Derivative Investments (Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 134,916		$ 169,314
Liability Derivatives	153,437	[1]	187,399	[1]
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	134,916		169,314
Liability Derivatives	153,437		187,399
Derivatives Not Designated as Hedging Instruments [Member] | Equity Index Options [Member] | Derivatives, Index Options [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	134,916		169,314
Derivatives Not Designated as Hedging Instruments [Member] | Fixed-Index Products [Member] | Universal Life and Annuity Contracts [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 153,437		$ 187,399

[1] Represents the fair value of certain product-related embedded derivatives that were recorded at fair value.