CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Stockholders Equity [Abstract]
Dividends and distributions, Per share and unit	$ 0.380	$ 0.380	$ 0.419	[1]

[1] Includes the $0.039 cash dividend for the 38 day period following the completion of our initial public offering and related Formation Transactions and ending on December 31, 2014.