Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Notional Value
Total Derivatives	$ 15,158,667	[1]	$ 10,959,486	[1]
Fair Value Asset
Total Derivatives	73,535	[1]	174,087	[1]
Fair Value Liability
Total Derivatives	94,580	[1]	42,352	[1]
Designated as Hedging Instrument [Member]
Notional Value
Qualifying Hedge Relationships	72,247		65,612
Fair Value Asset
Derivative Fair Value Of Derivative Asset	940		192
Fair Value Liability
Derivative Fair Value Of Derivative Liability	4,635		3,309
Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	15,086,420		10,893,874
Fair Value Asset
Derivative Fair Value Of Derivative Asset	72,595		173,895
Fair Value Liability
Derivative Fair Value Of Derivative Liability	89,945		39,043
Interest Rate Contract [Member] | Interest Rate Swap Member | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	1,533,750		2,332,950
Fair Value Asset
Derivative Fair Value Of Derivative Asset	59,872		139,258
Fair Value Liability
Derivative Fair Value Of Derivative Liability	80,601		24,075
Interest Rate Contract [Member] | InterestRateOption [Member] | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	100,000		100,000
Fair Value Asset
Derivative Fair Value Of Derivative Asset	6,534		15,330
Fair Value Liability
Derivative Fair Value Of Derivative Liability	0		0
Credit Risk Contract [Member] | Credit Default Swap Member | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	6,050		345,050
Fair Value Asset
Derivative Fair Value Of Derivative Asset	0		411
Fair Value Liability
Derivative Fair Value Of Derivative Liability	115		1,413
Cross Currency Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Notional Value
Qualifying Hedge Relationships	72,247		65,612
Fair Value Asset
Derivative Fair Value Of Derivative Asset	940		192
Fair Value Liability
Derivative Fair Value Of Derivative Liability	4,635		3,309
Cross Currency Interest Rate Contract [Member] | Currency Swap Member | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	55,919		61,126
Fair Value Asset
Derivative Fair Value Of Derivative Asset	19		1,715
Fair Value Liability
Derivative Fair Value Of Derivative Liability	1,349		2,894
Equity Contract [Member] | Equity Options [Member] | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	13,170,805		7,800,982
Fair Value Asset
Derivative Fair Value Of Derivative Asset	6,170		16,988
Fair Value Liability
Derivative Fair Value Of Derivative Liability	3,168		6,920
Equity Contract [Member] | Total Return Swap Member | Nondesignated [Member]
Notional Value
Qualifying Hedge Relationships	219,896		253,766
Fair Value Asset
Derivative Fair Value Of Derivative Asset	0		193
Fair Value Liability
Derivative Fair Value Of Derivative Liability	$ 4,712		$ 3,741

[1] (1) Excludes embedded derivatives which contain multiple underlyings. The fair value of these embedded derivatives was a liability of $778 million and $1,793 million as of December 31, 2013 and December 31, 2012, respectively, included in “Future policy benefits.”