Fair Values of Financial Instruments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) Basis_Points	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Basis_Points	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Level 1 to Level 2 transfers, amount	$ 0		$ 0		$ 0
Liabilities, Level 1 to Level 2 transfers, amount	0		0		0
Assets, Level 2 to Level 1 transfers, amount	0		0		0
Liabilities, Level 2 to Level 1 transfers, amount	0		0		0
Assets, transfers into Level 3, amount	0	$ 0	0	$ 0
Liabilities, transfers into Level 3, amount	0	0	0	0
Assets, transfers out of Level 3, amount	0	0	0	0
Liabilities, transfers out of Level 3, amount	0	$ 0	0	$ 0
Other investments	$ 297,068		$ 297,068		$ 291,530
Expected cost of annual call options	3.10%		3.10%		3.10%
Mortality rate assumption	65.00%		65.00%
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	$ 0		$ 0
Fair Value, Sensitivity, Increase in Discount Rate by 10 Percent [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, sensitivity, discount rate adjustment (basis points) | Basis_Points	100		100
Fixed index annuities embedded derivative, adjustment due to change in discount rate			$ (475,400)
Deferred policy scquisition costs and deferred sales inducements, combined balance, adjustment due to change in discount rate			$ (283,700)
Fair Value, Sensitivity, Decrease in Discount Rate by 10 Percent [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, sensitivity, discount rate adjustment (basis points) | Basis_Points	100		100
Fixed index annuities embedded derivative, adjustment due to change in discount rate			$ 532,700
Deferred policy scquisition costs and deferred sales inducements, combined balance, adjustment due to change in discount rate			$ 313,500