Investments Classified by Maturity Date (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, within One Year, Amortized Cost Basis, Percent of Total	11.00%
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value, Percent of Total	11.10%
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Amortized Cost Basis, Percent of Total	54.20%
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value, Percent of Total	54.30%
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized Cost Basis, Percent of Total	28.30%
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value, Percent of Total	28.00%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis, Percent of Total	6.50%
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value, Percent of Total	6.60%
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Percent of Total	100.00%
Available-for-sale Securities, Fair Value Disclosure	$ 288,926	$ 152,180
Available-for-sale Securities, Fair Value Disclosure, Percent of Total	100.00%
Fixed Maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	30,268
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	30,283
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	148,920
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	148,253
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	77,632
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	76,462
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	17,831
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	18,026
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	274,651
Available-for-sale Securities, Fair Value Disclosure	$ 273,024	$ 149,157