|
Fair Value Measurements and Marketable Securities - Marketable Securities with Unrealized Losses (Detail) (USD $)
In Thousands, unless otherwise specified |
Sep. 30, 2013
|
|---|---|
| Schedule of Available-for-sale Securities [Line Items] | |
| Marketable securities, In loss position for less than twelve months, Fair Value | $ 20,437 |
| Marketable securities, In loss position for less than twelve months, Unrealized Loss | (6) |
|
U.S. Government securities [Member]
|
|
| Schedule of Available-for-sale Securities [Line Items] | |
| Marketable securities, In loss position for less than twelve months, Fair Value | 3,002 |
| Marketable securities, In loss position for less than twelve months, Unrealized Loss | (1) |
|
Corporate debt securities [Member]
|
|
| Schedule of Available-for-sale Securities [Line Items] | |
| Marketable securities, In loss position for less than twelve months, Fair Value | 17,435 |
| Marketable securities, In loss position for less than twelve months, Unrealized Loss | $ (5) |