Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Additional Information (Detail)

v3.21.2
Stock Based Compensation - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Amortization of non-vested stock grants and performance-based awards     $ 2,920,000,000 $ 2,273,000,000
Stock options exercised by employees and directors 0 0 0 0
Number of shares of non-vested stock that vested 20,043 15,351 29,350 26,096
Performance Shares [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Amortization of non-vested stock grants and performance-based awards $ 1,464,000,000 $ 1,149,000,000    
Stock option plan, share based compensation, vesting period (in years)     3 years  
Aggregate fair value     $ 800  
Shares granted under performance plan     19,500  
Employees and Directors [Member] | Non-Vested Shares [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares of non-vested stock issued     35,666  
Aggregate fair value     $ 3,500,000  
Employees and Directors [Member] | Non-Vested Shares [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  
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value     $ 84.06  
Employees and Directors [Member] | Non-Vested Shares [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock option plan, share based compensation, vesting period (in years)     5 years  
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value     $ 100.57