Business Segment Information and Geographic Data Business Segment Information and Geographic Data - Net Revenue and Operating Income (Loss) by Segment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting Information [Line Items]
Net Revenue	$ 197.0	$ 175.0	$ 178.6	$ 178.9	$ 232.8	$ 191.9	$ 211.7	$ 224.4	$ 729.5	[1]	$ 860.8	[1]	$ 1,006.7
Operating Income (Loss)	(12.1)	(55.8)	(20.1)	(16.1)	21.1	(26.5)	0	(14.7)	(104.1)	[1]	(20.1)	[1]	(318.4)
Interest income									(0.5)		(0.2)		(0.5)
Interest expense									2.6		2.5		2.9
Other expense, net									3.1		0.6		2.6
Loss from continuing operations before income taxes									(109.3)		(23.0)		(323.4)
Corporate and Operating
Segment Reporting Information [Line Items]
Operating Income (Loss)									(104.1)		(20.1)		(318.4)
Operating Segments
Segment Reporting Information [Line Items]
Net Revenue									729.5		860.8		1,006.7
Operating Income (Loss)									(12.7)		36.2		34.8
Operating Segments | Consumer Storage and Accessories
Segment Reporting Information [Line Items]
Net Revenue									393.5		478.3		635.3
Operating Income (Loss)									19.3		52.3		61.5
Operating Segments | Consumer Storage Media
Segment Reporting Information [Line Items]
Net Revenue									342.9		435.7		594.3
Operating Segments | Audio and Accessories
Segment Reporting Information [Line Items]
Net Revenue									50.6		42.6		41.0
Operating Segments | Tiered Storage and Security Solutions
Segment Reporting Information [Line Items]
Net Revenue									336.0		382.5		371.4
Operating Income (Loss)									(32.0)		(16.1)		(26.7)
Operating Segments | Commercial Storage Media
Segment Reporting Information [Line Items]
Net Revenue									213.4		251.0		311.6
Operating Segments | Storage and Security Solutions
Segment Reporting Information [Line Items]
Net Revenue									122.6		131.5		59.8
Corporate and unallocated
Segment Reporting Information [Line Items]
Operating Income (Loss)									(91.4)		(56.3)		(353.2)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Interest income									(0.5)		(0.2)		(0.5)
Interest expense									2.6		2.5		2.9
Other expense, net									$ 3.1		$ 0.6		$ 2.6

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