Intangible Assets and Goodwill - Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended									0 Months Ended	12 Months Ended		0 Months Ended		0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011 Encryptx	Dec. 31, 2013 Nexsan Corporation	Dec. 31, 2012 Nexsan Corporation	Dec. 31, 2013 TSS	Dec. 31, 2012 TSS	Dec. 31, 2013 TSS Nexsan Corporation	Dec. 31, 2012 TSS Nexsan Corporation	Dec. 31, 2013 CSA	Dec. 31, 2012 CSA	Nov. 29, 2012 Income approach valuation technique Goodwill	Dec. 31, 2013 Income approach valuation technique Goodwill	Dec. 31, 2013 Mobile Security [Member]	Nov. 29, 2012 Mobile Security [Member] Income approach valuation technique Goodwill	Dec. 31, 2013 Storage and Security Solutions [Member]	Nov. 29, 2012 Storage and Security Solutions [Member] Income approach valuation technique Goodwill
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 250.7	$ 185.2							$ 201.3	$ 135.8			$ 49.4	$ 49.4
Accumulated impairment losses, beginning balance	(177.2)	(153.9)							(127.8)	(104.5)			(49.4)	(49.4)
Goodwill, beginning balance	73.5	31.3					65.5		73.5	31.3				0
Goodwill acquired						1.6		65.5				65.5		0
Goodwill impairment	0	(23.3)	(1.6)							(23.3)				0
Nexsan purchase price adjustment							(1.6)				(1.6)		0
Foreign currency translation	0.2								0.2				0
Goodwill, gross, ending balance	249.3	250.7	185.2						199.9	201.3			49.4	49.4
Accumulated impairment losses, ending balance	(177.2)	(177.2)	(153.9)						(127.8)	(127.8)			(49.4)	(49.4)
Goodwill, ending balance	$ 72.1	$ 73.5	$ 31.3				$ 63.9	$ 65.5	$ 72.1	$ 73.5			$ 0
Goodwill impairment test, estimated fair value in excess of carrying value, percentage				17.70%	43.30%												34.20%		25.70%
Discounted forecasted cash flows period															10 years	10 years
Discount rate															16.00%			15.50%		13.50%
Terminal growth rate															2.50%	3.00%