Short-Term Investments - Available-for-Sale Securities Recorded at Fair Value with Unrealized Gains or Losses (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	$ 1,220	$ 3,079
Gross unrealized gain (loss)	0	(1)
Fair value	1,220	3,078
Corporate notes, bonds and paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	500	919
Gross unrealized gain (loss)	0	(1)
Fair value	500	918
Government securities/money market [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	720	2,160
Gross unrealized gain (loss)	0
Fair value	$ 720	$ 2,160