CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets
Allowance for doubtful accounts receivable	$ 18,894	$ 17,203
Stockholders' Equity
Preferred stock, par value per share	$ 100	$ 100
Preferred stock, shares authorized	100,000us-gaap_PreferredStockSharesAuthorized	100,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares issued	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Common stock, par value per share	$ 1.00	$ 1.00
Common stock, shares authorized	500,000,000us-gaap_CommonStockSharesAuthorized	500,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	255,892,502us-gaap_CommonStockSharesIssued	255,320,345us-gaap_CommonStockSharesIssued

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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