RECEIVABLES - Amortized cost basis of financial assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, originated in fiscal year before latest fiscal year	$ 102.0	$ 131.3
Moody's, Ba2 Rating
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, originated in fiscal year before latest fiscal year	76.1	107.6
Moody's, B3 Rating
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, originated in fiscal year before latest fiscal year	$ 25.9	$ 23.7