RECEIVABLES - Roll-forward of allowance for credit losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Trade receivables
Accounts Receivable, Allowance for Credit Loss, Writeoff		$ (43.0)
Contract assets
Allowance for credit losses at December 31, 2020	$ 2.4
Write-offs charged against the allowance		0.0
Allowance for credit losses at December 31, 2021	1.1	2.4
Loans receivable
Write-offs charged against the allowance		0.0
Security deposit and other
Write-offs charged against the allowance		0.0
Held-to-maturity debt securities
Write-offs charged against the allowance		0.0
Trade receivables
Trade receivables
Allowance for credit losses at December 31, 2020	40.2	59.4
Current period provision (release) for expected credit losses	3.5	27.2
Recoveries	(5.6)	(3.4)
Allowance for credit losses at December 31, 2021	38.1	40.2
Contract assets
Contract assets
Allowance for credit losses at December 31, 2020	2.4	4.5
Current period provision (release) for expected credit losses	(1.3)	0.5
Recoveries	0.0	(2.6)
Allowance for credit losses at December 31, 2021	1.1	2.4
Loans receivable
Loans receivable
Allowance for credit losses at December 31, 2020	7.5	9.5
Current period provision (release) for expected credit losses	(7.2)	(0.2)
Recoveries	0.0	(1.8)
Allowance for credit losses at December 31, 2021	0.3	7.5
Security deposit and other
Security deposit and other
Allowance for credit losses at December 31, 2020	0.4	0.7
Current period provision (release) for expected credit losses	(0.1)	(0.3)
Recoveries	0.0	0.0
Allowance for credit losses at December 31, 2021	0.3	0.4
Held-to-maturity debt securities
Held-to-maturity debt securities
Allowance for credit losses at December 31, 2020	0.5	1.1
Current period provision (release) for expected credit losses	2.2	(0.6)
Recoveries	0.0	0.0
Allowance for credit losses at December 31, 2021	$ 2.7	$ 0.5