Investment Information (Details - Summary of Available For Sale Securities) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	$ 10,905,082,000	$ 10,535,007,000
Gross unrealized gains	341,384,000	316,500,000
Gross unrealized losses	(145,694,000)	(85,050,000)
Cost or amortized cost	10,709,392,000	10,303,557,000
OTTI unrealized losses	(45,730,000)	(47,033,000)
Available for sale securities, other details
OTTI unrealized losses at current fair value	13,800,000	7,100,000
Fixed maturities fair value [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	9,602,233,000	9,033,434,000
Gross unrealized gains	321,747,000	268,715,000
Gross unrealized losses	(94,610,000)	(79,802,000)
Cost or amortized cost	9,375,096,000	8,844,521,000
OTTI unrealized losses	(45,730,000)	(47,033,000)
Fixed maturities fair value [Member] | Corporate bonds [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	2,766,651,000	2,714,375,000
Gross unrealized gains	93,418,000	97,400,000
Gross unrealized losses	(42,230,000)	(18,343,000)
Cost or amortized cost	2,715,463,000	2,635,318,000
OTTI unrealized losses	(17,607,000)	(18,047,000)
Fixed maturities fair value [Member] | Mortgage backed securities [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	1,545,321,000	1,806,813,000
Gross unrealized gains	32,503,000	18,801,000
Gross unrealized losses	(21,110,000)	(26,893,000)
Cost or amortized cost	1,533,928,000	1,814,905,000
OTTI unrealized losses	(20,676,000)	(21,147,000)
Fixed maturities fair value [Member] | Municipal bonds [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	1,422,943,000	1,182,100,000
Gross unrealized gains	66,880,000	40,410,000
Gross unrealized losses	(2,322,000)	(6,958,000)
Cost or amortized cost	1,358,385,000	1,148,648,000
OTTI unrealized losses	(105,000)	(125,000)
Fixed maturities fair value [Member] | Commercial mortgage backed securities [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	1,118,905,000	1,167,299,000
Gross unrealized gains	26,981,000	31,743,000
Gross unrealized losses	(4,230,000)	(6,028,000)
Cost or amortized cost	1,096,154,000	1,141,584,000
OTTI unrealized losses	(3,259,000)	(3,481,000)
Fixed maturities fair value [Member] | US government and government agencies [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	1,263,665,000	872,149,000
Gross unrealized gains	39,866,000	20,150,000
Gross unrealized losses	(536,000)	(5,696,000)
Cost or amortized cost	1,224,335,000	857,695,000
OTTI unrealized losses	(207,000)	(207,000)
Fixed maturities fair value [Member] | Non-US government securities [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	837,043,000	732,666,000
Gross unrealized gains	42,570,000	39,539,000
Gross unrealized losses	(15,610,000)	(11,894,000)
Cost or amortized cost	810,083,000	705,021,000
OTTI unrealized losses	0	(72,000)
Fixed maturities fair value [Member] | Asset backed securities [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	647,705,000	558,032,000
Gross unrealized gains	19,529,000	20,672,000
Gross unrealized losses	(8,572,000)	(3,990,000)
Cost or amortized cost	636,748,000	541,350,000
OTTI unrealized losses	(3,876,000)	(3,954,000)
Equity securities [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	273,213,000	310,194,000
Gross unrealized gains	9,049,000	20,660,000
Gross unrealized losses	(36,171,000)	(3,424,000)
Cost or amortized cost	300,335,000	292,958,000
OTTI unrealized losses	0	0
Other investments fair value [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	229,974,000	275,538,000
Gross unrealized gains	10,530,000	24,280,000
Gross unrealized losses	(6,645,000)	(1,332,000)
Cost or amortized cost	226,089,000	252,590,000
OTTI unrealized losses	0	0
Short-term investments [Member]
Fixed maturities and fixed maturities pledged under securities lending agreements:
Estimated fair value	799,662,000	915,841,000
Gross unrealized gains	58,000	2,845,000
Gross unrealized losses	(8,268,000)	(492,000)
Cost or amortized cost	807,872,000	913,488,000
OTTI unrealized losses	$ 0	$ 0