Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets
Allowance for doubtful accounts receivable (in dollars)	$ 3,402	$ 3,230
Accumulated amortization on other intangible assets (in dollars)	9,541	9,296
Deferred income taxes included in other long-term liabilities (in dollars)	$ 53,935	$ 92,448
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	118,737,456	118,487,455
Treasury stock, shares	56,348,026	55,668,137