Markel (MKL) 10-Q 4 Nov 15 2015 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 28, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Entity Registrant Name	MARKEL CORP
Entity Central Index Key	1,096,343
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		13,950,253

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
ASSETS
Fixed maturities (amortized cost of $8,937,575 in 2015 and $9,929,137 in 2014)	$ 9,353,951	$ 10,422,882
Equity securities (cost of $2,290,017 in 2015 and $1,951,658 in 2014)	4,156,413	4,137,576
Short-term investments (estimated fair value approximates cost)	2,323,983	1,594,849
Total Investments	15,834,347	16,155,307
Cash and cash equivalents	2,261,201	1,960,169
Restricted cash and cash equivalents	371,794	522,225
Receivables	1,249,429	1,135,217
Reinsurance recoverable on unpaid losses	1,973,249	1,868,669
Reinsurance recoverable on paid losses	85,896	102,206
Deferred policy acquisition costs	379,767	353,410
Prepaid reinsurance premiums	367,626	365,458
Goodwill	1,043,713	1,049,115
Intangible assets	652,667	702,747
Other assets	961,884	985,834
Total Assets	25,181,573	25,200,357
LIABILITIES AND EQUITY
Unpaid losses and loss adjustment expenses	10,388,209	10,404,152
Life and annuity benefits	1,159,901	1,305,818
Unearned premiums	2,377,904	2,245,690
Payables to insurance and reinsurance companies	318,078	276,122
Senior long-term debt and other debt (estimated fair value of $2,441,000 in 2015 and $2,493,000 in 2014)	2,240,517	2,253,594
Other liabilities	942,873	1,051,931
Total Liabilities	17,427,482	17,537,307
Redeemable noncontrolling interests	$ 50,584	$ 61,048
Commitments and contingencies
Shareholders' equity:
Common stock	$ 3,335,208	$ 3,308,395
Retained earnings	2,942,606	2,581,866
Accumulated other comprehensive income	1,417,416	1,704,557
Total Shareholders' Equity	7,695,230	7,594,818
Noncontrolling interests	8,277	7,184
Total Equity	7,703,507	7,602,002
Total Liabilities and Equity	$ 25,181,573	$ 25,200,357

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 8,937,575	$ 9,929,137
Equity securities, cost	2,290,017	1,951,658
Senior long-term debt and other debt, estimated fair value	$ 2,441,000	$ 2,493,000

Consolidated Statements Of Inco

Consolidated Statements Of Income And Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
OPERATING REVENUES
Earned premiums	$ 963,675	$ 954,007	$ 2,864,882	$ 2,868,981
Net investment income	87,060	91,096	270,521	269,980
Other-than-temporary impairment losses	(18,281)	(2,851)	(23,373)	(3,858)
Net realized investment gains, excluding other-than-temporary impairment losses	3,574	7,046	20,342	32,567
Net realized investment gains (losses)	(14,707)	4,195	(3,031)	28,709
Other revenues	306,736	249,988	817,151	630,242
Total Operating Revenues	1,342,764	1,299,286	3,949,523	3,797,912
OPERATING EXPENSES
Losses and loss adjustment expenses	484,737	570,966	1,467,926	1,723,675
Underwriting, acquisition and insurance expenses	365,619	350,493	1,085,956	1,071,985
Amortization of intangible assets	18,914	13,505	50,503	40,992
Other expenses	290,749	231,193	763,986	598,303
Total Operating Expenses	1,160,019	1,166,157	3,368,371	3,434,955
Operating Income	182,745	133,129	581,152	362,957
Interest expense	30,064	29,648	88,664	89,136
Income Before Income Taxes	152,681	103,481	492,488	273,821
Income tax expense	48,271	26,657	101,619	68,355
Net Income	104,410	76,824	390,869	205,466
Net income attributable to noncontrolling interests	1,891	1,021	5,989	1,879
Net Income to Shareholders	102,519	75,803	384,880	203,587
OTHER COMPREHENSIVE INCOME (LOSS)
Net holding gains (losses) arising during the period	(149,266)	(7,532)	(258,386)	348,096
Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period	(8)	123	111	118
Reclassification adjustments for net gains (losses) included in net income	6,000	(4,990)	(8,037)	(15,752)
Change in net unrealized gains on investments, net of taxes	(143,274)	(12,399)	(266,312)	332,462
Change in foreign currency translation adjustments, net of taxes	(10,854)	(27,223)	(22,283)	(19,639)
Change in net actuarial pension loss, net of taxes	475	320	1,407	964
Total Other Comprehensive Income (Loss)	(153,653)	(39,302)	(287,188)	313,787
Comprehensive Income (Loss)	(49,243)	37,522	103,681	519,253
Comprehensive income attributable to noncontrolling interests	1,900	1,020	5,942	1,890
Comprehensive Income (Loss) to Shareholders	$ (51,143)	$ 36,502	$ 97,739	$ 517,363
NET INCOME PER SHARE
Basic (in dollars per share)	$ 7.43	$ 5.33	$ 27.76	$ 14.28
Diluted (in dollars per share)	$ 7.39	$ 5.30	$ 27.60	$ 14.21

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Equity - USD ($) shares in Thousands, $ in Thousands	Total	Total Equity [Member]	Total Shareholders' Equity [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Noncontrolling Interests [Member]	Redeemable Noncontrolling Interests [Member]
Balance at Dec. 31, 2013		$ 6,678,010	$ 6,673,577	$ 3,288,863	$ 2,294,909	$ 1,089,805	$ 4,433
Balance, shares at Dec. 31, 2013				13,986
Balance, redeemable noncontrolling interests at Dec. 31, 2013								$ 72,183
Net income (loss)	$ 205,466	202,515	203,587		203,587	0	(1,072)	2,951
Other comprehensive income (loss)	313,787	313,776	313,776		0	313,776	0	11
Comprehensive Income (Loss)	519,253	516,291	517,363				(1,072)	2,962
Issuance of common stock		4,960	4,960	$ 4,960	0	0	0	0
Issuance of common stock, shares				16
Repurchase of common stock		(25,922)	(25,922)	$ 0	(25,922)	0	0	0
Repurchase of common stock, shares				(44)
Restricted stock units expensed		18,421	18,421	$ 18,421	0	0	0	0
Restricted stock units expensed, shares				0
Adjustment of redeemable noncontrolling interests		(3,843)	(3,843)	$ 0	(3,843)	0	0	3,843
Adjustment of redeemable noncontrolling interests, shares				0
Purchase of noncontrolling interest		(9,352)	(10,257)	$ (10,257)	0	0	905	(18,566)
Purchase of noncontrolling interest, shares				0
Other		4,804	894	$ 881	13	0	3,910	(3,173)
Other, shares				0
Balance at Sep. 30, 2014		7,183,369	7,175,193	$ 3,302,868	2,468,744	1,403,581	8,176
Balance, shares at Sep. 30, 2014				13,958
Balance, redeemable noncontrolling interests at Sep. 30, 2014								57,249
Balance at Dec. 31, 2014	7,602,002	7,602,002	7,594,818	$ 3,308,395	2,581,866	1,704,557	7,184
Balance, shares at Dec. 31, 2014				13,962
Balance, redeemable noncontrolling interests at Dec. 31, 2014	61,048							61,048
Net income (loss)	390,869	385,625	384,880		384,880	0	745	5,244
Other comprehensive income (loss)	(287,188)	(287,141)	(287,141)		0	(287,141)	0	(47)
Comprehensive Income (Loss)	103,681	98,484	97,739				745	5,197
Issuance of common stock		3,971	3,971	$ 3,971	0	0	0	0
Issuance of common stock, shares				20
Repurchase of common stock		(27,262)	(27,262)	$ 0	(27,262)	0	0	0
Repurchase of common stock, shares				(32)
Restricted stock units expensed		19,983	19,983	$ 19,983	0	0	0	0
Restricted stock units expensed, shares				0
Adjustment of redeemable noncontrolling interests		3,091	3,091	$ 0	3,091	0	0	(3,091)
Adjustment of redeemable noncontrolling interests, shares				0
Purchase of noncontrolling interest		(1,447)	(1,447)	$ (1,447)	0	0	0	(8,224)
Purchase of noncontrolling interest, shares				0
Other		4,685	4,337	$ 4,306	31	0	348	(4,346)
Other, shares				0
Balance at Sep. 30, 2015	7,703,507	$ 7,703,507	$ 7,695,230	$ 3,335,208	$ 2,942,606	$ 1,417,416	$ 8,277
Balance, shares at Sep. 30, 2015				13,950
Balance, redeemable noncontrolling interests at Sep. 30, 2015	$ 50,584							$ 50,584

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES
Net income	$ 390,869	$ 205,466
Adjustments to reconcile net income to net cash provided by operating activities	159,516	331,162
Net Cash Provided By Operating Activities	550,385	536,628
INVESTING ACTIVITIES
Proceeds from sales of fixed maturities and equity securities	211,479	1,183,237
Proceeds from maturities, calls and prepayments of fixed maturities	1,162,500	1,110,128
Cost of fixed maturities and equity securities purchased	(928,601)	(2,687,075)
Net change in short-term investments	(687,673)	(213,618)
Proceeds from sales of equity method investments	22,204	101,938
Cost of equity method investments	(21,464)	(9,441)
Change in restricted cash and cash equivalents	136,203	203,635
Additions to property and equipment	(62,055)	(52,350)
Acquisitions, net of cash acquired	0	(316,307)
Other	(761)	(1,487)
Net Cash Used By Investing Activities	(168,168)	(681,340)
FINANCING ACTIVITIES
Additions to senior long-term debt and other debt	49,771	64,075
Repayment of senior long-term debt and other debt	(55,743)	(40,397)
Repurchases of common stock	(27,262)	(25,922)
Issuance of common stock	3,971	4,960
Purchase of noncontrolling interests	(12,474)	(25,918)
Distributions to noncontrolling interests	(3,724)	(3,463)
Other	(11,220)	(20,074)
Net Cash Used By Financing Activities	(56,681)	(46,739)
Effect of foreign currency rate changes on cash and cash equivalents	(24,504)	(21,484)
Increase (decrease) in cash and cash equivalents	301,032	(212,935)
Cash and cash equivalents at beginning of period	1,960,169	1,978,526
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 2,261,201	$ 1,765,591

Basis Of Presentation

Basis Of Presentation	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis Of Presentation	Basis of Presentation Markel Corporation is a diverse financial holding company serving a variety of niche markets. Markel Corporation's principal business markets and underwrites specialty insurance products and programs. Through its wholly-owned subsidiary, Markel Ventures, Inc. (Markel Ventures), Markel Corporation also owns interests in various industrial and service businesses that operate outside of the specialty insurance marketplace. The consolidated balance sheet as of September 30, 2015 , the related consolidated statements of income and comprehensive income (loss) for the quarters and nine months ended September 30, 2015 and 2014 , and the consolidated statements of changes in equity and cash flows for the nine months ended September 30, 2015 and 2014 are unaudited. In the opinion of management, all adjustments necessary for fair presentation of such consolidated financial statements have been included. Such adjustments consist only of normal, recurring items. Interim results are not necessarily indicative of results of operations for the entire year. The consolidated balance sheet as of December 31, 2014 was derived from Markel Corporation's audited annual consolidated financial statements. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) and include the accounts of Markel Corporation and its subsidiaries (the Company). All significant intercompany balances and transactions have been eliminated in consolidation. The Company consolidates the results of its Markel Ventures subsidiaries on a one-month lag. Certain prior year amounts have been reclassified to conform to the current presentation. The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results may differ materially from the estimates and assumptions used in preparing the consolidated financial statements. The consolidated financial statements and notes are presented as permitted by Form 10-Q and do not contain certain information included in the Company's annual consolidated financial statements and notes. Readers are urged to review the Company's 2014 Annual Report on Form 10-K for a more complete description of the Company's business and accounting policies.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which creates a new comprehensive revenue recognition standard that will serve as a single source of revenue guidance for all companies in all industries. The guidance applies to all companies that either enter into contracts with customers to transfer goods or services or enter into contracts for the transfer of nonfinancial assets, unless those contracts are within the scope of other standards, such as insurance contracts. ASU No. 2014-09's core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606), Deferral of the Effective Date , which deferred the original effective date of ASU No. 2014-09 by one year. As a result, ASU No. 2014-09 becomes effective for the Company during the first quarter of 2018 and may be applied retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Early application is permitted, but not before the first quarter of 2017. The Company is currently evaluating ASU No. 2014-09 to determine the potential impact that adopting this standard will have on its consolidated financial statements. Adoption of this ASU is not expected to have a significant impact on the Company's insurance operations, but may impact the Company's non-insurance operations. In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis, which changes the way reporting enterprises evaluate whether (a) they should consolidate limited partnerships and similar entities, (b) fees paid to a decision maker or service provider are variable interests in a variable interest entity (VIE), and (c) variable interests in a VIE held by related parties of the reporting enterprise require the reporting enterprise to consolidate the VIE. It also eliminates the VIE consolidation model based on majority exposure to variability that applied to certain investment companies and similar entities. The ASU also significantly changes how to evaluate voting rights for entities that are not similar to limited partnerships when determining whether the entity is a VIE, which may affect entities for which the decision making rights are conveyed through a contractual arrangement. ASU No. 2015-02 becomes effective for the Company during the first quarter of 2016 and may be applied retrospectively or under a modified retrospective method where the cumulative-effect adjustment to retained earnings is recognized as of the beginning of the fiscal year of adoption. Reporting enterprises may also restate previously issued financial statements for one or more years with a cumulative-effect adjustment to retained earnings as of the beginning of the first year restated. Early adoption is allowed. The Company is currently evaluating ASU No. 2015-02 but does not expect adoption of this ASU will have a material impact on the Company's financial position, results of operations or cash flows. In April 2015, the FASB issued ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): S implifying the Presentation of Debt Issuance Costs . The ASU requires that debt issuance costs related to a recognized debt liability be presented on the balance sheet as a direct deduction from the debt liability, similar to the presentation of debt discounts. The cost of issuing debt will no longer be recorded as a separate asset on the balance sheet. The amortization of debt issuance costs will continue to be included in interest expense. ASU No. 2015-03 becomes effective for the Company during the first quarter of 2016 and will be applied retrospectively to all prior periods presented. Early application is permitted. The adoption of this ASU is not expected to have a material impact on the Company's financial position, results of operations or cash flows. In April 2015, the FASB issued ASU No. 2015-05, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement , which clarifies that software licenses contained in a cloud computing arrangement should be capitalized if the customer has the right to take possession of the software and the ability to run the software outside of the cloud computing arrangement. ASU No. 2015-05 becomes effective for the Company during the first quarter of 2016 and may be applied prospectively or retrospectively. Early application is permitted. The adoption of this ASU is not expected to have a material impact on the Company's financial position, results of operations or cash flows. In May 2015, the FASB issued ASU No. 2015-09, Financial Services-Insurance (Topic 944): Disclosures about Short-Duration Contracts . The ASU requires significant new disclosures for insurers relating to short-duration insurance contract claims and the unpaid claims liability rollforward for long and short-duration contracts. The guidance requires annual tabular disclosure, on a disaggregated basis, of undiscounted incurred and paid claim and allocated claim adjustment expense development by accident year, on a net basis after reinsurance, for up to 10 years. Tables must also include the total incurred but not reported claims liabilities, plus expected development on reported claims, and claims frequency for each accident year. A description of estimation methodologies and any significant changes in methodologies and assumptions used to calculate the liability and frequency is also required. Based on the disaggregated claims information in the tables, disclosure of historical average annual percentage payout of incurred claims is also required. Interim period disclosures must include a tabular rollforward and related qualitative information for the liability for unpaid losses and loss adjustment expenses for both long-duration and short-duration contracts. ASU No. 2015-09 becomes effective for the Company during 2016, with interim disclosures required beginning in the first quarter of 2017. The ASU must be applied retrospectively by providing comparative disclosures for each period presented. Early application is permitted. The adoption of this ASU is not expected to have a material impact on the Company's financial position, results of operations or cash flows, but will expand the nature and extent of its insurance contract disclosures, as described above. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory. The ASU changes the measurement principle for inventory from the lower of cost or market to lower of cost and net realizable value and eliminates the requirement to consider replacement cost or net realizable value less an approximately normal profit margin when measuring inventory. ASU 2015-11 becomes effective for the Company during the first quarter of 2016 and will be applied prospectively. Early application is permitted. The Company is currently evaluating ASU No. 2015-11 to determine the potential impact that adopting this standard will have on its consolidated financial statements. Adoption of this ASU is not expected to impact the Company's insurance operations, but may impact the Company's non-insurance operations. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. The ASU eliminates the requirement to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after a business combination is consummated. ASU 2015-16 becomes effective for the Company during the first quarter of 2016 and will be applied prospectively. Early application is permitted. The adoption of this ASU is not expected to have a material impact on the Company's financial position, results of operations or cash flows.

Investments

Investments	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	Investments a) The following tables summarize the Company's available-for-sale investments. September 30, 2015 (dollars in thousands) Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Unrealized Other-Than- Temporary Impairment Losses Estimated Fair Value Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 696,980 $ 13,360 $ (1,545 ) $ — $ 708,795 Obligations of states, municipalities and political subdivisions 3,766,517 198,495 (8,688 ) — 3,956,324 Foreign governments 1,338,511 139,447 (826 ) — 1,477,132 Commercial mortgage-backed securities 441,814 10,808 (1,107 ) — 451,515 Residential mortgage-backed securities 860,869 34,272 (2,079 ) (2,258 ) 890,804 Asset-backed securities 45,470 55 (125 ) — 45,400 Corporate bonds 1,787,414 48,535 (10,288 ) (1,680 ) 1,823,981 Total fixed maturities 8,937,575 444,972 (24,658 ) (3,938 ) 9,353,951 Equity securities: Insurance, banks and other financial institutions 629,814 658,077 (12,482 ) — 1,275,409 Industrial, consumer and all other 1,660,203 1,281,314 (60,513 ) — 2,881,004 Total equity securities 2,290,017 1,939,391 (72,995 ) — 4,156,413 Short-term investments 2,323,917 71 (5 ) — 2,323,983 Investments, available-for-sale $ 13,551,509 $ 2,384,434 $ (97,658 ) $ (3,938 ) $ 15,834,347 December 31, 2014 (dollars in thousands) Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Unrealized Other-Than- Temporary Impairment Losses Estimated Fair Value Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 662,462 $ 12,963 $ (2,163 ) $ — $ 673,262 Obligations of states, municipalities and political subdivisions 4,075,748 245,158 (3,359 ) — 4,317,547 Foreign governments 1,458,255 154,707 (1,041 ) — 1,611,921 Commercial mortgage-backed securities 427,904 5,325 (2,602 ) — 430,627 Residential mortgage-backed securities 954,263 34,324 (3,482 ) (2,258 ) 982,847 Asset-backed securities 100,073 99 (682 ) — 99,490 Corporate bonds 2,250,432 69,016 (10,441 ) (1,819 ) 2,307,188 Total fixed maturities 9,929,137 521,592 (23,770 ) (4,077 ) 10,422,882 Equity securities: Insurance, banks and other financial institutions 523,739 789,717 (1,531 ) — 1,311,925 Industrial, consumer and all other 1,427,919 1,403,566 (5,834 ) — 2,825,651 Total equity securities 1,951,658 2,193,283 (7,365 ) — 4,137,576 Short-term investments 1,594,819 36 (6 ) — 1,594,849 Investments, available-for-sale $ 13,475,614 $ 2,714,911 $ (31,141 ) $ (4,077 ) $ 16,155,307 b) The following tables summarize gross unrealized investment losses by the length of time that securities have continuously been in an unrealized loss position. September 30, 2015 Less than 12 months 12 months or longer Total (dollars in thousands) Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 72,511 $ (1,265 ) $ 93,566 $ (280 ) $ 166,077 $ (1,545 ) Obligations of states, municipalities and political subdivisions 297,670 (5,618 ) 59,482 (3,070 ) 357,152 (8,688 ) Foreign governments 27,208 (594 ) 41,433 (232 ) 68,641 (826 ) Commercial mortgage-backed securities 66,074 (258 ) 100,233 (849 ) 166,307 (1,107 ) Residential mortgage-backed securities 24,353 (2,321 ) 147,001 (2,016 ) 171,354 (4,337 ) Asset-backed securities 5,678 (2 ) 26,720 (123 ) 32,398 (125 ) Corporate bonds 270,889 (6,364 ) 343,268 (5,604 ) 614,157 (11,968 ) Total fixed maturities 764,383 (16,422 ) 811,703 (12,174 ) 1,576,086 (28,596 ) Equity securities: Insurance, banks and other financial institutions 139,456 (11,308 ) 6,676 (1,174 ) 146,132 (12,482 ) Industrial, consumer and all other 387,475 (60,006 ) 19,085 (507 ) 406,560 (60,513 ) Total equity securities 526,931 (71,314 ) 25,761 (1,681 ) 552,692 (72,995 ) Short-term investments 139,990 (5 ) — — 139,990 (5 ) Total $ 1,431,304 $ (87,741 ) $ 837,464 $ (13,855 ) $ 2,268,768 $ (101,596 ) At September 30, 2015 , the Company held 567 securities with a total estimated fair value of $2.3 billion and gross unrealized losses of $101.6 million . Of these 567 securities, 268 securities had been in a continuous unrealized loss position for one year or longer and had a total estimated fair value of $837.5 million and gross unrealized losses of $13.9 million . Of these securities, 262 securities were fixed maturities and six were equity securities. The Company does not intend to sell or believe it will be required to sell these fixed maturities before recovery of their amortized cost. The Company has the ability and intent to hold these equity securities for a period of time sufficient to allow for the anticipated recovery of their fair value. December 31, 2014 Less than 12 months 12 months or longer Total (dollars in thousands) Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 108,250 $ (62 ) $ 163,359 $ (2,101 ) $ 271,609 $ (2,163 ) Obligations of states, municipalities and political subdivisions 58,583 (542 ) 92,441 (2,817 ) 151,024 (3,359 ) Foreign governments 18,856 (386 ) 56,217 (655 ) 75,073 (1,041 ) Commercial mortgage-backed securities 45,931 (210 ) 147,558 (2,392 ) 193,489 (2,602 ) Residential mortgage-backed securities 9,613 (2,285 ) 207,374 (3,455 ) 216,987 (5,740 ) Asset-backed securities 30,448 (20 ) 45,160 (662 ) 75,608 (682 ) Corporate bonds 141,176 (2,263 ) 621,821 (9,997 ) 762,997 (12,260 ) Total fixed maturities 412,857 (5,768 ) 1,333,930 (22,079 ) 1,746,787 (27,847 ) Equity securities: Insurance, banks and other financial institutions 16,219 (1,531 ) — — 16,219 (1,531 ) Industrial, consumer and all other 86,062 (5,834 ) — — 86,062 (5,834 ) Total equity securities 102,281 (7,365 ) — — 102,281 (7,365 ) Short-term investments 181,964 (6 ) — — 181,964 (6 ) Total $ 697,102 $ (13,139 ) $ 1,333,930 $ (22,079 ) $ 2,031,032 $ (35,218 ) At December 31, 2014 , the Company held 552 securities with a total estimated fair value of $2.0 billion and gross unrealized losses of $35.2 million . Of these 552 securities, 396 securities had been in a continuous unrealized loss position for one year or longer and had a total estimated fair value of $1.3 billion and gross unrealized losses of $22.1 million . All 396 securities were fixed maturities. The Company completes a detailed analysis each quarter to assess whether the decline in the fair value of any investment below its cost basis is deemed other-than-temporary. All securities with unrealized losses are reviewed. The Company considers many factors in completing its quarterly review of securities with unrealized losses for other-than-temporary impairment, including the length of time and the extent to which fair value has been below cost and the financial condition and near-term prospects of the issuer. For equity securities, the ability and intent to hold the security for a period of time sufficient to allow for anticipated recovery is considered. For fixed maturities, the Company considers whether it intends to sell the security or if it is more likely than not that it will be required to sell the security before recovery, the implied yield-to-maturity, the credit quality of the issuer and the ability to recover all amounts outstanding when contractually due. For equity securities, a decline in fair value that is considered to be other-than-temporary is recognized in net income based on the fair value of the security at the time of assessment, resulting in a new cost basis for the security. For fixed maturities where the Company intends to sell the security or it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost, a decline in fair value is considered to be other-than-temporary and is recognized in net income based on the fair value of the security at the time of assessment, resulting in a new cost basis for the security. If the decline in fair value of a fixed maturity below its amortized cost is considered to be other-than-temporary based upon other considerations, the Company compares the estimated present value of the cash flows expected to be collected to the amortized cost of the security. The extent to which the estimated present value of the cash flows expected to be collected is less than the amortized cost of the security represents the credit-related portion of the other-than-temporary impairment, which is recognized in net income, resulting in a new cost basis for the security. Any remaining decline in fair value represents the non-credit portion of the other-than-temporary impairment, which is recognized in other comprehensive income (loss). The discount rate used to calculate the estimated present value of the cash flows expected to be collected is the effective interest rate implicit for the security at the date of purchase. When assessing whether it intends to sell a fixed maturity or if it is likely to be required to sell a fixed maturity before recovery of its amortized cost, the Company evaluates facts and circumstances including decisions to reposition the investment portfolio, potential sales of investments to meet cash flow needs and, ultimately, current market prices. c) The amortized cost and estimated fair value of fixed maturities at September 30, 2015 are shown below by contractual maturity. (dollars in thousands) Amortized Cost Estimated Fair Value Due in one year or less $ 538,793 $ 541,638 Due after one year through five years 1,899,246 1,950,115 Due after five years through ten years 1,655,136 1,753,390 Due after ten years 3,496,247 3,721,089 7,589,422 7,966,232 Commercial mortgage-backed securities 441,814 451,515 Residential mortgage-backed securities 860,869 890,804 Asset-backed securities 45,470 45,400 Total fixed maturities $ 8,937,575 $ 9,353,951 d) The following table presents the components of net investment income. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Interest: Municipal bonds (tax-exempt) $ 21,979 $ 24,505 $ 72,124 $ 72,796 Municipal bonds (taxable) 14,667 13,523 42,917 35,133 Other taxable bonds 34,368 38,741 103,519 114,594 Short-term investments, including overnight deposits 1,287 1,530 3,654 4,612 Dividends on equity securities 17,887 14,678 55,544 46,042 Income (loss) from equity method investments (4 ) 2,253 3,052 7,294 Other 37 (266 ) 577 1,436 90,221 94,964 281,387 281,907 Investment expenses (3,161 ) (3,868 ) (10,866 ) (11,927 ) Net investment income $ 87,060 $ 91,096 $ 270,521 $ 269,980 e) Cumulative credit losses recognized in net income on fixed maturities where other-than-temporary impairment was identified and a portion of the other-than-temporary impairment was included in other comprehensive income (loss) were $10.7 million at September 30, 2015 and $12.7 million at December 31, 2014 . f) The following table presents net realized investment gains (losses) and the change in net unrealized gains on investments. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Realized gains: Sales of fixed maturities $ 435 $ 739 $ 2,769 $ 6,381 Sales of equity securities 11,329 10,793 34,285 36,942 Other 1,026 134 3,297 11,958 Total realized gains 12,790 11,666 40,351 55,281 Realized losses: Sales of fixed maturities (3,730 ) (1,658 ) (3,947 ) (17,805 ) Sales of equity securities (400 ) (175 ) (672 ) (373 ) Other-than-temporary impairments (18,281 ) (2,851 ) (23,373 ) (3,858 ) Other (5,086 ) (2,787 ) (15,390 ) (4,536 ) Total realized losses (27,497 ) (7,471 ) (43,382 ) (26,572 ) Net realized investment gains (losses) $ (14,707 ) $ 4,195 $ (3,031 ) $ 28,709 Change in net unrealized gains on investments: Fixed maturities $ 102,844 $ 41,615 $ (77,369 ) $ 337,865 Equity securities (313,075 ) (57,773 ) (319,522 ) 160,936 Short-term investments 45 37 36 35 Net increase (decrease) $ (210,186 ) $ (16,121 ) $ (396,855 ) $ 498,836 For the quarter ended September 30, 2015 , other-than-temporary impairment losses recognized in net income and included in net realized investment losses totaled $18.3 million and were attributable to eight equity securities. The write downs for the quarter included $14.3 million related to equities in industrial, consumer, or other types of business and $4.0 million related to equities in insurance, banks, and other financial institutions. For the nine months ended September 30, 2015 , other-than-temporary impairment losses recognized in net income and included in net realized investment losses totaled $23.4 million and were attributable to 16 equity securities. The write downs for the nine-month period included $18.8 million related to equities in industrial, consumer, or other types of business, and $4.6 million related to equities in insurance, banks, and other financial institutions. For the quarter ended September 30, 2014 , other-than-temporary impairment losses recognized in net income and included in net realized investment gains included losses attributable to fixed maturities totaling $0.1 million and losses attributable to equity securities totaling $2.7 million . For the nine months ended September 30, 2014 , other-than-temporary impairment losses recognized in net income and included in net realized investment gains included losses attributable to fixed maturities totaling $0.3 million and losses attributable to equity securities totaling $3.6 million . g) The following table presents the components of restricted assets. (dollars in thousands) September 30, December 31, Restricted assets held in trust or on deposit to support underwriting activities $ 4,733,990 $ 4,961,061 Investments and cash and cash equivalents pledged as security for letters of credit 654,208 635,340 Total $ 5,388,198 $ 5,596,401 Total restricted assets are included on the Company's consolidated balance sheets as follows. (dollars in thousands) September 30, December 31, Investments, available-for-sale $ 5,016,404 $ 5,040,413 Restricted cash and cash equivalents 371,794 522,225 Other assets — 33,763 Total $ 5,388,198 $ 5,596,401

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements FASB ASC 820-10, Fair Value Measurements and Disclosures, establishes a three-level hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). If the inputs used to measure the assets or liabilities fall within different levels of the hierarchy, the classification is based on the lowest level input that is significant to the fair value measurement of the asset or liability. Classification of assets and liabilities within the hierarchy considers the markets in which the assets and liabilities are traded and the reliability and transparency of the assumptions used to determine fair value. The hierarchy requires the use of observable market data when available. The levels of the hierarchy are defined as follows: Level 1 – Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities traded in active markets. Level 2 – Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and market-corroborated inputs. Level 3 – Inputs to the valuation methodology are unobservable for the asset or liability and are significant to the fair value measurement. In accordance with FASB ASC 820, the Company determines fair value based on 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. In determining fair value, the Company uses various methods, including the market, income and cost approaches. The Company uses valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The following section describes the valuation methodologies used by the Company to measure assets and liabilities at fair value, including an indication of the level within the fair value hierarchy in which each asset or liability is generally classified. Investments available-for-sale. Investments available-for-sale are recorded at fair value on a recurring basis and include fixed maturities, equity securities and short-term investments. Short-term investments include certificates of deposit, commercial paper, discount notes and treasury bills with original maturities of one year or less. Fair value for investments available-for-sale is determined by the Company after considering various sources of information, including information provided by a third party pricing service. The pricing service provides prices for substantially all of the Company's fixed maturities and equity securities. In determining fair value, the Company generally does not adjust the prices obtained from the pricing service. The Company obtains an understanding of the pricing service's valuation methodologies and related inputs, which include, but are not limited to, reported trades, benchmark yields, issuer spreads, bids, offers, duration, credit ratings, estimated cash flows and prepayment speeds. The Company validates prices provided by the pricing service by reviewing prices from other pricing sources and analyzing pricing data in certain instances. The Company has evaluated the various types of securities in its investment portfolio to determine an appropriate fair value hierarchy level based upon trading activity and the observability of market inputs. Level 1 investments include those traded on an active exchange, such as the New York Stock Exchange. Level 2 investments include U.S. Treasury securities and obligations of U.S. government agencies, municipal bonds, foreign government bonds, commercial mortgage-backed securities, residential mortgage-backed securities, asset-backed securities and corporate debt securities. Fair value for investments available-for-sale is measured based upon quoted prices in active markets, if available. Due to variations in trading volumes and the lack of quoted market prices, fixed maturities are classified as Level 2 investments. The fair value of fixed maturities is normally derived through recent reported trades for identical or similar securities, making adjustments through the reporting date based upon available market observable data described above. If there are no recent reported trades, the fair value of fixed maturities may be derived through the use of matrix pricing or model processes, where future cash flow expectations are developed based upon collateral performance and discounted at an estimated market rate. Significant inputs used to determine the fair value of obligations of states, municipalities and political subdivisions, corporate bonds and obligations of foreign governments include reported trades, benchmark yields, issuer spreads, bids, offers, credit information and estimated cash flows. Significant inputs used to determine the fair value of commercial mortgage-backed securities, residential mortgage-backed securities and asset-backed securities include the type of underlying assets, benchmark yields, prepayment speeds, collateral information, tranche type and volatility, estimated cash flows, credit information, default rates, recovery rates, issuer spreads and the year of issue. Senior long-term debt and other debt. Senior long-term debt and other debt is carried at amortized cost with the estimated fair value disclosed on the consolidated balance sheets. Senior long-term debt and other debt is classified as Level 2 within the fair value hierarchy due to variations in trading volumes and the lack of quoted market prices. Fair value for senior long-term debt and other debt is generally derived through recent reported trades for identical securities, making adjustments through the reporting date, if necessary, based upon available market observable data including U.S. Treasury securities and implied credit spreads. Significant inputs used to determine the fair value of senior long-term debt and other debt include reported trades, benchmark yields, issuer spreads, bids and offers. The following tables present the balances of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy. September 30, 2015 (dollars in thousands) Level 1 Level 2 Level 3 Total Assets: Investments available-for-sale: Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ — $ 708,795 $ — $ 708,795 Obligations of states, municipalities and political subdivisions — 3,956,324 — 3,956,324 Foreign governments — 1,477,132 — 1,477,132 Commercial mortgage-backed securities — 451,515 — 451,515 Residential mortgage-backed securities — 890,804 — 890,804 Asset-backed securities — 45,400 — 45,400 Corporate bonds — 1,823,981 — 1,823,981 Total fixed maturities — 9,353,951 — 9,353,951 Equity securities: Insurance, banks and other financial institutions 1,275,409 — — 1,275,409 Industrial, consumer and all other 2,881,004 — — 2,881,004 Total equity securities 4,156,413 — — 4,156,413 Short-term investments 2,224,533 99,450 — 2,323,983 Total investments available-for-sale $ 6,380,946 $ 9,453,401 $ — $ 15,834,347 December 31, 2014 (dollars in thousands) Level 1 Level 2 Level 3 Total Assets: Investments available-for-sale: Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ — $ 673,262 $ — $ 673,262 Obligations of states, municipalities and political subdivisions — 4,317,547 — 4,317,547 Foreign governments — 1,611,921 — 1,611,921 Commercial mortgage-backed securities — 430,627 — 430,627 Residential mortgage-backed securities — 982,847 — 982,847 Asset-backed securities — 99,490 — 99,490 Corporate bonds — 2,307,188 — 2,307,188 Total fixed maturities — 10,422,882 — 10,422,882 Equity securities: Insurance, banks and other financial institutions 1,311,925 — — 1,311,925 Industrial, consumer and all other 2,825,651 — — 2,825,651 Total equity securities 4,137,576 — — 4,137,576 Short-term investments 1,469,975 124,874 — 1,594,849 Total investments available-for-sale $ 5,607,551 $ 10,547,756 $ — $ 16,155,307 There were no transfers into or out of Level 1 and Level 2 during the nine months ended September 30, 2015 and 2014 . The Company did not have any assets or liabilities measured at fair value on a non-recurring basis during the nine months ended September 30, 2015 and 2014 .

Segment Reporting Disclosures

Segment Reporting Disclosures	9 Months Ended
	Sep. 30, 2015
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Segment Reporting Disclosures	Segment Reporting Disclosures The Company monitors and reports its ongoing underwriting operations in the following three segments: U.S. Insurance, International Insurance and Reinsurance. In determining how to aggregate and monitor its underwriting results, the Company considers many factors, including the geographic location and regulatory environment of the insurance entity underwriting the risk, the nature of the insurance product sold, the type of account written and the type of customer served. The U.S. Insurance segment includes all direct business and facultative placements written by the Company's insurance subsidiaries domiciled in the United States. The International Insurance segment includes all direct business and facultative placements written by the Company's insurance subsidiaries domiciled outside of the United States, including the Company's syndicate at Lloyd's of London. The Reinsurance segment includes all treaty reinsurance written across the Company. Results for lines of business discontinued prior to, or in conjunction with, acquisitions, including the results attributable to the run-off of life and annuity reinsurance business, are reported in the Other Insurance (Discontinued Lines) segment. All investing activities related to the Company's insurance operations are included in the Investing segment. The Company's non-insurance operations include the Company's Markel Ventures operations, which primarily consist of controlling interests in various industrial and service businesses. The Company's non-insurance operations also include the results of the Company's legal and professional consulting services. For purposes of segment reporting, the Company's non-insurance operations are not considered to be a reportable segment. Segment profit for the Investing segment is measured by net investment income and net realized investment gains or losses. Segment profit or loss for each of the Company's underwriting segments is measured by underwriting profit or loss. The property and casualty insurance industry commonly defines underwriting profit or loss as earned premiums net of losses and loss adjustment expenses and underwriting, acquisition and insurance expenses. Underwriting profit or loss does not replace operating income or net income computed in accordance with U.S. GAAP as a measure of profitability. Underwriting profit or loss provides a basis for management to evaluate the Company's underwriting performance. Segment profit or loss for the Company's underwriting segments also includes other revenues and other expenses, primarily related to the run-off of managing general agent operations that were discontinued in conjunction with acquisitions. Other revenues and other expenses in the Other Insurance (Discontinued Lines) segment are comprised of the results attributable to the run-off of life and annuity reinsurance business. For management reporting purposes, the Company allocates assets to its underwriting, investing and non-insurance operations. Underwriting assets are all assets not specifically allocated to the Investing segment or to the Company's non-insurance operations. Underwriting and investing assets are not allocated to the U.S. Insurance, International Insurance, Reinsurance or Other Insurance (Discontinued Lines) segments since the Company does not manage its assets by underwriting segment. The Company does not allocate capital expenditures for long-lived assets to any of its underwriting segments for management reporting purposes. a) The following tables summarize the Company's segment disclosures. Quarter Ended September 30, 2015 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 635,926 $ 284,576 $ 239,094 $ (1,232 ) $ — $ 1,158,364 Net written premiums 536,285 213,423 204,336 (860 ) — 953,184 Earned premiums 534,615 225,034 204,825 (799 ) — 963,675 Losses and loss adjustment expenses: Current accident year (357,400 ) (162,024 ) (128,428 ) — — (647,852 ) Prior accident years 74,976 57,860 24,241 6,038 — 163,115 Underwriting, acquisition and insurance expenses (200,272 ) (92,680 ) (72,449 ) (218 ) — (365,619 ) Underwriting profit 51,919 28,190 28,189 5,021 — 113,319 Net investment income — — — — 87,060 87,060 Net realized investment losses — — — — (14,707 ) (14,707 ) Other revenues (insurance) (41 ) 1,096 246 42 — 1,343 Other expenses (insurance) (960 ) (1,379 ) — (6,913 ) — (9,252 ) Segment profit (loss) $ 50,918 $ 27,907 $ 28,435 $ (1,850 ) $ 72,353 $ 177,763 Other revenues (non-insurance) 305,393 Other expenses (non-insurance) (281,497 ) Amortization of intangible assets (18,914 ) Interest expense (30,064 ) Income before income taxes $ 152,681 U.S. GAAP combined ratio (1) 90 % 87 % 86 % NM (2) 88 % Quarter Ended September 30, 2014 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 619,510 $ 271,045 $ 206,125 $ (230 ) $ — $ 1,096,450 Net written premiums 520,511 194,639 166,848 (217 ) — 881,781 Earned premiums 516,753 216,764 220,513 (23 ) — 954,007 Losses and loss adjustment expenses: Current accident year (348,877 ) (160,132 ) (155,189 ) — — (664,198 ) Prior accident years 60,944 30,791 8,258 (6,761 ) — 93,232 Underwriting, acquisition and insurance expenses (202,765 ) (81,706 ) (65,874 ) (148 ) — (350,493 ) Underwriting profit (loss) 26,055 5,717 7,708 (6,932 ) — 32,548 Net investment income — — — — 91,096 91,096 Net realized investment gains — — — — 4,195 4,195 Other revenues (insurance) 563 3,478 (864 ) 1,022 — 4,199 Other expenses (insurance) (1,325 ) (3,831 ) — (8,330 ) — (13,486 ) Segment profit (loss) $ 25,293 $ 5,364 $ 6,844 $ (14,240 ) $ 95,291 $ 118,552 Other revenues (non-insurance) 245,789 Other expenses (non-insurance) (217,707 ) Amortization of intangible assets (13,505 ) Interest expense (29,648 ) Income before income taxes $ 103,481 U.S. GAAP combined ratio (1) 95 % 97 % 97 % NM (2) 97 % (1) The U.S. GAAP combined ratio is a measure of underwriting performance and represents the relationship of incurred losses, loss adjustment expenses and underwriting, acquisition and insurance expenses to earned premiums. (2) NM – Ratio is not meaningful. Nine Months Ended September 30, 2015 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 1,890,144 $ 911,962 $ 875,676 $ (1,159 ) $ — $ 3,676,623 Net written premiums 1,587,092 700,260 736,068 (462 ) — 3,022,958 Earned premiums 1,569,615 654,936 640,719 (388 ) — 2,864,882 Losses and loss adjustment expenses: Current accident year (1,015,492 ) (479,764 ) (431,791 ) — — (1,927,047 ) Prior accident years 211,177 177,883 65,746 4,315 — 459,121 Underwriting, acquisition and insurance expenses (597,388 ) (266,091 ) (222,172 ) (305 ) — (1,085,956 ) Underwriting profit 167,912 86,964 52,502 3,622 — 311,000 Net investment income — — — — 270,521 270,521 Net realized investment losses — — — — (3,031 ) (3,031 ) Other revenues (insurance) 3,564 7,398 1,138 369 — 12,469 Other expenses (insurance) (3,149 ) (4,101 ) — (17,610 ) — (24,860 ) Segment profit (loss) $ 168,327 $ 90,261 $ 53,640 $ (13,619 ) $ 267,490 $ 566,099 Other revenues (non-insurance) 804,682 Other expenses (non-insurance) (739,126 ) Amortization of intangible assets (50,503 ) Interest expense (88,664 ) Income before income taxes $ 492,488 U.S. GAAP combined ratio (1) 89 % 87 % 92 % NM (2) 89 % Nine Months Ended September 30, 2014 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 1,876,114 $ 924,401 $ 999,036 $ 34 $ — $ 3,799,585 Net written premiums 1,554,847 694,311 855,930 335 — 3,105,423 Earned premiums 1,499,571 678,772 690,117 521 — 2,868,981 Losses and loss adjustment expenses: Current accident year (997,804 ) (495,441 ) (490,555 ) — — (1,983,800 ) Prior accident years 142,381 102,658 49,811 (34,725 ) — 260,125 Underwriting, acquisition and insurance expenses (595,208 ) (250,157 ) (226,109 ) (511 ) — (1,071,985 ) Underwriting profit (loss) 48,940 35,832 23,264 (34,715 ) — 73,321 Net investment income — — — — 269,980 269,980 Net realized investment gains — — — — 28,709 28,709 Other revenues (insurance) 3,333 15,183 2,304 1,208 — 22,028 Other expenses (insurance) (4,436 ) (11,539 ) (1,097 ) (25,615 ) — (42,687 ) Segment profit (loss) $ 47,837 $ 39,476 $ 24,471 $ (59,122 ) $ 298,689 $ 351,351 Other revenues (non-insurance) 608,214 Other expenses (non-insurance) (555,616 ) Amortization of intangible assets (40,992 ) Interest expense (89,136 ) Income before income taxes $ 273,821 U.S. GAAP combined ratio (1) 97 % 95 % 97 % NM (2) 97 % (1) The U.S. GAAP combined ratio is a measure of underwriting performance and represents the relationship of incurred losses, loss adjustment expenses and underwriting, acquisition and insurance expenses to earned premiums. (2) NM – Ratio is not meaningful. b) The following table reconciles segment assets to the Company's consolidated balance sheets. (dollars in thousands) September 30, 2015 December 31, 2014 Segment assets: Investing $ 18,342,049 $ 18,531,150 Underwriting 5,620,534 5,422,445 Total segment assets 23,962,583 23,953,595 Non-insurance operations 1,218,990 1,246,762 Total assets $ 25,181,573 $ 25,200,357

Senior Long-Term Debt And Other

Senior Long-Term Debt And Other Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Senior Long-Term Debt And Other Debt	Senior Long-Term Debt and Other Debt Alterra Capital Holdings Limited and Markel Bermuda Limited are party to a secured credit facility, which expires on December 15, 2015. On May 19, 2015, the Company reduced the capacity of the secured credit facility from $650 million to $550 million . On October 19, 2015, the Company further reduced the capacity of the secured credit facility to $450 million .

Other Revenues And Other Expens

Other Revenues And Other Expenses	9 Months Ended
	Sep. 30, 2015
Other Income and Expenses [Abstract]
Other Revenues And Other Expenses	Other Revenues and Other Expenses The following tables summarize the components of other revenues and other expenses. Quarter Ended September 30, 2015 2014 (dollars in thousands) Other Revenues Other Expenses Other Revenues Other Expenses Insurance: Managing general agent operations $ 1,055 $ 2,339 $ 3,812 $ 4,832 Life and annuity 42 6,913 1,022 8,330 Other 246 — (635 ) 324 1,343 9,252 4,199 13,486 Non-Insurance: Markel Ventures: Manufacturing 216,057 192,707 169,754 148,690 Markel Ventures: Non-Manufacturing 83,098 83,104 70,303 64,728 Other 6,238 5,686 5,732 4,289 305,393 281,497 245,789 217,707 Total $ 306,736 $ 290,749 $ 249,988 $ 231,193 Nine Months Ended September 30, 2015 2014 (dollars in thousands) Other Revenues Other Expenses Other Revenues Other Expenses Insurance: Managing general agent operations $ 10,043 $ 7,250 $ 17,764 $ 14,931 Life and annuity 369 17,610 1,208 25,615 Other 2,057 — 3,056 2,141 12,469 24,860 22,028 42,687 Non-Insurance: Markel Ventures: Manufacturing 567,960 513,087 395,448 355,480 Markel Ventures: Non-Manufacturing 216,191 209,947 199,457 185,648 Other 20,531 16,092 13,309 14,488 804,682 739,126 608,214 555,616 Total $ 817,151 $ 763,986 $ 630,242 $ 598,303 The Company's Markel Ventures operations primarily consist of controlling interests in various industrial and service businesses and are viewed by management as separate and distinct from the Company's insurance operations. While each of the companies is operated independently from one another, management aggregates financial results into two industry groups: manufacturing and non-manufacturing. On April 24, 2015, the Company completed a novation that transferred its obligations under a reinsurance contract for life and annuity benefit policies to a third party in exchange for cash payments totaling $29.0 million , net of commissions. At the time of the transaction, reserves for life and annuity benefits on the novated reinsurance contract totaled $32.6 million , resulting in a gain of $3.6 million that was recorded as an offset to other expenses.

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2015
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The following tables summarize the effect of reinsurance and retrocessional reinsurance on premiums written and earned. Quarter Ended September 30, 2015 2014 (dollars in thousands) Written Earned Written Earned Direct $ 878,269 $ 881,512 $ 841,582 $ 875,191 Assumed 280,095 293,481 254,868 301,665 Ceded (205,180 ) (211,318 ) (214,669 ) (222,849 ) Net premiums $ 953,184 $ 963,675 $ 881,781 $ 954,007 Nine Months Ended September 30, 2015 2014 (dollars in thousands) Written Earned Written Earned Direct $ 2,631,734 $ 2,601,458 $ 2,613,339 $ 2,556,350 Assumed 1,044,889 910,640 1,186,246 985,981 Ceded (653,665 ) (647,216 ) (694,162 ) (673,350 ) Net premiums $ 3,022,958 $ 2,864,882 $ 3,105,423 $ 2,868,981 The percentage of ceded earned premiums to gross earned premiums was 18% for the quarter and nine months ended September 30, 2015 and 19% for the quarter and nine months ended September 30, 2014 . The percentage of assumed earned premiums to net earned premiums was 30% and 32% , respectively, for the quarters ended September 30, 2015 and 2014 and 32% and 34% , respectively, for the nine months ended September 30, 2015 and 2014 . Incurred losses and loss adjustment expenses were net of reinsurance recoverables (ceded incurred losses and loss adjustment expenses) of $53.8 million and $91.1 million , respectively, for the quarters ended September 30, 2015 and 2014 and $285.9 million and $330.0 million , respectively, for the nine months ended September 30, 2015 and 2014 . On March 9, 2015, the Company completed a retrospective reinsurance transaction to cede a portfolio of policies primarily comprised of liabilities arising from asbestos and environmental exposures that originated before 1992 in exchange for payments totaling $89.0 million , which included cash paid at closing of $69.9 million . At the time of the transaction, reserves for unpaid losses and loss adjustment expenses on the policies ceded totaled $94.1 million , resulting in a deferred gain of $5.1 million which will be recognized in earnings in proportion to actual reinsurance recoveries received pursuant to the transaction. The ceded reserves attributable to asbestos and environmental exposures represented approximately 30% of our net asbestos and environmental reserves for losses and loss adjustment expenses as of December 31, 2014. On October 30, 2015, the Company completed a retrospective reinsurance transaction to cede a portfolio of policies primarily comprised of liabilities arising from asbestos and environmental exposures that originated before 1987 in exchange for cash payments totaling $86.5 million . The transaction provides up to $300 million of coverage for losses in excess of a $97.0 million retention on the ceded policies and 50% coverage on an additional $100 million of losses. The transaction is effective as of January 1, 2015, at which time reserves for unpaid losses and loss adjustment expenses on the policies ceded totaled $173.4 million . After considering our retention on the ceded policies, ceded reserves for unpaid losses and loss adjustment expenses totaled $76.4 million , resulting in a loss of $10.1 million on the transaction. The ceded reserves attributable to asbestos and environmental exposures represented approximately 25% of our net asbestos and environmental reserves for losses and loss adjustment expenses as of December 31, 2014.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate was 21% and 25% for the nine months ended September 30, 2015 and 2014 , respectively. For the nine months ended September 30, 2015 , the effective tax rate differs from the U.S. statutory tax rate of 35% primarily as a result of tax-exempt investment income and foreign tax credits for foreign taxes paid. In previous periods, foreign taxes paid were not available for use as tax credits against the Company's U.S. provision for income taxes. Based on the Company's estimated earnings from foreign operations in 2015, the Company expects that significant foreign taxes paid, both in the current period and prior periods, will be available for use as credits against its U.S. provision for income taxes in 2015. These projected tax credits will expire in 2025. For the nine months ended September 30, 2014 , the effective tax rate differs from the U.S. statutory tax rate of 35% primarily as a result of tax-exempt investment income. The decrease in the effective tax rate for 2015 compared to 2014 was primarily due to the impact of the foreign tax credits described above. This decrease was partially offset by the impact of anticipating a smaller tax benefit related to tax-exempt investment income, which resulted from having higher estimated income before income taxes in 2015 compared to 2014. The effective tax rate for the quarter ended September 30, 2015 was 32% . The difference in the effective tax rate for the quarter ended September 30, 2015 compared to the effective tax rate for the nine months ended September 30, 2015 is due to an increase in the 2015 estimated annual effective tax rate as of September 30, 2015 compared to the estimated annual effective tax rate as of June 30, 2015. This increase was primarily due to the impact of anticipating a smaller tax benefit related to tax-exempt investment income and foreign taxes paid, as a result of an increase in our estimated income before income taxes for 2015. The Internal Revenue Service is currently examining the Company’s 2012 federal income tax return. The Company believes its income tax liabilities were adequate as of September 30, 2015, however, these liabilities could be adjusted as a result of this examination.

Net Income Per Share

Net Income Per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income Per Share	Net Income per Share Net income per share was determined by dividing adjusted net income to shareholders by the applicable weighted average shares outstanding. Diluted net income per share is computed by dividing adjusted net income to shareholders by the weighted average number of common shares and dilutive potential common shares outstanding during the period. Quarter Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2015 2014 2015 2014 Net income to shareholders $ 102,519 $ 75,803 $ 384,880 $ 203,587 Adjustment of redeemable noncontrolling interests 1,376 (1,259 ) 3,091 (3,843 ) Adjusted net income to shareholders $ 103,895 $ 74,544 $ 387,971 $ 199,744 Basic common shares outstanding 13,983 13,981 13,977 13,986 Dilutive potential common shares from conversion of options 8 11 9 11 Dilutive potential common shares from conversion of restricted stock 71 65 70 58 Diluted shares outstanding 14,062 14,057 14,056 14,055 Basic net income per share $ 7.43 $ 5.33 $ 27.76 $ 14.28 Diluted net income per share $ 7.39 $ 5.30 $ 27.60 $ 14.21

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2015
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) includes net holding gains (losses) arising during the period, changes in unrealized other-than-temporary impairment losses on fixed maturities arising during the period and reclassification adjustments for net gains included in net income. Other comprehensive income (loss) also includes changes in foreign currency translation adjustments and changes in net actuarial pension loss. The following table presents the change in accumulated other comprehensive income by component, net of taxes and noncontrolling interests, for the nine months ended September 30, 2015 and 2014 . (dollars in thousands) Unrealized Holding Gains on Available-for-Sale Securities Foreign Currency Net Actuarial Pension Loss Total December 31, 2013 $ 1,131,507 $ (11,246 ) $ (30,456 ) $ 1,089,805 Other comprehensive income (loss) before reclassifications 348,214 (19,650 ) — 328,564 Amounts reclassified from accumulated other comprehensive income (15,752 ) — 964 (14,788 ) Total other comprehensive income (loss) 332,462 (19,650 ) 964 313,776 September 30, 2014 $ 1,463,969 $ (30,896 ) $ (29,492 ) $ 1,403,581 December 31, 2014 $ 1,793,254 $ (43,491 ) $ (45,206 ) $ 1,704,557 Other comprehensive loss before reclassifications (258,275 ) (22,236 ) — (280,511 ) Amounts reclassified from accumulated other comprehensive income (8,037 ) — 1,407 (6,630 ) Total other comprehensive income (loss) (266,312 ) (22,236 ) 1,407 (287,141 ) September 30, 2015 $ 1,526,942 $ (65,727 ) $ (43,799 ) $ 1,417,416 The following table summarizes the tax expense (benefit) associated with each component of other comprehensive income (loss). Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Change in net unrealized gains on investments: Net holding gains (losses) arising during the period $ (71,549 ) $ (1,895 ) $ (129,546 ) $ 171,309 Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period (10 ) 31 28 600 Reclassification adjustments for net gains (losses) included in net income 4,647 (1,858 ) (1,025 ) (5,535 ) Change in net unrealized gains on investments (66,912 ) (3,722 ) (130,543 ) 166,374 Change in foreign currency translation adjustments 829 43 1,662 1,509 Change in net actuarial pension loss 119 80 352 241 Total $ (65,964 ) $ (3,599 ) $ (128,529 ) $ 168,124 The following table presents the details of amounts reclassified from accumulated other comprehensive income into income, by component. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Unrealized holding gains on available-for-sale securities: Other-than-temporary impairment losses $ (18,281 ) $ (2,851 ) $ (23,373 ) $ (3,858 ) Net realized investment gains, excluding other-than-temporary impairment losses 7,634 9,699 32,435 25,145 Total before taxes (10,647 ) 6,848 9,062 21,287 Income taxes 4,647 (1,858 ) (1,025 ) (5,535 ) Reclassification of unrealized holding gains (losses), net of taxes $ (6,000 ) $ 4,990 $ 8,037 $ 15,752 Net actuarial pension loss: Underwriting, acquisition and insurance expenses $ (594 ) $ (400 ) $ (1,759 ) $ (1,205 ) Income taxes 119 80 352 241 Reclassification of net actuarial pension loss, net of taxes $ (475 ) $ (320 ) $ (1,407 ) $ (964 )

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contingencies arise in the normal course of the Company's operations and are not expected to have a material impact on the Company's financial condition or results of operations. On September 9, 2015, the Company entered into a definitive agreement to purchase substantially all of the assets of CATCo Investment Management, Ltd. (CATCo IM) and CATCo-Re Ltd. CATCo IM is a leading insurance-linked securities investment manager and reinsurance manager headquartered in Bermuda focused on building and managing highly diversified, collateralized retrocession and reinsurance portfolios covering global property catastrophe risks. The total purchase price for the acquired assets is expected to be approximately $200 million , all of which is expected to be paid in cash. The transaction is expected to close in the fourth quarter of 2015 and is subject to completion of various conditions and regulatory approvals.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Available-For-Sale Investments	The following tables summarize the Company's available-for-sale investments. September 30, 2015 (dollars in thousands) Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Unrealized Other-Than- Temporary Impairment Losses Estimated Fair Value Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 696,980 $ 13,360 $ (1,545 ) $ — $ 708,795 Obligations of states, municipalities and political subdivisions 3,766,517 198,495 (8,688 ) — 3,956,324 Foreign governments 1,338,511 139,447 (826 ) — 1,477,132 Commercial mortgage-backed securities 441,814 10,808 (1,107 ) — 451,515 Residential mortgage-backed securities 860,869 34,272 (2,079 ) (2,258 ) 890,804 Asset-backed securities 45,470 55 (125 ) — 45,400 Corporate bonds 1,787,414 48,535 (10,288 ) (1,680 ) 1,823,981 Total fixed maturities 8,937,575 444,972 (24,658 ) (3,938 ) 9,353,951 Equity securities: Insurance, banks and other financial institutions 629,814 658,077 (12,482 ) — 1,275,409 Industrial, consumer and all other 1,660,203 1,281,314 (60,513 ) — 2,881,004 Total equity securities 2,290,017 1,939,391 (72,995 ) — 4,156,413 Short-term investments 2,323,917 71 (5 ) — 2,323,983 Investments, available-for-sale $ 13,551,509 $ 2,384,434 $ (97,658 ) $ (3,938 ) $ 15,834,347 December 31, 2014 (dollars in thousands) Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Unrealized Other-Than- Temporary Impairment Losses Estimated Fair Value Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 662,462 $ 12,963 $ (2,163 ) $ — $ 673,262 Obligations of states, municipalities and political subdivisions 4,075,748 245,158 (3,359 ) — 4,317,547 Foreign governments 1,458,255 154,707 (1,041 ) — 1,611,921 Commercial mortgage-backed securities 427,904 5,325 (2,602 ) — 430,627 Residential mortgage-backed securities 954,263 34,324 (3,482 ) (2,258 ) 982,847 Asset-backed securities 100,073 99 (682 ) — 99,490 Corporate bonds 2,250,432 69,016 (10,441 ) (1,819 ) 2,307,188 Total fixed maturities 9,929,137 521,592 (23,770 ) (4,077 ) 10,422,882 Equity securities: Insurance, banks and other financial institutions 523,739 789,717 (1,531 ) — 1,311,925 Industrial, consumer and all other 1,427,919 1,403,566 (5,834 ) — 2,825,651 Total equity securities 1,951,658 2,193,283 (7,365 ) — 4,137,576 Short-term investments 1,594,819 36 (6 ) — 1,594,849 Investments, available-for-sale $ 13,475,614 $ 2,714,911 $ (31,141 ) $ (4,077 ) $ 16,155,307
Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position	December 31, 2014 Less than 12 months 12 months or longer Total (dollars in thousands) Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 108,250 $ (62 ) $ 163,359 $ (2,101 ) $ 271,609 $ (2,163 ) Obligations of states, municipalities and political subdivisions 58,583 (542 ) 92,441 (2,817 ) 151,024 (3,359 ) Foreign governments 18,856 (386 ) 56,217 (655 ) 75,073 (1,041 ) Commercial mortgage-backed securities 45,931 (210 ) 147,558 (2,392 ) 193,489 (2,602 ) Residential mortgage-backed securities 9,613 (2,285 ) 207,374 (3,455 ) 216,987 (5,740 ) Asset-backed securities 30,448 (20 ) 45,160 (662 ) 75,608 (682 ) Corporate bonds 141,176 (2,263 ) 621,821 (9,997 ) 762,997 (12,260 ) Total fixed maturities 412,857 (5,768 ) 1,333,930 (22,079 ) 1,746,787 (27,847 ) Equity securities: Insurance, banks and other financial institutions 16,219 (1,531 ) — — 16,219 (1,531 ) Industrial, consumer and all other 86,062 (5,834 ) — — 86,062 (5,834 ) Total equity securities 102,281 (7,365 ) — — 102,281 (7,365 ) Short-term investments 181,964 (6 ) — — 181,964 (6 ) Total $ 697,102 $ (13,139 ) $ 1,333,930 $ (22,079 ) $ 2,031,032 $ (35,218 ) The following tables summarize gross unrealized investment losses by the length of time that securities have continuously been in an unrealized loss position. September 30, 2015 Less than 12 months 12 months or longer Total (dollars in thousands) Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Estimated Fair Value Gross Unrealized Holding and Other-Than- Temporary Impairment Losses Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 72,511 $ (1,265 ) $ 93,566 $ (280 ) $ 166,077 $ (1,545 ) Obligations of states, municipalities and political subdivisions 297,670 (5,618 ) 59,482 (3,070 ) 357,152 (8,688 ) Foreign governments 27,208 (594 ) 41,433 (232 ) 68,641 (826 ) Commercial mortgage-backed securities 66,074 (258 ) 100,233 (849 ) 166,307 (1,107 ) Residential mortgage-backed securities 24,353 (2,321 ) 147,001 (2,016 ) 171,354 (4,337 ) Asset-backed securities 5,678 (2 ) 26,720 (123 ) 32,398 (125 ) Corporate bonds 270,889 (6,364 ) 343,268 (5,604 ) 614,157 (11,968 ) Total fixed maturities 764,383 (16,422 ) 811,703 (12,174 ) 1,576,086 (28,596 ) Equity securities: Insurance, banks and other financial institutions 139,456 (11,308 ) 6,676 (1,174 ) 146,132 (12,482 ) Industrial, consumer and all other 387,475 (60,006 ) 19,085 (507 ) 406,560 (60,513 ) Total equity securities 526,931 (71,314 ) 25,761 (1,681 ) 552,692 (72,995 ) Short-term investments 139,990 (5 ) — — 139,990 (5 ) Total $ 1,431,304 $ (87,741 ) $ 837,464 $ (13,855 ) $ 2,268,768 $ (101,596 )
Schedule Of Amortized Cost And Estimated Fair Value Of Fixed Maturities By Contractual Maturity Date	The amortized cost and estimated fair value of fixed maturities at September 30, 2015 are shown below by contractual maturity. (dollars in thousands) Amortized Cost Estimated Fair Value Due in one year or less $ 538,793 $ 541,638 Due after one year through five years 1,899,246 1,950,115 Due after five years through ten years 1,655,136 1,753,390 Due after ten years 3,496,247 3,721,089 7,589,422 7,966,232 Commercial mortgage-backed securities 441,814 451,515 Residential mortgage-backed securities 860,869 890,804 Asset-backed securities 45,470 45,400 Total fixed maturities $ 8,937,575 $ 9,353,951
Components Of Net Investment Income	The following table presents the components of net investment income. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Interest: Municipal bonds (tax-exempt) $ 21,979 $ 24,505 $ 72,124 $ 72,796 Municipal bonds (taxable) 14,667 13,523 42,917 35,133 Other taxable bonds 34,368 38,741 103,519 114,594 Short-term investments, including overnight deposits 1,287 1,530 3,654 4,612 Dividends on equity securities 17,887 14,678 55,544 46,042 Income (loss) from equity method investments (4 ) 2,253 3,052 7,294 Other 37 (266 ) 577 1,436 90,221 94,964 281,387 281,907 Investment expenses (3,161 ) (3,868 ) (10,866 ) (11,927 ) Net investment income $ 87,060 $ 91,096 $ 270,521 $ 269,980
Summary Of Net Realized Investment Gains (Losses) And The Change In Net Unrealized Gains On Investments	The following table presents net realized investment gains (losses) and the change in net unrealized gains on investments. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Realized gains: Sales of fixed maturities $ 435 $ 739 $ 2,769 $ 6,381 Sales of equity securities 11,329 10,793 34,285 36,942 Other 1,026 134 3,297 11,958 Total realized gains 12,790 11,666 40,351 55,281 Realized losses: Sales of fixed maturities (3,730 ) (1,658 ) (3,947 ) (17,805 ) Sales of equity securities (400 ) (175 ) (672 ) (373 ) Other-than-temporary impairments (18,281 ) (2,851 ) (23,373 ) (3,858 ) Other (5,086 ) (2,787 ) (15,390 ) (4,536 ) Total realized losses (27,497 ) (7,471 ) (43,382 ) (26,572 ) Net realized investment gains (losses) $ (14,707 ) $ 4,195 $ (3,031 ) $ 28,709 Change in net unrealized gains on investments: Fixed maturities $ 102,844 $ 41,615 $ (77,369 ) $ 337,865 Equity securities (313,075 ) (57,773 ) (319,522 ) 160,936 Short-term investments 45 37 36 35 Net increase (decrease) $ (210,186 ) $ (16,121 ) $ (396,855 ) $ 498,836
Components Of Restricted Assets	The following table presents the components of restricted assets. (dollars in thousands) September 30, December 31, Restricted assets held in trust or on deposit to support underwriting activities $ 4,733,990 $ 4,961,061 Investments and cash and cash equivalents pledged as security for letters of credit 654,208 635,340 Total $ 5,388,198 $ 5,596,401
Schedule Of Restricted Assets	Total restricted assets are included on the Company's consolidated balance sheets as follows. (dollars in thousands) September 30, December 31, Investments, available-for-sale $ 5,016,404 $ 5,040,413 Restricted cash and cash equivalents 371,794 522,225 Other assets — 33,763 Total $ 5,388,198 $ 5,596,401

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	The following tables present the balances of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy. September 30, 2015 (dollars in thousands) Level 1 Level 2 Level 3 Total Assets: Investments available-for-sale: Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ — $ 708,795 $ — $ 708,795 Obligations of states, municipalities and political subdivisions — 3,956,324 — 3,956,324 Foreign governments — 1,477,132 — 1,477,132 Commercial mortgage-backed securities — 451,515 — 451,515 Residential mortgage-backed securities — 890,804 — 890,804 Asset-backed securities — 45,400 — 45,400 Corporate bonds — 1,823,981 — 1,823,981 Total fixed maturities — 9,353,951 — 9,353,951 Equity securities: Insurance, banks and other financial institutions 1,275,409 — — 1,275,409 Industrial, consumer and all other 2,881,004 — — 2,881,004 Total equity securities 4,156,413 — — 4,156,413 Short-term investments 2,224,533 99,450 — 2,323,983 Total investments available-for-sale $ 6,380,946 $ 9,453,401 $ — $ 15,834,347 December 31, 2014 (dollars in thousands) Level 1 Level 2 Level 3 Total Assets: Investments available-for-sale: Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ — $ 673,262 $ — $ 673,262 Obligations of states, municipalities and political subdivisions — 4,317,547 — 4,317,547 Foreign governments — 1,611,921 — 1,611,921 Commercial mortgage-backed securities — 430,627 — 430,627 Residential mortgage-backed securities — 982,847 — 982,847 Asset-backed securities — 99,490 — 99,490 Corporate bonds — 2,307,188 — 2,307,188 Total fixed maturities — 10,422,882 — 10,422,882 Equity securities: Insurance, banks and other financial institutions 1,311,925 — — 1,311,925 Industrial, consumer and all other 2,825,651 — — 2,825,651 Total equity securities 4,137,576 — — 4,137,576 Short-term investments 1,469,975 124,874 — 1,594,849 Total investments available-for-sale $ 5,607,551 $ 10,547,756 $ — $ 16,155,307

Segment Reporting Disclosures (

Segment Reporting Disclosures (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Company's Segment Disclosures	The following tables summarize the Company's segment disclosures. Quarter Ended September 30, 2015 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 635,926 $ 284,576 $ 239,094 $ (1,232 ) $ — $ 1,158,364 Net written premiums 536,285 213,423 204,336 (860 ) — 953,184 Earned premiums 534,615 225,034 204,825 (799 ) — 963,675 Losses and loss adjustment expenses: Current accident year (357,400 ) (162,024 ) (128,428 ) — — (647,852 ) Prior accident years 74,976 57,860 24,241 6,038 — 163,115 Underwriting, acquisition and insurance expenses (200,272 ) (92,680 ) (72,449 ) (218 ) — (365,619 ) Underwriting profit 51,919 28,190 28,189 5,021 — 113,319 Net investment income — — — — 87,060 87,060 Net realized investment losses — — — — (14,707 ) (14,707 ) Other revenues (insurance) (41 ) 1,096 246 42 — 1,343 Other expenses (insurance) (960 ) (1,379 ) — (6,913 ) — (9,252 ) Segment profit (loss) $ 50,918 $ 27,907 $ 28,435 $ (1,850 ) $ 72,353 $ 177,763 Other revenues (non-insurance) 305,393 Other expenses (non-insurance) (281,497 ) Amortization of intangible assets (18,914 ) Interest expense (30,064 ) Income before income taxes $ 152,681 U.S. GAAP combined ratio (1) 90 % 87 % 86 % NM (2) 88 % Quarter Ended September 30, 2014 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 619,510 $ 271,045 $ 206,125 $ (230 ) $ — $ 1,096,450 Net written premiums 520,511 194,639 166,848 (217 ) — 881,781 Earned premiums 516,753 216,764 220,513 (23 ) — 954,007 Losses and loss adjustment expenses: Current accident year (348,877 ) (160,132 ) (155,189 ) — — (664,198 ) Prior accident years 60,944 30,791 8,258 (6,761 ) — 93,232 Underwriting, acquisition and insurance expenses (202,765 ) (81,706 ) (65,874 ) (148 ) — (350,493 ) Underwriting profit (loss) 26,055 5,717 7,708 (6,932 ) — 32,548 Net investment income — — — — 91,096 91,096 Net realized investment gains — — — — 4,195 4,195 Other revenues (insurance) 563 3,478 (864 ) 1,022 — 4,199 Other expenses (insurance) (1,325 ) (3,831 ) — (8,330 ) — (13,486 ) Segment profit (loss) $ 25,293 $ 5,364 $ 6,844 $ (14,240 ) $ 95,291 $ 118,552 Other revenues (non-insurance) 245,789 Other expenses (non-insurance) (217,707 ) Amortization of intangible assets (13,505 ) Interest expense (29,648 ) Income before income taxes $ 103,481 U.S. GAAP combined ratio (1) 95 % 97 % 97 % NM (2) 97 % (1) The U.S. GAAP combined ratio is a measure of underwriting performance and represents the relationship of incurred losses, loss adjustment expenses and underwriting, acquisition and insurance expenses to earned premiums. (2) NM – Ratio is not meaningful. Nine Months Ended September 30, 2015 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 1,890,144 $ 911,962 $ 875,676 $ (1,159 ) $ — $ 3,676,623 Net written premiums 1,587,092 700,260 736,068 (462 ) — 3,022,958 Earned premiums 1,569,615 654,936 640,719 (388 ) — 2,864,882 Losses and loss adjustment expenses: Current accident year (1,015,492 ) (479,764 ) (431,791 ) — — (1,927,047 ) Prior accident years 211,177 177,883 65,746 4,315 — 459,121 Underwriting, acquisition and insurance expenses (597,388 ) (266,091 ) (222,172 ) (305 ) — (1,085,956 ) Underwriting profit 167,912 86,964 52,502 3,622 — 311,000 Net investment income — — — — 270,521 270,521 Net realized investment losses — — — — (3,031 ) (3,031 ) Other revenues (insurance) 3,564 7,398 1,138 369 — 12,469 Other expenses (insurance) (3,149 ) (4,101 ) — (17,610 ) — (24,860 ) Segment profit (loss) $ 168,327 $ 90,261 $ 53,640 $ (13,619 ) $ 267,490 $ 566,099 Other revenues (non-insurance) 804,682 Other expenses (non-insurance) (739,126 ) Amortization of intangible assets (50,503 ) Interest expense (88,664 ) Income before income taxes $ 492,488 U.S. GAAP combined ratio (1) 89 % 87 % 92 % NM (2) 89 % Nine Months Ended September 30, 2014 (dollars in thousands) U.S. Insurance International Insurance Reinsurance Other Insurance (Discontinued Lines) Investing Consolidated Gross premium volume $ 1,876,114 $ 924,401 $ 999,036 $ 34 $ — $ 3,799,585 Net written premiums 1,554,847 694,311 855,930 335 — 3,105,423 Earned premiums 1,499,571 678,772 690,117 521 — 2,868,981 Losses and loss adjustment expenses: Current accident year (997,804 ) (495,441 ) (490,555 ) — — (1,983,800 ) Prior accident years 142,381 102,658 49,811 (34,725 ) — 260,125 Underwriting, acquisition and insurance expenses (595,208 ) (250,157 ) (226,109 ) (511 ) — (1,071,985 ) Underwriting profit (loss) 48,940 35,832 23,264 (34,715 ) — 73,321 Net investment income — — — — 269,980 269,980 Net realized investment gains — — — — 28,709 28,709 Other revenues (insurance) 3,333 15,183 2,304 1,208 — 22,028 Other expenses (insurance) (4,436 ) (11,539 ) (1,097 ) (25,615 ) — (42,687 ) Segment profit (loss) $ 47,837 $ 39,476 $ 24,471 $ (59,122 ) $ 298,689 $ 351,351 Other revenues (non-insurance) 608,214 Other expenses (non-insurance) (555,616 ) Amortization of intangible assets (40,992 ) Interest expense (89,136 ) Income before income taxes $ 273,821 U.S. GAAP combined ratio (1) 97 % 95 % 97 % NM (2) 97 % (1) The U.S. GAAP combined ratio is a measure of underwriting performance and represents the relationship of incurred losses, loss adjustment expenses and underwriting, acquisition and insurance expenses to earned premiums. (2) NM – Ratio is not meaningful.
Reconciliation Of Segment Assets To The Company's Consolidated Balance Sheets	The following table reconciles segment assets to the Company's consolidated balance sheets. (dollars in thousands) September 30, 2015 December 31, 2014 Segment assets: Investing $ 18,342,049 $ 18,531,150 Underwriting 5,620,534 5,422,445 Total segment assets 23,962,583 23,953,595 Non-insurance operations 1,218,990 1,246,762 Total assets $ 25,181,573 $ 25,200,357

Other Revenues And Other Expe22

Other Revenues And Other Expenses (Tables)	9 Months Ended
	Sep. 30, 2015
Other Income and Expenses [Abstract]
Summary Of Other Revenues And Other Expenses By Component	The following tables summarize the components of other revenues and other expenses. Quarter Ended September 30, 2015 2014 (dollars in thousands) Other Revenues Other Expenses Other Revenues Other Expenses Insurance: Managing general agent operations $ 1,055 $ 2,339 $ 3,812 $ 4,832 Life and annuity 42 6,913 1,022 8,330 Other 246 — (635 ) 324 1,343 9,252 4,199 13,486 Non-Insurance: Markel Ventures: Manufacturing 216,057 192,707 169,754 148,690 Markel Ventures: Non-Manufacturing 83,098 83,104 70,303 64,728 Other 6,238 5,686 5,732 4,289 305,393 281,497 245,789 217,707 Total $ 306,736 $ 290,749 $ 249,988 $ 231,193 Nine Months Ended September 30, 2015 2014 (dollars in thousands) Other Revenues Other Expenses Other Revenues Other Expenses Insurance: Managing general agent operations $ 10,043 $ 7,250 $ 17,764 $ 14,931 Life and annuity 369 17,610 1,208 25,615 Other 2,057 — 3,056 2,141 12,469 24,860 22,028 42,687 Non-Insurance: Markel Ventures: Manufacturing 567,960 513,087 395,448 355,480 Markel Ventures: Non-Manufacturing 216,191 209,947 199,457 185,648 Other 20,531 16,092 13,309 14,488 804,682 739,126 608,214 555,616 Total $ 817,151 $ 763,986 $ 630,242 $ 598,303

Reinsurance (Tables)

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2015
Reinsurance Disclosures [Abstract]
Effect Of Reinsurance And Retrocessional Reinsurance On Premiums Written And Earned	The following tables summarize the effect of reinsurance and retrocessional reinsurance on premiums written and earned. Quarter Ended September 30, 2015 2014 (dollars in thousands) Written Earned Written Earned Direct $ 878,269 $ 881,512 $ 841,582 $ 875,191 Assumed 280,095 293,481 254,868 301,665 Ceded (205,180 ) (211,318 ) (214,669 ) (222,849 ) Net premiums $ 953,184 $ 963,675 $ 881,781 $ 954,007 Nine Months Ended September 30, 2015 2014 (dollars in thousands) Written Earned Written Earned Direct $ 2,631,734 $ 2,601,458 $ 2,613,339 $ 2,556,350 Assumed 1,044,889 910,640 1,186,246 985,981 Ceded (653,665 ) (647,216 ) (694,162 ) (673,350 ) Net premiums $ 3,022,958 $ 2,864,882 $ 3,105,423 $ 2,868,981

Net Income Per Share (Tables)

Net Income Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Schedule Of Net Income Per Share	Net income per share was determined by dividing adjusted net income to shareholders by the applicable weighted average shares outstanding. Diluted net income per share is computed by dividing adjusted net income to shareholders by the weighted average number of common shares and dilutive potential common shares outstanding during the period. Quarter Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2015 2014 2015 2014 Net income to shareholders $ 102,519 $ 75,803 $ 384,880 $ 203,587 Adjustment of redeemable noncontrolling interests 1,376 (1,259 ) 3,091 (3,843 ) Adjusted net income to shareholders $ 103,895 $ 74,544 $ 387,971 $ 199,744 Basic common shares outstanding 13,983 13,981 13,977 13,986 Dilutive potential common shares from conversion of options 8 11 9 11 Dilutive potential common shares from conversion of restricted stock 71 65 70 58 Diluted shares outstanding 14,062 14,057 14,056 14,055 Basic net income per share $ 7.43 $ 5.33 $ 27.76 $ 14.28 Diluted net income per share $ 7.39 $ 5.30 $ 27.60 $ 14.21

Other Comprehensive Income (L25

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2015
Other Comprehensive Income (Loss), Tax [Abstract]
Change In Accumulated Other Comprehensive Income By Component, Net Of Taxes And Noncontrolling Interest	The following table presents the change in accumulated other comprehensive income by component, net of taxes and noncontrolling interests, for the nine months ended September 30, 2015 and 2014 . (dollars in thousands) Unrealized Holding Gains on Available-for-Sale Securities Foreign Currency Net Actuarial Pension Loss Total December 31, 2013 $ 1,131,507 $ (11,246 ) $ (30,456 ) $ 1,089,805 Other comprehensive income (loss) before reclassifications 348,214 (19,650 ) — 328,564 Amounts reclassified from accumulated other comprehensive income (15,752 ) — 964 (14,788 ) Total other comprehensive income (loss) 332,462 (19,650 ) 964 313,776 September 30, 2014 $ 1,463,969 $ (30,896 ) $ (29,492 ) $ 1,403,581 December 31, 2014 $ 1,793,254 $ (43,491 ) $ (45,206 ) $ 1,704,557 Other comprehensive loss before reclassifications (258,275 ) (22,236 ) — (280,511 ) Amounts reclassified from accumulated other comprehensive income (8,037 ) — 1,407 (6,630 ) Total other comprehensive income (loss) (266,312 ) (22,236 ) 1,407 (287,141 ) September 30, 2015 $ 1,526,942 $ (65,727 ) $ (43,799 ) $ 1,417,416
Summary Of Tax Expense (Benefit) Of Other Comprehensive Income (Loss)	The following table summarizes the tax expense (benefit) associated with each component of other comprehensive income (loss). Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Change in net unrealized gains on investments: Net holding gains (losses) arising during the period $ (71,549 ) $ (1,895 ) $ (129,546 ) $ 171,309 Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period (10 ) 31 28 600 Reclassification adjustments for net gains (losses) included in net income 4,647 (1,858 ) (1,025 ) (5,535 ) Change in net unrealized gains on investments (66,912 ) (3,722 ) (130,543 ) 166,374 Change in foreign currency translation adjustments 829 43 1,662 1,509 Change in net actuarial pension loss 119 80 352 241 Total $ (65,964 ) $ (3,599 ) $ (128,529 ) $ 168,124
Reclassifications From Accumulated Other Comprehensive Income Into Income, By Component	The following table presents the details of amounts reclassified from accumulated other comprehensive income into income, by component. Quarter Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2015 2014 2015 2014 Unrealized holding gains on available-for-sale securities: Other-than-temporary impairment losses $ (18,281 ) $ (2,851 ) $ (23,373 ) $ (3,858 ) Net realized investment gains, excluding other-than-temporary impairment losses 7,634 9,699 32,435 25,145 Total before taxes (10,647 ) 6,848 9,062 21,287 Income taxes 4,647 (1,858 ) (1,025 ) (5,535 ) Reclassification of unrealized holding gains (losses), net of taxes $ (6,000 ) $ 4,990 $ 8,037 $ 15,752 Net actuarial pension loss: Underwriting, acquisition and insurance expenses $ (594 ) $ (400 ) $ (1,759 ) $ (1,205 ) Income taxes 119 80 352 241 Reclassification of net actuarial pension loss, net of taxes $ (475 ) $ (320 ) $ (1,407 ) $ (964 )

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)securities	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)securities	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)securities
Schedule of Investments [Line Items]
Available-for-sale securities in unrealized loss position, number of positions | securities	567		567		552
Available-for-sale securities, estimated fair value	$ 2,268,768		$ 2,268,768		$ 2,031,032
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	$ (101,596)		$ (101,596)		$ (35,218)
Number of available-for-sale securities positions in a continuous unrealized loss position for one year or longer at period end | securities	268		268		396
Available-for-sale securities, estimated fair value, 12 months or longer	$ 837,464		$ 837,464		$ 1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(13,855)		(13,855)		(22,079)
Cumulative credit losses recognized in net income	10,700		10,700		12,700
Other-than-temporary impairment losses recognized in net income	(18,281)	$ (2,851)	(23,373)	$ (3,858)
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, estimated fair value	1,576,086		1,576,086		1,746,787
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	$ (28,596)		$ (28,596)		$ (27,847)
Number of available-for-sale securities positions in a continuous unrealized loss position for one year or longer at period end | securities	262		262		396
Available-for-sale securities, estimated fair value, 12 months or longer	$ 811,703		$ 811,703		$ 1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(12,174)		(12,174)		(22,079)
Other-than-temporary impairment losses recognized in net income	0	(100)	0	(300)
Equity Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, estimated fair value	552,692		552,692		102,281
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	$ (72,995)		$ (72,995)		(7,365)
Number of available-for-sale securities positions in a continuous unrealized loss position for one year or longer at period end | securities	6		6
Available-for-sale securities, estimated fair value, 12 months or longer	$ 25,761		$ 25,761		0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(1,681)		(1,681)		0
Other-than-temporary impairment losses recognized in net income	$ (18,300)	$ (2,700)	$ (23,400)	$ (3,600)
Other-than-temporary impairment losses recognized in earnings, number of investment positions | securities	8		16
Industrial, Consumer And All Other [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, estimated fair value	$ 406,560		$ 406,560		86,062
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(60,513)		(60,513)		(5,834)
Available-for-sale securities, estimated fair value, 12 months or longer	19,085		19,085		0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(507)		(507)		0
Other-than-temporary impairment losses recognized in net income	(14,300)		(18,800)
Insurance, Banks And Other Financial Institutions [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, estimated fair value	146,132		146,132		16,219
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(12,482)		(12,482)		(1,531)
Available-for-sale securities, estimated fair value, 12 months or longer	6,676		6,676		0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(1,174)		(1,174)		$ 0
Other-than-temporary impairment losses recognized in net income	$ (4,000)		$ (4,600)

Investments (Available-For-Sale

Investments (Available-For-Sale Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	$ 13,551,509	$ 13,475,614
Available-for-sale investments, gross unrealized holding gains	2,384,434	2,714,911
Available-for-sale investments, gross unrealized holding losses	(97,658)	(31,141)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(3,938)	(4,077)
Available-for-sale investments, estimated fair value	15,834,347	16,155,307
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	696,980	662,462
Available-for-sale investments, gross unrealized holding gains	13,360	12,963
Available-for-sale investments, gross unrealized holding losses	(1,545)	(2,163)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	708,795	673,262
Obligations Of States, Municipalities And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	3,766,517	4,075,748
Available-for-sale investments, gross unrealized holding gains	198,495	245,158
Available-for-sale investments, gross unrealized holding losses	(8,688)	(3,359)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	3,956,324	4,317,547
Foreign Governments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,338,511	1,458,255
Available-for-sale investments, gross unrealized holding gains	139,447	154,707
Available-for-sale investments, gross unrealized holding losses	(826)	(1,041)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	1,477,132	1,611,921
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	441,814	427,904
Available-for-sale investments, gross unrealized holding gains	10,808	5,325
Available-for-sale investments, gross unrealized holding losses	(1,107)	(2,602)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	451,515	430,627
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	860,869	954,263
Available-for-sale investments, gross unrealized holding gains	34,272	34,324
Available-for-sale investments, gross unrealized holding losses	(2,079)	(3,482)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(2,258)	(2,258)
Available-for-sale investments, estimated fair value	890,804	982,847
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	45,470	100,073
Available-for-sale investments, gross unrealized holding gains	55	99
Available-for-sale investments, gross unrealized holding losses	(125)	(682)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	45,400	99,490
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,787,414	2,250,432
Available-for-sale investments, gross unrealized holding gains	48,535	69,016
Available-for-sale investments, gross unrealized holding losses	(10,288)	(10,441)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(1,680)	(1,819)
Available-for-sale investments, estimated fair value	1,823,981	2,307,188
Total Fixed Maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	8,937,575	9,929,137
Available-for-sale investments, gross unrealized holding gains	444,972	521,592
Available-for-sale investments, gross unrealized holding losses	(24,658)	(23,770)
Available-for-sale investments, unrealized other-than-temporary impairment losses	(3,938)	(4,077)
Available-for-sale investments, estimated fair value	9,353,951	10,422,882
Insurance, Banks And Other Financial Institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	629,814	523,739
Available-for-sale investments, gross unrealized holding gains	658,077	789,717
Available-for-sale investments, gross unrealized holding losses	(12,482)	(1,531)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	1,275,409	1,311,925
Industrial, Consumer And All Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	1,660,203	1,427,919
Available-for-sale investments, gross unrealized holding gains	1,281,314	1,403,566
Available-for-sale investments, gross unrealized holding losses	(60,513)	(5,834)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	2,881,004	2,825,651
Total Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	2,290,017	1,951,658
Available-for-sale investments, gross unrealized holding gains	1,939,391	2,193,283
Available-for-sale investments, gross unrealized holding losses	(72,995)	(7,365)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	4,156,413	4,137,576
Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments, amortized cost	2,323,917	1,594,819
Available-for-sale investments, gross unrealized holding gains	71	36
Available-for-sale investments, gross unrealized holding losses	(5)	(6)
Available-for-sale investments, unrealized other-than-temporary impairment losses	0	0
Available-for-sale investments, estimated fair value	$ 2,323,983	$ 1,594,849

Investments (Summary Of Gross U

Investments (Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	$ 1,431,304	$ 697,102
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(87,741)	(13,139)
Available-for-sale securities, estimated fair value, 12 months or longer	837,464	1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(13,855)	(22,079)
Available-for-sale securities, estimated fair value	2,268,768	2,031,032
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(101,596)	(35,218)
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	72,511	108,250
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(1,265)	(62)
Available-for-sale securities, estimated fair value, 12 months or longer	93,566	163,359
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(280)	(2,101)
Available-for-sale securities, estimated fair value	166,077	271,609
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(1,545)	(2,163)
Obligations Of States, Municipalities And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	297,670	58,583
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(5,618)	(542)
Available-for-sale securities, estimated fair value, 12 months or longer	59,482	92,441
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(3,070)	(2,817)
Available-for-sale securities, estimated fair value	357,152	151,024
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(8,688)	(3,359)
Foreign Governments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	27,208	18,856
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(594)	(386)
Available-for-sale securities, estimated fair value, 12 months or longer	41,433	56,217
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(232)	(655)
Available-for-sale securities, estimated fair value	68,641	75,073
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(826)	(1,041)
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	66,074	45,931
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(258)	(210)
Available-for-sale securities, estimated fair value, 12 months or longer	100,233	147,558
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(849)	(2,392)
Available-for-sale securities, estimated fair value	166,307	193,489
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(1,107)	(2,602)
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	24,353	9,613
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(2,321)	(2,285)
Available-for-sale securities, estimated fair value, 12 months or longer	147,001	207,374
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(2,016)	(3,455)
Available-for-sale securities, estimated fair value	171,354	216,987
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(4,337)	(5,740)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	5,678	30,448
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(2)	(20)
Available-for-sale securities, estimated fair value, 12 months or longer	26,720	45,160
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(123)	(662)
Available-for-sale securities, estimated fair value	32,398	75,608
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(125)	(682)
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	270,889	141,176
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(6,364)	(2,263)
Available-for-sale securities, estimated fair value, 12 months or longer	343,268	621,821
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(5,604)	(9,997)
Available-for-sale securities, estimated fair value	614,157	762,997
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(11,968)	(12,260)
Total Fixed Maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	764,383	412,857
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(16,422)	(5,768)
Available-for-sale securities, estimated fair value, 12 months or longer	811,703	1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(12,174)	(22,079)
Available-for-sale securities, estimated fair value	1,576,086	1,746,787
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(28,596)	(27,847)
Insurance, Banks And Other Financial Institutions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	139,456	16,219
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(11,308)	(1,531)
Available-for-sale securities, estimated fair value, 12 months or longer	6,676	0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(1,174)	0
Available-for-sale securities, estimated fair value	146,132	16,219
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(12,482)	(1,531)
Industrial, Consumer And All Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	387,475	86,062
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(60,006)	(5,834)
Available-for-sale securities, estimated fair value, 12 months or longer	19,085	0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(507)	0
Available-for-sale securities, estimated fair value	406,560	86,062
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(60,513)	(5,834)
Total Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	526,931	102,281
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(71,314)	(7,365)
Available-for-sale securities, estimated fair value, 12 months or longer	25,761	0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	(1,681)	0
Available-for-sale securities, estimated fair value	552,692	102,281
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	(72,995)	(7,365)
Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, estimated fair value, less than 12 months	139,990	181,964
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months	(5)	(6)
Available-for-sale securities, estimated fair value, 12 months or longer	0	0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer	0	0
Available-for-sale securities, estimated fair value	139,990	181,964
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses	$ (5)	$ (6)

Investments (Schedule Of Amorti

Investments (Schedule Of Amortized Cost And Estimated Fair Value Of Fixed Maturities By Contractual Maturity Date) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Due in one year or less, amortized cost	$ 538,793
Due after one year through five years, amortized cost	1,899,246
Due after five years through ten years, amortized cost	1,655,136
Due after ten years, amortized cost	3,496,247
Amortized cost, sub-total	7,589,422
Total fixed maturities, amortized cost	8,937,575	$ 9,929,137
Due in one year or less, estimated fair value	541,638
Due after one year through five years, estimated fair value	1,950,115
Due after five years through ten years, estimated fair value	1,753,390
Due after ten years, estimated fair value	3,721,089
Estimated fair value, sub-total	7,966,232
Total fixed maturities, estimated fair value	9,353,951	$ 10,422,882
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, amortized cost	441,814
Fixed maturities, estimated fair value	451,515
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, amortized cost	860,869
Fixed maturities, estimated fair value	890,804
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, amortized cost	45,470
Fixed maturities, estimated fair value	$ 45,400

Investments (Components Of Net

Investments (Components Of Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Municipal bonds (tax-exempt)	$ 21,979	$ 24,505	$ 72,124	$ 72,796
Short-term investments, including overnight deposits	1,287	1,530	3,654	4,612
Dividends on equity securities	17,887	14,678	55,544	46,042
Income (loss) from equity method investments	(4)	2,253	3,052	7,294
Other	37	(266)	577	1,436
Total investment income	90,221	94,964	281,387	281,907
Investment expenses	(3,161)	(3,868)	(10,866)	(11,927)
Net investment income	87,060	91,096	270,521	269,980
Taxable Municipal Bonds [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Taxable bonds	14,667	13,523	42,917	35,133
Other Taxable Bonds [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Taxable bonds	$ 34,368	$ 38,741	$ 103,519	$ 114,594

Investments (Summary Of Net Rea

Investments (Summary Of Net Realized Investment Gains (Losses) And The Change In Net Unrealized Gains On Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Gain (Loss) on Investments [Line Items]
Realized gains	$ 12,790	$ 11,666	$ 40,351	$ 55,281
Realized losses	(27,497)	(7,471)	(43,382)	(26,572)
Other-than-temporary impairment losses recognized in net income	(18,281)	(2,851)	(23,373)	(3,858)
Net realized investment gains (losses)	(14,707)	4,195	(3,031)	28,709
Change in net unrealized gains on investments	(210,186)	(16,121)	(396,855)	498,836
Sales Of Fixed Maturities [Member]
Gain (Loss) on Investments [Line Items]
Realized gains	435	739	2,769	6,381
Realized losses	(3,730)	(1,658)	(3,947)	(17,805)
Sales Of Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Realized gains	11,329	10,793	34,285	36,942
Realized losses	(400)	(175)	(672)	(373)
Other [Member]
Gain (Loss) on Investments [Line Items]
Realized gains	1,026	134	3,297	11,958
Realized losses	(5,086)	(2,787)	(15,390)	(4,536)
Fixed Maturities [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses recognized in net income	0	(100)	0	(300)
Change in net unrealized gains on investments	102,844	41,615	(77,369)	337,865
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses recognized in net income	(18,300)	(2,700)	(23,400)	(3,600)
Change in net unrealized gains on investments	(313,075)	(57,773)	(319,522)	160,936
Short-Term Investments [Member]
Gain (Loss) on Investments [Line Items]
Change in net unrealized gains on investments	$ 45	$ 37	$ 36	$ 35

Investments Investments (Compon

Investments Investments (Components Of Restricted Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Components Of Restricted Assets [Line Items]
Restricted assets	$ 5,388,198	$ 5,596,401
Held In Trust Or On Deposit [Member]
Components Of Restricted Assets [Line Items]
Restricted assets	4,733,990	4,961,061
Cash And Cash Equivalents And Securities Pledged As Collateral [Member]
Components Of Restricted Assets [Line Items]
Restricted assets	$ 654,208	$ 635,340

Investments Investments (Schedu

Investments Investments (Schedule Of Restricted Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investments, available-for-sale	$ 5,016,404	$ 5,040,413
Restricted cash and cash equivalents	371,794	522,225
Other assets	0	33,763
Total	$ 5,388,198	$ 5,596,401

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Disclosures [Abstract]
Fair value, level 1 to level 2 transfers, amount	$ 0	$ 0	$ 0	$ 0
Fair value, level 2 to level 1 transfers, amount	0	0	0	0
Assets measured at fair value on a nonrecurring basis	0	0	0	0
Liabilities measured at fair value on a nonrecurring basis	$ 0	$ 0	$ 0	$ 0

Fair Value Measurements (Balanc

Fair Value Measurements (Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	$ 9,353,951	$ 10,422,882
Total equity securities	4,156,413	4,137,576
Short-term investments	2,323,983	1,594,849
Available-for-sale investments, estimated fair value	15,834,347	16,155,307
Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	9,353,951	10,422,882
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	708,795	673,262
Obligations Of States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	3,956,324	4,317,547
Foreign Governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	1,477,132	1,611,921
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	451,515	430,627
Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	890,804	982,847
Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	45,400	99,490
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	1,823,981	2,307,188
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	4,156,413	4,137,576
Insurance, Banks And Other Financial Institutions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	1,275,409	1,311,925
Industrial, Consumer And All Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments, estimated fair value	2,881,004	2,825,651
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	9,353,951	10,422,882
Total equity securities	4,156,413	4,137,576
Short-term investments	2,323,983	1,594,849
Available-for-sale investments, estimated fair value	15,834,347	16,155,307
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Total equity securities	4,156,413	4,137,576
Short-term investments	2,224,533	1,469,975
Available-for-sale investments, estimated fair value	6,380,946	5,607,551
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	9,353,951	10,422,882
Total equity securities	0	0
Short-term investments	99,450	124,874
Available-for-sale investments, estimated fair value	9,453,401	10,547,756
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Total equity securities	0	0
Short-term investments	0	0
Available-for-sale investments, estimated fair value	0	0
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	708,795	673,262
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	708,795	673,262
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	3,956,324	4,317,547
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	3,956,324	4,317,547
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	1,477,132	1,611,921
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	1,477,132	1,611,921
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	451,515	430,627
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	451,515	430,627
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	890,804	982,847
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	890,804	982,847
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	45,400	99,490
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	45,400	99,490
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	1,823,981	2,307,188
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	1,823,981	2,307,188
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturities	0	0
Fair Value, Measurements, Recurring [Member] | Insurance, Banks And Other Financial Institutions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	1,275,409	1,311,925
Fair Value, Measurements, Recurring [Member] | Insurance, Banks And Other Financial Institutions [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	1,275,409	1,311,925
Fair Value, Measurements, Recurring [Member] | Insurance, Banks And Other Financial Institutions [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Insurance, Banks And Other Financial Institutions [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	2,881,004	2,825,651
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	2,881,004	2,825,651
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	$ 0	$ 0

Segment Reporting Disclosures36

Segment Reporting Disclosures (Company's Segment Disclosures) (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)segment	Sep. 30, 2014USD ($)
Segment Reporting Information [Line Items]
Number of reportable ongoing underwriting segments | segment				3
Gross premium volume		$ 1,158,364	$ 1,096,450	$ 3,676,623	$ 3,799,585
Net written premiums		953,184	881,781	3,022,958	3,105,423
Earned premiums		963,675	954,007	2,864,882	2,868,981
Losses and loss adjustment expenses, current accident year		(647,852)	(664,198)	(1,927,047)	(1,983,800)
Losses and loss adjustment expenses, prior accident years		163,115	93,232	459,121	260,125
Underwriting, acquisition and insurance expenses		(365,619)	(350,493)	(1,085,956)	(1,071,985)
Underwriting profit (loss)		113,319	32,548	311,000	73,321
Net investment income		87,060	91,096	270,521	269,980
Net realized investment gains (losses)		(14,707)	4,195	(3,031)	28,709
Other revenues (insurance)		1,343	4,199	12,469	22,028
Other expenses (insurance)		(9,252)	(13,486)	(24,860)	(42,687)
Segment profit (loss)		177,763	118,552	566,099	351,351
Other revenues (non-insurance)		305,393	245,789	804,682	608,214
Other expenses (non-insurance)		(281,497)	(217,707)	(739,126)	(555,616)
Amortization of intangible assets		(18,914)	(13,505)	(50,503)	(40,992)
Interest expense		(30,064)	(29,648)	(88,664)	(89,136)
Income Before Income Taxes		$ 152,681	$ 103,481	$ 492,488	$ 273,821
U.S. GAAP combined ratio	[1]	88.00%	97.00%	89.00%	97.00%
U.S. Insurance [Member]
Segment Reporting Information [Line Items]
Gross premium volume		$ 635,926	$ 619,510	$ 1,890,144	$ 1,876,114
Net written premiums		536,285	520,511	1,587,092	1,554,847
Earned premiums		534,615	516,753	1,569,615	1,499,571
Losses and loss adjustment expenses, current accident year		(357,400)	(348,877)	(1,015,492)	(997,804)
Losses and loss adjustment expenses, prior accident years		74,976	60,944	211,177	142,381
Underwriting, acquisition and insurance expenses		(200,272)	(202,765)	(597,388)	(595,208)
Underwriting profit (loss)		51,919	26,055	167,912	48,940
Net investment income		0	0	0	0
Net realized investment gains (losses)		0	0	0	0
Other revenues (insurance)		(41)	563	3,564	3,333
Other expenses (insurance)		(960)	(1,325)	(3,149)	(4,436)
Segment profit (loss)		$ 50,918	$ 25,293	$ 168,327	$ 47,837
U.S. GAAP combined ratio	[1]	90.00%	95.00%	89.00%	97.00%
International Insurance [Member]
Segment Reporting Information [Line Items]
Gross premium volume		$ 284,576	$ 271,045	$ 911,962	$ 924,401
Net written premiums		213,423	194,639	700,260	694,311
Earned premiums		225,034	216,764	654,936	678,772
Losses and loss adjustment expenses, current accident year		(162,024)	(160,132)	(479,764)	(495,441)
Losses and loss adjustment expenses, prior accident years		57,860	30,791	177,883	102,658
Underwriting, acquisition and insurance expenses		(92,680)	(81,706)	(266,091)	(250,157)
Underwriting profit (loss)		28,190	5,717	86,964	35,832
Net investment income		0	0	0	0
Net realized investment gains (losses)		0	0	0	0
Other revenues (insurance)		1,096	3,478	7,398	15,183
Other expenses (insurance)		(1,379)	(3,831)	(4,101)	(11,539)
Segment profit (loss)		$ 27,907	$ 5,364	$ 90,261	$ 39,476
U.S. GAAP combined ratio	[1]	87.00%	97.00%	87.00%	95.00%
Reinsurance [Member]
Segment Reporting Information [Line Items]
Gross premium volume		$ 239,094	$ 206,125	$ 875,676	$ 999,036
Net written premiums		204,336	166,848	736,068	855,930
Earned premiums		204,825	220,513	640,719	690,117
Losses and loss adjustment expenses, current accident year		(128,428)	(155,189)	(431,791)	(490,555)
Losses and loss adjustment expenses, prior accident years		24,241	8,258	65,746	49,811
Underwriting, acquisition and insurance expenses		(72,449)	(65,874)	(222,172)	(226,109)
Underwriting profit (loss)		28,189	7,708	52,502	23,264
Net investment income		0	0	0	0
Net realized investment gains (losses)		0	0	0	0
Other revenues (insurance)		246	(864)	1,138	2,304
Other expenses (insurance)		0	0	0	(1,097)
Segment profit (loss)		$ 28,435	$ 6,844	$ 53,640	$ 24,471
U.S. GAAP combined ratio	[1]	86.00%	97.00%	92.00%	97.00%
Other Insurance (Discontinued Lines) [Member]
Segment Reporting Information [Line Items]
Gross premium volume		$ (1,232)	$ (230)	$ (1,159)	$ 34
Net written premiums		(860)	(217)	(462)	335
Earned premiums		(799)	(23)	(388)	521
Losses and loss adjustment expenses, current accident year		0	0	0	0
Losses and loss adjustment expenses, prior accident years		6,038	(6,761)	4,315	(34,725)
Underwriting, acquisition and insurance expenses		(218)	(148)	(305)	(511)
Underwriting profit (loss)		5,021	(6,932)	3,622	(34,715)
Net investment income		0	0	0	0
Net realized investment gains (losses)		0	0	0	0
Other revenues (insurance)		42	1,022	369	1,208
Other expenses (insurance)		(6,913)	(8,330)	(17,610)	(25,615)
Segment profit (loss)		$ (1,850)	$ (14,240)	$ (13,619)	$ (59,122)
U.S. GAAP combined ratio - not meaniningful	[1],[2]	NM	NM	NM	NM
Investing [Member]
Segment Reporting Information [Line Items]
Gross premium volume		$ 0	$ 0	$ 0	$ 0
Net written premiums		0	0	0	0
Earned premiums		0	0	0	0
Losses and loss adjustment expenses, current accident year		0	0	0	0
Losses and loss adjustment expenses, prior accident years		0	0	0	0
Underwriting, acquisition and insurance expenses		0	0	0	0
Underwriting profit (loss)		0	0	0	0
Net investment income		87,060	91,096	270,521	269,980
Net realized investment gains (losses)		(14,707)	4,195	(3,031)	28,709
Other revenues (insurance)		0	0	0	0
Other expenses (insurance)		0	0	0	0
Segment profit (loss)		$ 72,353	$ 95,291	$ 267,490	$ 298,689
[1]	The U.S. GAAP combined ratio is a measure of underwriting performance and represents the relationship of incurred losses, loss adjustment expenses and underwriting, acquisition and insurance expenses to earned premiums.
[2]	NM – Ratio is not meaningful.

Segment Reporting Disclosures37

Segment Reporting Disclosures (Reconciliation Of Segment Assets To The Company's Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Assets	$ 25,181,573	$ 25,200,357
Non-Insurance Operations [Member]
Segment Reporting Information [Line Items]
Assets	1,218,990	1,246,762
Segment Assets [Member]
Segment Reporting Information [Line Items]
Assets	23,962,583	23,953,595
Segment Assets [Member] | Investing [Member]
Segment Reporting Information [Line Items]
Assets	18,342,049	18,531,150
Segment Assets [Member] | Underwriting [Member]
Segment Reporting Information [Line Items]
Assets	$ 5,620,534	$ 5,422,445

Senior Long-Term Debt And Oth38

Senior Long-Term Debt And Other Debt (Narrative) (Details) - Senior Credit Facility [Member] - USD ($) $ in Millions	Oct. 19, 2015	May. 19, 2015
Debt Instrument [Line Items]
Previous line of credit facility, borrowing capacity		$ 650
Credit facility, maximum capacity		$ 550
Subsequent Event [Member]
Debt Instrument [Line Items]
Credit facility, maximum capacity	$ 450

Other Revenues And Other Expe39

Other Revenues And Other Expenses (Narrative) (Details) $ in Millions	Apr. 24, 2015USD ($)
Other Income and Expenses [Abstract]
Cash payments for life and annuity benefit policies transferred under novated reinsurance contract	$ 29
Reserves on novated life and annuity benefit reinsurance contract	32.6
Gain on novated life and annuity benefit reinsurance contract	$ 3.6

Other Revenues And Other Expe40

Other Revenues And Other Expenses (Summary Of Other Revenues And Other Expenses By Component) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Revenues and Other Expenses [Line Items]
Other revenues	$ 306,736	$ 249,988	$ 817,151	$ 630,242
Other expenses	290,749	231,193	763,986	598,303
Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	1,343	4,199	12,469	22,028
Other expenses	9,252	13,486	24,860	42,687
Non-Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	305,393	245,789	804,682	608,214
Other expenses	281,497	217,707	739,126	555,616
Managing General Agent Operations [Member] | Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	1,055	3,812	10,043	17,764
Other expenses	2,339	4,832	7,250	14,931
Life And Annuity [Member] | Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	42	1,022	369	1,208
Other expenses	6,913	8,330	17,610	25,615
Other Insurance [Member] | Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	246	(635)	2,057	3,056
Other expenses	0	324	0	2,141
Manufacturing [Member] | Non-Insurance Operations [Member] | Markel Ventures Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	216,057	169,754	567,960	395,448
Other expenses	192,707	148,690	513,087	355,480
Non-Manufacturing [Member] | Non-Insurance Operations [Member] | Markel Ventures Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	83,098	70,303	216,191	199,457
Other expenses	83,104	64,728	209,947	185,648
Other Non-Insurance [Member] | Non-Insurance Operations [Member]
Other Revenues and Other Expenses [Line Items]
Other revenues	6,238	5,732	20,531	13,309
Other expenses	$ 5,686	$ 4,289	$ 16,092	$ 14,488

Reinsurance (Narrative) (Detail

Reinsurance (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Oct. 30, 2015	Mar. 09, 2015	Dec. 31, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Percentage of ceded earned premiums to gross earned premiums	18.00%	19.00%	18.00%	19.00%
Percentage of assumed earned premiums to net earned premiums	30.00%	32.00%	32.00%	34.00%
Reinsurance recoverables	$ 53.8	$ 91.1	$ 285.9	$ 330
March 9, 2015 [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Total payment under retrospective reinsurance transaction on ceded asbestos and environmental policies						$ 89
Cash paid at closing under retrospective reinsurance transaction on ceded asbestos and environmental policies						69.9
Cumulative amount of reserves for losses and loss adjustment expenses on ceded asbestos and environmental policies						94.1
Deferred gain under retrospective reinsurance transaction on ceded asbestos and environmental policies						$ 5.1
Approximate percentage of ceded reserves under retrospective reinsurance transaction to net asbestos and environmental reserves for losses and loss adjustment expenses							30.00%
October 30, 2015 [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Approximate percentage of ceded reserves under retrospective reinsurance transaction to net asbestos and environmental reserves for losses and loss adjustment expenses							25.00%
Subsequent Event [Member] | October 30, 2015 [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Total payment under retrospective reinsurance transaction on ceded asbestos and environmental policies					$ 86.5
Cumulative amount of reserves for losses and loss adjustment expenses on ceded asbestos and environmental policies					173.4
Cumulative reserves for losses and loss adjustment expenses on ceded asbestos and environmental policies, net of retention					76.4
Loss on retrospective reinsurance transaction					$ 10.1

Reinsurance (Effect Of Reinsura

Reinsurance (Effect Of Reinsurance And Retrocessional Reinsurance On Premiums Written And Earned) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reinsurance Disclosures [Abstract]
Direct premiums written	$ 878,269	$ 841,582	$ 2,631,734	$ 2,613,339
Direct premiums earned	881,512	875,191	2,601,458	2,556,350
Assumed premiums written	280,095	254,868	1,044,889	1,186,246
Assumed premiums earned	293,481	301,665	910,640	985,981
Ceded premiums written	(205,180)	(214,669)	(653,665)	(694,162)
Ceded premiums earned	(211,318)	(222,849)	(647,216)	(673,350)
Net premiums written	953,184	881,781	3,022,958	3,105,423
Net premiums earned	$ 963,675	$ 954,007	$ 2,864,882	$ 2,868,981

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Effective tax rate	32.00%	21.00%	25.00%
U.S. statutory tax rate		35.00%	35.00%

Net Income Per Share (Schedule

Net Income Per Share (Schedule Of Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Line Items]
Net income to shareholders	$ 102,519	$ 75,803	$ 384,880	$ 203,587
Adjustment of redeemable noncontrolling interests	1,376	(1,259)	3,091	(3,843)
Adjusted net income to shareholders	$ 103,895	$ 74,544	$ 387,971	$ 199,744
Basic common shares outstanding	13,983	13,981	13,977	13,986
Diluted shares outstanding	14,062	14,057	14,056	14,055
Basic net income per share	$ 7.43	$ 5.33	$ 27.76	$ 14.28
Diluted net income per share	$ 7.39	$ 5.30	$ 27.60	$ 14.21
Stock Options [Member]
Earnings Per Share [Line Items]
Dilutive potential common shares	8	11	9	11
Restricted Stock Units (RSUs) [Member]
Earnings Per Share [Line Items]
Dilutive potential common shares	71	65	70	58

Other Comprehensive Income (L45

Other Comprehensive Income (Loss) (Change In Accumulated Other Comprehensive Income By Component, Net Of Taxes And Noncontrolling Interest) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	$ 1,704,557	$ 1,089,805
Other comprehensive income (loss) before reclassifications	(280,511)	328,564
Amounts reclassified from accumulated other comprehensive income	(6,630)	(14,788)
Total other comprehensive income (loss)	(287,141)	313,776
Accumulated other comprehensive income, ending balance	1,417,416	1,403,581
Unrealized Holding Gains On Available-For-Sale Securities [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	1,793,254	1,131,507
Other comprehensive income (loss) before reclassifications	(258,275)	348,214
Amounts reclassified from accumulated other comprehensive income	(8,037)	(15,752)
Total other comprehensive income (loss)	(266,312)	332,462
Accumulated other comprehensive income, ending balance	1,526,942	1,463,969
Foreign Currency [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	(43,491)	(11,246)
Other comprehensive income (loss) before reclassifications	(22,236)	(19,650)
Amounts reclassified from accumulated other comprehensive income	0	0
Total other comprehensive income (loss)	(22,236)	(19,650)
Accumulated other comprehensive income, ending balance	(65,727)	(30,896)
Net Actuarial Pension Loss [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	(45,206)	(30,456)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	1,407	964
Total other comprehensive income (loss)	1,407	964
Accumulated other comprehensive income, ending balance	$ (43,799)	$ (29,492)

Other Comprehensive Income (L46

Other Comprehensive Income (Loss) (Summary Of Tax Expense (Benefit) Of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Comprehensive Income (Loss), Tax [Abstract]
Net holding gains (losses) arising during the period	$ (71,549)	$ (1,895)	$ (129,546)	$ 171,309
Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period	(10)	31	28	600
Reclassification adjustments for net gains (losses) included in net income	4,647	(1,858)	(1,025)	(5,535)
Change in net unrealized gains on investments	(66,912)	(3,722)	(130,543)	166,374
Change in foreign currency translation adjustments	829	43	1,662	1,509
Change in net actuarial pension loss	119	80	352	241
Total	$ (65,964)	$ (3,599)	$ (128,529)	$ 168,124

Other Comprehensive Income (L47

Other Comprehensive Income (Loss) (Reclassifications From Accumulated Other Comprehensive Income Into Income, By Component) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]
Other-than-temporary impairment losses recognized in net income	$ (18,281)	$ (2,851)	$ (23,373)	$ (3,858)
Net realized investment gains, excluding other-than-temporary impairment losses	3,574	7,046	20,342	32,567
Income Before Income Taxes	152,681	103,481	492,488	273,821
Underwriting, acquisition and insurance expenses	(365,619)	(350,493)	(1,085,956)	(1,071,985)
Income taxes	(48,271)	(26,657)	(101,619)	(68,355)
Net Income	104,410	76,824	390,869	205,466
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Unrealized Holding Gains On Available-For-Sale Securities [Member]
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]
Other-than-temporary impairment losses recognized in net income	(18,281)	(2,851)	(23,373)	(3,858)
Net realized investment gains, excluding other-than-temporary impairment losses	7,634	9,699	32,435	25,145
Income Before Income Taxes	(10,647)	6,848	9,062	21,287
Income taxes	4,647	(1,858)	(1,025)	(5,535)
Net Income	(6,000)	4,990	8,037	15,752
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Net Actuarial Pension Loss [Member]
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]
Underwriting, acquisition and insurance expenses	(594)	(400)	(1,759)	(1,205)
Income taxes	119	80	352	241
Net Income	$ (475)	$ (320)	$ (1,407)	$ (964)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - CATCo Investment Management, Ltd. [Member] $ in Millions	Sep. 09, 2015USD ($)
Other Commitments [Line Items]
Approximate purchase price of acquired assets	$ 200
Estimated cash consideration of acquired assets	$ 200