Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 339,541	$ 430,316
Accounts receivable, net of allowances for doubtful accounts	504,322	476,903
Inventory	185,926	215,282
Other current assets	84,456	64,901
Total Current Assets	1,114,245	1,187,402
Property and Equipment, at cost	2,812,374	2,815,579
Less accumulated depreciation	1,798,370	1,751,375
Net Property and Equipment	1,014,004	1,064,204
Other Assets:
Goodwill	501,348	455,599
Other non-current assets	273,151	316,745
Total Other Assets	774,499	772,344
Total Assets	2,902,748	3,023,950
Current Liabilities:
Accounts payable	91,150	85,539
Accrued liabilities	336,226	350,258
Total Current Liabilities	427,376	435,797
Long-term Debt	782,228	792,312
Other Long-term Liabilities	122,610	131,323
Commitments and Contingencies
Stockholders' Equity:
Common Stock	27,709	27,709
Additional paid-in capital	215,073	225,125
Treasury stock, at cost	(704,502)	(718,946)
Retained earnings	2,334,666	2,417,412
Accumulated other comprehensive income	(307,766)	(292,136)
Total Shareholders' Equity	1,565,180	1,659,164
Stockholders' Equity Attributable to Noncontrolling Interest	5,354	5,354
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,570,534	1,664,518
Total Liabilities and Sharesholders' Equity	$ 2,902,748	$ 3,023,950