Supplemental Cash Flow Information (Summary of Non-Cash Transactions) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Accrued property construction costs	$ 13,590	$ 28,604
Accrued dividends payable	23,066
Right-of-use assets exchanged for operating lease liabilities	468	43,729
Increase in debt, net associated with the acquisition of real estate and land	17,952
Increase in other assets, net associated with the disposition of real estate and land	$ 9,930	$ 0