Long-Term Debt and Commitments (Details) (USD $)	3 Months Ended
	Mar. 30, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt, gross	$ 83,200,000		$ 83,200,000
Less: Current maturities	8,200,000	[1]	8,200,000	[2]
Long-term debt	75,000,000	[1]	75,000,000	[2]
Short-term Borrowings [Abstract]
Uncommitted short-term bank credit lines, maximum borrowing capacity	189,700,000
Uncommitted short-term bank credit lines, amount outstanding	4,800,000
Series A Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	30,000,000		30,000,000
Maturity date	Oct. 07, 2020
Series B Senior Notes Due 2023 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	45,000,000		45,000,000
Maturity date	Oct. 07, 2023
Variable/Fixed Rate Industrial Development Revenue Bonds Series 1999 Due 2014 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	8,200,000		8,200,000
Maturity date	Nov. 01, 2014
Installment Obligations [Member]
Debt Instrument [Line Items]
Long-term debt, gross	0		0
Other Borrowings [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 0		$ 0

[1] Unaudited

[2] Condensed from audited financial statements