XML 92 R77.htm IDEA: XBRL DOCUMENT v3.20.4
Stockholders' Equity - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 12 Months Ended
May 31, 2018
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Preferred stock, shares authorized           500,000 500,000    
Preferred stock, par value           $ 0.01 $ 0.01    
Authorized to purchase of common stock under the stock repurchase program           $ 535,000,000.0      
Cumulative repurchase of common stock           16,300,000      
Aggregate cost of repurchase of common stock           $ 474,900,000      
Dividend declared and paid per share   $ 0.20 $ 0.20 $ 0.20 $ 0.20        
Dividend declared per share               $ 0.80  
Aggregate dividend declared for the year               $ 14,500,000  
Option Outstanding and vested           292,000 436,000    
Common stock, par value           $ 0.01 $ 0.01    
Employee Stock Purchase Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Shares authorized 1,100,000                
Future awards granted or issued under plans 300,000                
Increase in number of shares issuable under plan 400,000                
Common stock, par value $ 0.01                
Hours of work per week 20 hours                
Duration of purchase periods under employee stock purchase plan 6 months                
Holding period of stocks acquired under employee stock purchase plan 1 year                
Value used to derive maximum number of shares per participant for employee stock purchase $ 12,500                
Employee maximum elected percentage reduction of compensation to purchase shares 10.00%                
Exercise price rate of fair value 85.00%                
Restricted Stock Units (RSUs) [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Weighted average grant date fair value for RSUs granted           $ 35.15 $ 43.84 $ 43.71  
Number of shares received per restricted stock unit on lapse of restrictions and vesting condition met           1      
Value of RSUs vested and converted to common stock           $ 10,000,000.0 $ 8,200,000 $ 9,100,000  
Stock Options [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Intrinsic value of options exercised           $ 500,000 $ 1,500,000 $ 3,300,000  
Equity Incentive Plan [Member] | Equity Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Shares authorized                 6,350,000
Shares returned                 793,275
Option expiration period           10 years      
Future awards granted or issued under plans           1,900,000      
Option Outstanding and vested           8,000      
Equity Incentive Plan [Member] | Equity Plan [Member] | Restricted Stock Units (RSUs) [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Options vested period           4 years      
Equity Incentive Plan [Member] | Equity Plan [Member] | Non-Employee Directors [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Future awards granted or issued under plans           0      
Equity Incentive Plan [Member] | Equity Plan [Member] | Non-Employee Directors [Member] | Restricted Stock Units (RSUs) [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Options vested period           1 year