Annual report pursuant to Section 13 and 15(d)

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail)

v3.3.1.900
Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
USD ($)
Dealerships
State
Brand
Collision
Store
Franchise
Segment
Dec. 31, 2014
USD ($)
Dec. 31, 2013
USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Number of dealerships | Dealerships 114    
Number of states | State 13    
Number of different brands of cars and light trucks | Brand 25    
Number of collision repair centers | Collision 18    
Book overdraft position $ 38,500 $ 37,100  
Revenue allowances for commission reserves 17,000 15,400  
Amount recognized for continue operation $ 42,100 39,700 $ 37,900
Term for funding of finance contracts 10 days    
Contracts in transit included in receivables, net $ 196,300 194,000  
Number of reporting units | Franchise 2    
Goodwill $ 471,493 475,929 476,315
Insurance reserves 24,900 23,900  
Concentrations of credit risk with respect to receivables are limited primarily to automobile manufacturers 90,300 90,100  
Deposits 74,000 57,500  
Reduction in interest expense 1,500 2,100 1,000
Advertising expense 61,600 57,400 56,600
Cooperative manufacturer credits advertising expenses $ 24,200 23,400 21,800
Number of reportable Segment | Segment 2    
Financial Institutions [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Concentrations of credit risk with respect to receivables are limited primarily to financial institutions $ 221,600 215,400  
Franchise Assets [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Franchise asset impairment charge 3,300 2,200  
Continuing Operations [Member] | Franchise Assets [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Franchise asset impairment charge 900 $ 2,200 $ 600
Discontinued Operations [Member] | Franchise Assets [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Franchise asset impairment charge $ 2,400    
Dealership [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Percentage of dealership that is accounted for under the equity method 50.00%    
Franchised Dealerships [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Number of stores | Store 96    
Echo Park [Member]      
Description Of Business And Summary Of Significant Accounting Policies [Line Items]      
Number of stores | Store 3