v3.2.0.727

Investments (Available-For-Sale Investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	$ 13,590,550	$ 13,475,614
Available-for-sale investments, gross unrealized holding gains	2,556,837	2,714,911
Available-for-sale investments, gross unrealized holding losses	(59,893)	(31,141)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(3,920)	(4,077)
Available-for-sale investments, estimated fair value	16,083,574	16,155,307
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	638,848	662,462
Available-for-sale investments, gross unrealized holding gains	10,695	12,963
Available-for-sale investments, gross unrealized holding losses	(3,855)	(2,163)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	645,688	673,262
Obligations Of States, Municipalities And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	3,862,159	4,075,748
Available-for-sale investments, gross unrealized holding gains	165,902	245,158
Available-for-sale investments, gross unrealized holding losses	(17,030)	(3,359)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	4,011,031	4,317,547
Foreign Governments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,343,152	1,458,255
Available-for-sale investments, gross unrealized holding gains	113,536	154,707
Available-for-sale investments, gross unrealized holding losses	(1,056)	(1,041)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	1,455,632	1,611,921
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	427,372	427,904
Available-for-sale investments, gross unrealized holding gains	3,530	5,325
Available-for-sale investments, gross unrealized holding losses	(1,865)	(2,602)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	429,037	430,627
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	890,612	954,263
Available-for-sale investments, gross unrealized holding gains	23,564	34,324
Available-for-sale investments, gross unrealized holding losses	(4,273)	(3,482)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(2,258)	(2,258)
Available-for-sale investments, estimated fair value	907,645	982,847
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	65,752	100,073
Available-for-sale investments, gross unrealized holding gains	58	99
Available-for-sale investments, gross unrealized holding losses	(510)	(682)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	65,300	99,490
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,981,737	2,250,432
Available-for-sale investments, gross unrealized holding gains	45,276	69,016
Available-for-sale investments, gross unrealized holding losses	(16,520)	(10,441)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(1,662)	(1,819)
Available-for-sale investments, estimated fair value	2,008,831	2,307,188
Total Fixed Maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	9,209,632	9,929,137
Available-for-sale investments, gross unrealized holding gains	362,561	521,592
Available-for-sale investments, gross unrealized holding losses	(45,109)	(23,770)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(3,920)	(4,077)
Available-for-sale investments, estimated fair value	9,523,164	10,422,882
Insurance, Banks And Other Financial Institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	617,618	523,739
Available-for-sale investments, gross unrealized holding gains	735,581	789,717
Available-for-sale investments, gross unrealized holding losses	(1,350)	(1,531)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	1,351,849	1,311,925
Industrial, Consumer And All Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,578,072	1,427,919
Available-for-sale investments, gross unrealized holding gains	1,458,669	1,403,566
Available-for-sale investments, gross unrealized holding losses	(13,429)	(5,834)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	3,023,312	2,825,651
Total Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	2,195,690	1,951,658
Available-for-sale investments, gross unrealized holding gains	2,194,250	2,193,283
Available-for-sale investments, gross unrealized holding losses	(14,779)	(7,365)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	4,375,161	4,137,576
Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	2,185,228	1,594,819
Available-for-sale investments, gross unrealized holding gains	26	36
Available-for-sale investments, gross unrealized holding losses	(5)	(6)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	$ 2,185,249	$ 1,594,849

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