INCOME TAXES - Deferred taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets
Accrued liabilities	$ 17.1	$ 24.2
Receivables	7.8	8.5
Investments	51.8	55.7
Capital loss carryforwards	1.6	1.2
Pension and deferred compensation	23.3	15.4
Corporate borrowings	35.2	42.0
Disallowed interest	170.6	32.3
Deferred revenue	180.6	193.3
Lease liabilities	1,304.9	1,294.3
Finance lease obligations	1.2	1.6
Other credit carryovers	25.4	19.6
Net operating loss carryforward	530.9	365.5
Total	2,350.4	2,053.6
Less: Valuation allowance	(1,114.1)	(764.9)	$ (312.8)
Net deferred income taxes	1,236.3	1,288.7
Liabilities
Tangible assets	(131.7)	(179.7)
Right-of-use assets	(1,023.4)	(1,043.1)
Intangible assets	(111.9)	(105.0)
Other comprehensive income		(1.1)
Total deferred income taxes	(1,267.0)	(1,328.9)
Rollforward of the Company's valuation allowance for deferred tax assets
Balance at Beginning of Period	764.9	312.8	323.6
Additions Charged to Expenses	349.2	615.2	24.2
Charged (Credited) to Other Accounts		(163.1)	(35.0)
Balance at End of Period	$ 1,114.1	$ 764.9	$ 312.8