XML 45 R32.htm IDEA: XBRL DOCUMENT v3.7.0.1
Short-Term Borrowings - Additional Information (Detail) - USD ($)
9 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Oct. 31, 2015
Line Of Credit Facility [Line Items]      
Additional borrowings $ 49,400,000    
Long-term debt $ 0    
Minimum [Member]      
Line Of Credit Facility [Line Items]      
Current ratio 1.20%    
Borrowing Base Amount and Aging Inventory [Member]      
Line Of Credit Facility [Line Items]      
Inventory and working capital needs $ 241,600,000    
Interest rate on short-term borrowings 4.50% 3.90%  
Amended Credit Facility [Member]      
Line Of Credit Facility [Line Items]      
Additional extension for two one-year periods Oct. 31, 2020    
Interest rate for amounts outstanding under the Amended Credit Facility 3.45%    
Amended Credit Facility [Member] | Borrowing Base Amount and Aging Inventory [Member]      
Line Of Credit Facility [Line Items]      
Amount of borrowing availability   $ 350,000,000 $ 300,000,000
Line of Credit Facility, Description The May 2017 amendment and restatement extended the maturity date of the Credit Facility to October 2020, and the Amended Credit Facility includes two additional one-year extension periods, with lender approval.    
Leverage ratio 2.75%    
Credit Facility interest rate description The interest rate for amounts outstanding under the Amended Credit Facility is 345 basis points above the one-month London Inter-Bank Offering Rate (“LIBOR”).    
Debt instrument, covenant compliance The covenants include provisions that our leverage ratio must not exceed 2.75 to 1.0 and that our current ratio must be greater than 1.2 to 1.0.    
Unused line fee on the unused portion of the amended Credit Facility 0.10%    
Advances on new inventory mature date 1080 days    
Advances on used inventory maturity period 361 days    
Advance is subject to a curtailment schedule, periodic basis 6 months    
Real estate property pledged for collateral $ 0