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Investments (Number of Securities in an Unrealized Unrecognized Loss Position) (Details) $ in Thousands | Mar. 31, 2016 USD ($) Securities | Dec. 31, 2015 USD ($) Securities
--- | --- | ---
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Unrealized Unrecognized Loss | $ 8,120 | $ 24,859
Eighty Percent to Ninety-Nine Percent [Member] |  |
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Number Of Securities In An Unrealized/Unrecognized Loss Position | Securities | 252 | 606
Unrealized Unrecognized Loss | $ 8,120 | $ 22,971
Sixty Percent to Seventy-Nine Percent [Member] |  |
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Number Of Securities In An Unrealized/Unrecognized Loss Position | Securities | 0 | 3
Unrealized Unrecognized Loss | $ 0 | $ 1,888
Forty Percent to Fifty-Nine Percent [Member] |  |
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Number Of Securities In An Unrealized/Unrecognized Loss Position | Securities | 0 | 0
Unrealized Unrecognized Loss | $ 0 | $ 0
Twenty Percent to Thirty-Nine Percent [Member] |  |
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Number Of Securities In An Unrealized/Unrecognized Loss Position | Securities | 0 | 0
Unrealized Unrecognized Loss | $ 0 | $ 0
Zero Percent to Nineteen Percent [Member] |  |
Schedule of Available-for-sale and held-to-maturity Securities [Line Items] |  |
Number Of Securities In An Unrealized/Unrecognized Loss Position | Securities | 0 | 0
Unrealized Unrecognized Loss | $ 0 | $ 0

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- Definition This item represents the sum of (i) the excess of amortized cost over fair value for available-for-sale securities that are in a loss position and (ii) the market fluctuations on held-to-maturity securities from the later of (a) the date a security is designated as held-to-maturity; or (b) the date that an other-than-temporary impairment charge is recognized on a held-to-maturity security for securities that are in an unrecognized loss position. + References No definition available. + Details
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