FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Long-term debt:
Long-term Debt, Fair Value	$ 2,304.2	$ 2,192.6
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Long-term debt:
Fair Value Adjustment to Interest Rate Hedge	1.4	1.9
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Long-term debt:
Long-term Debt, Fair Value	2,346.3	2,224.6
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Long-term debt:
Fair Value Adjustment to Interest Rate Hedge	1.4	1.9
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | $218.5 Million 8.00% 2020 1.5 Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $540 Million 8.25% 2020 First Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	506.3
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $544.2 Million 7.75% 2020 Second Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	339.1
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	88.6	224.5
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $500 Million 4.80% 2020 Senior Notes[Member]
Long-term debt:
Long-term Debt, Fair Value	122.0	235.9
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Notes[Member]
Long-term debt:
Long-term Debt, Fair Value	138.0	308.2
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $1.075 Billion 5.75% 2025 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	1,047.2	0.0
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $800 Million 6.25% 2040 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	292.6	292.5
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $316 Million 1.5% 2025 Senior Notes [Domain]
Long-term debt:
Long-term Debt, Fair Value	224.1	0.0
Senior Notes [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 4.875% 2024 Senior Notes [Domain]
Long-term debt:
Long-term Debt, Fair Value	390.3	0.0
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | $218.5 Million 8.00% 2020 1.5 Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	229.5
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $540 Million 8.25% 2020 First Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	595.0
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $544.2 Million 7.75% 2020 Second Lien Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	439.7
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 5.90% 2020 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	88.0	219.6
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $500 Million 4.80% 2020 Senior Notes[Member]
Long-term debt:
Long-term Debt, Fair Value	118.8	221.1
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Notes[Member]
Long-term debt:
Long-term Debt, Fair Value	130.8	283.1
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $1.075 Billion 5.75% 2025 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	1,029.3	0.0
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $800 Million 6.25% 2040 Senior Notes [Member]
Long-term debt:
Long-term Debt, Fair Value	227.1	234.7
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $316 Million 1.5% 2025 Senior Notes [Domain]
Long-term debt:
Long-term Debt, Fair Value	352.9	0.0
Senior Notes [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 4.875% 2024 Senior Notes [Domain]
Long-term debt:
Long-term Debt, Fair Value	398.0	0.0
Line of Credit [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | ABL Facility [Member]
Long-term debt:
Long-term Debt, Fair Value	0.0	0.0
Line of Credit [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | ABL Facility [Member]
Long-term debt:
Long-term Debt, Fair Value	$ 0.0	$ 0.0