Consolidated Statement of Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Cash distribution declared, per common share (in dollars per share)	$ 0.775	$ 0.72	$ 2.325	$ 2.16