This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

No definition available.

FAIR VALUE (DETAILS) (USD $) In Thousands, unless otherwise specified			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Counterparty Settlement Agreement Liability [Member]	Sep. 30, 2012 Counterparty Settlement Agreement Liability [Member]	Sep. 30, 2012 Auction Rate Securities [Member]	Sep. 30, 2012 Auction Rate Securities [Member]	Sep. 30, 2012 Fair Value Inputs Level 1 [Member]	Dec. 31, 2011 Fair Value Inputs Level 1 [Member]	Sep. 30, 2012 Fair Value Inputs Level 2 [Member]	Dec. 31, 2011 Fair Value Inputs Level 2 [Member]	Sep. 30, 2012 Fair Value Inputs Level 3 [Member]	Dec. 31, 2011 Fair Value Inputs Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Corporate Debt Securities Fair Value Disclosure	$ 326,357	$ 138,166					$ 4,155	$ 0	$ 322,202	$ 138,166	$ 0	$ 0
US Treasury And Government Fair Value Disclosure	254,381	125,289					0	0	254,381	125,289	0	0
Auction Rate Securities Fair Value Disclosure	12,778	12,793					0	0	0	0	12,778	12,793
Asset Backed Securities Fair Value Disclosure	49,070	9,519					0	0	49,070	9,519	0	0
Total Assets Measured At Fair Value	642,586	285,767					4,155	0	625,653	272,974	12,778	12,793
Counterparty Settlement Agreement Liability Fair Value Disclosure	24,925						0		0		24,925
Total Liabilities Measured At Fair Value	24,925						0		0		24,925
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance					12,766	12,793
Transfers To (From) Level 3					0	0
Total Gains (Losses) Included In Other (Income) Expense, Net					0	0
Total Gains Included In Other Comprehensive Income					12	35
Purchases					0	0
Settlements					0	(50)
Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance					12,778	12,778
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance			0	0
Transfers To (From) Level 3			17,182	17,182
Total Losses (Gains) Included in Other Expense (Income)			7,743	7,743
Total Losses (Gains) Included in Other Comprehensive Income			0	0
Purchases			0	0
Settlements			0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance			$ 24,925	$ 24,925