2013 Restructuring - Schedule of Costs in Results of Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Costs charged to expense	$ 46	$ 515
Cost of revenue-service [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense		163
Selling, general and administrative [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense	14	221
Research and development [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense	$ 32	$ 131