Quarterly report pursuant to Section 13 or 15(d)

Computations of Basic and Diluted Earnings Per Share (Parenthetical) (Detail)

v3.8.0.1
Computations of Basic and Diluted Earnings Per Share (Parenthetical) (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 shares of participating unvested restricted stock 643 596 581 526