Schedule II - Condensed Financial Information Of The Registrant (Condensed Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net investment income	$ 110,685	$ 115,511	$ 125,046	$ 122,583	$ 134,046	$ 142,143	$ 131,224	$ 123,157	$ 473,825	$ 530,570	$ 548,509
Net realized capital gains (losses)	10,507	(159,971)	(24,178)	(10,505)	13,352	(9,448)	59,016	21,126	(184,147)	84,046	300,227
Other income (expense)									60,435	18,437	(5,487)
Total revenues									5,837,889	5,790,589	5,640,836
Interest expense - affiliated									36,191	38,533	46,118
Total expenses	1,091,298	1,258,812	1,149,529	1,070,296	1,097,284	1,191,389	1,077,798	916,049	4,629,380	4,344,474	4,085,870
INCOME (LOSS) BEFORE TAXES									1,208,509	1,446,115	1,554,966
Income tax expense (benefit)									134,021	187,652	289,706
NET INCOME (LOSS)	$ 392,374	$ 107,572	$ 235,472	$ 339,070	$ 357,263	$ 301,253	$ 297,925	$ 302,022	1,074,488	1,258,463	1,265,260
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period									(274,127)	704	(395,797)
Reclassification adjustment for realized losses (gains) included in net income (loss)									(93,688)	(21,392)	6,977
Total URA(D) on securities arising during the period									(180,439)	22,096	(402,774)
Foreign currency translation adjustments									(111,530)	(95,417)	(162)
Benefit plan actuarial net gain (loss) for the period									5,681	(39,110)	17,837
Reclassification adjustment for amortization of net (gain) loss included in net income (loss)									6,216	3,020	5,778
Total benefit plan net gain (loss) for the period									11,897	(36,090)	23,615
Total other comprehensive income (loss), net of tax									(280,072)	(109,411)	(379,321)
COMPREHENSIVE INCOME (LOSS)									697,797	1,089,745	880,061
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income									3,895	824	982
Net realized capital gains (losses)									(3,057)	15
Other income (expense)									(459)	(574)	(902)
Net income (loss) of subsidiaries									997,730	1,214,334	1,275,955
Total revenues									998,109	1,214,599	1,276,035
Interest expense - affiliated									4,300
Other expenses									15,940	15,443	16,653
Total expenses									20,240	15,443	16,653
INCOME (LOSS) BEFORE TAXES									$ 977,869	$ 1,199,156	$ 1,259,382
Income tax expense (benefit)
NET INCOME (LOSS)									$ 977,869	$ 1,199,156	$ 1,259,382
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period									(274,127)	704	(395,797)
Reclassification adjustment for realized losses (gains) included in net income (loss)									(93,688)	(21,392)	6,977
Total URA(D) on securities arising during the period									(180,439)	22,096	(402,774)
Foreign currency translation adjustments									(111,530)	(95,417)	(162)
Benefit plan actuarial net gain (loss) for the period									5,681	(39,110)	17,837
Reclassification adjustment for amortization of net (gain) loss included in net income (loss)									6,216	3,020	5,778
Total benefit plan net gain (loss) for the period									11,897	(36,090)	23,615
Total other comprehensive income (loss), net of tax									(280,072)	(109,411)	(379,321)
COMPREHENSIVE INCOME (LOSS)									$ 697,797	$ 1,089,745	$ 880,061