Business Segment Information and Geographic Data - Segment Information by Geographic Region (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Net revenue	$ 232.8	$ 191.9	$ 211.7	$ 224.4	$ 266.8	$ 227.4	$ 249.2	$ 263.3	$ 860.8	[1]	$ 1,006.7	[1]	$ 1,166.6
Operating loss	21.1	(26.5)	0	(14.7)	(301.6)	(3.7)	(7.5)	(5.6)	(20.1)	[1]	(318.4)	[1]	(20.4)
Goodwill impairment									0		23.3		1.6
Intangible impairments									0		251.8		0
Restructuring and other costs									11.3		21.1		21.5
Litigation settlements									(2.5)		0		2.0
Long-Lived Assets	192.3				214.3				192.3		214.3		408.4
Interest income									(0.2)		(0.5)		(0.9)
Interest expense									2.5		2.9		3.7
Other expense, net									0.6		2.6		7.0
Loss from continuing operations before income taxes									(23.0)		(323.4)		(30.2)
United States
Segment Reporting Information [Line Items]
Net revenue									348.1		376.2		420.8
Long-Lived Assets	150.7				166.9				150.7		166.9		321.0
International
Segment Reporting Information [Line Items]
Net revenue									512.7		630.5		745.8
Long-Lived Assets	41.6				47.4				41.6		47.4		87.4
CSA
Segment Reporting Information [Line Items]
Net revenue									478.3		635.3		775.2
Goodwill impairment											0
TSS
Segment Reporting Information [Line Items]
Net revenue									382.5		371.4		391.4
Goodwill impairment											23.3
Net revenue | Japan | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage									20.60%		21.00%		19.40%
Operating Segments
Segment Reporting Information [Line Items]
Operating loss									36.2		34.8		66.3
Operating Segments | CSA
Segment Reporting Information [Line Items]
Operating loss									52.3		61.5		57.1
Operating Segments | TSS
Segment Reporting Information [Line Items]
Operating loss									(16.1)		(26.7)		9.2
Corporate and unallocated
Segment Reporting Information [Line Items]
Operating loss									(56.3)		(353.2)		(86.7)
Goodwill impairment											23.3		1.6
Intangible impairments											251.8
Restructuring and other costs									11.3		21.1		21.5
Litigation settlements									2.5				2.0
Commercial Storage Media [Member] | TSS
Segment Reporting Information [Line Items]
Net revenue									251.0		311.6		378.8
Storage and Security Solutions [Member] | TSS
Segment Reporting Information [Line Items]
Net revenue									131.5		59.8		12.6
Consumer Storage Media [Member] | CSA
Segment Reporting Information [Line Items]
Net revenue									435.7		594.3		740.2
Audio and Accessories [Member] | CSA
Segment Reporting Information [Line Items]
Net revenue									$ 42.6		$ 41.0		$ 35.0

[1] The sum of the quarterly loss per share may not equal the annual loss per share due to changes in average shares outstanding.