Noncontrolling Interest (Narrative) (Details) shares in Millions	9 Months Ended
Sep. 30, 2017 shares
Quality Tech LP ownership percentage in operating partnership	21.20%
Stock conversion ratio	1
Units redeemed for common stock	0.5
Qualitytech, LP
Quality Tech LP ownership percentage in operating partnership	11.50%

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Stock Split
-URI http://asc.fasb.org/extlink&oid=6525746

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