Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.19.1
Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]      
Percentage of dealership that is accounted for under the equity method 50.00%   50.00%
Contract work in process $ 4,600   $ 4,700
Effective tax rate from continuing operations 31.00% 47.80%  
Discrete charge for non-deductible executive compensation, transition costs $ 1,500    
Tax expense for uncertain tax positions 200 $ 200  
Discrete benefit related to vested or exercised stock compensation 200    
Discrete charge related to non-deductible asset impairment charge   900  
Income benefit $ (18,987) $ 1,842  
Minimum      
Schedule of Equity Method Investments [Line Items]      
Expected annual effective tax rate in future periods 26.00%    
Maximum      
Schedule of Equity Method Investments [Line Items]      
Expected annual effective tax rate in future periods 29.00%    
Dealership      
Schedule of Equity Method Investments [Line Items]      
Percentage of dealership that is accounted for under the equity method 50.00%    
ASU 2014-09 | Finance, insurance and other, net      
Schedule of Equity Method Investments [Line Items]      
Contract assets $ 4,800   $ 5,400