Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Allowance For Bad Debt	$ 15,549	$ 14,234
Preferred stock - par value per share	$ 0.01	$ 0.01
Preferred stock - authorized shares	10,000,000	10,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common stock - authorized shares	125,000,000	125,000,000
Common stock - issued shares	44,786,011	44,786,011
Common stock - outstanding shares	25,541,393	26,020,234
Treasury shares	19,244,618	18,765,777

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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