Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
CURRENT ASSETS:
Cash and cash equivalents	$ 39,113	$ 35,941
Accounts receivable, net	362,433	382,458
Materials and supplies	48,023	45,790
Prepaid expenses and other	52,218	43,197
Total current assets	501,787	507,386
PROPERTY AND EQUIPMENT, net	4,230,511	4,215,063
GOODWILL	829,058	826,575
INTANGIBLE ASSETS, net	1,116,804	1,128,952
DEFERRED INCOME TAX ASSETS, net	2,520	2,270
OTHER ASSETS, net	25,372	22,836
Total assets	6,706,052	6,703,082
CURRENT LIABILITIES:
Current portion of long-term debt	108,114	75,966
Accounts payable	257,166	282,275
Accrued expenses	181,509	169,586
Total current liabilities	546,789	527,827
LONG-TERM DEBT, less current portion	2,142,306	2,205,785
DEFERRED INCOME TAX LIABILITIES, net	983,925	983,136
DEFERRED ITEMS - grants from outside parties	298,085	292,198
OTHER LONG-TERM LIABILITIES	$ 159,647	$ 174,675
COMMITMENTS AND CONTINGENCIES
EQUITY:
Additional paid-in capital	$ 1,362,523	$ 1,355,345
Retained earnings	1,571,695	1,544,676
Accumulated other comprehensive loss	(129,844)	(153,457)
Treasury stock, at cost	(229,781)	(227,808)
Total equity	2,575,300	2,519,461
Total liabilities and equity	6,706,052	6,703,082
Class A Common Stock, $0.01 par value, one vote per share; 180,000,000 shares authorized at March 31, 2016 and December 31, 2015; 69,927,543 and 69,674,185 shares issued and 57,155,726 and 56,945,384 shares outstanding (net of 12,771,817 and 12,728,801 shares in treasury) on March 31, 2016 and December 31, 2015, respectively
EQUITY:
Common Stock	699	697
Class B Common Stock, $0.01 par value, ten votes per share; 30,000,000 shares authorized at March 31, 2016 and December 31, 2015; 793,138 shares issued and outstanding on March 31, 2016 and December 31, 2015.
EQUITY:
Common Stock	$ 8	$ 8