Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Performance-Based Awards (Details)

v3.6.0.2
Stock-Based Compensation - Performance-Based Awards (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number   4,774,408  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 3,289,569 2,996,151 1,541,395
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period 2,367,831    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period 362,624    
Allocated Share-based Compensation Expense $ 7.5 $ 8.4 $ 9.3
Performance Cash Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Nominal Value Per Share $ 100.00    
Percentage Of Number Of Shares Earned Related To Performance Maximum 200.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 26,352 33,555  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 17,091 17,091 16,574
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period 16,464    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period 7,830    
Allocated Share-based Compensation Expense $ 2.3 $ 2.3 $ 1.9
Performance-Based Phantom Stock Unit [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 1,315,228 541,127  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 1,164,880 541,127 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period 0    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period 390,779    
Allocated Share-based Compensation Expense $ 1.3 $ 0.4 $ 0.0