Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets
Preferred stock, par value (in dollar per share)	$ 0	$ 0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollar per share)	$ 0	$ 0
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	60,122,812	60,122,812
Treasury stock, shares	10,667,058	10,799,891