CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED BALANCE SHEETS
Trade accounts receivable, allowance for doubtful accounts (in dollars)	$ 977	$ 780
Trade accounts receivable from related parties	89	34
Accounts payable to related parties		$ 594
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	175,772,173	175,772,173
Common stock, shares issued	157,320,070	156,955,746
Common stock, shares outstanding	157,320,070	156,955,746