Summary of Significant Accounting Policies - Narrative (Details)	1 Months Ended	3 Months Ended		12 Months Ended
	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) property
Property, Plant and Equipment [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax				$ 8,857,000	$ 0	$ 0
Percentage of investments in subsidiaries				100.00%
Loss on asset impairment		$ 167,100,000	$ 22,700,000	$ 17,162,000	185,067,000	124,253,000
Loss on asset impairment in discontinuing operations						$ 79,800,000
Number of properties impaired | property						39
Number of buildings impaired | property						93
Losses on asset impairment for properties sold						$ 23,100,000
Accrued environmental remediation costs		500,000			$ 500,000
Minimum percentage of likelihood of realization of tax benefits					50.00%
Foreign currency translation adjustments		$ (48,900,000)		0	$ (48,900,000)
Total amounts reclassified				$ (65,051,000)
Maximum
Property, Plant and Equipment [Line Items]
Maximum percentage of investment accounted for under equity method of accounting				50.00%
Maximum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Maximum estimated useful life				40 years
Maximum | Personal property
Property, Plant and Equipment [Line Items]
Maximum estimated useful life				12 years
Foreign Currency Translation Adjustments
Property, Plant and Equipment [Line Items]
Total amounts reclassified				$ (63,207,000)
Foreign Currency Translation Adjustments | Australia Portfolio
Property, Plant and Equipment [Line Items]
Total amounts reclassified	$ 63,200,000