Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,126,301	$ 1,126,636
Accumulated Amortization	898,631	881,634
Net Carrying Amount	227,670	245,002
Domain names available for sale
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,160	18,160
Accumulated Amortization	18,160	18,160
Net Carrying Amount	$ 0	0
Weighted-Average Useful Life	Indefinite
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 280,269	280,330
Accumulated Amortization	215,068	207,844
Net Carrying Amount	$ 65,201	$ 72,486
Weighted-Average Useful Life	7 years	7 years
Subscriber relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 659,571	$ 659,837
Accumulated Amortization	536,797	529,276
Net Carrying Amount	$ 122,774	$ 130,561
Weighted-Average Useful Life	7 years	7 years
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 134,038	$ 134,046
Accumulated Amortization	97,027	94,982
Net Carrying Amount	$ 37,011	$ 39,064
Weighted-Average Useful Life	8 years	8 years
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 34,263	$ 34,263
Accumulated Amortization	31,579	31,372
Net Carrying Amount	$ 2,684	$ 2,891
Weighted-Average Useful Life	5 years	5 years