Deferred Revenue - Summary of Deferred Revenue (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 20,219	$ 12,123
Total current portion of deferred revenue	6,878	4,287
Total long-term portion of deferred revenue	13,341	7,836
Warranty [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	15,889	10,831
Total current portion of deferred revenue	4,900
EVIDENCE.com [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	4,026	1,292
Total current portion of deferred revenue	2,000
Other [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 304