Annual report pursuant to Section 13 and 15(d)

Dividends (Parenthetical) (Detail)

v3.6.0.2
Dividends (Parenthetical) (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dividend Declared [Line Items]      
Effective Date of change in amount of quarterly dividend Feb. 24, 2016    
Revised quarterly dividend $ 0.27    
Dividends related to outstanding restricted stock units $ 554 $ 593 $ 530