Investments - Net Investment Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	$ 137,149	$ 122,470	$ 95,779
Investment expenses	(6,057)	(5,255)	(4,427)
Net investment income	131,092	117,215	91,352
Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	132,394	118,203	89,350
Cash and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	2,578	2,224	3,120
Loan to related party
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	1,865	1,797	1,857
Other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	$ 312	$ 246	$ 1,452

Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.

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+ References

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a),(b))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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