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Fair Value of Financial Instruments - Additional Information (Details) - Level 3 - USD ($)
Mar. 31, 2019
Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets Measured at fair value on recurring basis $ 0 $ 0
Liabilities measured at fair value on recurring basis $ 0 $ 0