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Commitments and Contingencies - Additional Information (Detail) - USD ($)
12 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]    
Letters of credit outstanding, amount $ 6,500,000 $ 6,500,000
Contingently liable for performance, current 31,000,000.0  
Outstanding guarantees $ 0  
Percentage of expected natural gas usage 25.00%