Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Operating right-of-use assets	$ 104.2	$ 112.6
Liabilities
Current lease liabilities	$ 23.4	$ 24.0
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent
Long-term lease liabilities	$ 86.5	$ 91.5
Total lease liabilities	$ 109.9	$ 115.5
Weighted average remaining lease term (in years):
Weighted-average remaining lease term - operating leases	9 years 9 months 18 days	9 years 8 months 12 days
Weighted average discount rate:
Weighted-average discount rate - operating leases	3.80%	3.90%
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:accruedliabilities	us-gaap:accruedliabilities