Acquisitions (Details) $ in Millions	Apr. 12, 2019 USD ($) ft² a	Apr. 20, 2018 USD ($) ft²	Jan. 29, 2018 USD ($) ft² a	Aug. 29, 2017 USD ($) ft² a
Acquisitions
Net rentable space	200,000
SV8 Santa Clara CA
Acquisitions
Purchase price | $				$ 12.2
Area of land acquired | a				2
Net rentable space				162,000
Net Leased Space				108,000
SV9 Santa Clara CA
Acquisitions
Purchase price | $	$ 26.0
Area of land acquired | a	3.8
CH2 Chicago IL
Acquisitions
Purchase price | $			$ 4.5
Area of land acquired | a			2
Net rentable space			169,000
US Colo Los Angeles California
Acquisitions
Purchase price | $		$ 6.3
L A1 Facility Los Angeles CA
Acquisitions
Net Leased Space		6,723
LA4 Los Angeles CA
Acquisitions
Net Leased Space		21,850