Commitments and Contingencies - Amounts recognized in Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Finance lease right-of-use assets	$ 645.7	$ 660.1
Finance lease liabilities	717.2	713.9
Accumulated amortization of right-of-use assets	$ 90.5	$ 76.1
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization