v2.4.0.8
Fair Value Measurements - Additional Information (Details)
3 Months Ended 3 Months Ended
Mar. 31, 2014
USD ($)
Mar. 31, 2013
USD ($)
Mar. 31, 2014
Credit Agreement
USD ($)
Dec. 31, 2013
Credit Agreement
USD ($)
Mar. 31, 2014
Receivables securitization facility
USD ($)
Dec. 31, 2013
Receivables securitization facility
USD ($)
Mar. 31, 2014
Senior notes
USD ($)
Dec. 31, 2013
Senior notes
USD ($)
Mar. 31, 2013
ECP 2012 Contingent Payment
USD ($)
Mar. 31, 2013
ECP 2012 Contingent Payment
GBP (£)
Jun. 30, 2014
Subsequent Event
ECP 2012 Contingent Payment
USD ($)
Jun. 30, 2014
Subsequent Event
ECP 2012 Contingent Payment
GBP (£)
Apr. 02, 2014
Subsequent Event
ECP 2013 Contingent Payment
USD ($)
Fair Value Measurements                          
Maximum payment under contingent consideration agreement                   £ 25,000,000     $ 30,000,000
Contingent consideration payments 2,006,000 37,768,000             33,900,000 22,400,000 44,800,000 26,900,000  
Contingent consideration other settlements                 3,900,000 2,600,000 5,100,000 3,100,000  
(Gains) Losses related to contingent consideration obligations outstanding at period-end 700,000 (800,000)                      
Borrowings under credit agreement, carrying value     992,200,000 672,600,000                  
Borrowings under receivable securitization facility, carrying value 80,000,000       80,000,000 0              
Debt instrument, fair value             572,000,000            
Debt instrument, carrying amount             $ 600,000,000 $ 600,000,000