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FAIR VALUE MEASUREMENT AND FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 4) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Jun. 30, 2015
Quantitative information |  |  |
Available-for-sale investment securities |  | $ 2,626,365 | $ 2,982,146
Derivative liabilities |  | (56,493) | (54,746)
Corporate debt securities | Non-investment grade |  |  |
Quantitative information |  |  |
Available-for-sale investment securities | [1] | 14,681 | 10,025
Fair Value, Measurements, Recurring |  |  |
Quantitative information |  |  |
Available-for-sale investment securities |  | 2,626,365 | 2,982,146
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) |  |  |
Quantitative information |  |  |
Available-for-sale investment securities |  | 6,528 |
Fair Value, Measurements, Recurring | Embedded derivative liabilities |  |  |
Quantitative information |  |  |
Derivative liabilities |  | (3,392) |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Significant Unobservable Inputs (Level 3) |  |  |
Quantitative information |  |  |
Derivative liabilities |  | (3,392) |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Significant Unobservable Inputs (Level 3) |  |  |
Quantitative information |  |  |
Derivative liabilities |  | $ (3,392) |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Minimum |  |  |
Quantitative information |  |  |
Credit risk |  | 0.12% |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Maximum |  |  |
Quantitative information |  |  |
Credit risk |  | 0.14% |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Weighted Average |  |  |
Quantitative information |  |  |
Credit risk |  | 0.13% |
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade |  |  |
Quantitative information |  |  |
Available-for-sale investment securities |  | $ 14,681 | $ 10,025
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade | Significant Unobservable Inputs (Level 3) |  |  |
Quantitative information |  |  |
Available-for-sale investment securities |  | 6,528 |
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade | Discounted cash flow | Significant Unobservable Inputs (Level 3) |  |  |
Quantitative information |  |  |
Available-for-sale investment securities |  | $ 6,528 |
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Minimum |  |  |
Quantitative information |  |  |
Constant prepayment rate |  | 0.00% |
Constant default rate |  | 0.75% |
Discount margin |  | 4.50% |
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Maximum |  |  |
Quantitative information |  |  |
Constant prepayment rate |  | 1.00% |
Constant default rate |  | 1.20% |
Discount margin |  | 7.50% |
Fair Value, Measurements, Recurring | Corporate debt securities | Non-investment grade | Discounted cash flow | Significant Unobservable Inputs (Level 3) | Weighted Average |  |  |
Quantitative information |  |  |
Constant prepayment rate |  | 0.73% |
Constant default rate |  | 0.87% |
Loss severity |  | 85.00% |
Discount margin |  | 6.94% |
[1] | Available-for-sale investment securities rated BBB- or higher by S&P or Baa3 or higher by Moody's are considered investment grade. Conversely, available-for-sale investment securities rated lower than BBB- by S&P or lower than Baa3 by Moody's are considered non-investment grade.

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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + 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 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13495-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 + Details
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