Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 1.25	$ 1.25
Common stock, authorized	60,000,000	60,000,000
Common stock, outstanding	31,653,262	30,212,453	29,872,825	29,796,232