Derivative Instruments - Gross amounts of derivative fair values contained in the consolidated balance sheet (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Gross amounts recognized in balance sheet	$ 82,050		$ 27,487
Asset derivative fair value	74,471		26,145
Gross amounts recognized in balance sheet	40,423		105,485
Liability derivative fair value	32,844		104,143
Derivatives designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	1,688,527		1,005,610
Gross amounts recognized in balance sheet	68,095	[1]	26,098	[1]
Liability derivative notional amount	340,822		2,572,227
Gross amounts recognized in balance sheet	2,309	[1]	70,462	[1]
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	1,013,724		172,800
Gross amounts recognized in balance sheet	13,955	[1]	1,389	[1]
Liability derivative notional amount	5,870,225		513,512
Gross amounts recognized in balance sheet	38,114	[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	741,062		30,702
Gross amounts recognized in balance sheet	245	[1]	266	[1]
Liability derivative notional amount	27,690		10,259
Gross amounts recognized in balance sheet	9	[1]	8	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	119,272		17,497
Gross amounts recognized in balance sheet	1,693	[1]	12	[1]
Liability derivative notional amount	225,757		50,614
Gross amounts recognized in balance sheet	7,754	[1]	680	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Credit exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	2,221		0
Gross amounts recognized in balance sheet	198	[1]	0	[1]
Liability derivative notional amount	14,270		340,020
Gross amounts recognized in balance sheet	9,997	[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	36,974		58,232
Gross amounts recognized in balance sheet	222	[1]	1,111	[1]
Liability derivative notional amount	46,282		14,821
Gross amounts recognized in balance sheet	537	[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	37,188	[2]	44,234	[2]
Gross amounts recognized in balance sheet	8,220	[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	48,327		0
Gross amounts recognized in balance sheet	11,597	[1]	0	[1]
Liability derivative notional amount	48,327		53,564
Gross amounts recognized in balance sheet	11,597	[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	65,868	[3]	66,369	[3]
Gross amounts recognized in balance sheet	0	[1],[3]	0	[1],[3]
Liability derivative notional amount	5,470,711	[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 intention 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 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.