XML 79 R62.htm IDEA: XBRL DOCUMENT v3.6.0.2
Income Taxes (Detail)
$ in Millions
12 Months Ended
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
States
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Income Tax Disclosure [Line Items]        
Income tax receivable   $ 1.3 $ 0.5  
Valuation Allowance   0.4 0.3  
Net change in total valuation allowance   0.1 (0.3)  
Uncertain tax benefits accrued   4.1 4.7 $ 4.0
Interest and penalties recognized related to uncertain income tax positions   (0.1) 0.2  
Interest and penalties accrued related to uncertain income tax positions   $ 0.1 0.2  
Number of individual states subject to income taxes | States   50    
Unrecognized Tax Benefits Period Increase Decrease $ (0.3)      
Net Operating Loss [Member]        
Income Tax Disclosure [Line Items]        
Uncertain tax benefits accrued   $ 3.1 3.1  
Tax Credit Carryforward [Member]        
Income Tax Disclosure [Line Items]        
Uncertain tax benefits accrued   0.7 $ 0.7  
Research And Development Tax Credit [Member]        
Income Tax Disclosure [Line Items]        
Tax credits   1.9    
Employment Tax Credit [Member]        
Income Tax Disclosure [Line Items]        
Tax credits   0.2    
Alternative Minimum Tax Credit [Member]        
Income Tax Disclosure [Line Items]        
Tax credits   1.4    
State Tax Credit [Member]        
Income Tax Disclosure [Line Items]        
Tax credits   3.1    
Other Long Term Obligations [Member]        
Income Tax Disclosure [Line Items]        
Uncertain tax benefits accrued   0.3    
Deferred Income Taxes [Member]        
Income Tax Disclosure [Line Items]        
Uncertain tax benefits accrued   $ 3.8    
Minimum [Member]        
Income Tax Disclosure [Line Items]        
Tax years open to examination   2001    
Maximum [Member]        
Income Tax Disclosure [Line Items]        
Tax years open to examination   2016    
State and Local Jurisdiction [Member] | Net Operating Loss [Member]        
Income Tax Disclosure [Line Items]        
Net operating loss carryforwards   $ 268.4    
Federal [Member]        
Income Tax Disclosure [Line Items]        
Net operating loss carryforwards   $ 102.1