Deferred Revenue - Composition of Deferred Revenue (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Deferred revenue, current	$ 1,871.4	$ 1,711.3
Deferred revenue, noncurrent	767.0	725.1
Domains
Disaggregation of Revenue [Line Items]
Deferred revenue, current	880.2	810.7
Deferred revenue, noncurrent	440.5	410.4
Hosting and presence
Disaggregation of Revenue [Line Items]
Deferred revenue, current	620.8	574.8
Deferred revenue, noncurrent	220.2	218.1
Business applications
Disaggregation of Revenue [Line Items]
Deferred revenue, current	370.4	325.8
Deferred revenue, noncurrent	$ 106.3	$ 96.6