Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Allowance for doubtful accounts receivable	$ 2,557	$ 2,440
Stockholders' Equity:
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares issued	23,185,267	23,040,881
Common stock, shares outstanding	23,185,267	23,040,881