XML 81 R68.htm IDEA: XBRL DOCUMENT v3.10.0.1
Long-Term Debt and Financing Arrangements - Additional Information (Detail)
12 Months Ended
Jul. 01, 2017
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2011
Chassis
Line Of Credit Facility [Line Items]          
Number of chassis leased | Chassis         3,126
Chassis, lease agreement period (years)         10 years
Capital lease interest paid   $ 400,000 $ 500,000 $ 600,000  
Letter of Credit [Member]          
Line Of Credit Facility [Line Items]          
Commitment fee on unused commitments 2.00%        
Standby Letters of Credit [Member]          
Line Of Credit Facility [Line Items]          
Letters of credit expiration, year   2019      
Outstanding letters of credit   $ 27,000,000.0      
Revolving Line of Credit Facility [Member]          
Line Of Credit Facility [Line Items]          
Borrowings under bank revolving line of credit     45,000,000    
Revolving Line of Credit Facility [Member] | Bank Revolving Line of Credit [Member]          
Line Of Credit Facility [Line Items]          
Borrowings under bank revolving line of credit   0      
Unused and available borrowings under bank revolving line of credit and credit agreement   $ 323,000,000.0 $ 284,900,000    
Credit Agreement [Member]          
Line Of Credit Facility [Line Items]          
Amount of credit agreement $ 350,000,000        
Credit agreement interest rate description   (i) LIBOR plus a specified margin based upon the Borrowers' total net leverage ratio (as defined in the Credit Agreement) (the "Total Net Leverage Ratio"), or (ii) the base rate (which is the highest of (a) the administrative agent's prime rate, (b) the federal funds rate plus 0.50% or (c) the sum of 1% plus one-month LIBOR) plus a specified margin based upon the Total Net Leverage Ratio.      
Commitment fee on unused commitments 0.25%        
Credit Agreement [Member] | Federal Funds Rate [Member]          
Line Of Credit Facility [Line Items]          
Interest rate under the credit agreement 0.50%        
Credit Agreement [Member] | LIBOR rate [Member]          
Line Of Credit Facility [Line Items]          
Interest rate under the credit agreement 1.00%        
Description of variable rate basis one-month LIBOR        
Credit Agreement [Member] | Eurodollar          
Line Of Credit Facility [Line Items]          
Interest rate under the credit agreement 2.00%        
Credit Agreement [Member] | Base Rate          
Line Of Credit Facility [Line Items]          
Interest rate under the credit agreement 1.00%