Organization (Details) ft² in Millions	6 Months Ended
	Jun. 30, 2020 ft² property $ / shares	Dec. 31, 2019 $ / shares
Operations [Line Items]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Number of properties (property) | property	296
Rentable square feet (sqft) | ft²	34.6
Occupancy rate	99.60%
Weighted average remaining lease term	8 years 10 months 24 days
United States
Operations [Line Items]
Entity-wide revenue percentage	65.00%
Europe
Operations [Line Items]
Percentage of portfolio investments	35.00%
7.25% Series A Cumulative Redeemable Preferred Stock, $0.01 par value
Operations [Line Items]
Stated interest rate	7.25%
Preferred stock, par value (in dollars per share)	$ 0.01
6.875% Series B Cumulative Redeemable Perpetual Preferred Stock, $0.01 par value
Operations [Line Items]
Stated interest rate	6.875%
Preferred stock, par value (in dollars per share)	$ 0.01