Short-Term Investments - Available-for-Sale Securities Recorded at Fair Value with Unrealized Gains or Losses (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	$ 2,626	$ 3,079
Gross unrealized gain (loss)	(1)	(1)
Fair value	2,625	3,078
Corporate notes, bonds and paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	1,906	919
Gross unrealized gain (loss)	(1)	(1)
Fair value	1,905	918
Government securities/money market [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost basis	720	2,160
Gross unrealized gain (loss)
Fair value	$ 720	$ 2,160