Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Additional Information (Detail)

v3.3.1.900
Stock-based Compensation - Additional Information (Detail)
$ in Millions
1 Months Ended 11 Months Ended 12 Months Ended
Aug. 24, 2011
Employee
shares
Jan. 31, 2014
Dec. 31, 2014
shares
Dec. 31, 2015
USD ($)
shares
Dec. 31, 2014
USD ($)
shares
Dec. 31, 2013
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Compensation expense       $ 38.1 $ 37.1 $ 29.7
Tax benefit related to stock-based compensation expense       14.4 14.0 11.2
Unrecognized compensation cost       $ 45.6    
Unrecognized non-vested stock awards recognition period       1 year 8 months 12 days    
Cash proceeds from stock-based compensation arrangements       $ 12.1 9.9 10.6
Aggregate intrinsic value of stock options       $ 5.0 $ 8.5 23.3
Stock Option            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years)   3 years 9 months 3 years      
Vesting percentage   75.00%        
Expiration period from grant date (in years)       10 years    
Percentage of stock options to be vested during remaining period   25.00%        
Market Based Restricted Stock | Minimum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Requisite service period (in months)       15 months 24 months  
Market Based Restricted Stock | Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Requisite service period (in months)       33 months 30 months  
Time Based Restricted Stock            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years)   4 years 3 years      
Aggregate grant date fair value       $ 21.5 $ 23.3 $ 15.2
Common Stock            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options granted (in shares) | shares     22,580,741 25,634,259 22,580,741  
Vested Quarterly Over One Year | Market Based Restricted Stock            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years)       1 year    
Multifamily Technology Solutions, Inc [Member] | Stock Option            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options granted (in shares) | shares 349,693          
Number of Employees | Employee 96          
Stock options vesting period (in years) 10 years          
Multifamily Technology Solutions, Inc [Member] | Vesting period 1 | Stock Option            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years) 4 years          
Vesting percentage 25.00%          
Multifamily Technology Solutions, Inc [Member] | Vesting period 2 | Stock Option            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years) 1 year          
Vesting percentage 20.00%          
Multifamily Technology Solutions, Inc [Member] | Vesting period 3 | Stock Option            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock options vesting period (in years) 4 years