Property Dispositions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) property	Mar. 31, 2016 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate investments	$ 1,749	$ 34,321
Net income attributable to shareholders	415	12,868
Revenues	196,131
Provision for impairment	$ 0	$ (866)
Wholly Owned Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	100.00%	100.00%
Parent Company [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate investments	$ 1,749	$ 32,261
Net income attributable to shareholders	415	12,868
Revenues	196,131	149,628
Operating expenses	200,451	95,876
Provision for impairment	$ 0	$ (1,666)
Operating Segments [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | property	0	3
Land [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | property	2	5