CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
CONSOLIDATED BALANCE SHEETS
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	77,728,758	77,325,702
Treasury stock, at cost, shares	26,765,386	26,095,636