FAIR VALUE OF CERTAIN FINANCIAL ASSETS AND LIABILITIES (Details 3) (Discounted cash flow, Level 3, Assets at fair value on recurring basis)	3 Months Ended
	Mar. 31, 2013
Auction Rate Securities: Trading | Minimum
Quantitative information related to the significant unobservable inputs
Maximum rate probability (as a percent)	0.40%
Principal returned probability (as a percent)	86.69%
Default probability (as a percent)	3.88%
Liquidity risk (as a percent)	3.50%
Recovery rate (as a percent)	60.00%
Auction Rate Securities: Trading | Maximum
Quantitative information related to the significant unobservable inputs
Maximum rate probability (as a percent)	1.84%
Principal returned probability (as a percent)	95.49%
Default probability (as a percent)	11.69%
Liquidity risk (as a percent)	3.50%
Recovery rate (as a percent)	60.00%
Auction Rate Securities: Trading | Weighted Average
Quantitative information related to the significant unobservable inputs
Maximum rate probability (as a percent)	1.00%
Principal returned probability (as a percent)	87.80%
Default probability (as a percent)	11.20%
Liquidity risk (as a percent)	3.50%
Recovery rate (as a percent)	60.00%
Put Options | Minimum
Quantitative information related to the significant unobservable inputs
Counterparty risk (as a percent)	0.68%
Put Options | Maximum
Quantitative information related to the significant unobservable inputs
Counterparty risk (as a percent)	1.29%
Put Options | Weighted Average
Quantitative information related to the significant unobservable inputs
Counterparty risk (as a percent)	0.89%