Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.625	$ 0.625
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	63,946,222	63,565,453
Repurchased common stock, shares	7,644,407	7,583,471