Investments (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale, by contractual maturity
Due in 2013, Amortized Cost	$ 7,239
In 2014 through 2017, Amortized cost	24,641
In 2018 through 2022, Amortized cost	18,708
After 2021, Amortized cost	81,985
U.S. agency-based mortgage-backed securities, Amortized Cost	11,941
Total, Amortized Cost	144,514	98,077
Due in 2013, Fair value	7,223
In 2014 through 2017, Fair value	25,003
In 2018 through 2022, Fair value	19,342
After 2021, Fair value	86,484
U.S. agency-based mortgage-backed securities, Fair Value	11,087
Total, Fair Value	$ 149,139