CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Common stock, par value (in dollars per share)	$ 0.005	$ 0.005
Common stock, shares authorized	240,000	240,000
Common stock, shares issued	203,759	198,729
Common stock, shares outstanding	165,776	174,277
Common stock in treasury, shares	37,983	24,452