XML 54 R71.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Income Tax Contingency [Line Items]    
Increase (Decrease) in valuation allowance due to state net operating loss and tax credit carryforwards $ 1.0  
State net operating loss carryforwards 39.4  
State tax credit carryforwards 1.3  
Unrecognized tax benefits that would impact effective tax rate 1.6  
Reductions in the liability for unrecognized tax benefits due to expiration of statues of limitation 1.5  
Liability for interest expense 0.7 $ 0.7
Liability for penalties 0.2 0.2
Maximum [Member]    
Income Tax Contingency [Line Items]    
Accrued interest expense $ 0.1 $ 0.1
Earliest Tax Year [Member] | State [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards expiration period 2020  
Net operating loss carryforwards expiration period 2020  
Latest Tax Year [Member] | State [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards expiration period 2039  
Net operating loss carryforwards expiration period 2029