Consolidated and Combined Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	11 Months Ended	1 Months Ended	12 Months Ended		11 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2013 Successor [Member]	Jan. 23, 2013 Predecessor [Member]	Dec. 31, 2012 Predecessor [Member]	Dec. 31, 2011 Predecessor [Member]	Dec. 31, 2013 CyrusOne L.P. [Member] Successor [Member]	Jan. 23, 2013 CyrusOne L.P. [Member] Predecessor [Member]	Dec. 31, 2012 CyrusOne L.P. [Member] Predecessor [Member]	Dec. 31, 2011 CyrusOne L.P. [Member] Predecessor [Member]
Revenue	$ 248.4	$ 15.1	$ 220.8	$ 181.7	$ 248.4	$ 15.1	$ 220.8	$ 181.7
Costs and expenses:
Property operating expenses	88.4	4.8	76.0	58.2	88.4	4.8	76.0	58.2
Sales and marketing	9.9	0.7	9.7	9.1	9.9	0.7	9.7	9.1
General and administrative	26.5	1.5	20.7	12.5	26.5	1.5	20.7	12.5
Depreciation and amortization	89.9	5.3	73.4	55.5	89.9	5.3	73.4	55.5
Restructuring charges	0.7	0	0	0	0.7		0	0
Transaction-related compensation	0	20.0	0	0	0	20.0	0	0
Transaction costs	1.3	0.1	5.7	2.6	1.3	0.1	5.7	2.6
Management fees charged by CBI	0	0	2.5	2.3	0	0	2.5	2.3
Loss on sale of receivables to an affiliate	0	0	3.2	3.5	0	0	3.2	3.5
Asset impairments	2.8	0	13.3	0	2.8	0	13.3	0
Total costs and expenses	219.5	32.4	204.5	143.7	219.5	32.4	204.5	143.7
Operating income (loss)	28.9	(17.3)	16.3	38.0	28.9	(17.3)	16.3	38.0
Interest expense	41.2	2.5	41.8	32.9	41.2	2.5	41.8	32.9
Other income	(0.1)	0	0	0	(0.1)	0	0	0
Loss on extinguishment of debt	1.3	0	0	1.4	1.3	0	0	1.4
Net (loss) income before income taxes	(13.5)	(19.8)	(25.5)	3.7	(13.5)	(19.8)	(25.5)	3.7
Income tax (expense) benefit	(1.9)	(0.4)	5.1	(2.2)	(1.9)	(0.4)	5.1	(2.2)
(Loss) income from continuing operations	(15.4)	(20.2)	(20.4)	1.5	(15.4)	(20.2)	(20.4)	1.5
(Loss) gain on sale of real estate improvements	(0.2)	0	0.1	0	(0.2)	0	0.1	0
Net (loss) income	(15.6)	(20.2)	(20.3)	1.5	(15.6)	(20.2)	(20.3)	1.5
Noncontrolling interest in net loss	10.3
Net loss attributed to common shareholders	$ (5.3)	$ (20.2)	$ (20.3)	$ 1.5
Basic weighted average common shares outstanding (in shares)	20.9
Diluted weighted average common shares outstanding (in shares)	20.9
Loss per share - basic and diluted (in dollars per share)	$ (0.28)