Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 768,486	$ 758,159
Accumulated Amortization	(514,385)	(457,615)
Net	254,101	300,544
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	450,979	451,853
Accumulated Amortization	(295,584)	(269,989)
Net	155,395	181,864
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	75,302	75,562
Accumulated Amortization	(30,408)	(26,855)
Net	44,894	48,707
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	227,147	215,686
Accumulated Amortization	(182,177)	(155,309)
Net	44,970	60,377
Domain Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,118	10,118
Accumulated Amortization	(3,840)	(3,333)
Net	6,278	6,785
Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,940	4,940
Accumulated Amortization	(2,376)	(2,129)
Net	$ 2,564	$ 2,811
Minimum [Member] | Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	7 years
Minimum [Member] | Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	4 years
Minimum [Member] | Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years
Minimum [Member] | Domain Names [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years
Minimum [Member] | Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	4 years
Maximum [Member] | Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	17 years
Maximum [Member] | Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	16 years
Maximum [Member] | Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	7 years
Maximum [Member] | Domain Names [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	15 years
Maximum [Member] | Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	14 years