Acquisitions and Divestitures - Acquisitions (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended	12 Months Ended			0 Months Ended		12 Months Ended	0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Nexsan Corporation	Dec. 31, 2013 Nexsan Corporation	Dec. 31, 2012 Nexsan Corporation	Dec. 31, 2011 Nexsan Corporation	Dec. 31, 2012 Nexsan Corporation Other - research and development technology	Dec. 31, 2012 Nexsan Corporation Trade name	Dec. 31, 2012 Nexsan Corporation Trade name	Dec. 31, 2012 Nexsan Corporation Other - developed technology	Dec. 31, 2012 Nexsan Corporation Other - developed technology Minimum	Dec. 31, 2012 Nexsan Corporation Other - developed technology Maximum	Dec. 31, 2012 Nexsan Corporation Customer relationships	Dec. 31, 2012 Nexsan Corporation Customer relationships	Oct. 04, 2011 IronKey Systems Inc.	Dec. 31, 2012 IronKey Systems Inc.	Oct. 04, 2011 IronKey Systems Inc. Trade name	Dec. 31, 2012 IronKey Systems Inc. Trade name	Oct. 04, 2011 IronKey Systems Inc. License	Dec. 31, 2012 IronKey Systems Inc. License	Oct. 04, 2011 IronKey Systems Inc. Customer relationships	Dec. 31, 2012 IronKey Systems Inc. Customer relationships	Oct. 04, 2011 IronKey Systems Inc. Distributor relationships	Dec. 31, 2012 IronKey Systems Inc. Distributor relationships	Oct. 04, 2011 IronKey Systems Inc. Proprietary technology	Dec. 31, 2012 IronKey Systems Inc. Proprietary technology	Jun. 04, 2011 MXI Security	Dec. 31, 2013 MXI Security	Dec. 31, 2012 MXI Security	Jun. 04, 2011 MXI Security Trademark	Dec. 31, 2012 MXI Security Trademark	Jun. 04, 2011 MXI Security Supply agreement	Dec. 31, 2012 MXI Security Supply agreement	Jun. 04, 2011 MXI Security Customer relationships	Dec. 31, 2012 MXI Security Customer relationships	Jun. 04, 2011 MXI Security Proprietary technology	Dec. 31, 2012 MXI Security Proprietary technology	Feb. 28, 2011 BeCompliant Corporation (Encryptx)	Dec. 31, 2013 BeCompliant Corporation (Encryptx)	Dec. 31, 2012 BeCompliant Corporation (Encryptx)	Dec. 31, 2012 Variable Compensation Expense [Member] Nexsan Corporation	Dec. 31, 2012 Interest Expense [Member] Nexsan Corporation	Dec. 31, 2011 Interest Expense [Member] Nexsan Corporation	Dec. 31, 2012 Transaction Cost [Member] Nexsan Corporation	Dec. 31, 2012 Finite-Lived Intangible Assets [Member]	Dec. 31, 2011 Finite-Lived Intangible Assets [Member]	Dec. 31, 2012 Deferred Revenue [Member] Nexsan Corporation	Dec. 31, 2011 Deferred Revenue [Member] Nexsan Corporation
Business Acquisition, Contingent Consideration [Line Items]
Cash paid to acquired entity				$ 104.6												$ 19.0												$ 24.5											$ 1.0
Common stock paid to acquired entity, shares				3,319,324		3,319,324
Common stock paid to acquired entity, value				15.5
Nexsan purchase price adjustment					(1.6)
Purchase price for brand and license for products and service	0	4.0	0														4.0
Purchase price adjustment																	0.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash					0.8
Accounts receivable					14.6
Accounts receivable and other assets																3.5												0.8
Inventory					6.9											2.1												1.1
Prepaid and other					9.0
Property, plant, and equipment					5.2
Intangible assets					42.6											7.8												10.6
Goodwill	72.1	73.5	31.3	65.5	63.9	65.5										9.4												21.9											1.6
Accounts payable and other liabilities																(3.8)												(0.7)
Other assets					0.6
Accounts payable					(5.3)
Accrued expenses					(10.0)
Deferred revenue - current					(4.3)
Deferred revenue - non-current					(2.5)
Other long-term liabilities					(3.0)
Total purchase price				120.1	118.5	120.1										19.0												33.7											2.3
Cash paid to creditors of acquiree						11.9
Acquired finite-lived intangible assets				42.6				1.7	3.1		19.4			18.4		7.8		0.8		1.9		0.4		0.9		3.8		10.6			0.7		1.4		1.0		7.5
Acquired finite-lived intangible assets, weighted average life										5 years		3 years	7 years		12 years				2 years		7 years		7 years		9 years		4 years					10 years		3 years		8 years		6 years
Pro Foma, Net revenue						1,088.7	1,247.2
Pro Foma, Loss from continuing operations						(328.5)	(44.7)
Business Combination, Pro Forma Information, Adjustment																																										15.4	0.9	1.0	4.3	5.1	5.1	0.6	1.1
Intangible asset abandonment	0	1.9	0																													0.6
Contingent consideration maximum range outcome																												45.0
Contingent consideration obligation																												9.2	0	0.6									1.3	0
Changes in fair value of contingent consideration	(0.6)	(8.6)	0																										(0.6)	(8.6)
Contingent consideration payments	$ (0.5)	$ (1.2)	$ 0																																					$ 0.8	$ 0.7