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Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2018
Income Taxes [Line Items]    
Operating losses carryforward indefinitely with no carryback as percentage of taxable income   80.00%
Interest expense threshold percentage of adjusted taxable income beyond which interest expense is deductible   30.00%
Refund of unused alternative minimum tax credit carryforwards $ 10.2  
Net operating loss limitation $ 3.3  
Period of increase in net operating loss limitation 5 years  
Net operating loss expiration period 20 years  
U.S. Federal    
Income Taxes [Line Items]    
Estimated NOL carryforwards to expire unused $ 844.6  
State Taxes    
Income Taxes [Line Items]    
Estimated NOL carryforwards to expire unused $ 1,400.0