Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Swaps (Details)

v3.19.1
Long-Term Debt - Swaps (Details)
$ in Thousands
Feb. 20, 2015
USD ($)
contract
Mar. 31, 2019
USD ($)
item
Dec. 31, 2018
USD ($)
Sep. 30, 2018
Derivative [Line Items]        
Number of interest rate swap agreements | contract 3      
Inventories - truck chassis floor plan   $ 7,382 $ 4,204  
Interest rate swap        
Derivative [Line Items]        
Negative fair value   $ 3,484 2,031  
Number of financial institutions for which the entity is exposed to counterparty credit risk | item   1    
Interest rate swap | Accrued Expenses and Other Current Liabilities        
Derivative [Line Items]        
Negative fair value   $ 379 127  
Interest rate swap | Other Noncurrent Liabilities        
Derivative [Line Items]        
Negative fair value   $ 3,105 $ 1,904  
Interest Rate Swap Effective 31 December 2015 through 29 March 2018        
Derivative [Line Items]        
Notional amount $ 45,000      
Interest rate   1.86%    
Interest Rate Swap Effective 31 December 2015 through 29 March 2018 | London Interbank Offered Rate (LIBOR)        
Derivative [Line Items]        
LIBOR floor (as a percent)   1.00%    
Interest Rate Swap Effective 29 March 2018 through 31 March 2020        
Derivative [Line Items]        
Notional amount 90,000      
Interest rate   2.67%    
LIBOR floor (as a percent)   1.00%    
Interest Rate Swap Effective 29 March 2018 through 31 March 2020 | London Interbank Offered Rate (LIBOR)        
Derivative [Line Items]        
LIBOR floor (as a percent)       1.00%
Interest Rate Swap Effective 31 March 2020 through 30 June 2021        
Derivative [Line Items]        
Notional amount $ 135,000      
Interest rate   2.918%    
Interest Rate Swap Effective 31 March 2020 through 30 June 2021 | London Interbank Offered Rate (LIBOR)        
Derivative [Line Items]        
LIBOR floor (as a percent)   1.00%    
Interest rate swap effective December 31, 2018 through June 30, 2021        
Derivative [Line Items]        
Notional amount   $ 50    
Interest rate   2.613%    
Interest rate swap effective June 30, 2021 through December 10, 2021        
Derivative [Line Items]        
Notional amount   $ 150    
Interest rate swap effective June 30, 2021 through December 10, 2021 | Maximum        
Derivative [Line Items]        
Interest rate   2.793%