Employee Benefit Plans - Plan Assets and Projected Benefit Obligations Recognized in Other Comprehensive (Income) Loss (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Net actuarial (gain) loss	$ 1,760	$ (17,566)	$ (621)
Amortization of net actuarial loss	0	(2,037)	(2,718)
Prior service cost (credit)	0	0	0
Amortization of prior service cost (credit)	1,555	1,555	1,555
Settlement	(137)	(42)	(792)
Other comprehensive (income) loss	3,178	(18,090)	(2,576)
Total recognized in net periodic pension benefit (income) and other comprehensive (income) loss	$ (1,411)	$ (20,154)	$ (2,790)