Consolidated Statements of Beneficiaries' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Distributions declared per Common Share	$ 0.48	$ 0.47
Cumulative Distributions [Member]
Distributions declared per Common Share	0.48	0.47
Noncontrolling Interest [Member]
Distributions declared per Common Share	$ 0.48	$ 0.47