Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Cost Components of Supplemental Executive Retirement Plan (Detail)

v3.6.0.2
Employee Benefit Plans - Cost Components of Supplemental Executive Retirement Plan (Detail) - Supplemental Employee Retirement Plans, Defined Benefit [Member] - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]    
Service cost $ 1,590 $ 1,950
Interest cost 383 307
Net pension expense (benefit) $ 1,973 $ 2,257