CONSOLIDATED STATEMENTS OF INCOME (LOSS) (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONSOLIDATED STATEMENTS OF INCOME (LOSS) [Abstract]
Other-than-temporary impairment on debt security	$ 0	$ 0	$ 40,300
Less: other-than-temporary impairment recognized in accumulated other comprehensive income (loss)	0	0	(4,651)
Credit-related impairment on investment	$ 0	$ 0	$ 35,649