Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 35,941	$ 59,727
Accounts receivable, net	382,458	357,278
Materials and supplies	45,790	30,251
Prepaid expenses and other	43,197	24,176
Deferred income tax assets, net	69,174	76,994
Total current assets	576,560	548,426
PROPERTY AND EQUIPMENT, net	4,215,063	3,788,482
GOODWILL	826,575	628,815
INTANGIBLE ASSETS, net	1,128,952	587,663
DEFERRED INCOME TAX ASSETS, net	2,110	2,500
OTHER ASSETS, net	46,344	39,867
Total assets	6,795,604	5,595,753
CURRENT LIABILITIES:
Current portion of long-term debt	81,953	67,398
Accounts payable	282,275	290,746
Accrued expenses	169,586	106,094
Total current liabilities	533,814	464,238
LONG-TERM DEBT, less current portion	2,223,306	1,548,051
DEFERRED INCOME TAX LIABILITIES, net	1,052,150	908,852
DEFERRED ITEMS - grants from outside parties	292,198	279,286
OTHER LONG-TERM LIABILITIES	$ 174,675	$ 37,346
COMMITMENTS AND CONTINGENCIES
EQUITY:
Additional paid-in capital	$ 1,355,345	$ 1,334,474
Retained earnings	1,544,676	1,319,639
Accumulated other comprehensive loss	(153,457)	(72,252)
Treasury stock, at cost	(227,808)	(224,547)
Total equity	2,519,461	2,357,980
Total liabilities and equity	6,795,604	5,595,753
Class A Common Stock, $0.01 par value, one vote per share; 180,000,000 shares authorized at December 31, 2015 and 2014; 69,674,185 and 65,632,309 shares issued and 56,945,384 and 52,938,267 shares outstanding (net of 12,728,801 and 12,694,042 shares in treasury) on December 31, 2015 and 2014, respectively
EQUITY:
Common Stock	697	656
Class B Common Stock, $0.01 par value, ten votes per share; 30,000,000 shares authorized at December 31, 2015 and 2014; 793,138 and 1,020,485 shares issued and outstanding on December 31, 2015 and 2014, respectively
EQUITY:
Common Stock	$ 8	$ 10