Consolidated Statements Of Operations And Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
REVENUES:
Premiums earned	$ 2,006,361	$ 1,773,898	$ 1,793,855
Net investment income	296,996	306,145	312,933
Net realized capital gains (losses):
Other-than-temporary impairments on fixed maturity securities		(6,634)	(14,522)
Other-than-temporary impairments on fixed maturity securities transferred to other comprehensive income (loss)
Other net realized capital gains (losses)	723,149	398,336	(26,594)
Total net realized capital gains (losses)	723,149	391,702	(41,116)
Other income (expense)	(7,714)	12,136	(11,745)
Total revenues	3,018,792	2,483,881	2,053,927
CLAIMS AND EXPENSES:
Incurred losses and loss adjustment expenses	1,272,156	1,249,744	1,877,603
Commission, brokerage, taxes and fees	293,922	310,699	338,655
Other underwriting expenses	193,499	170,604	154,331
Corporate expenses	8,262	8,764	6,073
Interest, fee and bond issue cost amortization expense	45,452	50,746	50,763
Total claims and expenses	1,813,291	1,790,557	2,427,425
INCOME (LOSS) BEFORE TAXES	1,205,501	693,324	(373,498)
Income tax expense (benefit)	407,238	172,995	(170,677)
NET INCOME (LOSS)	798,263	520,329	(202,821)
Other comprehensive income (loss), net of tax :
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period	(99,241)	9,390	22,049
Less: reclassification adjustment for realized losses (gains) included in net income (loss)	(2,465)	633	20,240
Total URA(D) on securities arising during the period	(101,706)	10,023	42,289
Foreign currency translation adjustments	(19,128)	7,030	(2,805)
Benefit plan actuarial net gain (loss) for the period	17,837	(11,771)	(31,776)
Reclassification on amortization of net gain (loss) included in net income (loss)	5,778	4,795	2,324
Total benefit plan net gain (loss) for the period	23,615	(6,976)	(29,452)
Total other comprehensive income (loss), net of tax	(97,219)	10,077	10,032
COMPREHENSIVE INCOME (LOSS)	$ 701,044	$ 530,406	$ (192,789)