Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 9,409	$ 8,792
Accumulated amortization of intangibles	$ 52,168	$ 49,010
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	5,000,000us-gaap_PreferredStockSharesAuthorized	5,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares issued	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	300,000,000us-gaap_CommonStockSharesAuthorized	300,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	87,850,292us-gaap_CommonStockSharesIssued	87,850,292us-gaap_CommonStockSharesIssued
Treasury stock, shares	29,922,549us-gaap_TreasuryStockShares	29,698,893us-gaap_TreasuryStockShares

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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