Derivative Instruments - Gross amounts of derivative fair values contained in the consolidated balance sheet (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Gross amounts recognized in balance sheet	$ 60,570		$ 27,487
Asset derivative fair value	59,330		26,145
Gross amounts recognized in balance sheet	69,640		105,485
Liability derivative fair value	68,400		104,143
Derivatives designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	891,217		1,005,610
Gross amounts recognized in balance sheet	45,597	[1]	26,098	[1]
Liability derivative notional amount	1,315,385		2,572,227
Gross amounts recognized in balance sheet	35,265	[1]	70,462	[1]
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	1,653,871		172,800
Gross amounts recognized in balance sheet	14,973	[1]	1,389	[1]
Liability derivative notional amount	5,943,417		513,512
Gross amounts recognized in balance sheet	34,375	[1]	35,023	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Interest rate exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	1,295,267		30,702
Gross amounts recognized in balance sheet	259	[1]	266	[1]
Liability derivative notional amount	28,090		10,259
Gross amounts recognized in balance sheet	0	[1]	8	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	190,870		17,497
Gross amounts recognized in balance sheet	1,914	[1]	12	[1]
Liability derivative notional amount	105,797		50,614
Gross amounts recognized in balance sheet	3,004	[1]	680	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Credit exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	4,566		0
Gross amounts recognized in balance sheet	3	[1]	0	[1]
Liability derivative notional amount	14,270		340,020
Gross amounts recognized in balance sheet	9,988	[1]	15,128	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Financial market exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	46,645		58,232
Gross amounts recognized in balance sheet	344	[1]	1,111	[1]
Liability derivative notional amount	43,468		14,821
Gross amounts recognized in balance sheet	0	[1]	77	[1]
Derivatives not designated as hedging instruments | Financial operations derivatives | Credit exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	0	[2]	0	[2]
Gross amounts recognized in balance sheet	0	[1],[2]	0	[1],[2]
Liability derivative notional amount	41,346	[2]	44,234	[2]
Gross amounts recognized in balance sheet	8,930	[1],[2]	4,190	[1],[2]
Derivatives not designated as hedging instruments | Other non-investment derivatives | Guaranteed minimum income benefit contract
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	50,802		0
Gross amounts recognized in balance sheet	12,453	[1]	0	[1]
Liability derivative notional amount	50,802		53,564
Gross amounts recognized in balance sheet	12,453	[1]	14,940	[1]
Derivatives not designated as hedging instruments | Other non-investment derivatives | Modified coinsurance funds withheld contract
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	65,721	[3]	66,369	[3]
Gross amounts recognized in balance sheet	0	[1],[3]	0	[1],[3]
Liability derivative notional amount	5,659,644	[3]	0	[3]
Gross amounts recognized in balance sheet	$ 0	[1],[3]	$ 0	[1],[3]

[1] Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intentions to settle the contracts on a net basis.

[2] Financial operations derivatives represent interests in variable interest entities as described in Note 12, “Variable Interest Entities".

[3] The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the the associated asset or liability at each period end on the face of the balance sheets. Notional amounts associated with reinsurance agreements under which the Company assumes reinsurance risk are recorded as asset derivative notional amounts. Notional amounts associated with the Life Retro Arrangements under which the Company cedes reinsurance risk are recorded as liability derivative notional amounts.