Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Rent expense		$ 63.2
Sublease income		$ 3.8
Operating lease not yet commenced	$ 13.6
Future sublease income	216.7
Outstanding letter of credit	$ 5.8
Minimum
Lessee, Lease, Description [Line Items]
Term of operating lease not yet commenced	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of operating lease not yet commenced	7 years
Real Estate Arrangements
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	11 years 9 months 18 days		12 years 9 months 18 days
Weighted average discount rate	3.40%		3.50%
Co-location Arrangements
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	4 years 3 months 18 days		3 years 10 months 24 days
Weighted average discount rate	1.80%		2.20%