v2.4.0.8

Fair Value Measurements of Financial Assets (Detail) (Short Term Investments and Cash Equivalents, USD $) In Thousands, unless otherwise specified | Dec. 31, 2013 | Dec. 31, 2012
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash equivalents - Overnight Investments | $ 1,623 | $ 1,283
Fair Value, Inputs, Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash equivalents - Overnight Investments | $ 1,623 | $ 1,283

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- Definition Cash Cash Equivalents And Investments Fair Value Disclosure + References No definition available. + Details
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Namespace Prefix: | crv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
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