CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Data center revenue:
Rental revenue	$ 183,300	$ 149,294	$ 131,080
Power revenue	89,495	71,227	59,663
Interconnection revenue	44,234	35,355	28,932
Tenant reimbursement and other	8,295	8,702	7,317
Office, light-industrial and other revenue	7,968	7,842	7,841
Total operating revenues	333,292	272,420	234,833
Operating expenses:
Property operating and maintenance	89,805	75,119	64,260
Real estate taxes and insurance	12,144	7,578	8,458
Depreciation and amortization	95,702	80,722	65,785
Sales and marketing	15,930	14,554	14,405
General and administrative	34,179	27,842	27,317
Rent	21,075	20,397	19,659
Impairment of internal use software	322	1,959
Transaction costs	51	62	279
Total operating expenses	269,208	228,233	200,163
Operating income	64,084	44,187	34,670
Gain on real estate disposal	36	1,208
Interest income	6	6	32
Interest expense	(7,104)	(5,311)	(2,689)
Income before income taxes	57,022	40,090	32,013
Income tax expense	(163)	(38)	(401)
Net income	56,859	40,052	31,612
Net income attributable to noncontrolling interests	22,153	17,287	12,771
Net income attributable to CoreSite Realty Corporation	34,706	22,765	18,841
Preferred stock dividends	(8,338)	(8,338)	(8,338)
Net income attributable to common shares	$ 26,368	$ 14,427	$ 10,503
Net income per share attributable to common shares:
Basic (in dollars per share)	$ 1.05	$ 0.68	$ 0.50
Diluted (in dollars per share)	$ 1.03	$ 0.66	$ 0.49
Weighted average common shares outstanding
Basic (in shares)	25,218,500	21,161,614	20,826,622
Diluted (in shares)	25,706,568	21,740,707	21,503,212