Segment Reporting Segment Reporting (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting [Abstract]
Rental income from real estate assets sold or held for sale	$ 44,951	$ 73,168	$ 175,915
Operating expenses from real estate assets sold or held for sale	(16,539)	(27,814)	(62,841)
Net operating income from real estate assets sold or held for sale	$ 28,412	$ 45,354	$ 113,074