CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
REVENUES	$ 374.3	$ 500.2
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	170.0	204.8
Depreciation and amortization	99.1	98.9
Selling, general and administrative	24.0	26.9
Loss on disposals of property and equipment	3.4	2.2
Total costs and expenses	296.5	332.8
INCOME FROM OPERATIONS	77.8	167.4
OTHER INCOME (EXPENSE):
Interest expense	(39.6)	(38.9)
Gain (loss) on extinguishment of debt	(0.2)	0.6
Interest income	2.0	0.4
Other - net	0.0	(2.6)
Total other (expense), net	(37.8)	(40.5)
INCOME BEFORE INCOME TAXES	40.0	126.9
Provision for income taxes	29.7	4.1
NET INCOME	$ 10.3	$ 122.8
NET INCOME (LOSS) PER SHARE - BASIC (in dollars per share)	$ 0.08	$ 0.98
NET INCOME (LOSS) PER SHARE - DILUTED (in dollars per share)	$ 0.07	$ 0.98