Multiple Element Arrangements - Summary of Deferred Revenue (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
PPL [Member] \| Selling Price Method [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred revenue	$ 1,188	$ 1,110
COBRA [Member] \| Fair Market Value Method [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred revenue	$ 207	$ 297

For arrangements that precede the adoption of the amending guidance, the amount of deferred revenue at the end of the reporting period under the amended guidance.

No definition available.

Name:	us-gaap_RevenueRecognitionNewAccountingPronouncementMaterialEffectRevenueDeferredUnderAmendedGuidance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant