Goodwill and Other Intangible Assets - Estimated Other Intangible Assets Amortization Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for other intangible assets total	$ 88,972	$ 51,993	$ 40,870
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2019	88,299
2020	87,329
2021	87,062
2022	87,106
2023	86,567
Estimated other intangible assets amortization expense	$ 436,363