Fair Value Measurements - Schedule of Valuation Method for Material Financial Instruments (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Embedded Derivative - GMWB $ (2,843) $ (1,094)
Mortality 80.00% 80.00%
Lapse, low end 0.00% 0.00%
Lapse, high end 16.00% 16.00%
Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Benefit Utilization 0.00% 0.00%
Nonperformance Risk 0.75% 0.73%
Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Benefit Utilization 80.00% 80.00%
Nonperformance Risk 1.37% 1.35%