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Employee Benefit Plans - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Maximum defer of compensation subject to statutory limitations, percentage 70.00%    
Percentage of employer matching contributions condition, one 100.00%    
Percentage of employee entitled to employer matching contribution condition, one 3.00%    
Percentage of employer matching contributions condition, two 50.00%    
Percentage of employee entitled to employer matching contribution condition, two 2.00%    
Defined contribution plan, employer discretionary contribution amount $ 18,100,000 $ 17,300,000 $ 16,200,000
Deferred compensation arrangement with individual, cash awards granted, percentage 80.00%    
Deferred compensation on performance bonuses that eligible employee, percentage 100.00%    
Defined contribution plan, employers matching contribution, annual vesting percentage 100.00%    
Employee stock purchase plan shares authorized 1,000,000    
Employee stock purchase plan annual maximum payroll deduction $ 25,000    
Share-based compensation arrangement by share-based payment award, discount from market price, purchase date 5.00%    
Stock issued during period, shares, employee stock purchase plans 31,744 23,636  
Stock issued during period, value, employee stock purchase plans, per share $ 64.77 $ 78.05  
Employee stock purchase plan, number of shares available for grant 647,126 678,870