Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Common stock, par value	1.00	1.00
Common stock, shares authorized	24,000,000	24,000,000
Common stock, shares issued	21,456,880	21,457,000
Common stock, shares outstanding	13,726,000	13,846,000	14,112,000
Treasury stock, shares	7,730,878	7,611,245	7,344,624
Common Stock [Member]
Common stock, shares issued	21,457,000	21,457,000	21,457,000	21,457,000
Common stock, shares outstanding	21,457,000	21,457,000
Treasury Stock [Member]
Common stock, shares outstanding	7,731,000	7,611,000	7,345,000	6,885,000