Selected Quarterly Financial Data (unaudited) - Narrative (Details) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2019 USD ($) Property	Dec. 31, 2018 USD ($) Property	Jun. 30, 2018 USD ($) Property	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Quarterly Financial Information Disclosure [Abstract]
Gain on sales of real estate assets | $	$ 20,000	$ 10,800	$ 27,700	$ 25,101	$ 41,665	$ 39,524
Number of properties sold | Property	6	3	12