Derivatives (Tables)

12 Months Ended

Dec. 31, 2011

Disclosure - Derivatives [Abstract]

Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value Text Block

	Asset		Liability		Net derivatives
	derivatives		derivatives		Net notional
December 31, 2011	at fair value		at fair value		exposure		Fair value
Derivatives not designated as hedges
Foreign exchange forward contracts	$	7,865	$	(5,816)	$	2,555,230	$	2,049
Foreign currency option contracts		1,074		(321)		110,079		753
Futures contracts		13,572		(14,173)		2,534,995		(601)
Credit default swaps (protection purchased)		92		(1,285)		94,961		(1,193)
Credit default swaps (assumed risks)		246		(772)		17,500		(526)
Insurance-linked securities (1)		—		(968)		136,375		(968)
Total return swaps		7,673		(640)		122,230		7,033
Interest rate swaps (2)		—		(7,992)		—		(7,992)
TBAs		747		(58)		104,315		689
Total derivatives	$	31,269	$	(32,025)			$	(756)
	Asset		Liability		Net derivatives
	derivatives		derivatives		Net notional
December 31, 2010	at fair value		at fair value		exposure		Fair value
Derivatives designated as hedges
Foreign exchange forward contracts (net investment hedge)	$	—	$	(1,160)	$	198,448	$	(1,160)
Total derivatives designated as hedges	$	—	$	(1,160)			$	(1,160)
Derivatives not designated as hedges
Foreign exchange forward contracts	$	27,880	$	(12,487)	$	1,770,448	$	15,393
Foreign currency option contracts		3,516		—		104,386		3,516
Futures contracts		30,593		(7,956)		1,756,811		22,637
Credit default swaps (protection purchased)		93		(2,407)		113,752		(2,314)
Credit default swaps (assumed risks)		533		(401)		27,500		132
Insurance-linked securities		1,320		(1,393)		88,765		(73)
Total return swaps		6,041		(12,848)		161,408		(6,807)
Interest rate swaps(2)		246		(6,033)		—		(5,787)
TBAs		363		(553)		149,065		(190)
Total derivatives not designated as hedges	$	70,585	$	(44,078)			$	26,507
Total derivatives	$	70,585	$	(45,238)			$	25,347

Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block]

		2011		2010		2009
Foreign exchange forward contracts		$	98,089	$	65,973	$	39,573
Foreign currency option contracts			(9,927)		6,368		5,734
Total included in net foreign exchange gains and losses		$	88,162	$	72,341	$	45,307
Futures contracts		$	(185,816)	$	(81,789)	$	(10,147)
Credit default swaps (protection purchased)			(352)		(2,155)		(15,535)
Credit default swaps (assumed risks)			886		918		7,062
Insurance-linked securities			(9,584)		10,241		3,524
Total return swaps			2,473		4,029		22,083
Interest rate swaps			(2,200)		2,374		4,190
Interest rate derivatives			—		(3,848)		—
TBAs			15,366		1,737		(858)
Other			—		(158)		107
Total included in net realized and unrealized
	investment gains and losses	$	(179,227)	$	(68,651)	$	10,426
Total derivatives		$	(91,065)	$	3,690	$	55,733