Consolidated Statements of Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Issuance of shares, offering costs	$ 75	$ 2,042	$ 7,062
Common shares, dividend declared per share (in dollars per share)	$ 1.30	$ 1.28	$ 0.93
LTIP units, distributions per unit (in dollars per share)	$ 1.30	$ 1.28	$ 0.93