Organization (Details) ft² in Millions	9 Months Ended
	Sep. 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	299
Rentable square feet (sqft) | ft²	34.7
Occupancy rate	99.60%
Weighted average remaining lease term	8 years 8 months 12 days
United States
Operations [Line Items]
Entity-wide revenue percentage	63.00%
Europe
Operations [Line Items]
Percentage of portfolio investments	37.00%
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