Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 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)	66,162,839	66,032,929
Common stock, shares outstanding (in shares)	43,232,625	43,102,715
Treasury stock, shares (in shares)	22,930,214	22,930,214