Income taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Deferred tax assets:
Accrued expense and reserves	$ 37		$ 1,422
Deferred revenue	4,619		1,900
Goodwill and intangible assets	409,740		404,547
Net operating loss	0		603
Other	4,901		3,619
Deferred tax assets	419,297		412,091
Deferred tax liabilities:
Prepaid expenses	(922)		(773)
Property and equipment	(5,837)		(5,165)
Total deferred tax liabilities	(6,759)		(5,938)
Total deferred tax assets	412,538		406,153
Reported as:
Deferred income taxes - non-current assets	414,841	$ 411,067	407,782
Deferred income taxes - non-current liabilities	(2,303)	$ (1,629)	(1,629)
Total deferred tax assets	$ 412,538		$ 406,153