CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Data center revenue:
Rental revenue	$ 41,323	$ 34,899
Power revenue	19,669	16,002
Interconnection revenue	10,215	8,059
Tenant reimbursement and other	1,416	2,756
Office, light-industrial and other revenue	2,134	2,015
Total operating revenues	74,757	63,731
Operating expenses:
Property operating and maintenance	19,780	16,289
Real estate taxes and insurance	1,935	2,966
Depreciation and amortization	22,816	17,882
Sales and marketing	3,782	3,588
General and administrative	7,865	7,705
Rent	5,243	5,066
Impairment of internal-use software		922
Transaction costs		4
Total operating expenses	61,421	54,422
Operating income	13,336	9,309
Gain on land disposal	36
Interest income	2	2
Interest expense	(1,265)	(1,173)
Income before income taxes	12,109	8,138
Income tax expense	(49)	(20)
Net income	12,060	8,118
Net income attributable to noncontrolling interests	5,408	3,301
Net income attributable to CoreSite Realty Corporation	6,652	4,817
Preferred stock dividends	(2,084)	(2,084)
Net income attributable to common shares	$ 4,568	$ 2,733
Net income per share attributable to common shares:
Basic (in dollars per share)	$ 0.21	$ 0.13
Diluted (in dollars per share)	$ 0.21	$ 0.13
Weighted average common shares outstanding
Basic (in shares)	21,372,157	20,992,758
Diluted (in shares)	21,978,307	21,521,838