Commitment and Contingencies - Lease Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 70.5	$ 78.0
Operating lease liabilities - current	22.5	22.2
Operating lease liabilities - long-term	55.1	61.8
Total lease liabilities	$ 77.6	$ 84.0
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LiabilitiesNoncurrentAbstract	us-gaap:LiabilitiesNoncurrentAbstract