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Investments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified | 6 Months Ended
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Jun. 30, 2014 Individual Equity | Jun. 30, 2013
Investments Schedule [Abstract] |  |
Individual fixed maturity held in unrealized loss position | 88 |
Equity securities held in unrealized loss position | 1 |
Individual fixed maturity held in unrealized loss position | 26 |
Carrying value of investments | $ 11.1 |
Net realized investment gains (losses) | 0.3 | 0.6
Impairment losses recognized | $ 1.3 | $ 1.9

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- Definition Number of Equity Securities in Unrealized Loss Position + References No definition available. + Details
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- Definition Number Of Individual Fixed Maturity Securities In Unrealized Loss Position + References No definition available. + Details
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- Definition Number of Individual Investment Securities in Unrealized Loss Position Greater Than Twelve Months + References No definition available. + Details
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- Details
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- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26805-111562 + Details
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- Definition The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e25351-111560 + Details
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