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Share-based Compensation (Additional Information) (Details)
$ / shares in Units, fungible_unit in Millions
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Aug. 31, 2014
shares
Jun. 30, 2017
USD ($)
unit / shares
fungible_unit
unit
shares
Jun. 30, 2016
USD ($)
Jun. 30, 2017
USD ($)
unit / shares
fungible_unit
unit
$ / shares
shares
Jun. 30, 2016
USD ($)
shares
Dec. 31, 2016
USD ($)
shares
Dec. 31, 2015
shares
Jan. 01, 2008
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options   $ 2,000,000 $ 1,400,000 $ 3,600,000 $ 2,900,000      
Stock options                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Period of commencement of option vesting, from date of grant (in years)       1 year        
Exercise price of options granted, low end of the range (in dollars per share) | $ / shares       $ 20.67        
Exercise price of options granted, high end of the range (in dollars per share) | $ / shares       $ 128.82        
Remaining weighted average contractual life of the options outstanding (in years)       3 years 9 months        
Remaining average contractual life of the options exercisable (in years)       3 years 1 month        
Total unrecognized compensation cost related to unvested stock awards   12,500,000   $ 12,500,000        
Weighted average period for recognition of compensation cost related to unvested stock awards (in years)       1 year 11 months        
Weighted average fair value of options granted during the period       $ 3,733,043   $ 8,363,036    
Stock options | Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Award expiration period (in years)       5 years        
Options vesting period (in years)       1 year        
Stock options | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Award expiration period (in years)       10 years        
Options vesting period (in years)       5 years        
Restricted Stock Awards                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Compensation expense       $ 4,854,350 7,153,966      
Total unrecognized compensation cost related to unvested stock awards   $ 16,100,000   $ 16,100,000        
Weighted average period for recognition of compensation cost related to unvested stock awards (in years)       1 year 11 months        
Annual award vesting rate, low end of range (as a percent)       15.00%        
Annual award vesting rate, high end of range (as a percent)       35.00%        
Fair value of restricted stock vested during the period       $ 8,100,000   $ 7,600,000    
Weighted average fair value of options granted during the period       $ 30,813 $ 10,650,077      
Awards granted (in shares) | shares       300 98,800      
Awards outstanding (in shares) | shares   3,202,331   3,202,331   3,202,031 3,137,881  
LTIP units                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Weighted average fair value of options granted during the period       $ 20,500,000   $ 25,400,000    
Performance Shares                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Total unrecognized compensation cost related to unvested stock awards   $ 9,500,000   $ 9,500,000        
Weighted average period for recognition of compensation cost related to unvested stock awards (in years)       1 year 2 months        
Share-based compensation   $ 2,600,000 3,300,000 $ 12,600,000 $ 12,800,000      
Third Amendment and Restated 2005 Stock Option and Incentive Plan                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Maximum fungible units that may be granted (in shares) | unit   27,030,000   27,030,000        
Fungible units per share (in fungible units per share) | unit / shares   3.74   3.74        
Shares that may be issued if equal to fungible units (shares) (less than) | shares   27,030,000   27,030,000        
Fungible units | fungible_unit   8.7   8.7        
Third Amendment and Restated 2005 Stock Option and Incentive Plan | Stock options                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Compensation expense   $ 1,900,000 1,900,000 $ 3,900,000 3,900,000      
Stock options, stock appreciation rights and other awards                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Fungible units per share (in fungible units per share) | unit / shares   0.73   0.73        
Award expiration period (in years)       5 years        
All other awards                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Fungible units per share (in fungible units per share) | unit / shares   1.0   1.0        
Award expiration period (in years)       10 years        
Long Term Outperformance Compensation Program 2014 [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Compensation expense   $ 4,300,000 3,300,000 $ 6,300,000 4,800,000      
Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options       29,200,000        
LTIP units earned (in shares) | shares 610,000              
Award period (in years) 3 years              
Performance period (in years) 3 years              
Long Term Outperformance Compensation Program 2014 [Member] | Vesting on August 31, 2017                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Percentage of units vested 50.00%              
Long Term Outperformance Compensation Program 2014 [Member] | Vesting on August 31, 2018                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Percentage of units vested 50.00%              
Deferred Stock Compensation Plan for Directors                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Compensation expense   $ 200,000 $ 200,000 $ 2,100,000 $ 1,800,000      
Maximum percentage of the annual retainer fee, chairman fees and meeting fees that may be deferred by non-employee directors (percent)   100.00%   100.00%        
Awards granted (in shares) | shares       10,407        
Shares issued (in shares) | shares       8,883        
Awards outstanding (in shares) | shares   97,533   97,533        
Employee Stock Purchase Plan                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Shares of common stock available for issuance (shares) | shares               500,000
Duration of each offering period starting the first day of each calendar quarter (in months)       3 months        
Share Based Compensation Arrangement by Share Based Payment Award, Purchase Price as Percentage of Market Value of Common Stock   85.00%   85.00%        
Shares of common stock issued (shares) | shares   99,671   99,671