Condensed Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	2 Months Ended		3 Months Ended	2 Months Ended	3 Months Ended	1 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Successor [Member]	Mar. 31, 2014 Successor [Member]	Mar. 31, 2013 Successor [Member] CyrusOne L.P. [Member]	Mar. 31, 2014 Successor [Member] CyrusOne L.P. [Member]	Jan. 23, 2013 Predecessor [Member]	Jan. 23, 2013 Predecessor [Member] CyrusOne L.P. [Member]
Revenue		$ 45.0	$ 77.5	$ 45.0	$ 77.5	$ 15.1	$ 15.1
Costs and expenses:
Property operating expenses		15.3	27.7	15.3	27.7	4.8	4.8
Sales and marketing		2.1	3.0	2.1	3.0	0.7	0.7
General and administrative		5.4	7.3	5.4	7.3	1.5	1.5
Depreciation and amortization		16.4	27.6	16.4	27.6	5.3	5.3
Transaction costs		0	0.1	0	0.1	0.1	0.1
Total costs and expenses		39.2	65.7	39.2	65.7	32.4	32.4
Operating income (loss)		5.8	11.8	5.8	11.8	(17.3)	(17.3)
Interest expense		8.4	10.7	8.4	10.7	2.5	2.5
Income (loss) before income taxes		(2.6)	1.1	(2.6)	1.1	(19.8)	(19.8)
Income tax expense		(0.2)	(0.4)	0.2	0.4	(0.4)	0.4
Income (Loss) from Continuing Operations Attributable to Parent						(20.2)	(20.2)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		(2.8)	0.7	(2.8)	0.7	(20.2)	(20.2)
Other Contribution From Parent						1.3
Contributions From Parent						19.6
Noncontrolling interest in net income (loss)	0	1.9	(0.5)
Net income (loss) attributed to common shareholders		(0.9)	0.2
Basic weighted average common shares outstanding (in shares)		20.9	20.9
Diluted weighted average common shares outstanding (in shares)		20.9	20.9
Dividends		$ (10.3)	$ (13.7)
Loss per share - basic and diluted (in dollars per share)		$ (0.05)	$ 0.00
Dividend declared per share (in dollars per share)		$ 0.16	$ 0.21