Fair Value ( Assets and Liabilities Measured - Quantitative Information) (Details) - Level 3	Jun. 30, 2019	Dec. 31, 2018
Measurement Input, Mortality Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0002	0.0002
Measurement Input, Mortality Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.1131	0.1131
Measurement Input, Lapse Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0025	0.0025
Measurement Input, Lapse Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.1600	0.1600
Measurement Input, Utilization Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0000	0.0000
Measurement Input, Utilization Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.2500	0.2500
Measurement Input, Withdrawal Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0025	0.0025
Measurement Input, Withdrawal Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.1000	0.1000
Measurement Input, Long Term Equity Volatilities | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.1650	0.1650
Measurement Input, Long Term Equity Volatilities | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.2200	0.2200
Measurement Input, Entity Credit Risk | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0094	0.0191
Measurement Input, Entity Credit Risk | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.0243	0.0266