Schedule of Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, Beginning Balance		$ 1,019,239		$ 589,862
Goodwill, Acquisition				429,377
Acquisitions - measurement period adjustments, goodwill	[1]	(11,271)
Goodwill, Ending Balance		1,007,968		1,019,239
Net Book Value, Goodwill, Beginning Balance		1,019,239		589,862
Net Book Value, Goodwill, Acquisition		(11,271)	[1]	429,377
Net Book Value, Goodwill, Ending Balance		$ 1,007,968		$ 1,019,239

[1] The change in the carrying amount of goodwill during the year ended December 31, 2019 was primarily related to changes in the fair value of net deferred tax assets for the purchase price allocations of the Tapingo and LevelUp acquisitions during the measurement period.