Acquisition of Si En (Schedule of Purchase Price Allocation) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2012 Si En	Jan. 31, 2011 Si En	Jan. 31, 2011 In-process technology Si En	Jan. 31, 2011 Developed technology Si En	Jan. 31, 2011 Customer relationships Si En	Jan. 31, 2011 Other Si En
Business Acquisition [Line Items]
Cash and cash equivalents						$ 7,240
Accounts receivable						2,148
Inventories						2,117
Property, equipment and leasehold improvements						124
Other current and other assets						260
Intangible assets:
Intangible assets						23,519	2,610	4,650	3,800	570
Current liabilities						(2,533)
Deferred tax liability						(1,748)
Total liabilities assumed						(4,281)
Net identifiable assets acquired						19,238
Goodwill	9,178	9,463	1,301	1,251	3,900	8,162
Net assets acquired						$ 27,400