Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Stock-based compensation expense	$ 18.2	$ 11.7
Accrued expenses	43.3	37.6
Financing and operating leasing obligations	2,336.9	2,178.0
Unrecognized tax benefits	7.9	7.7
Net operating losses, interest limitation and tax credit carryforwards	153.9	87.6
Gross deferred tax assets	2,560.2	2,322.6
Less: Valuation allowance	(101.0)	(54.2)
Total deferred tax assets	2,459.2	2,268.4
Deferred tax liabilities:
Property and equipment, not subject to the Master Leases	(51.1)	(53.1)
Property and equipment, subject to the Master Leases	(1,051.2)	(1,088.9)
Investments in and advances to unconsolidated affiliates	(27.9)	(2.9)
Discount on convertible notes	(20.9)	0.0
Undistributed foreign earnings	(0.4)	(0.4)
Intangible assets	(183.4)	(287.3)
Lease right of use assets	(1,250.6)	(1,080.4)
Total deferred tax liabilities	(2,585.5)	(2,513.0)
Long-term deferred tax liabilities, net	$ (126.3)	$ (244.6)