CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Dividends and distributions declared, per share | $ / shares	$ 1.00
Class A Common Shares [Member]
Dividends and distributions declared, per share | $ / shares	$ 1.00
Share class exchanges, common shares	2,603,554
OP Unit exchanges, shares	3,958,182
Class B Common Shares [Member]
Share class surrenders, shares	260,154