Goodwill and Other Intangible Assets Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 435,640		$ 433,374
Total other intangible assets, net	342,204		$ 347,212
Amortization expense of intangible assets	6,126	$ 6,210
Estimated Future Amortization Expense by Fiscal Year [Abstract]
Remainder of 2016	18,400
2017	22,600
2018	17,400
2019	14,500
2020	9,800
2021	28,200
After 2021	$ 200