Employee Benefits (Detail) - Benefit Plans and Related Amounts Recorded in Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Projected benefit obligation	$ 38,400	$ 35,870	$ 38,115	$ 34,585
Pension plan assets at fair value	(14,465)	(13,190)	(13,220)
Funded status – shortfall	23,935	22,680	24,895
Amounts recorded in the Consolidated Balance Sheets for the plans:
Other liabilities — accrued pension obligation	23,935	22,680	24,895
Stockholders’ equity — deferred actuarial loss	$ (5,797)	$ (4,832)	$ (6,028)