GAIN (LOSS) ON INVESTMENTS, NET (Details) (USD $)	12 Months Ended			1 Months Ended	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Mar. 31, 2011 Common Shares	Jun. 30, 2011 Common Shares
Gain (loss) on investments, net
Loss on auction rate securities		$ (5,552,000)	$ (5,210,000)
Gain on auction rate securities settlement			22,000,000
Gain on disposal of investments	22,776,000		804,000
Gain (loss) on investments, net	22,776,000	(5,552,000)	17,594,000
Marketable securities by major security type
Investment in available-for-sale equity securities				60,000,000
Number of shares of common stock acquired				1,034,908
Percentage of outstanding common stock acquired				1.366%
Realized gain					21,300,000
Net proceeds from disposal of investment					$ 81,300,000