CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Data center revenue:
Rental revenue	$ 121,479	$ 106,867	$ 353,563	$ 309,837
Total operating revenues	139,180	123,068	405,246	355,875
Operating expenses:
Property operating and maintenance	41,161	37,091	112,870	98,098
Real estate taxes and insurance	4,699	2,622	14,329	10,950
Depreciation and amortization	36,264	32,077	105,598	96,622
Sales and marketing	5,180	4,643	15,629	13,560
General and administrative	10,074	9,759	29,556	27,391
Rent	7,329	6,077	20,276	17,970
Transaction Costs			75	139
Total operating expenses	104,707	92,269	298,333	264,730
Operating income	34,473	30,799	106,913	91,145
Interest expense	(9,433)	(6,447)	(26,078)	(17,512)
Income before income taxes	25,040	24,352	80,835	73,633
Income tax (expense) benefit	(20)	(64)	30	(150)
Net income	25,020	24,288	80,865	73,483
Net income attributable to noncontrolling interests	6,420	6,446	22,574	19,537
Net income attributable to CoreSite Realty Corporation	18,600	17,842	58,291	53,946
Preferred stock dividends		(2,084)		(6,253)
Net income attributable to common shares	$ 18,600	$ 15,758	$ 58,291	$ 47,693
Net income per share attributable to common shares:
Basic (in dollars per share)	$ 0.52	$ 0.47	$ 1.69	$ 1.41
Diluted (in dollars per share)	$ 0.52	$ 0.46	$ 1.68	$ 1.40
Weighted average common shares outstanding
Basic (in shares)	35,512,091	33,878,881	34,504,790	33,758,971
Diluted (in shares)	35,721,478	34,114,169	34,693,835	34,033,842
Rental Power And Related Revenue
Data center revenue:
Rental revenue	$ 118,590	$ 103,952	$ 344,745	$ 300,932
Interconnection Revenue
Data center revenue:
Revenue	17,701	16,201	51,683	46,038
Office Light Industrial And Other Revenue
Data center revenue:
Rental revenue	$ 2,889	$ 2,915	$ 8,818	$ 8,905