Description of Business (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017 property $ / shares shares	Dec. 31, 2016 $ / shares shares	May 17, 2013 $ / shares shares
Organization And Description Of Business [Line Items]
Number of properties | property	25
Common stock, shares issued | shares	50,701,795	47,831,250
Common stock, par value | $ / shares	$ 0.01	$ 0.01
Class A Common Stock
Organization And Description Of Business [Line Items]
Common stock, shares issued | shares			14,087,500
Common stock, par value | $ / shares			$ 0.01
QualityTech LP
Organization And Description Of Business [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	88.60%