Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Condensed Consolidated Financial Statements
Accounts receivable, allowance for doubtful accounts	$ 1,169	$ 1,729
Property, plant and equipment, accumulated depreciation	172,963	169,854
Other intangible assets, accumulated amortization	9,755	9,748
Other long-term liabilities, deferred income taxes	$ 67,947	$ 65,788
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	119,478,549	119,186,705
Treasury stock, shares (in shares)	56,698,498	56,600,972