Debt (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Notes payable - current:
Uncommitted lines of credit	$ 37,111	$ 15,038
Other	155	0
Short-term Debt	37,266	15,038
Long-term debt:
Credit facility	352,000	235,000
Senior notes	300,000	300,000
Industrial development revenue bonds	11,900	11,900
Other	2,393	3,468
Long-term debt	$ 666,293	$ 550,368