Deferred Revenue - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	$ 7,414	$ 6,878
EVIDENCE.com [Member]
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	2,100
Warranty [Member]
Deferred Revenue Arrangement [Line Items]
Total current portion of deferred revenue	$ 5,300