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Restricted Stock, Performance Share and Cash Awards - Additional Information (Detail)
 3 Months Ended 12 Months Ended
Mar. 16, 2017
USD ($)
shares
Mar. 17, 2016
USD ($)
shares
Mar. 31, 2017
USD ($)
Times
shares
Mar. 31, 2016
USD ($)
shares
Dec. 31, 2016
USD ($)
shares
Mar. 31, 2015
shares
Mar. 11, 2015
USD ($)
shares
Mar. 12, 2014
USD ($)
shares
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Share-based compensation, shares outstanding | shares     11,200,000   10,300,000      
Restricted Stock Units (RSUs) [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Share-based compensation, shares outstanding, Value     $ 2,000,000          
Share-based compensation, shares outstanding | shares     400,000          
Share based payment award vesting date     Mar. 16, 2021 Mar. 11, 2020        
Restricted stock or unit expense     $ 4,000,000 $ 4,000,000        
Restricted Stock Units (RSUs) [Member] | Minimum [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Period of service from grant date stock options awarded not subject to forfeiture     2 years 2 years        
Restricted Stock Units (RSUs) [Member] | Executive Officer [Member] | Minimum [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Minimum age of employee with not subject to award forfeiture on condition compliance     55 years 55 years        
Restricted Stock Plan [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Shares granted in the period | shares     477,500 466,600        
Fair value of grants in period     $ 26,800,000 $ 20,400,000        
Unvested Restricted Stock [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Total intrinsic value     90,400,000 62,900,000        
Equity awards with an aggregate fair value     $ 21,600,000 $ 14,200,000        
Performance Shares [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Shares authorized | shares 86,250 72,900            
Performance unit awards approved, Fair value $ 4,900,000 $ 3,200,000            
Provisional awards, terms     Granted units for the 2017 provisional awards will fully vest based on continuous employment through March 16, 2020 and will be settled in shares of our common stock on a one-for-one basis as soon as practicable thereafter.          
Performance period, years     1 year          
Vesting period, years     2 years          
Cash Awards [Member] | Officer and Key Employees [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Provisional awards, terms     The ultimate award value will be equal to the trailing twelve-month stock price on December 31, 2018, multiplied by the number of units subject to the award, but limited to between 0.5 and 1.5 times the original value of the units determined as of the grant date.          
Performance period, years     1 year          
Vesting period, years     2 years          
Provisional compensation cash awards approved for future grant by compensation committee, value $ 14,300,000 $ 17,400,000         $ 14,600,000 $ 10,800,000
Provisional compensation cash award approved for future grant by compensation committee, units | shares 255,000 397,000 383,000 294,000   220,000 315,000 229,000
Ultimate award value, multiples of original value of the units, minimum | Times     0.5          
Ultimate award value, multiples of original value of the units, maximum | Times     1.5          
2017 Provisional Cash Awards [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Cash-based compensation awards, expenses     $ 0          
2016 Provisional Cash Awards [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Cash-based compensation awards, expenses     2,600,000   $ 0      
2015 Provisional Cash Awards [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Cash-based compensation awards, expenses     $ 3,100,000 $ 1,600,000        
2014 Provisional Cash Awards [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Provisional compensation cash award approved for future grant by compensation committee, units | shares     200,000          
Cash-based compensation awards, expenses       $ 900,000        
Grants vested in period fair value     $ 9,300,000          
2013 Provisional Cash Awards [Member]                
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]                
Provisional compensation cash award approved for future grant by compensation committee, units | shares       200,000        
Grants vested in period fair value       $ 11,200,000