Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental disclosures:
Cash paid for interest	$ 67,588	$ 72,298
Cash paid for income taxes	384	843
Non-cash investing and financing activities:
Unsettled share issuances	6,650	0
Accrued capital expenditures, tenant improvements and real estate developments	10,903	1,716
Distributions declared and unpaid	$ 139,764	$ 139,405