CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS)
Proportionate share of other companies foreign currency translation adjustment, tax	$ 180	$ 390	$ 596
Net unrealized appreciation (depreciation) on marketable securities, tax	$ 327	$ 457	$ 2,158
Cash dividends declared (in dollars per share)	$ 0.16	$ 0.16	$ 0.16