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FAIR VALUE MEASUREMENT AND FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 3) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2015
Quantitative information |  |
Available-for-sale investment securities, at fair value | $ 2,626,617 | $ 3,773,226
Corporate debt securities: | Non-investment grade |  |
Quantitative information |  |
Available-for-sale investment securities, at fair value | 14,681 | 9,642
Fair Value, Measurements, Recurring | Fair Value Measurements (Level 3) |  |
Quantitative information |  |
Available-for-sale investment securities, at fair value | 6,528 | 0
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Fair Value Measurements (Level 3) |  |
Quantitative information |  |
Derivative liabilities | (3,392) |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Fair Value Measurements (Level 3) |  |
Quantitative information |  |
Derivative liabilities | $ (3,392) |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Fair Value Measurements (Level 3) | Minimum |  |
Quantitative information |  |
Credit risk | 0.12% |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Fair Value Measurements (Level 3) | Maximum |  |
Quantitative information |  |
Credit risk | 0.14% |
Fair Value, Measurements, Recurring | Embedded derivative liabilities | Discounted cash flow | Fair Value Measurements (Level 3) | Weighted Average |  |
Quantitative information |  |
Credit risk | 0.13% |
Fair Value, Measurements, Recurring | Corporate debt securities: | Non-investment grade | Fair Value Measurements (Level 3) |  |
Quantitative information |  |
Available-for-sale investment securities, at fair value | $ 6,528 | $ 0
Fair Value, Measurements, Recurring | Corporate debt securities: | Non-investment grade | Discounted cash flow | Fair Value Measurements (Level 3) |  |
Quantitative information |  |
Available-for-sale investment securities, at fair value | $ 6,528 |
Loss severity | 85.00% |
Fair Value, Measurements, Recurring | Corporate debt securities: | Non-investment grade | Discounted cash flow | Fair Value Measurements (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 | Fair Value Measurements (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 | Fair Value Measurements (Level 3) | Weighted Average |  |
Quantitative information |  |
Constant prepayment rate | 0.73% |
Constant default rate | 0.87% |
Loss severity | 85.00% |
Discount margin | 6.94% |

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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=51813488&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=49167202&loc=d3e26610-111562 + Details
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