DEBT AND CREDIT FACILITIES (Debt Extinguishment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Extinguishment of Debt [Line Items]
Debt Extinguished	$ 724.0	$ 227.4	$ 1,610.7
Gain (loss) on extinguishment of debt	(18.2)	(6.8)	(165.4)
Debt redemption premiums paid	(5.3)	(7.1)	(110.0)
$700 Million 4.875% 2021 Senior Notes [Member]
Extinguishment of Debt [Line Items]
Debt Extinguished	124.0	14.4	171.0
Gain (loss) on extinguishment of debt	$ (5.3)	0.1	(2.8)
$1.075 Billion 5.75% 2025 Senior Notes [Member]
Extinguishment of Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Debt Extinguished	$ 600.0	1.7
Gain (loss) on extinguishment of debt	$ (12.9)	0.1
$400 Million 5.90% 2020 Senior Notes
Extinguishment of Debt [Line Items]
Debt Extinguished		88.9	136.7
Gain (loss) on extinguishment of debt		(3.3)	(7.8)
$540 Million 8.25% 2020 First Lien Notes
Extinguishment of Debt [Line Items]
Debt Extinguished			540.0
Gain (loss) on extinguishment of debt			(93.5)
$218.5 Million 8.00% 2020 1.5 Lien Notes
Extinguishment of Debt [Line Items]
Debt Extinguished			218.5
Gain (loss) on extinguishment of debt			45.1
$544.2 Million 7.75% 2020 Second Lien Notes
Extinguishment of Debt [Line Items]
Debt Extinguished			430.1
Gain (loss) on extinguishment of debt			(104.5)
$500 Million 4.80% 2020 Senior Notes
Extinguishment of Debt [Line Items]
Debt Extinguished		122.4	114.4
Gain (loss) on extinguishment of debt		$ (3.7)	$ (1.9)
$800 Million 6.25% 2040 Senior Notes [Member]
Extinguishment of Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.25%