Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Condensed Consolidated Balance Sheets
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	66,313,950	66,032,929
Common stock, shares outstanding (in shares)	43,383,736	43,102,715
Treasury stock, shares (in shares)	22,930,214	22,930,214