Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 334,910	$ 430,316
Accounts receivable, net of allowances for doubtful accounts	471,345	476,903
Inventory	185,009	215,282
Total Current Assets	1,105,745	1,187,402
Property and Equipment, at cost	2,821,826	2,815,579
Less accumulated depreciation	1,767,503	1,751,375
Net Property and Equipment	1,054,323	1,064,204
Other Assets:
Goodwill	512,164	455,599
Other non-current assets	256,449
Total Other Assets	768,613	772,344
Total Assets	2,928,681	3,023,950
Current Liabilities:
Accounts payable	82,995	85,539
Accrued liabilities	289,527	350,258
Total Current Liabilities	372,522	435,797
Long-term Debt	785,068	792,312
Other Long-term Liabilities	132,888	131,323
Commitments and Contingencies
Stockholders' Equity:
Common Stock	27,709	27,709
Additional paid-in capital	211,988	225,125
Treasury stock, at cost	(704,630)	(718,946)
Retained earnings	2,367,742	2,417,412
Accumulated other comprehensive income	(269,960)	(292,136)
Total Shareholders' Equity	1,632,849	1,659,164
Stockholders' Equity Attributable to Noncontrolling Interest	5,354	5,354
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,638,203	1,664,518
Total Liabilities and Sharesholders' Equity	$ 2,928,681	$ 3,023,950