W. R. Berkley (WRB) 10-Q 8 Nov 13 2013 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'BERKLEY W R CORP	'
Entity Central Index Key	'0000011544	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	135,317,930

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments:	'	'
Fixed maturity securities	$11,612,047	$11,943,956
Equity securities	338,907	376,022
Arbitrage trading account	619,881	329,077
Investment funds	873,884	809,689
Loans receivable	411,851	401,961
Real estate	647,698	606,735
Total investments	14,504,268	14,467,440
Cash and cash equivalents	966,326	905,670
Premiums and fees receivable	1,585,773	1,440,752
Due from reinsurers	1,525,906	1,450,348
Accrued investment income	128,094	127,230
Prepaid reinsurance premiums	381,005	316,309
Deferred policy acquisition costs	452,695	404,047
Real estate, furniture and equipment	336,515	267,227
Federal and foreign income taxes - current and deferred	63,630	0
Goodwill	113,169	87,865
Trading account receivables from brokers and clearing organizations	123,320	446,873
Other assets	343,018	242,135
Total assets	20,523,719	20,155,896
Liabilities:	'	'
Reserves for losses and loss expenses	10,061,054	9,751,086
Unearned premiums	2,825,105	2,474,847
Due to reinsurers	285,152	316,388
Trading account securities sold but not yet purchased	88,489	121,487
Federal and foreign income taxes - current and deferred	0	82,801
Other liabilities	832,388	959,080
Junior subordinated debentures	339,772	243,206
Senior notes and other debt	1,696,461	1,871,535
Total liabilities	16,128,421	15,820,430
Equity:	'	'
Preferred stock, par value $.10 per share: Authorized 5,000,000 shares; issued and outstanding - none	0	0
Common stock, Value issued $.20 per share:Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 135,308,430 and 136,017,732 shares	47,024	47,024
Additional paid-in capital	961,304	945,166
Retained earnings	5,148,017	4,817,807
Accumulated other comprehensive income	217,479	465,631
Treasury stock, at cost, 99,979,546 and 99,100,186 shares, respectively	-2,006,750	-1,969,411
Total stockholders’ equity	4,367,074	4,306,217
Noncontrolling interests	28,224	29,249
Total equity	4,395,298	4,335,466
Total liabilities and equity	$20,523,719	$20,155,896

Consolidated_Balance_Sheets_Ba

Consolidated Balance Sheets Balance Sheet (Parentheticals) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Preferred Stock, Par or Stated Value Per Share	$0.10	$0.10
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$0.20	$0.20
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	135,058,372	136,017,732
Common Stock, Shares, Outstanding	135,058,372	136,017,732
Treasury Stock, Shares	100,059,546	99,100,186

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
REVENUES:	'	'	'	'
Net premiums written	$1,423,625	$1,275,887	$4,142,489	$3,670,404
Change in net unearned premiums	-94,763	-89,354	-298,993	-236,863
Net premiums earned	1,328,862	1,186,533	3,843,496	3,433,541
Net investment income	125,634	116,019	405,300	434,888
Insurance service fees	26,121	26,208	80,509	77,121
Net investment gains	43,869	17,226	96,896	84,989
Change in valuation allowance, net of other-than-temporary impairments	0	5,000	0	9,014
Revenues from wholly-owned investees	109,390	68,087	284,900	173,196
Other income	248	1,428	754	2,204
Total revenues	1,634,124	1,420,501	4,711,855	4,214,953
OPERATING COSTS AND EXPENSES:	'	'	'	'
Losses and loss expenses	798,276	736,632	2,348,425	2,147,306
Other operating costs and expenses	504,096	451,487	1,479,986	1,332,024
Expenses from wholly-owned investees	103,170	66,177	273,615	172,438
Interest expense	30,349	32,512	92,667	93,750
Total operating costs and expenses	1,435,891	1,286,808	4,194,693	3,745,518
Income before income taxes	198,233	133,693	517,162	469,435
Income tax expense	-60,045	-32,685	-147,249	-124,291
Net income before noncontrolling interests	138,188	101,008	369,913	345,144
Noncontrolling interests	-1,214	-61	-367	-41
Net income to common stockholders	$136,974	$100,947	$369,546	$345,103
NET INCOME PER SHARE:	'	'	'	'
Basic	$1.01	$0.74	$2.72	$2.51
Diluted	$0.97	$0.71	$2.62	$2.41

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income before noncontrolling interests	$138,188	$101,008	$369,913	$345,144
Other comprehensive income (loss):	'	'	'	'
Change in unrealized currency translation adjustments	44,328	26,056	-25,451	24,382
Change in unrealized investment gains (losses), net of taxes	-38,879	64,961	-228,129	126,520
Change in net pension asset, net of taxes	1,814	823	5,442	2,470
Other comprehensive income (loss)	7,263	91,840	-248,138	153,372
Comprehensive income	145,451	192,848	121,775	498,516
Comprehensive income to the noncontrolling interest	-1,223	-104	-381	-112
Comprehensive income to common stockholders	$144,228	$192,744	$121,394	$498,404

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common stocks	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Unrealized Investment Gains (Losses) [Member]	Currency Translation Adjustments [Member]	Net Pension Asset [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
In Thousands
Stockholders' Equity, beginning of period at Dec. 31, 2011	'	$47,024	$941,109	$4,491,162	'	$430,419	($61,239)	($14,329)	($1,880,790)	$7,526
Adjustments to Additional Paid in Capital Stock Issued During Period, Value, Stock Options Exercised, Value, Restricted Stock Issued Net of Tax Benefit Expense	'	'	-24,683	'	'	'	'	'	'	'
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	'	'	20,035	'	'	'	'	'	'	'
Stock issued to directors	'	'	454	'	'	'	'	'	581	'
Net income before noncontrolling interests	-345,144	'	'	-345,103	'	'	'	'	'	41
Dividends	'	'	'	-35,728	'	'	'	'	'	'
Unrealized investment gain related to non-controlling interest	126,520	'	'	'	'	123,579	'	'	'	'
Unrealized gains on other-than-temporarily impaired securities	'	'	'	'	'	2,870	'	'	'	'
Net change in period	24,382	'	'	'	'	'	24,382	'	'	'
Change in net pension asset, net of taxes	2,470	'	'	'	'	'	'	2,470	'	'
Stock exercised/vested	'	'	'	'	'	'	'	'	40,137	'
Stock repurchased	'	'	'	'	'	'	'	'	-128,155	'
Contributions (distributions)	'	'	'	'	'	'	'	'	'	1,808
Net income (loss)	-41	'	'	'	'	'	'	'	'	'
Other comprehensive income (loss), net of tax	153,372	'	'	'	'	'	'	'	'	71
Stockholders' Equity, end of period at Sep. 30, 2012	'	'	936,915	4,800,537	508,152	556,868	-36,857	-11,859	-1,968,227	9,446
Stockholders' Equity, beginning of period at Dec. 31, 2012	4,335,466	47,024	945,166	4,817,807	'	517,658	-36,676	-15,351	-1,969,411	29,249
Adjustments to Additional Paid in Capital Stock Issued During Period, Value, Stock Options Exercised, Value, Restricted Stock Issued Net of Tax Benefit Expense	'	'	-1,428	'	'	'	'	'	'	'
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	'	'	17,031	'	'	'	'	'	'	'
Stock issued to directors	'	'	535	'	'	'	'	'	597	'
Net income before noncontrolling interests	-369,913	'	'	-369,546	'	'	'	'	'	367
Dividends	'	'	'	-39,336	'	'	'	'	'	'
Unrealized investment gain related to non-controlling interest	-228,129	'	'	'	'	-228,677	'	'	'	'
Unrealized gains on other-than-temporarily impaired securities	'	'	'	'	'	534	'	'	'	'
Net change in period	-25,451	'	'	'	'	'	-25,451	'	'	'
Change in net pension asset, net of taxes	5,442	'	'	'	'	'	'	5,442	'	'
Stock exercised/vested	'	'	'	'	'	'	'	'	1,434	'
Stock repurchased	'	'	'	'	'	'	'	'	-39,370	'
Contributions (distributions)	'	'	'	'	'	'	'	'	'	-1,406
Net income (loss)	-367	'	'	'	'	'	'	'	'	'
Other comprehensive income (loss), net of tax	-248,138	'	'	'	-248,138	'	-25,451	5,442	'	14
Stockholders' Equity, end of period at Sep. 30, 2013	4,395,298	'	961,304	5,148,017	217,479	289,515	-62,127	-9,909	-2,006,750	28,224
Stockholders' Equity, beginning of period at Jun. 30, 2013	'	'	'	'	'	'	'	'	'	'
Net income before noncontrolling interests	-138,188	'	'	'	'	'	'	'	'	'
Unrealized investment gain related to non-controlling interest	-38,879	'	'	'	'	'	'	'	'	'
Net change in period	44,328	'	'	'	'	'	'	'	'	'
Change in net pension asset, net of taxes	1,814	'	'	'	'	'	'	'	'	'
Net income (loss)	-1,214	'	'	'	'	'	'	'	'	'
Other comprehensive income (loss), net of tax	7,263	'	'	'	7,263	'	44,328	1,814	'	'
Stockholders' Equity, end of period at Sep. 30, 2013	$4,395,298	'	'	'	$217,479	'	($62,127)	($9,909)	'	'

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
CASH FROM (USED IN) OPERATING ACTIVITIES:	'	'
Net income to common stockholders	$369,546	$345,103
Adjustments to reconcile net income to net cash from operating activities:	'	'
Net investment gains	-96,896	-94,003
Depreciation and amortization	80,049	65,089
Noncontrolling interests	367	41
Investment funds	-48,299	-50,124
Stock incentive plans	18,163	21,070
Change in:	'	'
Arbitrage trading account	-249	-2,355
Premiums and fees receivable	-161,660	-192,803
Reinsurance accounts	-168,863	-90,587
Deferred policy acquisition costs	-51,629	-34,843
Income taxes	-25,396	5,719
Reserves for losses and loss expenses	341,266	215,993
Unearned premiums	363,354	284,908
Other	6,942	-19,859
Net cash from (used in) operating activities	626,695	453,349
CASH FROM (USED IN) INVESTING ACTIVITIES:	'	'
Proceeds from sale of fixed maturity securities	891,357	549,876
Proceeds from sale of equity securities	222,396	233,239
Distributions from (contributions to) investment funds	-57,812	-6,293
Proceeds from maturities and prepayments of fixed maturity securities	2,244,665	1,659,751
Purchase of fixed maturity securities	-3,198,204	-2,510,322
Purchase of equity securities	-184,829	-218,490
Real estate purchased	-47,279	-71,348
Change in loans receivable	-99,356	-106,721
Net additions to real estate, furniture and equipment	-49,425	-22,319
Change in balances due to security brokers	-37,554	79,344
Cash distributed in connection with business disposition	-21,408	'
Payment for business purchased, net of cash acquired	-38,556	0
Net cash from (used in) investing activities	-376,005	-413,283
CASH FROM (USED IN) FINANCING ACTIVITIES:	'	'
Repayment of senior notes and other debt	-463,600	0
Net proceeds from issuance of debt	349,423	375,641
Net proceeds from stock options exercised	51	8,667
Cash dividends to common stockholders	-39,336	-35,730
Purchase of common treasury shares	-39,370	-121,362
Other, net	7,290	15,799
Net cash from (used in) financing activities	-185,542	243,015
Net impact on cash due to change in foreign exchange rates	-4,492	-5,259
Net change in cash and cash equivalents	60,656	277,822
Cash and cash equivalents at beginning of year	905,670	911,742
Cash and cash equivalents at end of period	$966,326	$1,189,564

General

General	9 Months Ended
	Sep. 30, 2013
General Policies Disclosure [Abstract]	'
General	'
	General
	The accompanying unaudited consolidated financial statements of W. R. Berkley Corporation and its subsidiaries (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all the information and notes required by GAAP for annual financial statements. The unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring items, which are necessary to present fairly the Company’s financial position and results of operations on a basis consistent with the prior audited consolidated financial statements. Operating results for interim periods are not necessarily indicative of the results that may be expected for the year. All significant intercompany accounts and transactions have been eliminated. The preparation of financial statements requires the use of management estimates. For further information related to a description of areas of judgment and estimates and other information necessary to understand the Company’s financial position and results of operations, refer to the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. Reclassifications have been made in the 2012 financial statements as originally reported to conform to the presentation of the 2013 financial statements.
	The income tax provision has been computed based on the Company’s estimated annual effective tax rate. The effective tax rate for the quarter differs from the federal income tax rate of 35% principally because of tax-exempt investment income.

Per_Share_Data

Per Share Data	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Per Share Data	'
	Per Share Data
	The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted EPS is based upon the weighted average number of common and common equivalent shares outstanding during the period and is calculated using the treasury stock method for stock incentive plans. Common equivalent shares are excluded from the computation in periods in which they have an anti-dilutive effect. Stock options for which the exercise price exceeds the average market price over the period have an anti-dilutive effect on EPS and, accordingly, are excluded from the calculation.
	The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows:
	(In thousands)	For the Three Months Ended		For the Nine Months Ended
		September 30,		September 30,
		2013	2012	2013	2012
	Basic	135,268	136,553	135,726	137,512
	Diluted	140,758	141,637	141,095	142,941

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board issued ASU 2013-02 relating to disclosures about items reclassified out of accumulated other comprehensive income ("AOCI"). The Company’s adoption of the updated guidance effective January 1, 2013 resulted in a change in the disclosures for AOCI in the Company’s consolidated financial statements but did not have any impact on the Company’s results of operations, financial position or liquidity.
	All recently issued but not yet effective accounting and reporting standards are either not applicable to the Company or are not expected to have a material impact on the Company.

Acquistions_Notes

Acquistions (Notes)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	In 2012, the Company acquired a 49% interest in a worldwide supplier of after-market original equipment manufacturer (OEM) parts, systems and custom logistic support services for military aircraft operations for $43 million. In January 2013, the Company acquired the remaining 51% of this business for $43 million. The estimated useful lives of the intangible assets acquired range from 2 years to 15 years, with approximately $3 million having an indefinite life.
	The following table summarizes the estimated fair value of net assets acquired and liabilities assumed at the date of acquisition:
	(In thousands)	Acquired in 2013
	Cash and cash equivalents	$	3,911
	Real estate, furniture and equipment	898
	Goodwill	19,664
	Intangible assets	44,800
	Other assets	60,661
	Total assets acquired	129,934
	Debt	(27,612		)
	Other liabilities assumed	(17,076		)
	Net assets acquired	$	85,246

Statements_of_Cash_Flow

Statements of Cash Flow	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow Information [Abstract]	'
Statements of Cash Flow	'
	Statements of Cash Flow
	Interest payments were $114,026,000 and $109,045,000 and income taxes paid were $176,632,000 and $114,343,000 in the nine months ended September 30, 2013 and 2012, respectively.

Statements_of_Comprehensive_In

Statements of Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Statement of Comprehensive Income (Loss)	'
	Statement of Comprehensive Income (Loss)
	The following table presents the components of the changes in accumulated other comprehensive income (loss) (AOCI):
		Unrealized Investment Gains				Currency Translation Adjustments			Net Pension Asset				Accumulated Other Comprehensive Income (Loss)
	As of and for the nine months ended September 30, 2013:
	(In thousands)
	Changes in AOCI
	Beginning of period	$	517,658			$	(36,676	)	$	(15,351	)		$	465,631
	Other comprehensive income (loss) before reclassifications	(172,276		)		(25,451		)	—				(197,727		)
	Amounts reclassified from AOCI	(55,853		)		—			5,442				(50,411		)
	Other comprehensive income (loss)	(228,129		)		(25,451		)	5,442				(248,138		)
	Unrealized investment gain related to non-controlling interest	(14		)		—			—				(14		)
	End of period	$	289,515			$	(62,127	)	$	(9,909	)		$	217,479
	Amounts reclassified from AOCI
	Pre-tax	$	(85,928	)	-1	$	—		$	8,372		-2	$	(77,556	)
	Tax effect (3)	30,075				—			(2,930		)		27,145
	After-tax amounts reclassified	$	(55,853	)		$	—		$	5,442			$	(50,411	)
	Other comprehensive income (loss)
	Pre-tax	$	(350,968	)		$	(25,451	)	$	8,372			$	(368,047	)
	Tax effect	122,839				—			(2,930		)		119,909
	Other comprehensive income (loss)	$	(228,129	)		$	(25,451	)	$	5,442			$	(248,138	)
	As of and for the three months ended September 30, 2013:
	Changes in AOCI
	Beginning of period	$	328,403			$	(106,455	)	$	(11,723	)		$	210,225
	Other comprehensive income (loss) before reclassifications	(10,331		)		44,328			—				33,997
	Amounts reclassified from AOCI	(28,548		)		—			1,814				(26,734		)
	Other comprehensive income (loss)	(38,879		)		44,328			1,814				7,263
	Unrealized investment gain related to non-controlling interest	(9		)					—				(9		)
	End of period	$	289,515			$	(62,127	)	$	(9,909	)		$	217,479
	Amounts reclassified from AOCI
	Pre-tax	$	(43,920	)		$	—		$	2,790			$	(41,130	)
	Tax effect (3)	15,372				—			(976		)		14,396
	After-tax amounts reclassified	$	(28,548	)		$	—		$	1,814			$	(26,734	)
	Other comprehensive income (loss)
	Pre-tax	$	(59,814	)		$	44,328		$	2,790			$	(12,696	)
	Tax effect	20,935				—			(976		)		19,959
	Other comprehensive income (loss)	$	(38,879	)		$	44,328		$	1,814			$	7,263
	(1) Net investment gains in the consolidated statements of operations.
	(2) Other operating costs and expenses in the consolidated statements of operations.
	(3) Income tax expense in the consolidated statements of operations.

Investments_In_Fixed_Maturity_

Investments In Fixed Maturity Securities (Debt Securities [Member])	9 Months Ended
	Sep. 30, 2013
Debt Securities [Member]	'
Schedule of Marketable Securities [Line Items]	'
Investments In Fixed Maturity Securities	'
	Investments in Fixed Maturity Securities
	At September 30, 2013 and December 31, 2012, investments in fixed maturity securities were as follows:
	(In thousands)	Amortized		Gross Unrealized					Fair		Carrying
		Cost		Gains		Losses			Value		Value
	September 30, 2013
	Held to maturity:
	State and municipal	$	67,982	$	12,488	$	—		$	80,470	$	67,982
	Residential mortgage-backed	28,570		3,845		—			32,415		28,570
	Corporate	4,998		470		—			5,468		4,998
	Total held to maturity	101,550		16,803		—			118,353		101,550
	Available for sale:
	U.S. government and government agency	787,326		42,195		(4,462		)	825,059		825,059
	State and municipal	3,954,226		185,876		(21,965		)	4,118,137		4,118,137
	Mortgage-backed securities:
	Residential (1)	1,350,961		33,231		(21,653		)	1,362,539		1,362,539
	Commercial	126,036		6,135		(1,245		)	130,926		130,926
	Corporate	3,800,276		128,909		(28,713		)	3,900,472		3,900,472
	Foreign	1,104,233		81,193		(12,062		)	1,173,364		1,173,364
	Total available for sale	11,123,058		477,539		(90,100		)	11,510,497		11,510,497
	Total investments in fixed maturity securities	$	11,224,608	$	494,342	$	(90,100	)	$	11,628,850	$	11,612,047
	December 31, 2012
	Held to maturity:
	State and municipal	$	65,190	$	18,529	$	—		$	83,719	$	65,190
	Residential mortgage-backed	32,764		5,286		—			38,050		32,764
	Corporate	4,997		605		—			5,602		4,997
	Total held to maturity	102,951		24,420		—			127,371		102,951
	Available for sale:
	U.S. government and government agency	827,591		72,532		(1,660		)	898,463		898,463
	State and municipal	4,449,238		328,974		(9,693		)	4,768,519		4,768,519
	Mortgage-backed securities:
	Residential (1)	1,395,739		53,846		(7,456		)	1,442,129		1,442,129
	Commercial	268,671		5,641		(744		)	273,568		273,568
	Corporate	3,144,480		214,322		(12,083		)	3,346,719		3,346,719
	Foreign	1,029,284		83,347		(1,024		)	1,111,607		1,111,607
	Total available for sale	11,115,003		758,662		(32,660		)	11,841,005		11,841,005
	Total investments in fixed maturity securities	$	11,217,954	$	783,082	$	(32,660	)	$	11,968,376	$	11,943,956
	___________
	-1	Gross unrealized losses for residential mortgage-backed securities include $2,216,000 and $3,037,000 as of September 30, 2013 and December 31, 2012, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.
	The amortized cost and fair value of fixed maturity securities at September 30, 2013, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations.
	(In thousands)	Amortized		Fair Value
		Cost
	Due in one year or less	$	824,784	$	833,107
	Due after one year through five years	3,480,083		3,625,395
	Due after five years through ten years	2,927,972		3,091,396
	Due after ten years	2,486,202		2,553,072
	Mortgage-backed securities	1,505,567		1,525,880
	Total	$	11,224,608	$	11,628,850
	At September 30, 2013, there were no investments, other than investments in United States government and government agency securities, which exceeded 10% of common stockholders’ equity.

Investments_in_Equity_Securiti

Investments in Equity Securities (Equity Securities [Member])	9 Months Ended
	Sep. 30, 2013
Equity Securities [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Investments in Equity Securities	'
	Investments in Equity Securities
	At September 30, 2013 and December 31, 2012, investments in equity securities were as follows:
	(In thousands)	Cost		Gross Unrealized					Fair		Carrying
				Gains		Losses			Value		Value
	September 30, 2013
	Common stocks	$	195,705	$	48,413	$	(5,576	)	$	238,542	$	238,542
	Preferred stocks	80,969		27,032		(7,636		)	100,365		100,365
	Total	$	276,674	$	75,445	$	(13,212	)	$	338,907	$	338,907
	December 31, 2012
	Common stocks	$	222,671	$	60,102	$	(707	)	$	282,066	$	282,066
	Preferred stocks	85,504		10,103		(1,651		)	93,956		93,956
	Total	$	308,175	$	70,205	$	(2,358	)	$	376,022	$	376,022

Arbitrage_Trading_Account

Arbitrage Trading Account	9 Months Ended
	Sep. 30, 2013
Trading Securities [Abstract]	'
Arbitrage Trading Account	'
	Arbitrage Trading Account
	At September 30, 2013 and December 31, 2012, the carrying value of the arbitrage trading account was $620 million and $329 million, respectively. The primary focus of the trading account is merger arbitrage. Merger arbitrage is the business of investing in the securities of publicly held companies which are the targets in announced tender offers and mergers. Arbitrage investing differs from other types of investing in its focus on transactions and events believed likely to bring about a change in value over a relatively short time period (usually four months or less). The Company believes that this makes arbitrage investments less vulnerable to changes in general financial market conditions.

Net_Investment_Income

Net Investment Income	9 Months Ended
	Sep. 30, 2013
Net Investment Income [Abstract]	'
Net Investment Income	'
	Net Investment Income
	Net investment income consists of the following:
		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
	(In thousands)	2013			2012			2013			2012
	Investment income earned on:
	Fixed maturity securities, including cash and cash equivalents and loans receivable	$	104,033		$	121,454		$	333,072		$	360,577
	Investment funds	5,492			(13,118		)	45,248			50,124
	Arbitrage trading account	11,738			2,397			14,265			8,938
	Equity securities available for sale	3,192			4,001			9,073			10,980
	Real estate	3,086			3,097			9,343			8,621
	Gross investment income	127,541			117,831			411,001			439,240
	Investment expense	(1,907		)	(1,812		)	(5,701		)	(4,352		)
	Net investment income	$	125,634		$	116,019		$	405,300		$	434,888

Investment_Funds

Investment Funds	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Investment Funds [Text Block]	'
	Investment Funds
	Investment funds consist of the following:
		Carrying Value as of				Income from Investment Funds
		September 30,		December 31,		For the Nine Months Ended September 30,
	(In thousands)	2013		2012		2013		2012
	Real estate	$	387,296	$	373,259	$	5,777	$	13,513
	Energy	154,819		146,325		25,959		28,966
	Arbitrage	66,970		63,920		3,050		3,041
	Other	264,799		226,185		10,462		4,604
	Total	$	873,884	$	809,689	$	45,248	$	50,124
	The Company's share of the earnings or losses of investment funds is generally reported on a one-quarter lag in order to facilitate the timely completion of the Company's consolidated financial statements.

Real_Estate

Real Estate	9 Months Ended
	Sep. 30, 2013
Real Estate [Abstract]	'
Real Estate	'
	Real Estate
	Investment in real estate represents directly owned property held for investment, as follows:
		Carrying Value
		September 30,		December 31,
	(In thousands)	2013		2012
	Properties in operation	$	279,674	$	282,899
	Properties under development	368,024		323,836
	Total	$	647,698	$	606,735
	The primary properties in operation are an office building in London and a long-term ground lease in Washington, D.C. These properties are net of accumulated depreciation and amortization of $15,668,000 and $10,354,000, as of September 30, 2013 and December 31, 2012, respectively. Related depreciation expense was $5,111,000 and $5,571,000 for the nine months ended September 30, 2013 and 2012, respectively. Future minimum rental income expected on operating leases relating to real estate held for investment is $372,000 in 2013, $1,504,000 in 2014, $1,549,000 in 2015, $1,596,000 in 2016, $1,644,000 in 2017 and $329,013,000 thereafter.
	The properties under development are an office building in London, a mixed-use project in Washington, D.C. and an office complex in New York City. The Company expects to fund further development costs for these projects with a combination of its own funds and external financing.

Loans_Receivable

Loans Receivable	9 Months Ended
	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]	'
Loans Receivable	'
	Loans Receivable
	Loans receivable are as follows:
	(In thousands)	September 30, 2013		31-Dec-12
	Loans receivable	$	411,851	$	401,961
	Valuation allowance:
	Specific	$	—	$	3,000
	General	1,916		2,620
	Total	$	1,916	$	5,620
	Impaired loans:
	With a specific valuation allowance	$	—	$	1,775
	Without a valuation allowance	30,000		31,023
	Unpaid principal balance	30,000		35,872
	For the nine months ended September 30:	2013		2012
	Increase (decrease) in valuation allowance	$	137	$	(14,053	)
	Loans receivable charged off	—		139
	For the three months ended September 30:
	Increase (decrease) in valuation allowance	72		(7,280		)
	Loans receivable charged off	—		54
	The Company monitors the performance of its loans receivable and assesses the ability of each borrower to pay principal and interest based upon loan structure, underlying property values, cash flow and related financial and operating performance of the property and market conditions. Loans receivable with a potential for default are further assessed using a discounted cash flow analysis and comparable cost and sales methodologies, if appropriate.
	The Company's eight largest loans receivable, which have an aggregate amortized cost of $304 million and an aggregate fair value of $308 million at September 30, 2013, are secured by commercial real estate located primarily in New York City, California, Hawaii and Chicago. These loans earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) through August 2025.
	The Company utilizes an internal risk rating system to assign a risk to each of its commercial loans. The loan rating system takes into consideration credit quality indicators including loan to value ratios, which compare the outstanding loan amount to the estimated value of the property, the borrower's financial condition and performance with respect to loan terms, the Company's position in the capital structure, and the overall leverage in the capital structure. Based on this rating system, one loan with an aggregate cost basis of $30 million was considered to be impaired at September 30, 2013. After considering the amount of loss in the event of a default and whether a loss is probable, the Company determined that a specific valuation allowance was not required.

Realized_And_Unrealized_Invest

Realized And Unrealized Investment Gains (Losses)	9 Months Ended
	Sep. 30, 2013
Realized and Unrealized Investment Gains (Losses) [Abstract]	'
Realized and Unrealized Investment Gains (Losses)	'
	Realized and Unrealized Investment Gains (Losses)
	Realized and unrealized investment gains (losses) are as follows:
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	(In thousands)	2013			2012			2013			2012
	Realized investment gains (losses):
	Fixed maturity securities:
	Gains	$	19,500		$	4,439		$	39,643		$	25,046
	Losses	(739		)	(1,937		)	(12,205		)	(4,243		)
	Equity securities available for sale	25,158			14,447			58,489			58,873
	Investment funds	(34		)	277			11,003			3,778
	Other	(16		)	—			(34		)	1,535
	Total	43,869			17,226			96,896			84,989
	Change in valuation allowance, net of other-than-temporary impairments:
	Decrease in valuation allowance	—			5,000			—			13,998
	Other-than-temporary impairments	—			—			—			(4,984		)
	Total	—			5,000			—			9,014
	Net investment gains	43,869			22,226			96,896			94,003
	Income tax expense	(15,355		)	(7,415		)	(33,914		)	(32,260		)
	Total after-tax realized investment gains	$	28,514		$	14,811		$	62,982		$	61,743
	Change in unrealized investment gains and losses:
	Fixed maturity securities	$	(46,004	)	$	96,077		$	(339,384	)	$	186,637
	Previously impaired fixed maturity securities	299			2,483			821			4,416
	Equity securities available for sale	(13,984		)	(2,891		)	(5,614		)	186
	Investment funds	3,926			4,255			(5,248		)	3,281
	Total change in unrealized investment gains and losses	(55,763		)	99,924			(349,425		)	194,520
	Income tax benefit (expense)	16,884			(34,963		)	121,296			(68,000		)
	Noncontrolling interests	(9		)	(43		)	(14		)	(71		)
	Total after-tax unrealized gains (losses)	$	(38,888	)	$	64,918		$	(228,143	)	$	126,449

Securities_In_An_Unrealized_Lo

Securities In An Unrealized Loss Position	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Securities In An Unrealized Loss Position	'
	Securities in an Unrealized Loss Position
	The following table summarizes all securities in an unrealized loss position at September 30, 2013 and December 31, 2012 by the length of time those securities have been continuously in an unrealized loss position:
		Less Than 12 Months						12 Months or Greater				Total
	(In thousands)	Fair Value			Gross			Fair Value		Gross		Fair Value		Gross
					Unrealized					Unrealized				Unrealized
					Losses					Losses				Losses
	September 30, 2013
	U.S. government and agency	$	145,472		$	4,462		$	—	$	—	$	145,472	$	4,462
	State and municipal	644,312			19,393			61,210		2,572		705,522		21,965
	Mortgage-backed securities	498,700			17,880			84,047		5,018		582,747		22,898
	Corporate	1,069,096			17,738			70,276		10,975		1,139,372		28,713
	Foreign	344,301			12,062			—		—		344,301		12,062
	Fixed maturity securities	2,701,881			71,535			215,533		18,565		2,917,414		90,100
	Common stocks	36,899			5,576			—		—		36,899		5,576
	Preferred stocks	26,906			1,901			19,939		5,735		46,845		7,636
	Equity securities	63,805			7,477			19,939		5,735		83,744		13,212
	Total	$	2,765,686		$	79,012		$	235,472	$	24,300	$	3,001,158	$	103,312
	December 31, 2012
	U.S. government and agency	$	69,551		$	1,660		$	—	$	—	$	69,551	$	1,660
	State and municipal	152,694			1,639			135,967		8,054		288,661		9,693
	Mortgage-backed securities	484,731			3,629			58,292		4,571		543,023		8,200
	Corporate	371,781			2,964			70,537		9,119		442,318		12,083
	Foreign	95,623			996			11,210		28		106,833		1,024
	Fixed maturity securities	1,174,380			10,888			276,006		21,772		1,450,386		32,660
	Common stocks	46,725			707			—		—		46,725		707
	Preferred stocks	—			—			39,812		1,651		39,812		1,651
	Equity securities	46,725			707			39,812		1,651		86,537		2,358
	Total	$	1,221,105		$	11,595		$	315,818	$	23,423	$	1,536,923	$	35,018
	Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2013 is presented in the table below.
	($ in thousands)	Number of		Aggregate			Gross
		Securities		Fair Value			Unrealized
							Loss
	Mortgage-backed securities	12		$	56,553		$	4,141
	Corporate	10		44,525			2,534
	State and municipal	1		10,864			2
	Foreign	3		24,529			744
	Total	26		$	136,471		$	7,421
	For OTTI of fixed maturity securities that management does not intend to sell or, more likely than not, would not be required to sell, the portion of the decline in value considered to be due to credit factors is recognized in earnings and the portion of the decline in value considered to be due to non-credit factors is recognized in other comprehensive income. For the nine months ended September 30, 2013 and 2012, there were no changes in the portion of impairments recognized in earnings for those securities that have been impaired due to both credit factors and non-credit factors.
	The Company has evaluated its fixed maturity securities in an unrealized loss position and believes the unrealized losses are due primarily to temporary market and sector-related factors rather than to issuer-specific factors. None of these securities are delinquent or in default under financial covenants. Based on its assessment of these issuers, the Company expects them to continue to meet their contractual payment obligations as they become due and does not consider any of these securities to be OTTI.
	Preferred Stocks – At September 30, 2013, there were four preferred stocks in an unrealized loss position, with an aggregate fair value of $47 million and a gross unrealized loss of $8 million. Based upon management’s view of the underlying value of these securities, the Company does not consider these preferred stocks to be OTTI.
	Common Stocks – At September 30, 2013, the Company owned two common stocks in an unrealized loss position with an aggregate fair value of $37 million and an aggregate unrealized loss of $6 million. The Company does not consider these common stocks to be OTTI.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Assets, Fair Value Disclosure [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The Company’s fixed maturity and equity securities available for sale and its arbitrage trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for similar assets in active markets. Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs may only be used to measure fair value to the extent that observable inputs are not available.
	Because many fixed maturity securities do not trade on a daily basis, the Company utilizes pricing models and processes, which may include benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. Market inputs used to evaluate securities include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Quoted prices are often unavailable for recently issued securities, securities that are infrequently traded or securities that are only traded in private transactions. For publicly traded securities for which quoted prices are unavailable, the Company determines fair value based on independent broker quotations and other observable market data. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information.
	The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2013 and December 31, 2012 by Level:
	(In thousands)	Total		Level 1			Level 2			Level 3
	September 30, 2013
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	825,059	$	—		$	825,059		$	—
	State and municipal	4,118,137		—			4,118,137			—
	Mortgage-backed securities	1,493,465		—			1,493,465			—
	Corporate	3,900,472		—			3,854,455			46,017
	Foreign	1,173,364		—			1,173,364			—
	Total fixed maturity securities available for sale	11,510,497		—			11,464,480			46,017
	Equity securities:
	Common stocks	238,542		237,303			—			1,239
	Preferred stocks	100,365		—			96,593			3,772
	Total equity securities	338,907		237,303			96,593			5,011
	Arbitrage trading account	619,881		252,832			366,862			187
	Total	$	12,469,285	$	490,135		$	11,927,935		$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	88,489	$	88,482		$	7		$	—
	December 31, 2012
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	898,463	$	—		$	898,463		$	—
	State and municipal	4,768,519		—			4,768,519			—
	Mortgage-backed securities	1,715,697		—			1,715,697			—
	Corporate	3,346,719		—			3,287,654			59,065
	Foreign	1,111,607		—			1,111,607			—
	Total fixed maturity securities available for sale	11,841,005		—			11,781,940			59,065
	Equity securities:
	Common stocks	282,066		280,658			—			1,408
	Preferred stocks	93,956		—			93,335			621
	Total equity securities	376,022		280,658			93,335			2,029
	Arbitrage trading account	329,077		233,603			94,546			928
	Total	$	12,546,104	$	514,261		$	11,969,821		$	62,022
	Liabilities:
	Securities sold but not yet purchased	$	121,487	$	114,909		$	6,558		$	20
	There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2013 or during the year ended December 31, 2012.
	The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2013 and for the year ended December 31, 2012:
				Gains (Losses) Included in
	(In thousands)	Beginning		Earnings			Other			Purchases		(Sales)			Maturities			Transfer in		Ending
		Balance					Comprehensive													Balance
							Income
	Nine months ended September 30, 2013:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	59,065	$	608		$	(137	)	$	127	$	(3,767	)	$	(9,879	)	$	—	$	46,017
	Total	59,065		608			(137		)	127		(3,767		)	(9,879		)	—		46,017
	Equity securities available for sale:
	Common stocks	1,408		—			—			—		(169		)	—			—		1,239
	Preferred stocks	621		(279		)	—			3,430		—			—			—		3,772
	Total	2,029		(279		)	—			3,430		(169		)	—			—		5,011
	Arbitrage trading account	928		(712		)	—			824		(853		)	—			—		187
	Total	$	62,022	$	(383	)	$	(137	)	$	4,381	$	(4,789	)	$	(9,879	)	$	—	$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	20	$	(4	)	$	—		$	4	$	(20	)	$	—		$	—	$	—
	Year ended December 31, 2012:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	67,828	$	(1,497	)	$	9,622		$	283	$	—		$	(17,171	)	$	—	$	59,065
	Total	67,828		(1,497		)	9,622			283		—			(17,171		)	—		59,065
Equity securities available for sale:
Common stocks	1,559		—			—			—		(151		)	—			—		1,408
Preferred stocks	12,303		1,126			(1,737		)	—		(11,071		)	—			—		621
Total	13,862		1,126			(1,737		)	—		(11,222		)	—			—		2,029
Arbitrage trading account	851		(3,534		)	3,570			—		(52		)	—			93		928
Total	$	82,541	$	(3,905	)	$	11,455		$	283	$	(11,274	)	$	(17,171	)	$	93	$	62,022
Liabilities:
Securities sold but not yet purchased	$	21	$	(1	)	$	—		$	—	$	—		$	—		$	—	$	20
There were no significant transfers in or out of Level 3 during the nine months ended September 30, 2013 or during the year ended December 31, 2012.
Fair Value of Financial Instruments
The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:
	September 30, 2013					December 31, 2012
(In thousands)	Carrying Value		Fair Value			Carrying Value			Fair Value
Assets:
Fixed maturity securities	$	11,612,047	$	11,628,850		$	11,943,956		$	11,968,376
Equity securities available for sale	338,907		338,907			376,022			376,022
Arbitrage trading account	619,881		619,881			329,077			329,077
Loans receivable	411,851		417,323			401,961			406,443
Cash and cash equivalents	966,326		966,326			905,670			905,670
Trading account receivables from brokers and clearing organizations	123,320		123,320			446,873			446,873
Due from broker	24,890		24,890			14,449			14,449
Liabilities:
Trading account securities sold but not yet purchased	88,489		88,489			121,487			121,487
Junior subordinated debentures	339,772		302,540			243,206			252,000
Senior notes and other debt	1,696,461		1,887,751			1,871,535			2,190,173
The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the junior subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input.

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2013
Reinsurance Disclosures [Abstract]	'
Reinsurance	'
	Reinsurance
	The following is a summary of reinsurance financial information:
		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
	(In thousands)	2013			2012			2013			2012
	Written premiums:
	Direct	$	1,415,775		$	1,267,882		$	4,221,370		$	3,718,477
	Assumed	251,331			226,842			695,293			608,693
	Ceded	(243,481		)	(218,837		)	(774,174		)	(656,766		)
	Total net premiums written	$	1,423,625		$	1,275,887		$	4,142,489		$	3,670,404
	Earned premiums:
	Direct	$	1,351,542		$	1,208,257		$	3,893,806		$	3,475,375
	Assumed	226,530			193,024			658,063			559,304
	Ceded	(249,210		)	(214,748		)	(708,373		)	(601,138		)
	Total net premiums earned	$	1,328,862		$	1,186,533		$	3,843,496		$	3,433,541
	Ceded losses incurred	$	186,504		$	114,273		$	439,415		$	308,692
	The Company reinsures a portion of its insurance exposures in order to reduce its net liability on individual risks and catastrophe losses. The Company also cedes premiums to state assigned risk plans and captive insurance companies. Estimated amounts due from reinsurers are reported net of reserves for uncollectible reinsurance of $1 million as of September 30, 2013 and $2 million as of December 31, 2012.

Fair_Value_Of_Financial_Instru

Fair Value Of Financial Instruments	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Of Financial Instruments	'
	Fair Value Measurements
	The Company’s fixed maturity and equity securities available for sale and its arbitrage trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for similar assets in active markets. Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs may only be used to measure fair value to the extent that observable inputs are not available.
	Because many fixed maturity securities do not trade on a daily basis, the Company utilizes pricing models and processes, which may include benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. Market inputs used to evaluate securities include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Quoted prices are often unavailable for recently issued securities, securities that are infrequently traded or securities that are only traded in private transactions. For publicly traded securities for which quoted prices are unavailable, the Company determines fair value based on independent broker quotations and other observable market data. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information.
	The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2013 and December 31, 2012 by Level:
	(In thousands)	Total		Level 1			Level 2			Level 3
	September 30, 2013
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	825,059	$	—		$	825,059		$	—
	State and municipal	4,118,137		—			4,118,137			—
	Mortgage-backed securities	1,493,465		—			1,493,465			—
	Corporate	3,900,472		—			3,854,455			46,017
	Foreign	1,173,364		—			1,173,364			—
	Total fixed maturity securities available for sale	11,510,497		—			11,464,480			46,017
	Equity securities:
	Common stocks	238,542		237,303			—			1,239
	Preferred stocks	100,365		—			96,593			3,772
	Total equity securities	338,907		237,303			96,593			5,011
	Arbitrage trading account	619,881		252,832			366,862			187
	Total	$	12,469,285	$	490,135		$	11,927,935		$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	88,489	$	88,482		$	7		$	—
	December 31, 2012
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	898,463	$	—		$	898,463		$	—
	State and municipal	4,768,519		—			4,768,519			—
	Mortgage-backed securities	1,715,697		—			1,715,697			—
	Corporate	3,346,719		—			3,287,654			59,065
	Foreign	1,111,607		—			1,111,607			—
	Total fixed maturity securities available for sale	11,841,005		—			11,781,940			59,065
	Equity securities:
	Common stocks	282,066		280,658			—			1,408
	Preferred stocks	93,956		—			93,335			621
	Total equity securities	376,022		280,658			93,335			2,029
	Arbitrage trading account	329,077		233,603			94,546			928
	Total	$	12,546,104	$	514,261		$	11,969,821		$	62,022
	Liabilities:
	Securities sold but not yet purchased	$	121,487	$	114,909		$	6,558		$	20
	There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2013 or during the year ended December 31, 2012.
	The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2013 and for the year ended December 31, 2012:
				Gains (Losses) Included in
	(In thousands)	Beginning		Earnings			Other			Purchases		(Sales)			Maturities			Transfer in		Ending
		Balance					Comprehensive													Balance
							Income
	Nine months ended September 30, 2013:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	59,065	$	608		$	(137	)	$	127	$	(3,767	)	$	(9,879	)	$	—	$	46,017
	Total	59,065		608			(137		)	127		(3,767		)	(9,879		)	—		46,017
	Equity securities available for sale:
	Common stocks	1,408		—			—			—		(169		)	—			—		1,239
	Preferred stocks	621		(279		)	—			3,430		—			—			—		3,772
	Total	2,029		(279		)	—			3,430		(169		)	—			—		5,011
	Arbitrage trading account	928		(712		)	—			824		(853		)	—			—		187
	Total	$	62,022	$	(383	)	$	(137	)	$	4,381	$	(4,789	)	$	(9,879	)	$	—	$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	20	$	(4	)	$	—		$	4	$	(20	)	$	—		$	—	$	—
	Year ended December 31, 2012:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	67,828	$	(1,497	)	$	9,622		$	283	$	—		$	(17,171	)	$	—	$	59,065
	Total	67,828		(1,497		)	9,622			283		—			(17,171		)	—		59,065
Equity securities available for sale:
Common stocks	1,559		—			—			—		(151		)	—			—		1,408
Preferred stocks	12,303		1,126			(1,737		)	—		(11,071		)	—			—		621
Total	13,862		1,126			(1,737		)	—		(11,222		)	—			—		2,029
Arbitrage trading account	851		(3,534		)	3,570			—		(52		)	—			93		928
Total	$	82,541	$	(3,905	)	$	11,455		$	283	$	(11,274	)	$	(17,171	)	$	93	$	62,022
Liabilities:
Securities sold but not yet purchased	$	21	$	(1	)	$	—		$	—	$	—		$	—		$	—	$	20
There were no significant transfers in or out of Level 3 during the nine months ended September 30, 2013 or during the year ended December 31, 2012.
Fair Value of Financial Instruments
The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:
	September 30, 2013					December 31, 2012
(In thousands)	Carrying Value		Fair Value			Carrying Value			Fair Value
Assets:
Fixed maturity securities	$	11,612,047	$	11,628,850		$	11,943,956		$	11,968,376
Equity securities available for sale	338,907		338,907			376,022			376,022
Arbitrage trading account	619,881		619,881			329,077			329,077
Loans receivable	411,851		417,323			401,961			406,443
Cash and cash equivalents	966,326		966,326			905,670			905,670
Trading account receivables from brokers and clearing organizations	123,320		123,320			446,873			446,873
Due from broker	24,890		24,890			14,449			14,449
Liabilities:
Trading account securities sold but not yet purchased	88,489		88,489			121,487			121,487
Junior subordinated debentures	339,772		302,540			243,206			252,000
Senior notes and other debt	1,696,461		1,887,751			1,871,535			2,190,173
The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the junior subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input.

Restricted_Stock_Units

Restricted Stock Units	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Restricted Stock Units	'
	Restricted Stock Units
	Pursuant to its stock incentive plan, the Company may issue restricted stock units (RSUs) to employees of the Company and its subsidiaries. The RSUs generally vest five years from the award date and are subject to other vesting and forfeiture provisions contained in the award agreement. RSUs are expensed pro-ratably over the vesting period. RSU expenses were $16 million and $20 million for the nine months ended September 30, 2013 and 2012, respectively. Grants of RSUs are made periodically, generally every other year. A summary of RSUs issued in the nine months ended September 30, 2013 and 2012 follows:
	($ in thousands)	Units	Fair Value
	Nine months ended September 30:
	2013	93,150	$	3,957
	2012	2,114,720	$	78,351

Industry_Segments

Industry Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Industry Segments	'
	Business Segments
	The Company’s financial results are presented for the following reportable business segments:
	•	Insurance-Domestic - commercial insurance business, including excess and surplus lines and admitted lines, throughout the United States;
	•	Insurance-International - insurance business primarily in the United Kingdom, Continental Europe, South America, Canada, Scandinavia, and Australia; and
	•	Reinsurance-Global - reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Europe, Australia, and the Asia-Pacific Region.
	During the first quarter of 2013, the Company changed the aggregation of its business segments. All domestic insurance operating companies, previously included in the Specialty, Regional and Alternative Markets segments, were aggregated into the Insurance-Domestic segment; all international insurance companies were aggregated into the Insurance-International segment; and all reinsurance operating companies were aggregated into the Reinsurance-Global segment. The segment disclosures for prior periods have been revised to be consistent with the new reportable business segment presentation. The segment disclosures for the years ended December 31, 2012, 2011 and 2010, and as of December 31, 2012 and 2011, have also been included herein, revised for the new reportable business segment presentation.
	The accounting policies of the segments are the same as those described in the summary of significant accounting policies. Income tax expense and benefits are calculated based upon the Company’s overall effective tax rate.
	Summary financial information about the Company's business segments is presented in the following tables.
		Revenues
	(In thousands)	Earned		Investment		Other		Total		Pre-Tax			Net
		Premiums		Income						Income			Income
										(Loss)			(Loss)
	Three months ended September 30, 2013:
	Insurance-Domestic	$	958,994	$	94,071	$	26,125	$	1,079,190	$	172,177		$	118,183
	Insurance-International	189,054		11,151		—		200,205		16,129			11,225
	Reinsurance-Global	180,814		20,121		—		200,935		24,559			17,300
	Corporate and eliminations (1)	—		291		109,634		109,925		(58,501		)	(38,248		)
	Net investment gains	—		—		43,869		43,869		43,869			28,514
	Total	$	1,328,862	$	125,634	$	179,628	$	1,634,124	$	198,233		$	136,974
	Three months ended September 30, 2012:
	Insurance-Domestic	$	873,835	$	82,565	$	26,208	$	982,608	$	132,498		$	94,852
	Insurance-International	157,773		10,411		—		168,184		13,806			10,027
	Reinsurance-Global	154,925		21,149		—		176,074		23,048			17,202
	Corporate and eliminations (1)	—		1,894		69,515		71,409		(57,885		)	(35,945		)
	Net investment gains	—		—		22,226		22,226		22,226			14,811
	Total	$	1,186,533	$	116,019	$	117,949	$	1,420,501	$	133,693		$	100,947
	Nine months ended September 30, 2013:
	Insurance-Domestic	$	2,769,369	$	299,430	$	80,513	$	3,149,312	$	465,861		$	324,069
	Insurance-International	540,365		36,383		—		576,748		51,094			35,794
	Reinsurance-Global	533,762		65,656		—		599,418		87,252			61,375
	Corporate and eliminations (1)	—		3,831		285,650		289,481		(183,941		)	(114,674		)
	Net investment gains	—		—		96,896		96,896		96,896			62,982
	Total	$	3,843,496	$	405,300	$	463,059	$	4,711,855	$	517,162		$	369,546
	Nine months ended September 30, 2012:
	Insurance-Domestic	$	2,530,638	$	315,307	$	77,121	$	2,923,066	$	424,873		$	304,167
	Insurance-International	456,159		31,936		—		488,095		43,287			30,972
	Reinsurance-Global	446,744		78,287		—		525,031		82,140			60,343
	Corporate and eliminations (1)	—		9,358		175,400		184,758		(174,868		)	(112,122		)
	Net investment gains	—		—		94,003		94,003		94,003			61,743
	Total	$	3,433,541	$	434,888	$	346,524	$	4,214,953	$	469,435		$	345,103
	___________
	(1) Corporate and eliminations represent corporate revenues and expenses that are not allocated to business segments.
	Identifiable assets by segment are as follows:
	(In thousands)	September 30, 2013		31-Dec-12
	Insurance-Domestic	$	15,097,667	$	14,661,476
	Insurance-International	1,451,487		1,541,365
	Reinsurance-Global	3,090,334		3,337,937
	Corporate and eliminations	884,231		615,118
	Total	$	20,523,719	$	20,155,896
	Net premiums earned by major line of business are as follows:
		For the Three Months Ended				For the Nine Months Ended
		September 30,				September 30,
	(In thousands)	2013		2012		2013		2012
	Insurance-Domestic:
	Other liability	$	314,878	$	280,808	$	917,910	$	812,153
	Workers’ compensation	252,220		223,477		722,422		637,583
	Short-tail lines (1)	199,181		189,613		570,868		552,905
	Commercial automobile	125,942		116,418		361,964		339,317
	Products liability	66,773		63,519		196,205		188,680
	Total	958,994		873,835		2,769,369		2,530,638
	Insurance-International:
	Other liability	18,457		29,719		48,745		47,559
	Workers’ compensation	20,847		21,102		65,482		59,618
Short-tail lines (1)	92,213		52,043		248,637		183,791
Commercial automobile	30,898		30,557		97,929		90,831
Products liability	26,639		24,352		79,572		74,360
Total	189,054		157,773		540,365		456,159
Reinsurance-Global:
Casualty	128,127		112,914		371,571		321,277
Property	52,687		42,011		162,191		125,467
Total	180,814		154,925		533,762		446,744
Total	$	1,328,862	$	1,186,533	$	3,843,496	$	3,433,541
_____________________
(1) Short-tail lines includes commercial multi-peril (non-liability), inland and ocean marine, accident and health, fidelity and surety, boiler and machinery and other lines.

Per_Share_Data_Tables

Per Share Data (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Weighted average number of common shares used in computation of basic and diluted earnings per share	'
	The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows:
	(In thousands)	For the Three Months Ended		For the Nine Months Ended
		September 30,		September 30,
		2013	2012	2013	2012
	Basic	135,268	136,553	135,726	137,512
	Diluted	140,758	141,637	141,095	142,941

Acquistions_Tables

Acquistions (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Summary of fair value of net assets acquired and liabilities assumed	'
	The following table summarizes the estimated fair value of net assets acquired and liabilities assumed at the date of acquisition:
	(In thousands)	Acquired in 2013
	Cash and cash equivalents	$	3,911
	Real estate, furniture and equipment	898
	Goodwill	19,664
	Intangible assets	44,800
	Other assets	60,661
	Total assets acquired	129,934
	Debt	(27,612		)
	Other liabilities assumed	(17,076		)
	Net assets acquired	$	85,246

Statements_of_Comprehensive_In1

Statements of Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Components of changes in accumulated other comprehensive income (loss)	'
	The following table presents the components of the changes in accumulated other comprehensive income (loss) (AOCI):
		Unrealized Investment Gains				Currency Translation Adjustments			Net Pension Asset				Accumulated Other Comprehensive Income (Loss)
	As of and for the nine months ended September 30, 2013:
	(In thousands)
	Changes in AOCI
	Beginning of period	$	517,658			$	(36,676	)	$	(15,351	)		$	465,631
	Other comprehensive income (loss) before reclassifications	(172,276		)		(25,451		)	—				(197,727		)
	Amounts reclassified from AOCI	(55,853		)		—			5,442				(50,411		)
	Other comprehensive income (loss)	(228,129		)		(25,451		)	5,442				(248,138		)
	Unrealized investment gain related to non-controlling interest	(14		)		—			—				(14		)
	End of period	$	289,515			$	(62,127	)	$	(9,909	)		$	217,479
	Amounts reclassified from AOCI
	Pre-tax	$	(85,928	)	-1	$	—		$	8,372		-2	$	(77,556	)
	Tax effect (3)	30,075				—			(2,930		)		27,145
	After-tax amounts reclassified	$	(55,853	)		$	—		$	5,442			$	(50,411	)
	Other comprehensive income (loss)
	Pre-tax	$	(350,968	)		$	(25,451	)	$	8,372			$	(368,047	)
	Tax effect	122,839				—			(2,930		)		119,909
	Other comprehensive income (loss)	$	(228,129	)		$	(25,451	)	$	5,442			$	(248,138	)
	As of and for the three months ended September 30, 2013:
	Changes in AOCI
	Beginning of period	$	328,403			$	(106,455	)	$	(11,723	)		$	210,225
	Other comprehensive income (loss) before reclassifications	(10,331		)		44,328			—				33,997
	Amounts reclassified from AOCI	(28,548		)		—			1,814				(26,734		)
	Other comprehensive income (loss)	(38,879		)		44,328			1,814				7,263
	Unrealized investment gain related to non-controlling interest	(9		)					—				(9		)
	End of period	$	289,515			$	(62,127	)	$	(9,909	)		$	217,479
	Amounts reclassified from AOCI
	Pre-tax	$	(43,920	)		$	—		$	2,790			$	(41,130	)
	Tax effect (3)	15,372				—			(976		)		14,396
	After-tax amounts reclassified	$	(28,548	)		$	—		$	1,814			$	(26,734	)
	Other comprehensive income (loss)
	Pre-tax	$	(59,814	)		$	44,328		$	2,790			$	(12,696	)
	Tax effect	20,935				—			(976		)		19,959
	Other comprehensive income (loss)	$	(38,879	)		$	44,328		$	1,814			$	7,263
	(1) Net investment gains in the consolidated statements of operations.
	(2) Other operating costs and expenses in the consolidated statements of operations.
	(3) Income tax expense in the consolidated statements of operations.

Investments_In_Fixed_Maturity_1

Investments In Fixed Maturity Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Marketable Securities [Line Items]	'
Amortized cost and fair value of fixed maturity securities by contractual maturity	'
	The amortized cost and fair value of fixed maturity securities at September 30, 2013, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations.
	(In thousands)	Amortized		Fair Value
		Cost
	Due in one year or less	$	824,784	$	833,107
	Due after one year through five years	3,480,083		3,625,395
	Due after five years through ten years	2,927,972		3,091,396
	Due after ten years	2,486,202		2,553,072
	Mortgage-backed securities	1,505,567		1,525,880
	Total	$	11,224,608	$	11,628,850
Debt Securities [Member]	'
Schedule of Marketable Securities [Line Items]	'
Schedule of investments in fixed maturity securities	'
	At September 30, 2013 and December 31, 2012, investments in fixed maturity securities were as follows:
	(In thousands)	Amortized		Gross Unrealized					Fair		Carrying
		Cost		Gains		Losses			Value		Value
	September 30, 2013
	Held to maturity:
	State and municipal	$	67,982	$	12,488	$	—		$	80,470	$	67,982
	Residential mortgage-backed	28,570		3,845		—			32,415		28,570
	Corporate	4,998		470		—			5,468		4,998
	Total held to maturity	101,550		16,803		—			118,353		101,550
	Available for sale:
	U.S. government and government agency	787,326		42,195		(4,462		)	825,059		825,059
	State and municipal	3,954,226		185,876		(21,965		)	4,118,137		4,118,137
	Mortgage-backed securities:
	Residential (1)	1,350,961		33,231		(21,653		)	1,362,539		1,362,539
	Commercial	126,036		6,135		(1,245		)	130,926		130,926
	Corporate	3,800,276		128,909		(28,713		)	3,900,472		3,900,472
	Foreign	1,104,233		81,193		(12,062		)	1,173,364		1,173,364
	Total available for sale	11,123,058		477,539		(90,100		)	11,510,497		11,510,497
	Total investments in fixed maturity securities	$	11,224,608	$	494,342	$	(90,100	)	$	11,628,850	$	11,612,047
	December 31, 2012
	Held to maturity:
	State and municipal	$	65,190	$	18,529	$	—		$	83,719	$	65,190
	Residential mortgage-backed	32,764		5,286		—			38,050		32,764
	Corporate	4,997		605		—			5,602		4,997
	Total held to maturity	102,951		24,420		—			127,371		102,951
	Available for sale:
	U.S. government and government agency	827,591		72,532		(1,660		)	898,463		898,463
	State and municipal	4,449,238		328,974		(9,693		)	4,768,519		4,768,519
	Mortgage-backed securities:
	Residential (1)	1,395,739		53,846		(7,456		)	1,442,129		1,442,129
	Commercial	268,671		5,641		(744		)	273,568		273,568
	Corporate	3,144,480		214,322		(12,083		)	3,346,719		3,346,719
	Foreign	1,029,284		83,347		(1,024		)	1,111,607		1,111,607
	Total available for sale	11,115,003		758,662		(32,660		)	11,841,005		11,841,005
	Total investments in fixed maturity securities	$	11,217,954	$	783,082	$	(32,660	)	$	11,968,376	$	11,943,956
	___________
	-1	Gross unrealized losses for residential mortgage-backed securities include $2,216,000 and $3,037,000 as of September 30, 2013 and December 31, 2012, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

Investments_in_Equity_Securiti1

Investments in Equity Securities (Tables) (Equity Securities [Member])	9 Months Ended
	Sep. 30, 2013
Equity Securities [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Schedule of Investments in Equity Securities	'
	At September 30, 2013 and December 31, 2012, investments in equity securities were as follows:
	(In thousands)	Cost		Gross Unrealized					Fair		Carrying
				Gains		Losses			Value		Value
	September 30, 2013
	Common stocks	$	195,705	$	48,413	$	(5,576	)	$	238,542	$	238,542
	Preferred stocks	80,969		27,032		(7,636		)	100,365		100,365
	Total	$	276,674	$	75,445	$	(13,212	)	$	338,907	$	338,907
	December 31, 2012
	Common stocks	$	222,671	$	60,102	$	(707	)	$	282,066	$	282,066
	Preferred stocks	85,504		10,103		(1,651		)	93,956		93,956
	Total	$	308,175	$	70,205	$	(2,358	)	$	376,022	$	376,022

Net_Investment_Income_Tables

Net Investment Income (Tables)	9 Months Ended
	Sep. 30, 2013
Net Investment Income [Abstract]	'
Schedule of Net Investment Income	'
	Net investment income consists of the following:
		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
	(In thousands)	2013			2012			2013			2012
	Investment income earned on:
	Fixed maturity securities, including cash and cash equivalents and loans receivable	$	104,033		$	121,454		$	333,072		$	360,577
	Investment funds	5,492			(13,118		)	45,248			50,124
	Arbitrage trading account	11,738			2,397			14,265			8,938
	Equity securities available for sale	3,192			4,001			9,073			10,980
	Real estate	3,086			3,097			9,343			8,621
	Gross investment income	127,541			117,831			411,001			439,240
	Investment expense	(1,907		)	(1,812		)	(5,701		)	(4,352		)
	Net investment income	$	125,634		$	116,019		$	405,300		$	434,888

Investment_Funds_Investment_Fu

Investment Funds Investment Funds (Tables)	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Schedule of Investment Funds	'
	Investment funds consist of the following:
		Carrying Value as of				Income from Investment Funds
		September 30,		December 31,		For the Nine Months Ended September 30,
	(In thousands)	2013		2012		2013		2012
	Real estate	$	387,296	$	373,259	$	5,777	$	13,513
	Energy	154,819		146,325		25,959		28,966
	Arbitrage	66,970		63,920		3,050		3,041
	Other	264,799		226,185		10,462		4,604
	Total	$	873,884	$	809,689	$	45,248	$	50,124

Real_Estate_Real_Estate_Tables

Real Estate Real Estate (Tables)	9 Months Ended
	Sep. 30, 2013
Real Estate [Abstract]	'
Schedule of Real Estate Investments	'
	Investment in real estate represents directly owned property held for investment, as follows:
		Carrying Value
		September 30,		December 31,
	(In thousands)	2013		2012
	Properties in operation	$	279,674	$	282,899
	Properties under development	368,024		323,836
	Total	$	647,698	$	606,735

Loans_Receivable_Loans_Receiva

Loans Receivable Loans Receivable (Tables)	9 Months Ended
	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]	'
Schedule of Loans Receivable	'
	Loans receivable are as follows:
	(In thousands)	September 30, 2013		31-Dec-12
	Loans receivable	$	411,851	$	401,961
	Valuation allowance:
	Specific	$	—	$	3,000
	General	1,916		2,620
	Total	$	1,916	$	5,620
	Impaired loans:
	With a specific valuation allowance	$	—	$	1,775
	Without a valuation allowance	30,000		31,023
	Unpaid principal balance	30,000		35,872
	For the nine months ended September 30:	2013		2012
	Increase (decrease) in valuation allowance	$	137	$	(14,053	)
	Loans receivable charged off	—		139
	For the three months ended September 30:
	Increase (decrease) in valuation allowance	72		(7,280		)
	Loans receivable charged off	—		54

Realized_And_Unrealized_Invest1

Realized And Unrealized Investment Gains (Losses) (Tables)	9 Months Ended
	Sep. 30, 2013
Realized and Unrealized Investment Gains (Losses) [Abstract]	'
Realized and Unrealized Investment Gains (Losses)	'
	Realized and unrealized investment gains (losses) are as follows:
		For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	(In thousands)	2013			2012			2013			2012
	Realized investment gains (losses):
	Fixed maturity securities:
	Gains	$	19,500		$	4,439		$	39,643		$	25,046
	Losses	(739		)	(1,937		)	(12,205		)	(4,243		)
	Equity securities available for sale	25,158			14,447			58,489			58,873
	Investment funds	(34		)	277			11,003			3,778
	Other	(16		)	—			(34		)	1,535
	Total	43,869			17,226			96,896			84,989
	Change in valuation allowance, net of other-than-temporary impairments:
	Decrease in valuation allowance	—			5,000			—			13,998
	Other-than-temporary impairments	—			—			—			(4,984		)
	Total	—			5,000			—			9,014
	Net investment gains	43,869			22,226			96,896			94,003
	Income tax expense	(15,355		)	(7,415		)	(33,914		)	(32,260		)
	Total after-tax realized investment gains	$	28,514		$	14,811		$	62,982		$	61,743
Unrealized Gain (Loss) on Investments	'
	Change in unrealized investment gains and losses:
	Fixed maturity securities	$	(46,004	)	$	96,077		$	(339,384	)	$	186,637
	Previously impaired fixed maturity securities	299			2,483			821			4,416
	Equity securities available for sale	(13,984		)	(2,891		)	(5,614		)	186
	Investment funds	3,926			4,255			(5,248		)	3,281
	Total change in unrealized investment gains and losses	(55,763		)	99,924			(349,425		)	194,520
	Income tax benefit (expense)	16,884			(34,963		)	121,296			(68,000		)
	Noncontrolling interests	(9		)	(43		)	(14		)	(71		)
	Total after-tax unrealized gains (losses)	$	(38,888	)	$	64,918		$	(228,143	)	$	126,449

Securities_In_An_Unrealized_Lo1

Securities In An Unrealized Loss Position (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Securities In An Unrealized Loss Position	'
	The following table summarizes all securities in an unrealized loss position at September 30, 2013 and December 31, 2012 by the length of time those securities have been continuously in an unrealized loss position:
		Less Than 12 Months						12 Months or Greater				Total
	(In thousands)	Fair Value			Gross			Fair Value		Gross		Fair Value		Gross
					Unrealized					Unrealized				Unrealized
					Losses					Losses				Losses
	September 30, 2013
	U.S. government and agency	$	145,472		$	4,462		$	—	$	—	$	145,472	$	4,462
	State and municipal	644,312			19,393			61,210		2,572		705,522		21,965
	Mortgage-backed securities	498,700			17,880			84,047		5,018		582,747		22,898
	Corporate	1,069,096			17,738			70,276		10,975		1,139,372		28,713
	Foreign	344,301			12,062			—		—		344,301		12,062
	Fixed maturity securities	2,701,881			71,535			215,533		18,565		2,917,414		90,100
	Common stocks	36,899			5,576			—		—		36,899		5,576
	Preferred stocks	26,906			1,901			19,939		5,735		46,845		7,636
	Equity securities	63,805			7,477			19,939		5,735		83,744		13,212
	Total	$	2,765,686		$	79,012		$	235,472	$	24,300	$	3,001,158	$	103,312
	December 31, 2012
	U.S. government and agency	$	69,551		$	1,660		$	—	$	—	$	69,551	$	1,660
	State and municipal	152,694			1,639			135,967		8,054		288,661		9,693
	Mortgage-backed securities	484,731			3,629			58,292		4,571		543,023		8,200
	Corporate	371,781			2,964			70,537		9,119		442,318		12,083
	Foreign	95,623			996			11,210		28		106,833		1,024
	Fixed maturity securities	1,174,380			10,888			276,006		21,772		1,450,386		32,660
	Common stocks	46,725			707			—		—		46,725		707
	Preferred stocks	—			—			39,812		1,651		39,812		1,651
	Equity securities	46,725			707			39,812		1,651		86,537		2,358
	Total	$	1,221,105		$	11,595		$	315,818	$	23,423	$	1,536,923	$	35,018
Non-Investment Grade Fixed Maturity Securities	'
	Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2013 is presented in the table below.
	($ in thousands)	Number of		Aggregate			Gross
		Securities		Fair Value			Unrealized
							Loss
	Mortgage-backed securities	12		$	56,553		$	4,141
	Corporate	10		44,525			2,534
	State and municipal	1		10,864			2
	Foreign	3		24,529			744
	Total	26		$	136,471		$	7,421

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Assets And Liabilities Measured At Fair value, On A Recurring Basis	'
	The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2013 and December 31, 2012 by Level:
	(In thousands)	Total		Level 1			Level 2			Level 3
	September 30, 2013
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	825,059	$	—		$	825,059		$	—
	State and municipal	4,118,137		—			4,118,137			—
	Mortgage-backed securities	1,493,465		—			1,493,465			—
	Corporate	3,900,472		—			3,854,455			46,017
	Foreign	1,173,364		—			1,173,364			—
	Total fixed maturity securities available for sale	11,510,497		—			11,464,480			46,017
	Equity securities:
	Common stocks	238,542		237,303			—			1,239
	Preferred stocks	100,365		—			96,593			3,772
	Total equity securities	338,907		237,303			96,593			5,011
	Arbitrage trading account	619,881		252,832			366,862			187
	Total	$	12,469,285	$	490,135		$	11,927,935		$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	88,489	$	88,482		$	7		$	—
	December 31, 2012
	Assets:
	Fixed maturity securities available for sale:
	U.S. government and agency	$	898,463	$	—		$	898,463		$	—
	State and municipal	4,768,519		—			4,768,519			—
	Mortgage-backed securities	1,715,697		—			1,715,697			—
	Corporate	3,346,719		—			3,287,654			59,065
	Foreign	1,111,607		—			1,111,607			—
	Total fixed maturity securities available for sale	11,841,005		—			11,781,940			59,065
	Equity securities:
	Common stocks	282,066		280,658			—			1,408
	Preferred stocks	93,956		—			93,335			621
	Total equity securities	376,022		280,658			93,335			2,029
	Arbitrage trading account	329,077		233,603			94,546			928
	Total	$	12,546,104	$	514,261		$	11,969,821		$	62,022
	Liabilities:
	Securities sold but not yet purchased	$	121,487	$	114,909		$	6,558		$	20
Summarize Changes In Level 3 Assets	'
	The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2013 and for the year ended December 31, 2012:
				Gains (Losses) Included in
	(In thousands)	Beginning		Earnings			Other			Purchases		(Sales)			Maturities			Transfer in		Ending
		Balance					Comprehensive													Balance
							Income
	Nine months ended September 30, 2013:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	59,065	$	608		$	(137	)	$	127	$	(3,767	)	$	(9,879	)	$	—	$	46,017
	Total	59,065		608			(137		)	127		(3,767		)	(9,879		)	—		46,017
	Equity securities available for sale:
	Common stocks	1,408		—			—			—		(169		)	—			—		1,239
	Preferred stocks	621		(279		)	—			3,430		—			—			—		3,772
	Total	2,029		(279		)	—			3,430		(169		)	—			—		5,011
	Arbitrage trading account	928		(712		)	—			824		(853		)	—			—		187
	Total	$	62,022	$	(383	)	$	(137	)	$	4,381	$	(4,789	)	$	(9,879	)	$	—	$	51,215
	Liabilities:
	Securities sold but not yet purchased	$	20	$	(4	)	$	—		$	4	$	(20	)	$	—		$	—	$	—
	Year ended December 31, 2012:
	Assets:
	Fixed maturities available for sale:
	Corporate	$	67,828	$	(1,497	)	$	9,622		$	283	$	—		$	(17,171	)	$	—	$	59,065
	Total	67,828		(1,497		)	9,622			283		—			(17,171		)	—		59,065
	Equity securities available for sale:
	Common stocks	1,559		—			—			—		(151		)	—			—		1,408
	Preferred stocks	12,303		1,126			(1,737		)	—		(11,071		)	—			—		621
	Total	13,862		1,126			(1,737		)	—		(11,222		)	—			—		2,029
	Arbitrage trading account	851		(3,534		)	3,570			—		(52		)	—			93		928
	Total	$	82,541	$	(3,905	)	$	11,455		$	283	$	(11,274	)	$	(17,171	)	$	93	$	62,022
	Liabilities:
	Securities sold but not yet purchased	$	21	$	(1	)	$	—		$	—	$	—		$	—		$	—	$	20

Reinsurance_Tables

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2013
Reinsurance Disclosures [Abstract]	'
Reinsurance Financial Information	'
	The following is a summary of reinsurance financial information:
		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
	(In thousands)	2013			2012			2013			2012
	Written premiums:
	Direct	$	1,415,775		$	1,267,882		$	4,221,370		$	3,718,477
	Assumed	251,331			226,842			695,293			608,693
	Ceded	(243,481		)	(218,837		)	(774,174		)	(656,766		)
	Total net premiums written	$	1,423,625		$	1,275,887		$	4,142,489		$	3,670,404
	Earned premiums:
	Direct	$	1,351,542		$	1,208,257		$	3,893,806		$	3,475,375
	Assumed	226,530			193,024			658,063			559,304
	Ceded	(249,210		)	(214,748		)	(708,373		)	(601,138		)
	Total net premiums earned	$	1,328,862		$	1,186,533		$	3,843,496		$	3,433,541
	Ceded losses incurred	$	186,504		$	114,273		$	439,415		$	308,692

Recovered_Sheet1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Carrying Amounts And Estimated Fair Values Of Financial Instruments	'
	The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:
		September 30, 2013				December 31, 2012
	(In thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
	Assets:
	Fixed maturity securities	$	11,612,047	$	11,628,850	$	11,943,956	$	11,968,376
	Equity securities available for sale	338,907		338,907		376,022		376,022
	Arbitrage trading account	619,881		619,881		329,077		329,077
	Loans receivable	411,851		417,323		401,961		406,443
	Cash and cash equivalents	966,326		966,326		905,670		905,670
	Trading account receivables from brokers and clearing organizations	123,320		123,320		446,873		446,873
	Due from broker	24,890		24,890		14,449		14,449
	Liabilities:
	Trading account securities sold but not yet purchased	88,489		88,489		121,487		121,487
	Junior subordinated debentures	339,772		302,540		243,206		252,000
	Senior notes and other debt	1,696,461		1,887,751		1,871,535		2,190,173

Restricted_Stock_Units_Tables

Restricted Stock Units (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary Of Restricted Stock Units Issued	'
	A summary of RSUs issued in the nine months ended September 30, 2013 and 2012 follows:
	($ in thousands)	Units	Fair Value
	Nine months ended September 30:
	2013	93,150	$	3,957
	2012	2,114,720	$	78,351

Industry_Segments_Tables

Industry Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Financial Information Of Company Operating Segments	'
		Revenues
	(In thousands)	Earned		Investment		Other		Total		Pre-Tax			Net
		Premiums		Income						Income			Income
										(Loss)			(Loss)
	Three months ended September 30, 2013:
	Insurance-Domestic	$	958,994	$	94,071	$	26,125	$	1,079,190	$	172,177		$	118,183
	Insurance-International	189,054		11,151		—		200,205		16,129			11,225
	Reinsurance-Global	180,814		20,121		—		200,935		24,559			17,300
	Corporate and eliminations (1)	—		291		109,634		109,925		(58,501		)	(38,248		)
	Net investment gains	—		—		43,869		43,869		43,869			28,514
	Total	$	1,328,862	$	125,634	$	179,628	$	1,634,124	$	198,233		$	136,974
	Three months ended September 30, 2012:
	Insurance-Domestic	$	873,835	$	82,565	$	26,208	$	982,608	$	132,498		$	94,852
	Insurance-International	157,773		10,411		—		168,184		13,806			10,027
	Reinsurance-Global	154,925		21,149		—		176,074		23,048			17,202
	Corporate and eliminations (1)	—		1,894		69,515		71,409		(57,885		)	(35,945		)
	Net investment gains	—		—		22,226		22,226		22,226			14,811
	Total	$	1,186,533	$	116,019	$	117,949	$	1,420,501	$	133,693		$	100,947
	Nine months ended September 30, 2013:
	Insurance-Domestic	$	2,769,369	$	299,430	$	80,513	$	3,149,312	$	465,861		$	324,069
	Insurance-International	540,365		36,383		—		576,748		51,094			35,794
	Reinsurance-Global	533,762		65,656		—		599,418		87,252			61,375
	Corporate and eliminations (1)	—		3,831		285,650		289,481		(183,941		)	(114,674		)
	Net investment gains	—		—		96,896		96,896		96,896			62,982
	Total	$	3,843,496	$	405,300	$	463,059	$	4,711,855	$	517,162		$	369,546
	Nine months ended September 30, 2012:
	Insurance-Domestic	$	2,530,638	$	315,307	$	77,121	$	2,923,066	$	424,873		$	304,167
	Insurance-International	456,159		31,936		—		488,095		43,287			30,972
	Reinsurance-Global	446,744		78,287		—		525,031		82,140			60,343
	Corporate and eliminations (1)	—		9,358		175,400		184,758		(174,868		)	(112,122		)
	Net investment gains	—		—		94,003		94,003		94,003			61,743
	Total	$	3,433,541	$	434,888	$	346,524	$	4,214,953	$	469,435		$	345,103
Identifiable Assets By Segment	'
	___________
	(1) Corporate and eliminations represent corporate revenues and expenses that are not allocated to business segments.
	Identifiable assets by segment are as follows:
	(In thousands)	September 30, 2013		31-Dec-12
	Insurance-Domestic	$	15,097,667	$	14,661,476
	Insurance-International	1,451,487		1,541,365
	Reinsurance-Global	3,090,334		3,337,937
	Corporate and eliminations	884,231		615,118
	Total	$	20,523,719	$	20,155,896
Net Premiums Earned By Major Line Of Business	'
	Net premiums earned by major line of business are as follows:
		For the Three Months Ended				For the Nine Months Ended
		September 30,				September 30,
	(In thousands)	2013		2012		2013		2012
	Insurance-Domestic:
	Other liability	$	314,878	$	280,808	$	917,910	$	812,153
	Workers’ compensation	252,220		223,477		722,422		637,583
	Short-tail lines (1)	199,181		189,613		570,868		552,905
	Commercial automobile	125,942		116,418		361,964		339,317
	Products liability	66,773		63,519		196,205		188,680
	Total	958,994		873,835		2,769,369		2,530,638
	Insurance-International:
	Other liability	18,457		29,719		48,745		47,559
	Workers’ compensation	20,847		21,102		65,482		59,618
	Short-tail lines (1)	92,213		52,043		248,637		183,791
	Commercial automobile	30,898		30,557		97,929		90,831
	Products liability	26,639		24,352		79,572		74,360
	Total	189,054		157,773		540,365		456,159
	Reinsurance-Global:
	Casualty	128,127		112,914		371,571		321,277
	Property	52,687		42,011		162,191		125,467
	Total	180,814		154,925		533,762		446,744
	Total	$	1,328,862	$	1,186,533	$	3,843,496	$	3,433,541

General_Details

General (Details)	9 Months Ended
	Sep. 30, 2013
General Policies Disclosure [Abstract]	'
Federal income tax rate	35.00%

Per_Share_Data_Weighted_Averag

Per Share Data (Weighted Average Number of Common Shares Used In the Computation of Basic and Diluted Earnings per Share) (Details)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'	'	'
Basic (shares)	135,268	136,553	135,726	137,512
Diluted (shares)	140,758	141,637	141,095	142,941

Acquistions_Details

Acquistions (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Business Acquisition [Line Items]	'	'
Goodwill	$113,169	$87,865
After Market Original Equipment Manufacturer	'	'
Business Acquisition [Line Items]	'	'
Cash and cash equivalents	3,911	'
Real estate, furniture and equipment	898	'
Goodwill	19,664	'
Intangible assets	44,800	'
Other assets	60,661	'
Total assets acquired	129,934	'
Debt	-27,612	'
Other liabilities assumed	-17,076	'
Net assets acquired	$85,246	'

Acquistions_intangible_Details

Acquistions intangible (Details) (After Market Original Equipment Manufacturer, USD $)	1 Months Ended	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Business Acquisition [Line Items]	'	'	'
Percentage acquired	51.00%	'	49.00%
Purchase amount	$43	'	$43
Acquired Indefinite-lived Intangible Assets	'	$3	'
Minimum	'	'	'
Business Acquisition [Line Items]	'	'	'
Amortization of Acquired Intangible Assets	'	'2 years	'
Maximum	'	'	'
Business Acquisition [Line Items]	'	'	'
Amortization of Acquired Intangible Assets	'	'15 years	'

Statements_of_Cash_Flow_Detail

Statements of Cash Flow (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Supplemental Cash Flow Information [Abstract]	'	'
Interest payments	$114,026,000	$109,045,000
Income taxes paid	$176,632,000	$114,343,000

Statements_of_Comprehensive_In2

Statements of Comprehensive Income (Loss) (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Jun. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Currency Translation Adjustments [Member]

Currency Translation Adjustments [Member]

Currency Translation Adjustments [Member]

Currency Translation Adjustments [Member]

Net Pension Asset [Member]

Net Pension Asset [Member]

Net Pension Asset [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Currency Translation Adjustments [Member]

Currency Translation Adjustments [Member]

Net Pension Asset [Member]

Net Pension Asset [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income (Loss), Beginning of Period

'

'

$465,631

'

'

$517,658

$328,403

'

($36,676)

'

($106,455)

'

($15,351)

($11,723)

'

$465,631

$210,225

'

'

'

'

'

'

'

'

Other comprehensive income (loss) before reclassifications

'

'

'

'

-10,331

-172,276

'

44,328

-25,451

'

'

0

0

'

33,997

-197,727

'

'

'

'

'

'

'

'

'

Amounts reclassified from AOCI

'

'

'

'

-28,548

-55,853

'

0

0

'

'

1,814

5,442

'

-26,734

-50,411

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss)

7,263

91,840

-248,138

153,372

-38,879

-228,129

'

44,328

-25,451

'

'

1,814

5,442

'

7,263

-248,138

'

'

'

'

'

'

'

'

'

Unrealized investment gain related to non-controlling interest

'

'

'

'

-9

-14

'

'

'

'

'

'

'

'

-9

-14

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income (Loss), End of Period

217,479

'

217,479

'

289,515

289,515

328,403

-62,127

-62,127

'

-106,455

-9,909

-9,909

-11,723

217,479

217,479

210,225

'

'

'

'

'

'

'

'

Net investment gains

43,869

17,226

96,896

84,989

'

'

'

'

'

'

'

'

'

'

'

'

'

-43,920

[1]

-85,928

[1]

'

'

'

'

'

'

Income before income taxes

198,233

133,693

517,162

469,435

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

0

'

'

-41,130

-77,556

Income before taxes

504,096

451,487

1,479,986

1,332,024

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,790

[2]

8,372

[2]

'

'

Tax effect

-60,045

-32,685

-147,249

-124,291

'

'

'

'

'

'

'

'

'

'

'

'

'

15,372

[3]

30,075

[3]

0

0

-976

[3]

-2,930

[3]

14,396

27,145

After-tax amounts reclassified

138,188

101,008

369,913

345,144

'

'

'

'

'

'

'

'

'

'

'

'

'

-28,548

-55,853

0

0

1,814

5,442

-26,734

-50,411

Unrealized investment gains, pre-tax

-59,814

'

-350,968

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrealized investment gains, tax effect

20,935

'

122,839

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrealized investment gains, after-tax amounts

-38,879

'

-228,129

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Currency translation adjustment, pre-tax

44,328

'

-25,451

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Currency translation adjustment, tax effect

0

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in unrealized currency translation adjustments

44,328

26,056

-25,451

24,382

'

'

'

'

-25,451

24,382

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net pension asset, pre-tax

2,790

'

8,372

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net pension asset, tax effect

-976

'

-2,930

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Met pension asset, after-tax amounts

1,814

'

5,442

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss), pre-tax

-12,696

'

-368,047

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss), tax effect

$19,959

'

$119,909

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Net investment gains in the consolidated statements of operations.

[2]

Other operating costs and expenses in the consolidated statements of operations.

[3]

Income tax expense in the consolidated statements of operations.

Recovered_Sheet2

Investments in Fixed Maturity Securities (Investments in Fixed Maturity Securities) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total held to maturity, Amortized Cost	$101,550,000		$102,951,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain	16,803,000		24,420,000
Held to Maturity Securities Accumulated Unrecognized Holding Loss	0		0
Total held to maturity, Fair Value	118,353,000		127,371,000
Total held to maturity, Carrying Value	101,550,000		102,951,000
Total available for sale, Amortized Cost	11,123,058,000		11,115,003,000
Total available for sale, Gross Unrealized Gains	477,539,000		758,662,000
Total available for sale, Gross Unrealized Losses	-90,100,000		-32,660,000
Total available for sale, Fair Value	11,510,497,000		11,841,005,000
Total available for sale, Carrying Value	11,510,497,000		11,841,005,000
Total investment in fixed maturity securities, Amortized Cost	11,224,608,000		11,217,954,000
Total investments in fixed maturity securities, Gross Unrealized Gains	494,342,000		783,082,000
Total investments in fixed maturity securities, Gross Unrealized Losses	-90,100,000		-32,660,000
Total investments in fixed maturity securities, Fair Value	11,628,850,000		11,968,376,000
Total investments in fixed maturity securities, carrying value	11,612,047,000		11,943,956,000
Minimum ownership of Common stockholders equity	10.00%		'
State and municipal	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	3,954,226,000		4,449,238,000
Total available for sale, Gross Unrealized Gains	185,876,000		328,974,000
Total available for sale, Gross Unrealized Losses	-21,965,000		-9,693,000
Total available for sale, Fair Value	4,118,137,000		4,768,519,000
Total available for sale, Carrying Value	4,118,137,000		4,768,519,000
U.S. government and agency	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	787,326,000		827,591,000
Total available for sale, Gross Unrealized Gains	42,195,000		72,532,000
Total available for sale, Gross Unrealized Losses	-4,462,000		-1,660,000
Total available for sale, Fair Value	825,059,000		898,463,000
Total available for sale, Carrying Value	825,059,000		898,463,000
Residential Mortgage-Backed [Member]	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	1,350,961,000	[1]	1,395,739,000	[1]
Total available for sale, Gross Unrealized Gains	33,231,000	[1]	53,846,000	[1]
Total available for sale, Gross Unrealized Losses	-21,653,000	[1]	-7,456,000	[1]
Total available for sale, Fair Value	1,362,539,000	[1]	1,442,129,000	[1]
Total available for sale, Carrying Value	1,362,539,000	[1]	1,442,129,000	[1]
Non-credit portion of other-than-temporary impairments ("OTTI")	2,216,000		3,037,000
Commercial Mortgage-Backed Securities [Member]	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	126,036,000		268,671,000
Total available for sale, Gross Unrealized Gains	6,135,000		5,641,000
Total available for sale, Gross Unrealized Losses	-1,245,000		-744,000
Total available for sale, Fair Value	130,926,000		273,568,000
Total available for sale, Carrying Value	130,926,000		273,568,000
Corporate	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	3,800,276,000		3,144,480,000
Total available for sale, Gross Unrealized Gains	128,909,000		214,322,000
Total available for sale, Gross Unrealized Losses	-28,713,000		-12,083,000
Total available for sale, Fair Value	3,900,472,000		3,346,719,000
Total available for sale, Carrying Value	3,900,472,000		3,346,719,000
Foreign	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total available for sale, Amortized Cost	1,104,233,000		1,029,284,000
Total available for sale, Gross Unrealized Gains	81,193,000		83,347,000
Total available for sale, Gross Unrealized Losses	-12,062,000		-1,024,000
Total available for sale, Fair Value	1,173,364,000		1,111,607,000
Total available for sale, Carrying Value	1,173,364,000		1,111,607,000
State and municipal	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total held to maturity, Amortized Cost	67,982,000		65,190,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain	12,488,000		18,529,000
Held to Maturity Securities Accumulated Unrecognized Holding Loss	0		0
Total held to maturity, Fair Value	80,470,000		83,719,000
Total held to maturity, Carrying Value	67,982,000		65,190,000
Residential Mortgage-Backed [Member]	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total held to maturity, Amortized Cost	28,570,000		32,764,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain	3,845,000		5,286,000
Held to Maturity Securities Accumulated Unrecognized Holding Loss	0		0
Total held to maturity, Fair Value	32,415,000		38,050,000
Total held to maturity, Carrying Value	28,570,000		32,764,000
Corporate	'		'
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]	'		'
Total held to maturity, Amortized Cost	4,998,000		4,997,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain	470,000		605,000
Held to Maturity Securities Accumulated Unrecognized Holding Loss	0		0
Total held to maturity, Fair Value	5,468,000		5,602,000
Total held to maturity, Carrying Value	$4,998,000		$4,997,000
[1]	Gross unrealized losses for residential mortgage-backed securities include $2,216,000 and $3,037,000 as of September 30, 2013 and December 31, 2012, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

Recovered_Sheet3

Investments in Fixed Maturity Securities (The Amortized Cost and Fair Value of Fixed Maturity Securities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Marketable Securities, Fixed Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]	'	'
Amortized Cost, Due in one year or less	$824,784	'
Amortized Cost, Due after one year through five years	3,480,083	'
Amortized Cost, Due after five years through ten years	2,927,972	'
Amortized Cost, Due after ten years	2,486,202	'
Amortized Cost, Mortgage-backed securities	1,505,567	'
Total investment in fixed maturity securities, Amortized Cost	11,224,608	11,217,954
Fair Value, Due in one year or less	833,107	'
Fair Value, Due after one year through five years	3,625,395	'
Fair Value, Due after five years through ten years	3,091,396	'
Fair Value, Due after ten years	2,553,072	'
Fair Value, Mortgage-backed securities	1,525,880	'
Total investments in fixed maturity securities, Fair Value	$11,628,850	$11,968,376

Investments_in_Equity_Securiti2

Investments in Equity Securities (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	$276,674	$308,175
Gross Unrealized, Gains	75,445	70,205
Gross Unrealized, Losses	-13,212	-2,358
Carrying and fair value of equity securities	338,907	376,022
Common stocks	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	195,705	222,671
Gross Unrealized, Gains	48,413	60,102
Gross Unrealized, Losses	-5,576	-707
Carrying and fair value of equity securities	238,542	282,066
Preferred stocks	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	80,969	85,504
Gross Unrealized, Gains	27,032	10,103
Gross Unrealized, Losses	-7,636	-1,651
Carrying and fair value of equity securities	$100,365	$93,956

Arbitrage_Trading_Account_Deta

Arbitrage Trading Account (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Trading Securities [Abstract]	'	'
Arbitrage trading account	$619,881	$329,077

Net_Investment_Income_Details

Net Investment Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Investment Income [Line Items]	'	'	'	'
Investment income	$127,541	$117,831	$411,001	$439,240
Investment expense	-1,907	-1,812	-5,701	-4,352
Net investment income	125,634	116,019	405,300	434,888
Fixed maturity securities, including cash and cash equivalents and loans receivable	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'
Investment income	104,033	121,454	333,072	360,577
Investment funds	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'
Investment income	5,492	-13,118	45,248	50,124
Arbitrage trading account	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'
Investment income	11,738	2,397	14,265	8,938
Equity securities available for sale	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'
Investment income	3,192	4,001	9,073	10,980
Real estate	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'
Investment income	$3,086	$3,097	$9,343	$8,621

Investment_Funds_Investment_Fu1

Investment Funds Investment Funds (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]	'	'	'
Investment funds	$873,884	'	$809,689
Income from Investment Funds	45,248	50,124	'
Real estate	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'
Investment funds	387,296	'	373,259
Income from Investment Funds	5,777	13,513	'
Energy	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'
Investment funds	154,819	'	146,325
Income from Investment Funds	25,959	28,966	'
Arbitrage	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'
Investment funds	66,970	'	63,920
Income from Investment Funds	3,050	3,041	'
Other	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'
Investment funds	264,799	'	226,185
Income from Investment Funds	$10,462	$4,604	'

Real_Estate_Real_Estate_Detail

Real Estate Real Estate (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Real Estate [Abstract]	'	'
Properties in operation	$279,674	$282,899
Properties under development	368,024	323,836
Total	$647,698	$606,735

Real_Estate_Real_Estate_Detail1

Real Estate Real Estate (Details 1) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Real Estate [Abstract]	'	'	'
Accumulated depreciation and amortization on properties	$15,668	'	$10,354
Real estate depreciation expense	5,111	5,571	'
Lease future minimum payments 2013	372	'	'
Lease future minimum payments 2014	1,504	'	'
Lease future minimum payments 2015	1,549	'	'
Lease future minimum payments 2016	1,596	'	'
Lease future minimum payments 2017	1,644	'	'
Lease future minimum payments after 2017	$329,013	'	'

Loans_Receivable_Details

Loans Receivable (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Loans receivable	$411,851,000	'	$411,851,000	'	$401,961,000
Valuation allowance of loans receivable	1,916,000	'	1,916,000	'	5,620,000
Impaired loans, with a valuation allowance	0	'	0	'	1,775,000
Impaired loans, without a valuation allowance	30,000,000	'	30,000,000	'	31,023,000
Impaired loans, unpaid principal balance	30,000,000	'	30,000,000	'	35,872,000
Decrease in valuation allowance	72,000	-7,280,000	137,000	-14,053,000	'
Loans receivable charged off	0	54,000	0	139,000	'
Aggregate cost basis of loans cosidered impaired	30,000,000	'	30,000,000	'	'
Number of Loans Deemed Impaired [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Number of loans	'	'	1	'	'
Commercial and Construction Real Estate and Consumer Portfolio Segment [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Valuation allowance, specific	0	'	0	'	3,000,000
Valuation allowance, general	1,916,000	'	1,916,000	'	2,620,000
Six Larget Loans Receivable [Member] | Credit Concentration Risk [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Loans receivable	308,000,000	'	308,000,000	'	'
Aggregate amortized cost	$304,000,000	'	$304,000,000	'	'

Recovered_Sheet4

Realized and Unrealized Investment Gains (Losses) (Realized and Unrealized Investment Gains (Losses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Realized And Unrealized Investment Gains (Losses)	'	'	'	'
Fixed maturity securities, gains	$19,500	$4,439	$39,643	$25,046
Fixed maturity securities, losses	-739	-1,937	-12,205	-4,243
Equity securities available for sale	25,158	14,447	58,489	58,873
Investment funds	-34	277	11,003	3,778
Other	-16	0	-34	1,535
Realized Gain (Loss) on Investments, Including Equity Method Investments, Excluding Other than Temporary Impairments and Allowances	43,869	17,226	96,896	84,989
Decrease in valuation allowance	0	5,000	0	13,998
Other-than-temporary impairments	0	0	0	-4,984
Change in valuation allowance, net of other-than-temporary impairments	0	5,000	0	9,014
Net investment gains	43,869	22,226	96,896	94,003
Income tax expense	-15,355	-7,415	-33,914	-32,260
Total after-tax realized investment gains	$28,514	$14,811	$62,982	$61,743

Recovered_Sheet5

Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Realized and Unrealized Investment Gains Losses [Line Items]	'	'	'	'
Change in unrealized gains (losses) before income taxes and noncontrolling interests	($55,763)	$99,924	($349,425)	$194,520
Income tax benefit (expense)	16,884	-34,963	121,296	-68,000
Noncontrolling interests	-9	-43	-14	-71
Total change in unrealized gains	-38,888	64,918	-228,143	126,449
Debt Securities [Member]	'	'	'	'
Realized and Unrealized Investment Gains Losses [Line Items]	'	'	'	'
Change in unrealized gains (losses) before income taxes and noncontrolling interests	-46,004	96,077	-339,384	186,637
Debt Securities Previously Impaired [Member]	'	'	'	'
Realized and Unrealized Investment Gains Losses [Line Items]	'	'	'	'
Change in unrealized gains (losses) before income taxes and noncontrolling interests	299	2,483	821	4,416
Equity securities available for sale	'	'	'	'
Realized and Unrealized Investment Gains Losses [Line Items]	'	'	'	'
Change in unrealized gains (losses) before income taxes and noncontrolling interests	-13,984	-2,891	-5,614	186
Investment funds	'	'	'	'
Realized and Unrealized Investment Gains Losses [Line Items]	'	'	'	'
Change in unrealized gains (losses) before income taxes and noncontrolling interests	$3,926	$4,255	($5,248)	$3,281

Recovered_Sheet6

Securities in an Unrealized Loss Position (Securities in an Unrealized Loss Position) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	$2,765,686	$1,221,105
Gross Unrealized Losses, Less than 12 Months	79,012	11,595
Fair Value, 12 Months or Greater	235,472	315,818
Gross Unrealized Losses, 12 Months or Greater	24,300	23,423
Fair Value, Total	3,001,158	1,536,923
Gross Unrealized Losses, Total	103,312	35,018
U.S. government and agency	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	145,472	69,551
Gross Unrealized Losses, Less than 12 Months	4,462	1,660
Fair Value, 12 Months or Greater	0	0
Gross Unrealized Losses, 12 Months or Greater	0	0
Fair Value, Total	145,472	69,551
Gross Unrealized Losses, Total	4,462	1,660
State and municipal	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	644,312	152,694
Gross Unrealized Losses, Less than 12 Months	19,393	1,639
Fair Value, 12 Months or Greater	61,210	135,967
Gross Unrealized Losses, 12 Months or Greater	2,572	8,054
Fair Value, Total	705,522	288,661
Gross Unrealized Losses, Total	21,965	9,693
Mortgage-backed securities	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	498,700	484,731
Gross Unrealized Losses, Less than 12 Months	17,880	3,629
Fair Value, 12 Months or Greater	84,047	58,292
Gross Unrealized Losses, 12 Months or Greater	5,018	4,571
Fair Value, Total	582,747	543,023
Gross Unrealized Losses, Total	22,898	8,200
Corporate	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	1,069,096	371,781
Gross Unrealized Losses, Less than 12 Months	17,738	2,964
Fair Value, 12 Months or Greater	70,276	70,537
Gross Unrealized Losses, 12 Months or Greater	10,975	9,119
Fair Value, Total	1,139,372	442,318
Gross Unrealized Losses, Total	28,713	12,083
Foreign	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	344,301	95,623
Gross Unrealized Losses, Less than 12 Months	12,062	996
Fair Value, 12 Months or Greater	0	11,210
Gross Unrealized Losses, 12 Months or Greater	0	28
Fair Value, Total	344,301	106,833
Gross Unrealized Losses, Total	12,062	1,024
Debt Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	2,701,881	1,174,380
Gross Unrealized Losses, Less than 12 Months	71,535	10,888
Fair Value, 12 Months or Greater	215,533	276,006
Gross Unrealized Losses, 12 Months or Greater	18,565	21,772
Fair Value, Total	2,917,414	1,450,386
Gross Unrealized Losses, Total	90,100	32,660
Common stocks	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	36,899	46,725
Gross Unrealized Losses, Less than 12 Months	5,576	707
Fair Value, 12 Months or Greater	0	0
Gross Unrealized Losses, 12 Months or Greater	0	0
Fair Value, Total	36,899	46,725
Gross Unrealized Losses, Total	5,576	707
Preferred stocks	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	26,906	0
Gross Unrealized Losses, Less than 12 Months	1,901	0
Fair Value, 12 Months or Greater	19,939	39,812
Gross Unrealized Losses, 12 Months or Greater	5,735	1,651
Fair Value, Total	46,845	39,812
Gross Unrealized Losses, Total	7,636	1,651
Equity Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less than 12 Months	63,805	46,725
Gross Unrealized Losses, Less than 12 Months	7,477	707
Fair Value, 12 Months or Greater	19,939	39,812
Gross Unrealized Losses, 12 Months or Greater	5,735	1,651
Fair Value, Total	83,744	86,537
Gross Unrealized Losses, Total	$13,212	$2,358

Recovered_Sheet7

Securities in an Unrealized Loss Position (Non-Investment Grade Fixed Maturity Securities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	$3,001,158	$1,536,923
Mortgage-backed securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	582,747	543,023
Corporate	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	1,139,372	442,318
State and municipal	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	705,522	288,661
Foreign	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	344,301	106,833
Noninvestment Grade Investments at Loss Less than 5 Million	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	26	'
Aggregate fair value of securities in a continuous unrealized loss position	136,471	'
Gross Unrealized Loss	7,421	'
Noninvestment Grade Investments at Loss Less than 5 Million | Mortgage-backed securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	12	'
Aggregate fair value of securities in a continuous unrealized loss position	56,553	'
Gross Unrealized Loss	4,141	'
Noninvestment Grade Investments at Loss Less than 5 Million | Corporate	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	10	'
Aggregate fair value of securities in a continuous unrealized loss position	44,525	'
Gross Unrealized Loss	2,534	'
Noninvestment Grade Investments at Loss Less than 5 Million | State and municipal	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	1	'
Aggregate fair value of securities in a continuous unrealized loss position	10,864	'
Gross Unrealized Loss	2	'
Noninvestment Grade Investments at Loss Less than 5 Million | Foreign	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	3	'
Aggregate fair value of securities in a continuous unrealized loss position	24,529	'
Gross Unrealized Loss	$744	'

Securities_In_An_Unrealized_Lo2

Securities In An Unrealized Loss Position Securities In An Unrealized Loss Position (Narrative) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	$3,001,158	$1,536,923
Gross Unrealized Losses	103,312	35,018
Preferred stocks	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	46,845	39,812
Gross Unrealized Losses	7,636	1,651
Preferred stocks | Noninvestment Grade Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	4	'
Aggregate fair value of securities in a continuous unrealized loss position	47,000	'
Gross Unrealized Losses	8,000	'
Common stocks	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Aggregate fair value of securities in a continuous unrealized loss position	36,899	46,725
Gross Unrealized Losses	5,576	707
Common stocks | Noninvestment Grade Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities	2	'
Aggregate fair value of securities in a continuous unrealized loss position	37,000	'
Gross Unrealized Losses	$6,000	'

Fair_Value_Measurements_Assets

Fair Value Measurements (Assets and Liabilities Measured At Fair Value, On a Recurring Basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	$11,510,497	$11,841,005
Equity securities	338,907	376,022
Arbitrage trading account	619,881	329,077
Level 1 | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Equity securities	237,303	280,658
Assets, fair value disclosure	490,135	514,261
Arbitrage trading account	252,832	233,603
Securities sold but not yet purchased	88,482	114,909
Level 1 | Fair Value, Measurements, Recurring [Member] | U.S. government and agency	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | State and municipal	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Corporate	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Foreign	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Common stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	237,303	280,658
Level 1 | Fair Value, Measurements, Recurring [Member] | Preferred stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	11,464,480	11,781,940
Equity securities	96,593	93,335
Assets, fair value disclosure	11,927,935	11,969,821
Arbitrage trading account	366,862	94,546
Securities sold but not yet purchased	7	6,558
Level 2 | Fair Value, Measurements, Recurring [Member] | U.S. government and agency	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	825,059	898,463
Level 2 | Fair Value, Measurements, Recurring [Member] | State and municipal	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	4,118,137	4,768,519
Level 2 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	1,493,465	1,715,697
Level 2 | Fair Value, Measurements, Recurring [Member] | Corporate	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	3,854,455	3,287,654
Level 2 | Fair Value, Measurements, Recurring [Member] | Foreign	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	1,173,364	1,111,607
Level 2 | Fair Value, Measurements, Recurring [Member] | Common stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 | Fair Value, Measurements, Recurring [Member] | Preferred stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	96,593	93,335
Level 3 | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	46,017	59,065
Equity securities	5,011	2,029
Assets, fair value disclosure	51,215	62,022
Arbitrage trading account	187	928
Securities sold but not yet purchased	0	20
Level 3 | Fair Value, Measurements, Recurring [Member] | U.S. government and agency	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | State and municipal	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Corporate	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	46,017	59,065
Level 3 | Fair Value, Measurements, Recurring [Member] | Foreign	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Common stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	1,239	1,408
Level 3 | Fair Value, Measurements, Recurring [Member] | Preferred stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	3,772	621
Fair Value | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	11,510,497	11,841,005
Equity securities	338,907	376,022
Assets, fair value disclosure	12,469,285	12,546,104
Arbitrage trading account	619,881	329,077
Securities sold but not yet purchased	88,489	121,487
Fair Value | Fair Value, Measurements, Recurring [Member] | U.S. government and agency	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	825,059	898,463
Fair Value | Fair Value, Measurements, Recurring [Member] | State and municipal	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	4,118,137	4,768,519
Fair Value | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	1,493,465	1,715,697
Fair Value | Fair Value, Measurements, Recurring [Member] | Corporate	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	3,900,472	3,346,719
Fair Value | Fair Value, Measurements, Recurring [Member] | Foreign	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturity securities	1,173,364	1,111,607
Fair Value | Fair Value, Measurements, Recurring [Member] | Common stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	238,542	282,066
Fair Value | Fair Value, Measurements, Recurring [Member] | Preferred stocks	'	'
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	$100,365	$93,956

Fair_Value_Measurements_Summar

Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) (Level 3, USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	$62,022	$82,541
Assets, earnings	-383	-3,905
Assets, other comprehensive income	-137	11,455
Assets, purchases	4,381	283
Assets, (sales)	-4,789	-11,274
Assets, maturities	-9,879	-17,171
Assets, transfer out	0	93
Assets, ending balance	51,215	62,022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Liabilities, beginning balance	20	21
Liabilities, earnings	-4	-1
Liabilities, Other Comprehensive Income	0	0
Liabilities, purchases	4	0
Liabilities, (sales)	20	0
Liabilities, maturities	0	0
Liabilities, transfer out	0	0
Liabilities, ending balance	0	20
Debt Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	59,065	67,828
Assets, earnings	608	-1,497
Assets, other comprehensive income	-137	9,622
Assets, purchases	127	283
Assets, (sales)	-3,767	0
Assets, maturities	-9,879	-17,171
Assets, transfer out	0	0
Assets, ending balance	46,017	59,065
Corporate	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	59,065	67,828
Assets, earnings	608	-1,497
Assets, other comprehensive income	-137	9,622
Assets, purchases	127	283
Assets, (sales)	-3,767	0
Assets, maturities	-9,879	-17,171
Assets, transfer out	0	0
Assets, ending balance	46,017	59,065
Equity Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	2,029	13,862
Assets, earnings	-279	1,126
Assets, other comprehensive income	0	-1,737
Assets, purchases	3,430	0
Assets, (sales)	-169	-11,222
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	5,011	2,029
Preferred stocks	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	621	12,303
Assets, earnings	-279	1,126
Assets, other comprehensive income	0	-1,737
Assets, purchases	3,430	0
Assets, (sales)	0	-11,071
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	3,772	621
Common stocks	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	1,408	1,559
Assets, earnings	0	0
Assets, other comprehensive income	0	0
Assets, purchases	0	0
Assets, (sales)	-169	-151
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	1,239	1,408
Trading Assets, Excluding Debt and Equity Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Assets, beginning balance	928	851
Assets, earnings	-712	-3,534
Assets, other comprehensive income	0	3,570
Assets, purchases	824	0
Assets, (sales)	-853	-52
Assets, maturities	0	0
Assets, transfer out	0	93
Assets, ending balance	$187	$928

Reinsurance_Reinsurance_Financ

Reinsurance (Reinsurance Financial Information) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Written premiums:	'	'	'	'	'
Written premiums, direct	$1,415,775,000	$1,267,882,000	$4,221,370,000	$3,718,477,000	'
Written premiums, assumed	251,331,000	226,842,000	695,293,000	608,693,000	'
Written premiums, ceded	-243,481,000	-218,837,000	-774,174,000	-656,766,000	'
Total net premiums written	1,423,625,000	1,275,887,000	4,142,489,000	3,670,404,000	'
Premiums Earned, Net [Abstract]	'	'	'	'	'
Earned premiums, direct	1,351,542,000	1,208,257,000	3,893,806,000	3,475,375,000	'
Earned premiums, assumed	226,530,000	193,024,000	658,063,000	559,304,000	'
Earned premiums, ceded	-249,210,000	-214,748,000	-708,373,000	-601,138,000	'
Net premiums earned	1,328,862,000	1,186,533,000	3,843,496,000	3,433,541,000	'
Ceded losses incurred	186,504,000	114,273,000	439,415,000	308,692,000	'
Uncollectible reinsurance	$1,000,000	'	$1,000,000	'	$2,000,000

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets:	'	'
Arbitrage trading account	$619,881	$329,077
Carrying Value	'	'
Assets:	'	'
Fixed maturity securities	11,612,047	11,943,956
Equity securities available for sale	338,907	376,022
Arbitrage trading account	619,881	329,077
Loans receivable	411,851	401,961
Cash and cash equivalents	966,326	905,670
Trading account receivables from brokers and clearing organizations	123,320	446,873
Due from broker	24,890	14,449
Liabilities:	'	'
Trading account securities sold but not yet purchased	88,489	121,487
Junior subordinated debentures	339,772	243,206
Senior notes and other debt	1,696,461	1,871,535
Fair Value	'	'
Assets:	'	'
Fixed maturity securities	11,628,850	11,968,376
Equity securities available for sale	338,907	376,022
Arbitrage trading account	619,881	329,077
Loans receivable	417,323	406,443
Cash and cash equivalents	966,326	905,670
Trading account receivables from brokers and clearing organizations	123,320	446,873
Due from broker	24,890	14,449
Liabilities:	'	'
Trading account securities sold but not yet purchased	88,489	121,487
Junior subordinated debentures	302,540	252,000
Senior notes and other debt	$1,887,751	$2,190,173

Restricted_Stock_Units_Summary

Restricted Stock Units (Summary of Restricted Stock Units Issued) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]	'	'
Share based compensation expense	$16,000,000	$20,000,000
Restricted Stock [Member]	'	'
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]	'	'
Award vesting period	'5 years	'
Restricted Stock Units	93,150	2,114,720
Restricted Stock Units, Fair Value	$3,957,000	$78,351,000

Industry_Segments_Financial_In

Industry Segments (Financial Information of Company Operating Segments) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Jun. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	$1,328,862		$1,186,533		$3,843,496		$3,433,541
Investment Income and Funds	125,634		116,019		405,300		434,888
Other Revenues	179,628		117,949		463,059		346,524
Total revenues	1,634,124		1,420,501		4,711,855		4,214,953
Pre-Tax Income (Loss)	198,233		133,693		517,162		469,435
Net Income (Loss)	136,974		100,947		369,546		345,103
Net investment gains, before tax	43,869		22,226		96,896		94,003
Net investment gains, net of tax	28,514		14,811		62,982		61,743
Intersegment Eliminations and Corporate, Non-Segment [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	0		0		0	[1]	0	[1]
Investment Income and Funds	291		1,894		3,831	[1]	9,358	[1]
Other Revenues	109,634		69,515		285,650	[1]	175,400	[1]
Total revenues	109,925	[1]	71,409	[1]	289,481	[1]	184,758	[1]
Pre-Tax Income (Loss)	-58,501		-57,885		-183,941	[1]	-174,868	[1]
Net Income (Loss)	-38,248		-35,945		-114,674	[1]	-112,122	[1]
Insurance-Domestic Segment [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	958,994		873,835		2,769,369		2,530,638
Insurance-Domestic Segment [Member] | Operating Segments [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	958,994		873,835		2,769,369		2,530,638
Investment Income and Funds	94,071		82,565		299,430		315,307
Other Revenues	26,125		26,208		80,513		77,121
Total revenues	1,079,190		982,608		3,149,312		2,923,066
Pre-Tax Income (Loss)	172,177		132,498		465,861		424,873
Net Income (Loss)	118,183		94,852		324,069		304,167
Insurance-International Segment [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	189,054		157,773		540,365		456,159
Insurance-International Segment [Member] | Operating Segments [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	189,054		157,773		540,365		456,159
Investment Income and Funds	11,151		10,411		36,383		31,936
Other Revenues	0		0		0		0
Total revenues	200,205		168,184		576,748		488,095
Pre-Tax Income (Loss)	16,129		13,806		51,094		43,287
Net Income (Loss)	11,225		10,027		35,794		30,972
Reinsurance-Global Segment [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	180,814		154,925		533,762		446,744
Reinsurance-Global Segment [Member] | Operating Segments [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Earned Premiums	180,814		154,925		533,762		446,744
Investment Income and Funds	20,121		21,149		65,656		78,287
Other Revenues	0		0		0		0
Total revenues	200,935		176,074		599,418		525,031
Pre-Tax Income (Loss)	24,559		23,048		87,252		82,140
Net Income (Loss)	$17,300		$17,202		$61,375		$60,343
[1]

Industry_Segments_Identifiable

Industry Segments (Identifiable Assets by Segment) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Segment Reporting, Asset Reconciling Item [Line Items]	'		'
Consolidated Assets	$20,523,719		$20,155,896
Operating Segments [Member] | Reinsurance-Global Segment [Member]	'		'
Segment Reporting, Asset Reconciling Item [Line Items]	'		'
Consolidated Assets	3,090,334		3,337,937
Operating Segments [Member] | Insurance-International Segment [Member]	'		'
Segment Reporting, Asset Reconciling Item [Line Items]	'		'
Consolidated Assets	1,451,487		1,541,365
Operating Segments [Member] | Insurance-Domestic Segment [Member]	'		'
Segment Reporting, Asset Reconciling Item [Line Items]	'		'
Consolidated Assets	15,097,667		14,661,476
Intersegment Eliminations and Corporate, Non-Segment [Member]	'		'
Segment Reporting, Asset Reconciling Item [Line Items]	'		'
Consolidated Assets	$884,231	[1]	$615,118	[1]
[1]

Industry_Segments_Net_Premiums

Industry Segments (Net Premiums Earned By Major Line of Business) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Jun. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	$1,328,862		$1,186,533		$3,843,496		$3,433,541
Insurance-Domestic Segment [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	958,994		873,835		2,769,369		2,530,638
Insurance-Domestic Segment [Member] | Other Liability [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	314,878		280,808		917,910		812,153
Insurance-Domestic Segment [Member] | Workers' Compensation [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	252,220		223,477		722,422		637,583
Insurance-Domestic Segment [Member] | Short-tail lines [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	199,181	[1]	189,613	[1]	570,868	[1]	552,905	[1]
Insurance-Domestic Segment [Member] | Commercial Automobile [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	125,942		116,418		361,964		339,317
Insurance-Domestic Segment [Member] | Products Liability [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	66,773		63,519		196,205		188,680
Insurance-International Segment [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	189,054		157,773		540,365		456,159
Insurance-International Segment [Member] | Other Liability [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	18,457		29,719		48,745		47,559
Insurance-International Segment [Member] | Workers' Compensation [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	20,847		21,102		65,482		59,618
Insurance-International Segment [Member] | Short-tail lines [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	92,213	[1]	52,043	[1]	248,637	[1]	183,791	[1]
Insurance-International Segment [Member] | Commercial Automobile [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	30,898		30,557		97,929		90,831
Insurance-International Segment [Member] | Products Liability [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	26,639		24,352		79,572		74,360
Reinsurance-Global Segment [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	180,814		154,925		533,762		446,744
Reinsurance-Global Segment [Member] | Short-tail lines [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	52,687		42,011		162,191		125,467
Reinsurance-Global Segment [Member] | Casualty [Member]	'		'		'		'
Revenue from External Customer [Line Items]	'		'		'		'
Net premiums earned	$128,127		$112,914		$371,571		$321,277
[1]	Short-tail lines includes commercial multi-peril (non-liability), inland and ocean marine, accident and health, fidelity and surety, boiler and machinery and other lines.