Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Disclosure Summary Of Accrued Expenses And Other Current Liabilities [Abstract]
Taxes payable	$ 30,927	$ 25,617
Bonuses and commissions	70,104	84,972
Accrued compensation	51,827	45,428
Other employee related liabilities	47,762	44,284
Other	73,374	52,956
Total accrued expenses and other current liabilities	$ 273,994	$ 253,257	[1]

[1] As adjusted to reflect the impact of the full retrospective adoption of Topic 606. See Note 2 for further details.