Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Accounts and other receivables, allowances for doubtful accounts	$ 21	$ 97
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	31,786,030	31,016,812
Common stock, shares outstanding	27,857,824	28,228,603
Treasury stock, shares	3,928,206	2,788,209