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Fair Value Measurements - Additional Information (Details) $ in Thousands | Sep. 30, 2021 USD ($) MutualFund shares | Dec. 31, 2020 USD ($) MutualFund
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Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Number of mutual fund investment | MutualFund | 2 | 2
Warrant | 2,065,000 |
IronNet [Member] | Common Stock [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Restricted shares | 1,300,000 |
IronNet [Member] | Common Stock [Member] | Level 2 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Restricted shares | 1,250,000 |
IronNet [Member] | PIPE Related Common Shares [Member] | Level 1 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Non-restricted shares | 272,529 |
Non-Recurring [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Other liabilities, fair value disclosure, non-recurring | $ | $ 0 | $ 0

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