Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Common stock, par value	$ 0.625	$ 0.625
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	63,363,118	63,065,931
Repurchased common stock, shares	7,569,160	7,468,869