Schedule II - Condensed Financial Information Of The Registrant (Condensed Statements Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net investment income	$ 74,441	$ 83,446	$ 68,636	$ 63,787	$ 69,563	$ 68,828	$ 81,736	$ 76,869	$ 290,310	$ 296,996	$ 306,145
Total net realized capital gains (losses)	85,775	(160)	125,114	(4,050)	189,391	208,426	15,526	309,806	206,679	723,149	391,702
Other income (expense)									(22,278)	(7,714)	12,136
Total revenues									2,588,437	3,018,792	2,483,881
Interest expense									37,970	45,452	50,746
Corporate expenses									7,252	8,262	8,764
Total expenses	527,768	510,371	453,997	393,391	498,118	427,626	453,548	380,285	1,930,749	1,813,291	1,790,557
INCOME (LOSS) BEFORE TAXES									657,688	1,205,501	693,324
Income tax expense (benefit)									203,562	407,238	172,995
NET INCOME (LOSS)	109,345	100,141	158,174	86,466	183,597	243,753	85,262	285,651	454,126	798,263	520,329
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period									(44,902)	(99,241)	9,390
Less: reclassification adjustment for realized losses (gains) included in net income (loss)									27,073	(2,465)	633
Total URA(D) on securities arising during the period									(17,829)	(101,706)	10,023
Foreign currency translation adjustments									(29,210)	(19,128)	7,030
Benefit plan actuarial net gain (loss) for the period									(39,110)	17,837	(11,771)
Reclassification adjustment for amortization of net (gain) loss included in net income (loss)									3,020	5,778	4,795
Total benefit plan net gain (loss) for the period									(36,090)	23,615	(6,976)
Total other comprehensive income (loss), net of tax									(83,129)	(97,219)	10,077
COMPREHENSIVE INCOME (LOSS)									370,997	701,044	530,406
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income									32,774	23,451	21,526
Total net realized capital gains (losses)									149,932	467,999	254,680
Other income (expense)									(309)	(420)	(371)
Net income (loss) of subsidiaries									364,869	511,976	377,963
Total revenues									547,266	1,003,006	653,798
Interest expense									37,970	45,452	50,685
Corporate expenses									5,070	6,065	7,108
Total expenses									43,040	51,517	57,793
INCOME (LOSS) BEFORE TAXES									504,226	951,489	596,005
Income tax expense (benefit)									50,100	153,226	75,676
NET INCOME (LOSS)									454,126	798,263	520,329
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period									(44,902)	(99,241)	9,390
Less: reclassification adjustment for realized losses (gains) included in net income (loss)									27,073	(2,465)	633
Total URA(D) on securities arising during the period									(17,829)	(101,706)	10,023
Foreign currency translation adjustments									(29,210)	(19,128)	7,030
Benefit plan actuarial net gain (loss) for the period									(39,110)	17,837	(11,771)
Reclassification adjustment for amortization of net (gain) loss included in net income (loss)									3,020	5,778	4,795
Total benefit plan net gain (loss) for the period									(36,090)	23,615	(6,976)
Total other comprehensive income (loss), net of tax									(83,129)	(97,219)	10,077
COMPREHENSIVE INCOME (LOSS)									$ 370,997	$ 701,044	$ 530,406