Investments - Schedule of Information about Acquisition Activity (Parenthetical) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Property	Dec. 31, 2018 USD ($) Property
Investments [Abstract]
Ownership type	fee interest	fee interest
Number of properties in which fee interest acquired	279	203
Number of properties acquired subject to ground lease arrangement	2	1
Capitalized interest expense | $	$ 0.3	$ 0.2