Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share of Common Stock - Additional Information (Detail)

v3.8.0.1
Earnings Per Share of Common Stock - Additional Information (Detail) - shares
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Earnings Per Share [Abstract]        
Weighted average number of operating partnership units held by noncontrolling limited partners (in shares) 1,444,435 854,116 1,447,633 613,446