FAIR VALUE MEASUREMENTS: (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Available for Sale:
Amortized Cost	$ 92,629	$ 65,844
Fair Value	94,053	65,288
Unrealized Gains	1,427	402
Unrealized Losses	(3)	(958)
Auction rate security
Available for Sale:
Amortized Cost	8,410	8,410
Fair Value	9,485	7,453
Unrealized Gains	1,075
Unrealized Losses		(957)
Available for sale, non-current	9,485
Auction rate securities, original cost	13,550
Minimum period estimated by the entity for the ARS market to improve	12 months
Auction rate security \| Minimum
Available for Sale:
Trading price as a percentage of the original par value	71.00%
Auction rate security \| Maximum
Available for Sale:
Trading price as a percentage of the original par value	76.00%
Municipal bonds
Available for Sale:
Amortized Cost	84,199	57,389
Fair Value	84,551	57,791
Unrealized Gains	352	402
Mutual funds
Available for Sale:
Amortized Cost	20	45
Fair Value	17	44
Unrealized Losses	$ (3)	$ (1)

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

Total of debt securities categorized neither as held-to-maturity nor trading which are intended be sold or mature more than one year from the balance sheet date or operating cycle, if longer.

+ References

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+ Details

- Definition

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.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details