Business Segment Information and Geographic Data - Segment Information by Product (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue from External Customer [Line Items]
Net revenue	$ 299.1	$ 248.2	$ 270.6	$ 281.7	$ 342.3	$ 308.6	$ 323.0	$ 316.5	$ 1,099.6	$ 1,290.4	$ 1,460.9
Total traditional storage
Revenue from External Customer [Line Items]
Net revenue									728.4	887.0	1,029.9
Traditional storage, optical products
Revenue from External Customer [Line Items]
Net revenue									426.8	511.9	619.3
Traditional storage, Magentic products
Revenue from External Customer [Line Items]
Net revenue									286.2	327.4	347.8
Traditional storage, Other traditional storage
Revenue from External Customer [Line Items]
Net revenue									15.4	47.7	62.8
Secure and scalable storage
Revenue from External Customer [Line Items]
Net revenue									210.1	210.1	207.5
Audio and video information
Revenue from External Customer [Line Items]
Net revenue									$ 161.1	$ 193.3	$ 223.5