CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
REVENUES	$ 291.6	$ 379.4	$ 986.1	$ 1,491.4
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	167.4	186.0	504.9	598.3
Depreciation and amortization	103.4	102.2	304.0	301.2
Selling, general and administrative	25.0	23.5	71.0	76.5
Loss on disposals of property and equipment	2.8	1.2	9.3	5.3
Material charges and other operating items	0.0	32.9	0.0	32.9
Total costs and expenses	298.6	345.8	889.2	1,014.2
INCOME (LOSS) FROM OPERATIONS	(7.0)	33.6	96.9	477.2
OTHER INCOME (EXPENSE):
Interest expense	(38.5)	(39.4)	(117.0)	(116.6)
Interest income	3.7	1.2	8.9	2.1
Gain (loss) on extinguishment of debt	(0.5)	0.0	1.7	2.4
Other - net	(0.4)	(2.1)	(0.5)	(5.4)
Total other (expense), net	(35.7)	(40.3)	(106.9)	(117.5)
INCOME (LOSS) BEFORE INCOME TAXES	(42.7)	(6.7)	(10.0)	359.7
Provision (benefit) for income taxes	(21.8)	(12.2)	29.3	14.7
NET INCOME (LOSS)	$ (20.9)	$ 5.5	$ (39.3)	$ 345.0
NET INCOME (LOSS) PER SHARE - BASIC (in dollars per share)	$ (0.17)	$ 0.04	$ (0.31)	$ 2.75
NET INCOME (LOSS) PER SHARE - DILUTED (in dollars per share)	$ (0.17)	$ 0.04	$ (0.31)	$ 2.73