Fair Value of Assets and Liabilities (Quantiative Info for Level 3 Inputs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Fair Value Quantiative Information [Line Items]
Fixed maturities, available for sale, at fair value	3,948,208		4,203,450
Fair Value, Inputs, Level 3 [Member]
Fair Value Quantiative Information [Line Items]
Reinsurance Recoverables	1,191,409		1,732,094
Future policy benefits	1,230,323		1,793,137
Maximum [Member]
Fair Value Quantiative Information [Line Items]
Discount Rate	15.00%	[1]	17.50%
Volatility Curve	33.00%		34.00%
Call Price	100.00%	[1]	100.00%
Lapse Rate	14.00%	[1],[2]	14.00%	[2]
NPR Spread	1.52%	[1],[3]	1.60%	[3]
Utilization Rate	94.00%	[1],[4]	94.00%	[4]
Withdrawal Rate	100.00%	[1],[5]	100.00%	[5]
Mortality Rate	13.00%	[1],[6]	13.00%	[6]
Minimum [Member]
Fair Value Quantiative Information [Line Items]
Discount Rate	3.26%	[1]	3.27%
Volatility Curve	16.00%		19.00%
Call Price	100.00%	[1]	100.00%
Lapse Rate	0.00%	[1],[2]	0.00%	[2]
NPR Spread	0.18%	[1],[3]	0.20%	[3]
Utilization Rate	70.00%	[1],[4]	70.00%	[4]
Withdrawal Rate	85.00%	[1],[5]	85.00%	[5]
Mortality Rate	0.00%	[1],[6]	0.00%	[6]
Weighted Average[ Member]
Fair Value Quantiative Information [Line Items]
Discount Rate	3.65%	[1]	3.74%
Call Price	100.00%	[1]	100.00%
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Quantiative Information [Line Items]
Fixed maturities, available for sale, at fair value	93,484		92,263
Future Policy Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Quantiative Information [Line Items]
Future policy benefits	1,230,323		1,793,137

[1] Conversely, the impact of a decrease in input would have the opposite impact for the fair value as that presented in the table.

[2] Base lapse rates are adjusted at the contract level based on a comparison of the actuarially calculated guaranteed amount and the current contractholder account value as well as other factors, such as the applicability of any surrender charges. A dynamic lapse adjustment reduces the base lapse rate when the guaranteed amount is greater than the account value, as in-the-money contracts are less likely to lapse. Lapse rates are also generally assumed to be lower for the period where surrender charges apply.

[3] To reflect NPR, the Company incorporates an additional spread over LIBOR into the discount rate used in the valuation of individual living benefit contracts in a liability position and generally not to those in a contra-liability position. In determining the NPR spread, the Company believes it appropriate to reflect the financial strength ratings of the Company as these are insurance liabilities and senior to debt. The additional spread over LIBOR is determined taking into consideration publicly available information relating to the financial strength of the Company adjusted for any illiquidity risk premium.

[4] The utilization rate assumption estimates the percentage of contracts that will utilize the benefit during the contract duration, and begin lifetime withdrawals at various time intervals from contract inception. The remaining contractholders are assumed to either begin lifetime withdrawals immediately or never utilize the benefit. These assumptions vary based on the product type, the age of the contractholder, and the age of the contract. The impact of changes in these assumptions is highly dependent on the contract type and age of the contractholder at the time of the sale and the timing of the first lifetime income withdrawal.

[5] The withdrawal rate assumption estimates the magnitude of annual contractholder withdrawals relative to the maximum allowable amount under the contract. The fair value of the liability will generally increase the closer the withdrawal rate is to 100%.

[6] Range reflects the mortality rate for the vast majority of business with living benefits, with contractholders ranging from 35 to 90 years old. While the majority of living benefits have a minimum age requirement, certain benefits do not have an age restriction. This results in contractholders for certain benefits with mortality rates approaching 0%. Based on historical experience, the Company applies a set of age and duration specific mortality rate adjustments compared to standard industry tables. A mortality improvement assumption is also incorporated into the overall mortality table.