Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 1,290	$ 1,072
Common stock, par value	$ 1.50	$ 1.50
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	24,934,981	24,934,981
Treasury stock, shares	4,673,952	4,790,920