Consolidated Statements Of Operations And Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
REVENUES:
Premiums earned	$ 427,112	$ 442,862	$ 1,299,293	$ 1,354,305
Net investment income	76,342	78,325	231,790	249,916
Net realized capital gains (losses):
Other-than-temporary impairments on fixed maturity securities	(486)	(911)	(6,627)	(14,522)
Other-than-temporary impairments on fixed maturity securities transferred to other comprehensive income (loss)
Other net realized capital gains (losses)	96,429	(178,125)	361,300	(192,222)
Total net realized capital gains (losses)	95,943	(179,036)	354,673	(206,744)
Other income (expense)	425	(8,865)	19,599	(20,401)
Total revenues	599,822	333,286	1,905,355	1,377,076
CLAIMS AND EXPENSES:
Incurred losses and loss adjustment expenses	242,877	322,099	786,851	1,187,936
Commission, brokerage, taxes and fees	70,464	70,842	251,320	239,659
Other underwriting expenses	45,938	42,708	126,551	120,148
Corporate expenses	2,019	1,143	5,317	3,498
Interest, fee and bond issue cost amortization expense	12,682	12,706	38,061	38,083
Total claims and expenses	373,980	449,498	1,208,100	1,589,324
INCOME (LOSS) BEFORE TAXES	225,842	(116,212)	697,255	(212,248)
Income tax expense (benefit)	69,857	(116,473)	200,893	(123,783)
NET INCOME (LOSS)	155,985	261	496,362	(88,465)
Other comprehensive income (loss), net of tax :
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period	18,036	8,842	23,511	12,640
Less: reclassification adjustment for realized losses (gains) included in net income (loss)	261	(1,049)	1,696	19,661
Total URA(D) on securities arising during the period	18,297	7,793	25,207	32,301
Foreign currency translation adjustments	15,301	(4,558)	12,737	4,695
Pension adjustments	1,199	746	3,166	2,238
Other comprehensive income (loss), net of tax	34,797	3,981	41,110	39,234
COMPREHENSIVE INCOME (LOSS)	$ 190,782	$ 4,242	$ 537,472	$ (49,231)