INVESTMENTS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Investments, Current
Cost	$ 5,422,111	$ 5,462,613
Available For Sale Debt Securities Gross Unrealized Gain Accumulated in Investments	596	483
Available For Sale Securities Gross Unrealized Loss Accumulated in Investments	(349)	(376)
Fair Value	5,422,358	5,462,720
Foreign government securities [Member]
Investments, Current
Cost	3,823,066	4,019,530
Available For Sale Debt Securities Gross Unrealized Gain Accumulated in Investments	242	233
Available For Sale Securities Gross Unrealized Loss Accumulated in Investments	(328)	(356)
Fair Value	3,822,980	4,019,407
U.S. government securities [Member]
Investments, Current
Cost	1,599,045	1,443,083
Available For Sale Debt Securities Gross Unrealized Gain Accumulated in Investments	354	250
Available For Sale Securities Gross Unrealized Loss Accumulated in Investments	(21)	(20)
Fair Value	$ 1,599,378	$ 1,443,313

Amount of accumulated pre-tax unrealized gains before deducting pre-tax unrealized losses on investments in available-for-sale securities impacting investments.

No definition available.

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- Definition

Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in available-for-sale securities impacting investments.

+ References

No definition available.

+ Details

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- Definition

This item represents the cost of debt 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

No definition available.

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- Definition

Amount of investments in debt securities classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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