														1,200,000
Net loss	$ 13,118,000	[1]	$ (3,147,000)	$ (3,597,000)	$ (3,769,000)	$ (35,056,000)	[2]	$ (8,095,000)	$ (5,758,000)	$ (7,214,000)	$ 2,605,000	$ (56,123,000)	$ (42,755,000)	$ 1,200,000

[1] In the September 2012 quarter, the Company recorded a charge of approximately $14.3 million for the impairment of certain tangible and intangible assets related to the acquisition of Si En and a charge of approximately $2.3 million to write-down its investment in SMIC due to the decline in fair market value being considered other than temporary.

[2] In the September 2011 quarter, the Company recorded an income tax benefit of approximately $28.1 million from the release of the valuation allowance for certain deferred tax assets.