Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated foreign currency translation adjustments	$ 778	$ 4,787
Accumulated net retirement plan transition asset (net of tax of $148 and $148, respectively)	17	47
Accumulated net retirement plan actuarial losses (net of tax of $470 and $470, respectively)	(2,036)	(2,091)
Total accumulated other comprehensive income (loss)	(217)	9,121	[1]
Accumulated net retirement plan transition asset, tax	148	148
Accumulated net retirement plan actuarial losses, tax	470	470
Semiconductor Manufacturing International Corp.
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated net unrealized gain	0	419
Accumulated unrealized gain, tax	0	275
Nanya Technology Corporation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated net unrealized gain	1,024	5,959
Accumulated unrealized gain, tax	$ 592	$ 3,565

[1] Derived from audited financial statements.