Investments (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale, by contractual maturity
Less than one year, Carrying Value	$ 15,019
One to five years, Carrying Value	29,431
Five to ten years, Carrying Value	18,914
More than ten years, Carrying Value	101,923
Total, Carrying Value	176,376	144,514
Less than one year, Fair Value	15,066
One to five years, Fair Value	29,791
Five to ten years, Fair Value	19,608
More than ten years, Fair Value	105,581
Total, Fair Value	180,112	149,139
U.S. agency-based mortgage-backed securities [Member]
Schedule of Available For Sale securities [Line Items]
U.S. agency-based mortgage-backed securities, Carrying Value	11,089
U.S. agency-based mortgage-backed securities, Fair Value	$ 10,066

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