CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
REVENUES	$ 508,736	$ 422,878	$ 1,055,775	$ 800,480
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	253,944	244,578	509,678	464,947
Depreciation and amortization	95,390	77,678	185,080	148,551
Selling, general and administrative	31,158	29,142	58,744	59,017
Loss (gain) on disposals of property and equipment	338	859	(175)	1,662
Proceeds from litigation settlement	0	0	0	(20,875)
Material charges and other operating expenses	5,000	8,300	5,000	8,300
Total costs and expenses	385,830	360,557	758,327	661,602
INCOME (LOSS) FROM OPERATIONS	122,906	62,321	297,448	138,878
OTHER INCOME (EXPENSE):
Interest expense, net of interest capitalized	(30,840)	(27,692)	(63,586)	(48,652)
Interest income	435	762	590	1,349
Other - net	(80)	(545)	(1,121)	(896)
Total other income (expense) - net	(30,485)	(27,475)	(64,117)	(48,199)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	92,421	34,846	233,331	90,679
Provision for income taxes	7,686	1,982	24,927	2,263
NET INCOME FROM CONTINUING OPERATIONS	84,735	32,864	208,404	88,416
INCOME (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAX	0	(20)	0	4,023
NET INCOME	$ 84,735	$ 32,844	$ 208,404	$ 92,439
INCOME PER SHARE - BASIC:
Income from continuing operations (in dollars per share)	$ 0.68	$ 0.26	$ 1.67	$ 0.71
Discontinued operations (in dollars per share)	0.00	0.00	0.00	0.04
Net income (in dollars per share)	0.68	0.26	1.67	0.75
INCOME PER SHARE - DILUTED:
Income from continuing operations (in dollars per share)	0.68	0.26	1.67	0.71
Discontinued operations (in dollars per share)	0.00	0.00	0.00	0.03
Net income (in dollars per share)	0.68	0.26	1.67	0.74
CASH DIVIDENDS DECLARED PER SHARE (in dollars per share)	$ 0.1	$ 0.1	$ 0.2	$ 0.1