CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	150,000	150,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares issued	114,193	116,257
Common stock, shares outstanding	114,193	116,257