Pension Plans and Defined Contribution Plan - Schedule of Change in Plan Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 145,563
Benefits paid	(6,937)	(3,622)
Fair value of plan assets at end of year	162,250	145,563
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	145,563	120,295
Actual return on plan assets	10,624	15,883
Company contributions	13,000	13,007
Benefits paid	(6,937)	(3,622)
Fair value of plan assets at end of year	$ 162,250	$ 145,563