Stock Based Compensation - Stock Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Based Compensation [Line Items]
Stock-based compensation expense	$ 1,145	$ 745	$ 243
Cost of Revenue [Member]
Stock Based Compensation [Line Items]
Stock-based compensation expense	49	71	4
Research and Development [Member]
Stock Based Compensation [Line Items]
Stock-based compensation expense	273	204	26
Selling, General and Administrative [Member]
Stock Based Compensation [Line Items]
Stock-based compensation expense	$ 823	$ 470	$ 213

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Name:	us-gaap_ShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration