Pension Plans and Defined Contribution Plan - Schedule of Components of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefit earned during the period	$ 1,479	$ 962
Interest cost on projected benefit obligation	8,379	8,417
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefit earned during the period	1,479	962	769
Interest cost on projected benefit obligation	8,379	8,417	8,482
Expected return on plan assets	(11,338)	(10,005)	(9,715)
Amortization of prior service cost	192	176	135
Amortization of actuarial loss	5,741	6,194	1,940
Net periodic pension cost	$ 4,453	$ 5,744	$ 1,611