Consolidated and Combined Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investment in real estate:
Goodwill	$ 276.2	$ 276.2
Liabilities and equity
Deferred revenue	55.9	52.8
Other financing arrangements	56.3	60.8
Successor [Member]
Investment in real estate:
Land	89.3
Buildings and improvements	783.7
Equipment	190.2
Construction in progress	57.3
Subtotal	1,120.5
Accumulated depreciation	(236.7)
Net investment in real estate	883.8
Cash and cash equivalents	148.8
Rent and other receivables, net of allowance for doubtful accounts of $0.5 and $0.3 as of December 31, 2013 and December 31, 2012, respectively	41.2
Restricted cash	0
Goodwill	276.2
Intangible assets, net of accumulated amortization of $55.1 and $38.2 as of December 31, 2013, and December 31, 2012	85.9
Due from affiliates	0.6
Other assets	70.3
Total assets	1,506.8
Liabilities and equity
Accounts payable and accrued expenses	66.8
Deferred revenue	55.9
Due to affiliates	8.5
Capital lease obligations	16.7
Long-term debt	525.0
Other financing arrangements	56.3
Total liabilities	729.2
Commitment and contingencies
Equity
Preferred stock, $.01 par value, 100,000,000 authorized; no shares issued or outstanding	0
Common stock, $.01 par value, 500,000,000 shares authorized and 21,991,669 shares issued and outstanding at December 31, 2013 Common stock, $.01 par value, 1,000 shares authorized and 100 shares issued and outstanding at December 31, 2012	0.2	0
Additional paid in capital	340.7
Accumulated deficit	(18.9)
Partnership capital	0
Total shareholders’ equity/Parent’s net investments	322.0
Noncontrolling interest	455.6
Total equity	777.6
Total liabilities and equity	1,506.8
Predecessor [Member]
Investment in real estate:
Land		44.5
Buildings and improvements		722.5
Equipment		52.4
Construction in progress		64.2
Subtotal		883.6
Accumulated depreciation		(176.7)
Net investment in real estate		706.9
Cash and cash equivalents		16.5
Rent and other receivables, net of allowance for doubtful accounts of $0.5 and $0.3 as of December 31, 2013 and December 31, 2012, respectively		33.2
Restricted cash		6.3
Goodwill		276.2
Intangible assets, net of accumulated amortization of $55.1 and $38.2 as of December 31, 2013, and December 31, 2012		102.6
Due from affiliates		2.2
Other assets		67.0
Total assets		1,210.9
Liabilities and equity
Accounts payable and accrued expenses		37.1
Deferred revenue		52.8
Due to affiliates		2.9
Capital lease obligations		32.2
Long-term debt		525.0
Other financing arrangements		60.8
Total liabilities		710.8
Commitment and contingencies
Equity
Preferred stock, $.01 par value, 100,000,000 authorized; no shares issued or outstanding		0
Common stock, $.01 par value, 500,000,000 shares authorized and 21,991,669 shares issued and outstanding at December 31, 2013 Common stock, $.01 par value, 1,000 shares authorized and 100 shares issued and outstanding at December 31, 2012	0	0
Additional paid in capital		7.1
Accumulated deficit		0
Partnership capital		493.0
Total shareholders’ equity/Parent’s net investments		500.1
Noncontrolling interest		0
Total equity		500.1
Total liabilities and equity		1,210.9
CyrusOne L.P. [Member] | Successor [Member]
Investment in real estate:
Land	89.3
Buildings and improvements	783.7
Equipment	190.2
Construction in progress	57.3
Subtotal	1,120.5
Accumulated depreciation	(236.7)
Net investment in real estate	883.8
Cash and cash equivalents	148.8
Rent and other receivables, net of allowance for doubtful accounts of $0.5 and $0.3 as of December 31, 2013 and December 31, 2012, respectively	41.2
Restricted cash	0
Goodwill	276.2
Intangible assets, net of accumulated amortization of $55.1 and $38.2 as of December 31, 2013, and December 31, 2012	85.9
Due from affiliates	0.6
Other assets	70.3
Total assets	1,506.8
Liabilities and equity
Accounts payable and accrued expenses	66.8
Deferred revenue	55.9
Due to affiliates	8.5
Capital lease obligations	16.7
Long-term debt	525.0
Other financing arrangements	56.3
Total liabilities	729.2
Commitment and contingencies
Equity
Partnership capital	777.6
Total liabilities and equity	1,506.8
CyrusOne L.P. [Member] | Predecessor [Member]
Investment in real estate:
Land		44.5
Buildings and improvements		722.5
Equipment		52.4
Construction in progress		64.2
Subtotal		883.6
Accumulated depreciation		(176.7)
Net investment in real estate		706.9
Cash and cash equivalents		16.5
Rent and other receivables, net of allowance for doubtful accounts of $0.5 and $0.3 as of December 31, 2013 and December 31, 2012, respectively		33.2
Restricted cash		6.3
Goodwill		276.2
Intangible assets, net of accumulated amortization of $55.1 and $38.2 as of December 31, 2013, and December 31, 2012		102.6
Due from affiliates		2.2
Other assets		59.1
Total assets		1,203.0
Liabilities and equity
Accounts payable and accrued expenses		36.3
Deferred revenue		52.8
Due to affiliates		2.9
Capital lease obligations		32.2
Long-term debt		525.0
Other financing arrangements		60.8
Total liabilities		710.0
Commitment and contingencies
Equity
Partnership capital		493.0
Total liabilities and equity		$ 1,203.0