Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Amounts of long-term debt
Borrowings under revolving credit agreement	$ 120,906	$ 88,249	[1]
Senior notes	125,000	125,000	[1]
Industrial revenue bond	0	4,800	[1]
Other notes payable	15,502	18,253	[1]
Total long term debt	261,408	236,302	[1]
Less: current portion	(738)	(634)	[1]
Long-term debt, excluding current maturities	$ 260,670	$ 235,668	[1]

[1] Restated