Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Operating properties, accumulated depreciation	$ 577,139	$ 421,495
Real estate assets and other assets held for sale, accumulated depreciation	61,093
Intangible liabilities, accumulated amortization	55,798	$ 42,473
Liabilities of real estate assets held for sale, net of accumulated amortization	$ 7,771
Preferred stock, par value (in usd per share)	$ 1	$ 1
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	1,716,837	1,716,837
Preferred stock, shares outstanding	1,716,837	1,716,837
Common stock, par value (in usd per share)	$ 1	$ 1
Common stock, shares authorized	300,000,000	175,000,000
Common stock, shares issued	149,347,382	107,681,130
Treasury stock, shares	2,584,933	2,584,933