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FAIR VALUE MEASUREMENTS (Carrying Value And Fair Value Of Financial Instruments Disclosure) (Details) - USD ($) $ in Millions | Sep. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Interest Rate Swap [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Fair Value Adjustment to Interest Rate Hedge |  | $ 0.2
Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | $ 2,187.5 | 2,039.9
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Fair Value Adjustment to Interest Rate Hedge | 0.0 | 0.2
Carrying Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 2,109.1 | 2,092.9
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Fair Value Adjustment to Interest Rate Hedge | 0.0 | 0.2
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 4.875% 2024 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 408.9 | 370.2
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 0.0 | 122.3
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $316.25 Million 1.50% 2025 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 345.8 | 352.4
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $1.075 Billion 5.75% 2025 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 466.2 | 962.0
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $750 Million 5.875% 2027 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 712.2 | 0.0
Senior Notes [Member] | Fair Value [Member] | Fair Value, Inputs, Level 1 [Member] | $800 Million 6.25% 2040 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 254.4 | 232.8
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $400 Million 4.875% 2024 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 393.2 | 392.1
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $700 Million 4.875% 2021 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 0.0 | 123.8
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $316.25 Million 1.50% 2025 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 243.8 | 235.2
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $1.075 Billion 5.75% 2025 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 463.7 | 1,048.8
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $750 Million 5.875% 2027 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 715.5 | 0.0
Senior Notes [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 1 [Member] | $800 Million 6.25% 2040 Senior Notes [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 292.9 | 292.8
Line of Credit [Member] | Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | 0.0 | 0.0
Line of Credit [Member] | Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total long-term debt, fair value | $ 0.0 | $ 0.0

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