Goodwill and Intangible Assets - Schedule of Finite Lived Intangible Assets Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 147,480	$ 312,242
Additions	192	1,588
Amortization expense	(115,613)	(166,350)	$ (220,900)
Other	(282)
Ending balance	31,777	147,480	312,242
Client relationships
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	85,615	211,811
Additions	0	0
Amortization expense	(85,331)	(126,196)
Other	0
Ending balance	284	85,615	211,811
Trademarks and domain names
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	60,533	96,537
Additions	0	0
Amortization expense	(29,778)	(36,004)
Other	0
Ending balance	30,755	60,533	96,537
Patented technologies
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	0	3,894
Additions	0	0
Amortization expense	0	(3,894)
Other	0
Ending balance	0	0	3,894
Covenants not to compete
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	1,332	0
Additions	192	1,588
Amortization expense	(504)	(256)
Other	(282)
Ending balance	$ 738	$ 1,332	$ 0