Goodwill and Other Intangible Assets - Summary of Estimated Charges to Amortization Expense of Intangible Assets (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]        
Amortization expense $ 8,423 $ 7,259 $ 23,966 $ 21,455
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]        
July 1, 2016 through Dec. 31, 2016 19,454   19,454  
2015 43,542   43,542  
2016 43,046   43,046  
2017 42,162   42,162  
2018 41,916   41,916  
Total amortization expense $ 190,120   $ 190,120