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 notes receivable, allowance	$ 251	$ 507
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	49,745,989	48,396,134
Common stock, shares outstanding	43,999,443	42,833,342
Treasury stock, shares	5,746,546	5,562,792