Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 87.5	$ 31.8
Short-term investments	12.9	18.4	[1]
Prepaid expenses and other current assets	45.3	27.1	[1]
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	76.1	15.7
Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	11.4	16.1
Level 1 | Measured on a recurring basis | Forward-starting interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets		0.0
Deferred costs and other assets, net of current portion		0.0
Level 1 | Measured on a recurring basis | Interest rate cap contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	0.0
Deferred costs and other assets, net of current portion	0.0	0.0
Derivative liability		0.0
Level 1 | Measured on a recurring basis | Interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	0.0
Deferred costs and other assets, net of current portion	0.0
Derivative liability		0.0
Level 1 | Measured on a recurring basis | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0.0	0.0
Short-term investments	0.0	0.0
Level 1 | Measured on a recurring basis | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	11.4	16.1
Level 1 | Measured on a recurring basis | Securities guaranteed by U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0.0
Level 1 | Measured on a recurring basis | Other governmental securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0.0
Level 1 | Measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired lease-related assets		0.0
Level 2 | Measured on a recurring basis | Forward-starting interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets		0.7
Deferred costs and other assets, net of current portion		15.2
Level 2 | Measured on a recurring basis | Interest rate cap contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	1.4
Deferred costs and other assets, net of current portion	1.8	0.1
Derivative liability		(0.4)
Level 2 | Measured on a recurring basis | Interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	13.2
Deferred costs and other assets, net of current portion	29.2
Derivative liability		(2.4)
Level 2 | Measured on a recurring basis | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	76.1	15.7
Short-term investments	7.4	18.4
Level 2 | Measured on a recurring basis | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0.0	0.0
Level 2 | Measured on a recurring basis | Securities guaranteed by U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	2.5
Level 2 | Measured on a recurring basis | Other governmental securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	3.0
Level 2 | Measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired lease-related assets		0.0
Level 3 | Measured on a recurring basis | Forward-starting interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets		0.0
Deferred costs and other assets, net of current portion		0.0
Level 3 | Measured on a recurring basis | Interest rate cap contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	0.0
Deferred costs and other assets, net of current portion	0.0	0.0
Derivative liability		0.0
Level 3 | Measured on a recurring basis | Interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets	0.0
Deferred costs and other assets, net of current portion	0.0
Derivative liability		0.0
Level 3 | Measured on a recurring basis | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0.0	0.0
Short-term investments	0.0	0.0
Level 3 | Measured on a recurring basis | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0.0	0.0
Level 3 | Measured on a recurring basis | Securities guaranteed by U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0.0
Level 3 | Measured on a recurring basis | Other governmental securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0.0
Level 3 | Measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired lease-related assets		$ 14.2
Secured Debt | First Lien Term Loan | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument fair value	579.0
Senior Notes | Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument fair value	$ 542.8

[1] The Condensed Consolidated Balance Sheet as of December 31, 2021 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.