Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Supplemental Disclosures:
Cash paid for interest	$ 200,617	$ 246,602
Cash paid for income taxes	10,690	18,822
Non-cash investing and financing activities:
Accrued capital expenditures and real estate developments	6,750	3,556
Accrued deferred financing costs	181	860
Distributions declared and unpaid	146,596	146,118
Accrued equity issuance costs	0	9
Mortgage note payable relieved by foreclosure or a deed-in-lieu of foreclosure	100,388	38,050
Mortgage notes payable assumed in real estate disposition	66,000	55,000
Nonmonetary Exchanges:
Intangible lease liability received	(151)	0
Real estate investments received	50,204	0
Real estate investments relinquished and gain on disposition	(47,474)	0
Rent and tenant receivables and other assets, net relinquished	(2,602)	0
Intangible lease liability relinquished	242	0
Real estate investments received from a ground lease expiration	$ 259	$ 0