CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	250,000	250,000
Common stock, issued	35,658	35,324
Common stock, outstanding	35,658	35,324
Preferred stock, Series A
Preferred stock, authorized	200	200
Preferred stock, Undesignated series
Preferred stock, authorized	59,800	59,800