DERIVATIVE INSTRUMENTS - OFFSETTING TABLE (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Cash collateral
Collateral in margin account	$ 1.3
Cash collateral received		$ 3.4
Offsetting Derivative Assets
Gross amount recognized on the balance sheet	6.4	12.0
Gross amount not offset on the balance sheet	(0.4)	(3.6)
Net amount	6.0	8.4
Collateral received		3.4
Offsetting Derivative Liabilities
Gross amount recognized on the balance sheet	1.6	0.7
Gross amount not offset on the balance sheet	(0.4)	(0.2)
Net amount	$ 1.2	$ 0.5

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