Consolidated Statements of Beneficiaries' Equity (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Distributions declared per Common Share	$ 0.32	$ 0.31
Cumulative Distributions [Member]
Distributions declared per Common Share	0.32	0.31
Noncontrolling Interest [Member]
Distributions declared per Common Share	$ 0.32	$ 0.31