Fair Value Measurements and Marketable Securities - Marketable Securities with Unrealized Losses (Detail) (USD $)
In Thousands, unless otherwise specified |
Sep. 30, 2013
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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]
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|
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]
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|
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) |