Fair Value Measurements - Fair Value Measurements (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets:
Restricted cash	$ 50	$ 53
Short-term investments	3,000
Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents	9,500
Restricted cash	50	53
Short-term investments	3,000
Total assets measured and recorded at fair value	12,550	53
Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents
Restricted cash
Short-term investments
Total assets measured and recorded at fair value
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents	9,500
Restricted cash	50	53
Short-term investments	3,000
Total assets measured and recorded at fair value	12,550	53
Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents
Restricted cash
Short-term investments
Total assets measured and recorded at fair value