Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, Authorized shares	5,000	5,000
Preferred stock, Issued shares	0	0
Preferred stock, Outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, Authorized shares	100,000	100,000
Common stock, Issued shares	26,774	26,481
Common stock, Outstanding shares	23,650	23,451
Treasury stock, Shares	3,124	3,030