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Fair Value of Financial Instruments - Narrative (Details) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Unrealized gains on equity securities $ 0 $ (852,000)  
Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Unrealized gains on equity securities (900,000)    
Fair value of equity securities $ 0   $ 0