Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.20.4
Income Taxes - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Operating Loss Carryforwards [Line Items]      
Unrecognized tax benefits that would affect our effective tax rate if recognized $ 0 $ 73,000 $ 202,000
Decrease in unrecognized tax benefits due to state taxes 73,000 129,000  
Decrease in unrecognized tax benefits due to lapse of statute of limitations 0 0 837,000
Valuation allowance 4,352,000 $ 4,852,000 $ 4,852,000
Federal and state income tax $ 214,800,000    
CARES Act      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryback period 5 years    
Federal      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryforwards $ 14,800,000    
Federal | California      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryforwards 152,300,000    
Federal | Illinois      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryforwards 62,500,000    
State      
Operating Loss Carryforwards [Line Items]      
Low income housing tax credit $ 0