CONSOLIDATED STATEMENTS OF Financial Position (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 29, 2014
Trade accounts receivable, allowances	$ 1,976	$ 1,968	$ 2,068
Treasury stock, shares	80,000us-gaap_TreasuryStockShares	78,000us-gaap_TreasuryStockShares	78,000us-gaap_TreasuryStockShares
Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Common stock, shares authorized	120,000,000	120,000,000	120,000,000
Common stock, shares issued	38,257,000	37,285,000	37,861,000
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Common stock, shares authorized	40,000,000	40,000,000	40,000,000
Common stock, shares issued	23,571,000	22,887,000	22,915,000

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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