Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Additional Information (Detail)

v3.10.0.1
Stock Based Compensation - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option expense     $ 0 $ 4,000 $ 7,000 $ 11,000
Amortization of non-vested stock grants and performance-based awards     $ 1,456,000 $ 1,659,000 $ 4,203,000 $ 4,905,000
Stock options exercised by employees and directors         71,606 0
Number of shares of non-vested stock that vested     11,114 19,537 51,067 66,565
Chief Executive Officer, David Rogers [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Compensation expense     $ 200,000   $ 200,000  
Chief Executive Officer, David Rogers [Member] | Scenario, Forecast [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Compensation expense $ 400,000 $ 700,000        
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Shares of non-vested stock issued         14,865  
Aggregate fair value         $ 1,400,000  
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member] | Maximum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option plan, share based compensation, vesting period (in years)         8 years  
Fair market value of the non-vested stock on the date of grant         $ 94.08  
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member] | Minimum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option plan, share based compensation, vesting period (in years)         1 year  
Fair market value of the non-vested stock on the date of grant         $ 81.86  
Performance Shares [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option plan, share based compensation, vesting period (in years)         3 years  
Aggregate fair value         $ 300,000  
Performance Shares [Member] | Maximum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Shares granted under performance plan         7,732