Debt (Details) (USD $)
3 Months Ended 9 Months Ended 0 Months Ended 0 Months Ended 9 Months Ended 12 Months Ended 1 Months Ended 9 Months Ended 12 Months Ended 1 Months Ended 3 Months Ended 9 Months Ended 9 Months Ended 1 Months Ended 1 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Dec. 31, 2013
Jul. 02, 2012
Jul. 02, 2012
Term Loan Facility [Member]
Sep. 30, 2014
Term Loan Facility [Member]
Jul. 02, 2012
Revolving Credit Facility [Member]
Sep. 30, 2014
Secured Debt [Member]
Term Loan Facility [Member]
Dec. 31, 2013
Secured Debt [Member]
Term Loan Facility [Member]
Mar. 31, 2014
Secured Debt [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
Secured Debt [Member]
Revolving Credit Facility [Member]
Dec. 31, 2013
Secured Debt [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
4.75% Senior Notes [Member]
Mar. 31, 2014
4.75% Senior Notes [Member]
Sep. 30, 2014
4.75% Senior Notes [Member]
Sep. 30, 2014
4.75% Senior Notes [Member]
Dec. 31, 2013
4.75% Senior Notes [Member]
Sep. 30, 2014
Federal Funds Rate [Member]
Secured Debt [Member]
Term Loan Facility [Member]
Sep. 30, 2014
Federal Funds Rate [Member]
Secured Debt [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
LIBOR [Member]
Secured Debt [Member]
Term Loan Facility [Member]
Sep. 30, 2014
LIBOR [Member]
Secured Debt [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
Base Rate [Member]
Secured Debt [Member]
Term Loan Facility [Member]
Sep. 30, 2014
Base Rate [Member]
Secured Debt [Member]
Revolving Credit Facility [Member]
Jul. 31, 2014
Amended Credit Agreement [Member]
Term Loan Facility [Member]
Sep. 30, 2014
Amended Credit Agreement [Member]
Term Loan Facility [Member]
Mar. 31, 2014
Amended Credit Agreement [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
Amended Credit Agreement [Member]
Revolving Credit Facility [Member]
Sep. 30, 2014
Debt Instrument, Redemption, Period One [Member]
4.75% Senior Notes [Member]
Sep. 30, 2014
Debt Instrument, Redemption, Period One [Member]
Minimum [Member]
4.75% Senior Notes [Member]
Sep. 30, 2014
Debt Instrument, Redemption, Period One [Member]
Maximum [Member]
4.75% Senior Notes [Member]
Sep. 30, 2014
Financial guarantee [Member]
4.75% Senior Notes [Member]
Long-term Debt, by Category, Current and Noncurrent [Abstract]                                                                  
Long-term debt               $ 962,500,000   $ 944,122,000 $ 965,363,000   $ 0 $ 300,000,000 $ 493,080,000   $ 493,080,000 $ 493,080,000 $ 0               $ 962,500,000            
Less current maturities (75,000,000)   (75,000,000)   (50,000,000)                                                        
Long-term debt 1,362,202,000   1,362,202,000   1,215,363,000                                                        
Debt amount           1,800,000,000.0 1,000,000,000   800,000,000             500,000,000                                  
Stated interest rate                               4.75%                                  
Interest Expense, Debt                             12,100,000                                    
Proceeds from issuance of debt                               492,500,000                                  
Debt discount                               7,500,000                                  
Debt issuance cost paid                               2,000,000                                  
Repayments of Long-term Lines of Credit                       300,000,000                           12,500,000   300,000,000          
Amortization of financing costs and debt discounts                                 300,000 700,000                              
Trigger amount for redemption of debt                                                                 175,000,000
Redemption period                                                             30 days 60 days  
Redemption price, percentage of principle amount redeemable                                                           100.00%      
Change of control triggering event redemption price, percentage                                                           101.00%      
Percentage of aggregate amount of debt required to make note due and payable immediately                                                           25.00%      
Term of long-term debt             5 years   5 years                                                
Line of credit, remaining borrowing capacity                                                         800,000,000        
Amortization related to financing costs and debt discounts $ 2,100,000 $ 2,100,000 $ 6,400,000 $ 7,000,000                                                          
Initial applicable margin for borrowings                                       0.50% 0.50% 1.00% 1.00%             0.50%      
Interest rate margin                                           1.625% 1.625% 0.625% 0.625%                
Interest rate during period                   1.81% 1.81%   1.81% 1.81%