Restructuring and Severance Costs (Detail) - Lease Termination Restructuring Accrual (Facility Closing [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	$ 1,277	$ 484
Provision for additional expense	406	1,525
Payments and adjustments	(1,475)	(732)
Balance at end of period	$ 208	$ 1,277