Derivatives (Details - Income Statement) (Derivates not designated as hedges [Member], USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	$ (903)	$ (40,353)	$ (43,138)	$ (63,457)
Foreign exchange forward contracts [Member] | Net foreign exchange gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	65,250	14,557	48,234	10,542
Foreign currency option contracts [Member] | Net foreign exchange gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	2,457	(1,066)	2,381	1,134
Futures contracts [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	(66,231)	(55,170)	(86,514)	(76,115)
Credit default swaps (protection purchased) [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	(306)	311	(551)	(341)
Credit default swaps (assumed risks) [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	770	(1,400)	1,607	(1,379)
Insurance-linked securities [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	(2,546)	2,676	(9,620)	3,814
Total return swaps [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	(115)	(212)	684	2,409
Interest rate swaps [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	(182)	(104)	641	393
Interest rate derivatives [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	0	0	0	(3,848)
Other [Member] | Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	0	55	0	(66)
Net foreign exchange gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	67,707	13,491	50,615	11,676
Net realized and unrealized investment gains and losses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in income	$ (68,610)	$ (53,844)	$ (93,753)	$ (75,133)