Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation and Cash-Based Incentive Compensation - Additional Information (Details)

v2.4.0.8
Share-Based Compensation and Cash-Based Incentive Compensation - Additional Information (Details) (USD $)
In Millions, except Share data, unless otherwise specified
9 Months Ended 12 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2014
Sep. 30, 2014
Common Stock
Sep. 30, 2014
Restricted Stock Units (RSUs)
Sep. 30, 2013
Restricted Stock Units (RSUs)
Dec. 31, 2013
Restricted Stock Units (RSUs)
Dec. 31, 2012
Restricted Stock Units (RSUs)
Dec. 31, 2013
Restricted Stock Units (RSUs)
London Interbank Offered Rate (LIBOR)
Dec. 31, 2012
Restricted Stock Units (RSUs)
London Interbank Offered Rate (LIBOR)
Mar. 31, 2014
CEO's 2013 Award
Sep. 30, 2014
Directors Compensation Plan
Sep. 30, 2014
Restricted Stock
Sep. 30, 2013
Restricted Stock
Sep. 30, 2014
Minimum
Restricted Stock Units (RSUs)
Dec. 31, 2013
Minimum
Restricted Stock Units (RSUs)
Dec. 31, 2012
Minimum
Restricted Stock Units (RSUs)
Sep. 30, 2014
Maximum
Restricted Stock Units (RSUs)
Dec. 31, 2013
Maximum
Restricted Stock Units (RSUs)
Dec. 31, 2012
Maximum
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                                    
Restricted stock units adjustments, percentage                         0.00%     100.00%    
Common stock, price per share                 $ 14.66                  
Common stock available for award under plans 5,032,939                 500,564                
Shares granted, grant date fair value     $ 20.0 $ 12.8             $ 0.3 $ 0.3            
Shares vested, vested date fair value     0.1 0             0.3 0.4            
Risk-free interest rate, minimum             0.27% 0.15%                    
Risk-free interest rate, maximum             0.91% 0.72%                    
Expected volatility, minimum         30.00% 33.00%                        
Expected volatility, maximum         63.00% 74.00%                        
Expected dividend yield                           0.00% 0.00%   3.10% 2.50%
Correlation of movement of total shareholder return                           (84.00%) (67.00%)   95.00% 94.00%
Number of shares granted     1,190,920           42,547   18,815              
Number of shares issued                 42,547                  
Unrecognized share-based compensation expense   $ 0.2 $ 21.7               $ 0.6              
Recognition period for unrecognized compensation expense   2015-02 2016-11               2016-04