Organization and Description of Business (Details) - Operating partnership	Sep. 30, 2018	Dec. 31, 2017
Coresite Realty Corporation
Organization
Percentage of ownership interests held by the entity	75.80%	71.00%
Carlyle Group
Organization
Percentage of ownership interests held by others	24.20%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	cor_OrganizationLineItems
Namespace Prefix:	cor_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration