DERIVATIVE INSTRUMENTS - BALANCE SHEET OFFSETTING (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Cash collateral
Cash collateral posted	$ 6.3	$ 3.7
Cash collateral received	23.9
Offsetting derivative assets
Gross amount recognized on the balance sheet	57.2	3.3
Gross amount not offset on the balance sheet	(23.9)	(1.6)
Net amount	33.3	1.7
Cash collateral received	23.9
Offsetting derivative liabilities
Gross amount recognized on balance sheet	0.4	2.4
Gross amount not offset on balance sheet	0.0	(1.6)
Net amount	$ 0.4	$ 0.8

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