Fair Value Measurements on a Recurring Basis - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Detail) (Fair Value, Measurements, Recurring [Member], USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | $857 | $1,858 |
US government agencies [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | 1,400 |
Money market funds [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | 857 | 458 |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | 857 | 458 |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US government agencies [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | ' |
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Money market funds [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | 857 | 458 |
Significant Other Observable Inputs (Level 2) [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | 1,400 |
Significant Other Observable Inputs (Level 2) [Member] | US government agencies [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | 1,400 |
Significant Other Observable Inputs (Level 2) [Member] | Money market funds [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | ' |
Significant Unobservable Inputs (Level 3) [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | ' |
Significant Unobservable Inputs (Level 3) [Member] | US government agencies [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | ' |
Significant Unobservable Inputs (Level 3) [Member] | Money market funds [Member] | ' | ' |
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items] | ' | ' |
Financial assets | ' | ' |