Deferred Revenue - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	$ 6,878	$ 4,287
EVIDENCE.com [Member]
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	2,000
Warranty [Member]
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	$ 4,900