Long-Term Debt and Commitments (Tables)

12 Months Ended

Dec. 31, 2011

Long-Term Debt and Commitments [Abstract]

Summary of long term debt

    The following is a summary of long term debt:

(thousands of dollars)			Dec. 31, 2011	Dec. 31, 2010
5.53% Series 2006A Senior Notes
	Due October 5, 2013		$    50,000	$    50,000
Floating Rate Series 2006A Senior Notes
	Due October 5, 2013 25,000		25,000	25,000
Variable/Fixed Rate Industrial
	Development Revenue Bonds Due August 1, 2012		8,000	8,000
Variable/Fixed Rate Industrial
	Development Revenue Bonds Series 1999 Due November 1, 2014		8,200	8,200
Installment obligations
	Due 2013		1,421	1,421
Other Borrowings
	Due 2013		1,380	--
		Total	94,001	92,621
Less: Current maturities			8,552	--
Long-term debt			85,449	$   92,621