Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 127,990	$ 120,549
Accounts receivable, net of allowances for doubtful accounts of $577 and $594	618,738	666,930
Inventory	355,008	331,280
Other current assets	89,289	84,231
Total Current Assets	1,191,025	1,202,990
Property and Equipment, at cost	2,136,025	2,069,119
Less accumulated depreciation	1,075,835	1,043,987
Net Property and Equipment	1,060,190	1,025,132
Other Assets:
Goodwill	343,483	363,193
Equity Method Investments	41,072	42,619
Other non-current assets	135,851	134,184
Total Other Assets	520,406	539,996
Total Assets	2,771,621	2,768,118
Current Liabilities:
Accounts payable	138,439	130,489
Accrued liabilities	374,456	408,303
Income taxes payable	85,344	78,393
Total Current Liabilities	598,239	617,185
Long-term Debt	90,000	94,000
Other Long-term Liabilities	249,308	241,473
Commitments and Contingencies
Stockholders' Equity:
Common Stock, par value $0.25; 180,000,000 shares authorized; 110,834,088 shares issued	27,709	27,709
Additional paid-in capital	206,411	212,940
Treasury stock; 2,531,039 and 2,799,118 shares, at cost	(75,793)	(84,062)
Retained earnings	1,696,401	1,641,027
Accumulated other comprehensive income	(20,654)	17,846
Total Shareholders' Equity	1,834,074	1,815,460
Total Liabilities and Sharesholders' Equity	$ 2,771,621	$ 2,768,118