Everest Re (EG) 10-Q 9 Nov 17 2017 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 01, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Entity Registrant Name	EVEREST RE GROUP LTD
Entity Central Index Key	1,095,073
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		41,069,690

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS:
Fixed maturities - available for sale, at market value (amortized cost: 2017, $14,626,754; 2016, $13,932,613)	$ 14,778,175	$ 14,107,408
Equity securities - available for sale, at market value (cost: 2017, $128,116; 2016, $129,553)	127,425	119,067
Equity securities - available for sale, at fair value	1,141,146	1,010,085
Short-term investments	362,376	431,478
Other invested assets (cost: 2017, $1,484,599; 2016, $1,333,069)	1,487,519	1,333,129
Cash	585,395	481,922
Total investments and cash	18,482,036	17,483,089
Accrued investment income	101,092	96,473
Premiums receivable	2,071,714	1,485,990
Reinsurance receivables	1,366,890	1,018,325
Funds held by reinsureds	269,783	260,644
Deferred acquisition costs	396,858	344,052
Prepaid reinsurance premiums	314,949	191,768
Income taxes	415,182	177,704
Other assets	517,765	263,459
TOTAL ASSETS	23,936,269	21,321,504
LIABILITIES:
Reserve for losses and loss adjustment expenses	12,455,357	10,312,313
Future policy benefit reserve	54,279	55,074
Unearned premium reserve	1,992,907	1,577,546
Funds held under reinsurance treaties	21,768	21,278
Commission reserves	40,075	70,335
Other net payable to reinsurers	269,230	190,986
Losses in course of payment	205,215	67,107
4.868% Senior notes due 6/1/2044	396,804	396,714
6.6% Long term notes due 5/1/2067	236,536	236,462
Accrued interest on debt and borrowings	7,564	3,537
Equity index put option liability	16,006	22,059
Unsettled securities payable	54,711	27,927
Other liabilities	216,486	264,770
Total liabilities	15,966,938	13,246,108
Commitments and contingencies (Note 8)
SHAREHOLDERS' EQUITY:
Preferred shares, par value: $0.01; 50,000 shares authorized; no shares issued and outstanding
Common shares, par value: $0.01; 200,000 shares authorized; (2017) 69,040 and (2016) 68,871 outstanding before treasury shares	691	689
Additional paid-in capital	2,158,143	2,140,783
Accumulated other comprehensive income (loss), net of deferred income tax expense (benefit) of $21,672 at 2017 and $8,240 at 2016	(84,247)	(216,764)
Treasury shares, at cost; 27,972 shares 2017 and 2016	(3,272,244)	(3,272,244)
Retained earnings	9,166,988	9,422,932
Total shareholders' equity	7,969,331	8,075,396
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 23,936,269	$ 21,321,504

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fixed maturities - available for sale, at market value, amortized cost	$ 14,626,754	$ 13,932,613
Equity securities - available for sale, at market value, cost	128,116	129,553
Other invested assets, at cost	$ 1,484,599	$ 1,333,069
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, authorized	50,000,000	50,000,000
Preferred shares, issued	0	0
Preferred shares, outstanding	0	0
Common shares, par value	$ 0.01	$ 0.01
Common shares, authorized	200,000,000	200,000,000
Common shares, outstanding	69,040,000	68,871,000
Accumulated other comprehensive income (loss), net of deferred income tax expense (benefit)	$ 21,672	$ 8,240
Treasury shares	27,972,000	27,972,000
6.6 % Long Term Subordinated Notes [Member]
Debt instrument, stated interest rate	6.60%	6.60%
Debt instrument, maturity date	May 1, 2067
4.868% Senior notes due 6/1/2044 [Member] | Senior Notes [Member]
Debt instrument, stated interest rate	4.868%	4.868%
Debt instrument, maturity date	Jun. 1, 2044

Consolidated Statements Of Oper

Consolidated Statements Of Operations And Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
REVENUES:
Premiums earned	$ 1,598,875	$ 1,371,474	$ 4,280,653	$ 3,879,201
Net investment income	136,973	122,657	393,770	357,918
Net realized capital gains (losses):
Other-than-temporary impairments on fixed maturity securities	(1,485)	(867)	(5,188)	(31,130)
Other-than-temporary impairments on fixed maturity securities transferred to other comprehensive income (loss)
Other net realized capital gains (losses)	43,020	1,247	124,719	(10,091)
Total net realized capital gains (losses)	41,535	380	119,531	(41,221)
Net derivative gain (loss)	2,656	6,510	6,052	5,486
Other income (expense)	(54,568)	9,435	(59,146)	(20,998)
Total revenues	1,725,471	1,510,456	4,740,860	4,180,386
CLAIMS AND EXPENSES:
Incurred losses and loss adjustment expenses	2,210,082	786,168	3,842,145	2,344,733
Commission, brokerage, taxes and fees	333,113	309,545	915,338	880,053
Other underwriting expenses	73,145	78,563	227,901	222,750
Corporate expenses	5,932	6,400	21,308	21,403
Interest, fees and bond issue cost amortization expense	7,266	8,893	24,289	27,194
Total claims and expenses	2,629,538	1,189,569	5,030,981	3,496,133
INCOME (LOSS) BEFORE TAXES	(904,067)	320,887	(290,121)	684,253
Income tax expense (benefit)	(264,693)	25,493	(188,064)	61,481
NET INCOME (LOSS)	(639,374)	295,394	(102,057)	622,772
Other comprehensive income (loss), net of tax :
Unrealized appreciation (depreciation) ("URA(D)") on securities arising during the period	(5,671)	(9,032)	18,745	258,286
Reclassification adjustment for realized losses (gains) included in net income (loss)	(5,537)	(3,222)	(16,729)	27,711
Total URA(D) on securities arising during the period	(11,208)	(12,254)	2,016	285,997
Foreign currency translation adjustments	77,564	2,816	125,124	17,639
Benefit plan actuarial net gain (loss) for the period
Reclassification adjustment for amortization of net (gain) loss included in net income (loss)	1,369	1,268	5,377	3,949
Total benefit plan net gain (loss) for the period	1,369	1,268	5,377	3,949
Total other comprehensive income (loss), net of tax	67,725	(8,170)	132,517	307,585
COMPREHENSIVE INCOME (LOSS)	$ (571,649)	$ 287,224	$ 30,460	$ 930,357
EARNINGS PER COMMON SHARE:
Basic	$ (15.73)	$ 7.11	$ (2.51)	$ 14.80
Diluted	(15.73)	7.06	(2.51)	14.70
Dividends declared	$ 1.25	$ 1.15	$ 3.75	$ 3.45

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Common Shares [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Shares At Cost [Member]	Total
Balance, beginning of period, shares at Dec. 31, 2015	42,694,252
Issued during the period, shares	215,887
Treasury shares acquired, shares	(2,022,945)
Balance, beginning of period at Dec. 31, 2015	$ 686	$ 2,103,638	$ (231,755)	$ 8,621,972	$ (2,885,956)
Issued during the period, net	$ 2
Share-based compensation plans		25,673
Net increase (decrease) during the period			307,585			$ 307,585
Net income (loss)				622,772		622,772
Dividends declared ($1.25 per share in third quarter 2017 and $3.75 year to date per share in 2017 and $1.15 per share in third quarter 2016 and $3.45 year-to-date per share in 2016)						(144,299)
Purchase of treasury shares					(379,228)
Balance, end of period, shares at Sep. 30, 2016	40,887,194
Balance, end of period at Sep. 30, 2016	$ 688	2,129,311	75,830	9,100,447	(3,265,184)	$ 8,041,092
Balance, beginning of period, shares at Dec. 31, 2015	42,694,252
Balance, beginning of period at Dec. 31, 2015	$ 686	2,103,638	(231,755)	8,621,972	(2,885,956)
Balance, end of period, shares at Dec. 31, 2016	40,898,864					68,871,000
Balance, end of period at Dec. 31, 2016	$ 689	2,140,783	(216,764)	9,422,932	(3,272,244)	$ 8,075,396
Balance, beginning of period, shares at Jun. 30, 2016	41,883,430
Issued during the period, shares	17,621
Treasury shares acquired, shares	(1,013,857)
Balance, beginning of period at Jun. 30, 2016	$ 688	2,120,581	84,000	8,852,512	(3,072,313)
Share-based compensation plans		8,730
Net increase (decrease) during the period			(8,170)			(8,170)
Net income (loss)				295,394		295,394
Dividends declared ($1.25 per share in third quarter 2017 and $3.75 year to date per share in 2017 and $1.15 per share in third quarter 2016 and $3.45 year-to-date per share in 2016)						(47,463)
Purchase of treasury shares					(192,871)
Balance, end of period, shares at Sep. 30, 2016	40,887,194
Balance, end of period at Sep. 30, 2016	$ 688	2,129,311	75,830	9,100,447	(3,265,184)	$ 8,041,092
Balance, beginning of period, shares at Dec. 31, 2016	40,898,864					68,871,000
Issued during the period, shares	169,244
Balance, beginning of period at Dec. 31, 2016	$ 689	2,140,783	(216,764)	9,422,932	(3,272,244)	$ 8,075,396
Issued during the period, net	$ 2
Share-based compensation plans		17,360
Net increase (decrease) during the period			132,517			132,517
Net income (loss)				(102,057)		(102,057)
Dividends declared ($1.25 per share in third quarter 2017 and $3.75 year to date per share in 2017 and $1.15 per share in third quarter 2016 and $3.45 year-to-date per share in 2016)						$ (153,887)
Purchase of treasury shares
Balance, end of period, shares at Sep. 30, 2017	41,068,108					69,040,000
Balance, end of period at Sep. 30, 2017	$ 691	2,158,143	(84,247)	9,166,988	(3,272,244)	$ 7,969,331
Balance, beginning of period, shares at Jun. 30, 2017	41,065,212
Issued during the period, shares	2,896
Balance, beginning of period at Jun. 30, 2017	$ 691	2,150,659	(151,972)	9,857,664	(3,272,244)
Share-based compensation plans		7,484
Net increase (decrease) during the period			67,725			67,725
Net income (loss)				(639,374)		(639,374)
Dividends declared ($1.25 per share in third quarter 2017 and $3.75 year to date per share in 2017 and $1.15 per share in third quarter 2016 and $3.45 year-to-date per share in 2016)						$ (51,302)
Purchase of treasury shares
Balance, end of period, shares at Sep. 30, 2017	41,068,108					69,040,000
Balance, end of period at Sep. 30, 2017	$ 691	$ 2,158,143	$ (84,247)	$ 9,166,988	$ (3,272,244)	$ 7,969,331

Consolidated Statements Of Cha6

Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]
Dividends declared	$ 1.25	$ 1.15	$ 3.75	$ 3.45

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (102,057)	$ 622,772
Adjustments to reconcile net income to net cash provided by operating activities:
Decrease (increase) in premiums receivable	(564,080)	(185,559)
Decrease (increase) in funds held by reinsureds, net	(4,742)	46,134
Decrease (increase) in reinsurance receivables	(245,275)	(87,807)
Decrease (increase) in income taxes	(247,571)	15,935
Decrease (increase) in prepaid reinsurance premiums	(109,913)	(66,147)
Increase (decrease) in reserve for losses and loss adjustment expenses	1,927,538	470,560
Increase (decrease) in future policy benefit reserve	(795)	(1,912)
Increase (decrease) in unearned premiums	389,731	89,013
Increase (decrease) in other net payable to reinsurers	59,356	85,493
Increase (decrease) in losses in course of payment	137,805	7,673
Change in equity adjustments in limited partnerships	(54,155)	(33,289)
Distribution of limited partnership income	36,859	52,913
Change in other assets and liabilities, net	(116,623)	(154,765)
Non-cash compensation expense	23,011	20,359
Amortization of bond premium (accrual of bond discount)	34,657	38,151
Amortization of underwriting discount on senior notes	3	3
Net realized capital (gains) losses	(119,531)	41,221
Net cash provided by (used in) operating activities	1,044,218	960,748
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from fixed maturities matured/called - available for sale, at market value	1,619,552	1,439,002
Proceeds from fixed maturities sold - available for sale, at market value	1,691,937	888,761
Proceeds from fixed maturity securities sold - available for sale, at fair value		1,588
Proceeds from equity securities sold - available for sale, at market value	18,802	155
Proceeds from equity securities sold - available for sale, at fair value	316,087	542,560
Distributions from other invested assets	3,555,941	3,600,587
Proceeds from sale of subsidiary (net of cash disposed)		47,721
Cost of fixed maturities acquired - available for sale, at market value	(3,774,584)	(2,974,792)
Cost of fixed maturities acquired - available for sale, at fair value		(3,940)
Cost of equity securities acquired - available for sale, at market value	(19,196)	(4,194)
Cost of equity securities acquired - available for sale, at fair value	(351,220)	(269,544)
Cost of other invested assets acquired	(3,676,606)	(4,131,419)
Net change in short-term investments	74,000	488,047
Net change in unsettled securities transactions	(219,208)	44,494
Net cash provided by (used in) investing activities	(764,495)	(330,974)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common shares issued during the period, net	(5,650)	5,315
Purchase of treasury shares		(379,228)
Dividends paid to shareholders	(153,887)	(144,297)
Cost of shares withheld for taxes on settlements of share-based compensation awards	(12,707)	(10,017)
Net cash provided by (used in) financing activities	(172,244)	(528,227)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	(4,006)	50,590
Net increase (decrease) in cash	103,473	152,137
Cash, beginning of period	481,922	283,658
Cash, end of period	585,395	435,795
SUPPLEMENTAL CASH FLOW INFORMATION:
Income taxes paid (recovered)	58,701	40,072
Interest paid	$ 19,783	$ 18,227

General

General	9 Months Ended
	Sep. 30, 2017
General [Abstract]
General	1. GENERAL Everest Re Group, Ltd. ("Group"), a Bermuda company, through its subsidiaries, principally provides reinsurance and insurance in the U.S., Bermuda and international markets. As used in this document, "Company" means Group and its subsidiaries. During the third quarter of 2016, the Company established domestic subsidiaries, Everest Premier Insurance Company ("Everest Premier") and Everest Denali Insurance Company ("Everest Denali"), which will be used in the continued expansion of the Insurance operations. Effective August 24, 2016, the Company sold its wholly-owned subsidiary, Heartland Crop Insurance Company ("Heartland"), a managing agent for crop insurance, to CGB Diversified Services, Inc. ("CGB"). The operating results of Heartland through August 24, 2016, are included within the Company's financial statements. Effective July 1, 2016, the Company established a new Irish holding company, Everest Dublin Insurance Holdings Limited (Ireland) ("Everest Dublin Holdings"). During the fourth quarter of 2015, the Company established new subsidiaries, Everest Preferred International Holdings, Ltd. ("Preferred International"), a Bermuda based company and Everest International Holdings (Bermuda), Ltd. ("International Holdings"), a Bermuda based company. These new subsidiaries were part of a capital restructuring within the Company to support a planned increase in international business production, which includes directly supporting Group's new Lloyd's of London Syndicate corporate member.

Basis Of Presentation

Basis Of Presentation	9 Months Ended
	Sep. 30, 2017
Basis Of Presentation[Abstract]
Basis Of Presentation	2. BASIS OF PRESENTATION The unaudited consolidated financial statements of the Company for the three and nine months ended September 30, 2017 and 2016 include all adjustments, consisting of normal recurring accruals, which, in the opinion of management, are necessary for a fair statement of the results on an interim basis. Certain financial information, which is normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"), has been omitted since it is not required for interim reporting purposes. The December 31, 2016 consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The results for the three and nine months ended September 30, 2017 and 2016 are not necessarily indicative of the results for a full year. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the years ended December 31, 2016, 2015 and 2014 included in the Company's most recent Form 10-K filing. The Company consolidates the results of operations and financial position of all voting interest entities ("VOE") in which the Company has a controlling financial interest and all variable interest entities ("VIE") in which the Company is considered to be the primary beneficiary. The consolidation assessment, including the determination as to whether an entity qualifies as a VIE or VOE, depends on the facts and circumstances surrounding each entity. Effective January 1, 2016, the Company adopted Accounting Standards Update ("ASU") 2015-02, "Consolidation (Topic 810) Amendments to the Consolidation Analysis" The amended guidance includes changes in the identification of the primary beneficiary of companies considered to be VIEs. These changes resulted in the Company concluding that Mt. Logan Re is a VIE given it has insufficient equity at risk and that each underlying separate segregated account is likewise a VIE. The Company has concluded that it is the primary beneficiary of Mt. Logan Re, but not of the underlying separate segregated accounts and therefore has deconsolidated these segregated accounts. This change had no impact to the net income or retained earnings of the Company. All significant intercompany accounts and transactions have been eliminated. Certain reclassifications and format changes have been made to prior years' amounts to conform to the 2017 presentation. Application of Recently Issued Accounting Standard Changes. Amortization of Bond Premium. Presentation and Disclosure of Net Periodic Benefit Costs. Disclosure of Restricted Cash. Intra-Entity Asset Transfers. Valuation of Financial Instruments. Accounting for Share-Based Compensation. The following table presents certain financial statement line items as previously reported in 2016, the effect of those line items due to treating the cost of shares withheld upon settlement of share-based compensation awards as a financing activity with the Statements of Cash Flows and the line items as currently reported within the financial statements. Consolidated Statements of Cash Flows: Nine Months Ended September 30, 2016 Effect of adoption of As previously new accounting reported policy As adopted (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES: Change in other assets and liabilities, net $ (164,782 ) $ 10,017 $ (154,765 ) Net cash provided by (used in) operating activities 950,731 10,017 960,748 CASH FLOWS FROM FINANCING ACTIVITIES: Cost of shares withheld for taxes on settlements of share-based compensation awards - (10,017 ) (10,017 ) Net cash provided by (used in) financing activities (518,210 ) (10,017 ) (528,227 ) Leases. Recognition and Measurement of Financial Instruments. Disclosures about Short-Duration Contracts. Disclosures for Investments in Certain Entities that Calculate Net Asset Value Per Share. Debt Issuance Costs. Consolidation. Revenue Recognition. Any issued guidance and pronouncements, other than those directly references above, are deemed by the Company to be either not applicable or immaterial to its financial statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments [Abstract]
Investments	3. INVESTMENTS The amortized cost, market value and gross unrealized appreciation and depreciation of available for sale, fixed maturity, equity security investments, carried at market value and other-than-temporary impairments ("OTTI") in accumulated other comprehensive income ("AOCI") are as follows for the periods indicated: At September 30, 2017 Amortized Unrealized Unrealized Market OTTI in AOCI (Dollars in thousands) Cost Appreciation Depreciation Value (a) Fixed maturity securities U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,141,002 $ 12,475 $ (6,608 ) $ 1,146,869 $ - Obligations of U.S. states and political subdivisions 652,525 24,061 (4,744 ) 671,842 - Corporate securities 5,599,904 108,072 (31,814 ) 5,676,162 2,902 Asset-backed securities 555,451 1,390 (444 ) 556,397 - Mortgage-backed securities Commercial 253,154 1,462 (1,825 ) 252,791 - Agency residential 2,390,238 13,680 (23,589 ) 2,380,329 - Non-agency residential 519 42 (44 ) 517 - Foreign government securities 1,317,697 46,225 (34,489 ) 1,329,433 182 Foreign corporate securities 2,716,264 89,202 (41,631 ) 2,763,835 961 Total fixed maturity securities $ 14,626,754 $ 296,609 $ (145,188 ) $ 14,778,175 $ 4,045 Equity securities $ 128,116 $ 2,542 $ (3,233 ) $ 127,425 $ - At December 31, 2016 Amortized Unrealized Unrealized Market OTTI in AOCI (Dollars in thousands) Cost Appreciation Depreciation Value (a) Fixed maturity securities U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,115,208 $ 20,410 $ (5,303 ) $ 1,130,315 $ - Obligations of U.S. states and political subdivisions 723,938 18,016 (11,970 ) 729,984 - Corporate securities 5,059,388 131,651 (35,758 ) 5,155,281 7,936 Asset-backed securities 488,824 1,110 (1,286 ) 488,648 - Mortgage-backed securities Commercial 308,827 1,983 (3,878 ) 306,932 - Agency residential 2,415,901 17,478 (27,910 ) 2,405,469 - Non-agency residential 642 44 (45 ) 641 - Foreign government securities 1,254,175 61,226 (57,241 ) 1,258,160 115 Foreign corporate securities 2,565,710 130,714 (64,446 ) 2,631,978 1,184 Total fixed maturity securities $ 13,932,613 $ 382,632 $ (207,837 ) $ 14,107,408 $ 9,235 Equity securities $ 129,553 $ 2,298 $ (12,784 ) $ 119,067 $ - (a) Represents the amount of OTTI recognized in AOCI. Amount includes unrealized gains and losses on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date The amortized cost and market value of fixed maturity securities are shown in the following table by contractual maturity. Mortgage-backed securities are generally more likely to be prepaid than other fixed maturity securities. As the stated maturity of such securities may not be indicative of actual maturities, the totals for mortgage-backed and asset-backed securities are shown separately. At September 30, 2017 At December 31, 2016 Amortized Market Amortized Market (Dollars in thousands) Cost Value Cost Value Fixed maturity securities – available for sale: Due in one year or less $ 1,091,257 $ 1,095,288 $ 956,945 $ 966,970 Due after one year through five years 7,267,248 7,334,494 6,769,585 6,870,056 Due after five years through ten years 2,096,762 2,124,265 2,020,215 2,052,733 Due after ten years 972,125 1,034,094 971,674 1,015,959 Asset-backed securities 555,451 556,397 488,824 488,648 Mortgage-backed securities: Commercial 253,154 252,791 308,827 306,932 Agency residential 2,390,238 2,380,329 2,415,901 2,405,469 Non-agency residential 519 517 642 641 Total fixed maturity securities $ 14,626,754 $ 14,778,175 $ 13,932,613 $ 14,107,408 The changes in net unrealized appreciation (depreciation) for the Company's investments are derived from the following sources for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Increase (decrease) during the period between the market value and cost of investments carried at market value, and deferred taxes thereon: Fixed maturity securities $ (13,993 ) $ (13,544 ) $ (18,184 ) $ 324,147 Fixed maturity securities, other-than-temporary impairment 306 (1,836 ) (5,189 ) 7,088 Equity securities 2,603 2,527 9,795 9,898 Other invested assets 1,595 - 2,860 - Change in unrealized appreciation (depreciation), pre-tax (9,489 ) (12,853 ) (10,718 ) 341,133 Deferred tax benefit (expense) (1,774 ) (256 ) 11,343 (53,666 ) Deferred tax benefit (expense), other-than-temporary impairment 55 855 1,391 (1,470 ) Change in unrealized appreciation (depreciation), net of deferred taxes, included in shareholders' equity $ (11,208 ) $ (12,254 ) $ 2,016 $ 285,997 The Company frequently reviews all of its fixed maturity, available for sale securities for declines in market value and focuses its attention on securities whose fair value has fallen below 80 The Company's assessments are based on the issuers' current and expected future financial position, timeliness with respect to interest and/or principal payments, speed of repayments and any applicable credit enhancements or breakeven constant default rates on mortgage-backed and asset-backed securities, as well as relevant information provided by rating agencies, investment advisors and analysts. The majority of the Company's equity securities available for sale at market value are primarily comprised of mutual fund investments whose underlying securities consist of fixed maturity securities. When a fund's value reflects an unrealized loss, the Company assesses whether the decline in value is temporary or other-than-temporary. In making its assessment, the Company considers the composition of its portfolios and their related markets, reports received from the portfolio managers and discussions with portfolio managers. If the Company determines that the declines are temporary and it has the ability and intent to continue to hold the investments, then the declines are recorded as unrealized losses in accumulated other comprehensive income (loss). If declines are deemed to be other-than-temporary, then the carrying value of the investment is written down to fair value and recorded in net realized capital gains (losses) in the Company's consolidated statements of operations and comprehensive income (loss). Retrospective adjustments are employed to recalculate the values of asset-backed securities The tables below display the aggregate market value and gross unrealized depreciation of fixed maturity and equity securities, by security type and contractual maturity, in each case subdivided according to length of time that individual securities had been in a continuous unrealized loss position for the periods indicated: Duration of Unrealized Loss at September 30, 2017 By Security Type Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities - available for sale U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 376,128 $ (4,865 ) $ 53,039 $ (1,743 ) $ 429,167 $ (6,608 ) Obligations of U.S. states and political subdivisions 89,509 (2,104 ) 67,956 (2,640 ) 157,465 (4,744 ) Corporate securities 1,214,762 (20,914 ) 283,985 (10,900 ) 1,498,747 (31,814 ) Asset-backed securities 189,752 (369 ) 6,262 (75 ) 196,014 (444 ) Mortgage-backed securities Commercial 63,101 (540 ) 40,432 (1,285 ) 103,533 (1,825 ) Agency residential 1,345,113 (13,416 ) 450,890 (10,173 ) 1,796,003 (23,589 ) Non-agency residential - - 77 (44 ) 77 (44 ) Foreign government securities 385,494 (14,007 ) 258,478 (20,482 ) 643,972 (34,489 ) Foreign corporate securities 660,017 (17,136 ) 312,821 (24,495 ) 972,838 (41,631 ) Total fixed maturity securities $ 4,323,876 $ (73,351 ) $ 1,473,940 $ (71,837 ) $ 5,797,816 $ (145,188 ) Equity securities - - 112,015 (3,233 ) 112,015 (3,233 ) Total $ 4,323,876 $ (73,351 ) $ 1,585,955 $ (75,070 ) $ 5,909,831 $ (148,421 ) Duration of Unrealized Loss at September 30, 2017 By Maturity Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities Due in one year or less $ 270,695 $ (848 ) $ 123,092 $ (13,069 ) $ 393,787 $ (13,917 ) Due in one year through five years 1,680,251 (31,686 ) 644,557 (37,591 ) 2,324,808 (69,277 ) Due in five years through ten years 639,836 (22,619 ) 136,548 (6,469 ) 776,384 (29,088 ) Due after ten years 135,128 (3,873 ) 72,082 (3,131 ) 207,210 (7,004 ) Asset-backed securities 189,752 (369 ) 6,262 (75 ) 196,014 (444 ) Mortgage-backed securities 1,408,214 (13,956 ) 491,399 (11,502 ) 1,899,613 (25,458 ) Total fixed maturity securities $ 4,323,876 $ (73,351 ) $ 1,473,940 $ (71,837 ) $ 5,797,816 $ (145,188 ) The aggregate market value and gross unrealized losses related to investments in an unrealized loss position at September 30, 2017 were $ 5,909,831 148,421 0.4 73,351 69,276 71,837 67,753 The Company, given the size of its investment portfolio and capital position, does not have the intent to sell these securities; and it is more likely than not that the Company will not have to sell the securities before recovery of cost basis. In addition, all securities currently in an unrealized loss position are current with respect to principal and interest payments. The tables below display the aggregate market value and gross unrealized depreciation of fixed maturity and equity securities, by security type and contractual maturity, in each case subdivided according to length of time that individual securities had been in a continuous unrealized loss position for the periods indicated: Duration of Unrealized Loss at December 31, 2016 By Security Type Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities - available for sale U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 638,740 $ (5,303 ) $ - $ - $ 638,740 $ (5,303 ) Obligations of U.S. states and political subdivisions 221,088 (11,486 ) 564 (484 ) 221,652 (11,970 ) Corporate securities 1,360,743 (24,023 ) 177,153 (11,735 ) 1,537,896 (35,758 ) Asset-backed securities 150,023 (565 ) 18,786 (721 ) 168,809 (1,286 ) Mortgage-backed securities Commercial 143,554 (3,223 ) 7,184 (655 ) 150,738 (3,878 ) Agency residential 1,618,372 (22,461 ) 189,665 (5,449 ) 1,808,037 (27,910 ) Non-agency residential - - 113 (45 ) 113 (45 ) Foreign government securities 360,289 (12,041 ) 236,820 (45,200 ) 597,109 (57,241 ) Foreign corporate securities 687,599 (12,769 ) 295,500 (51,677 ) 983,099 (64,446 ) Total fixed maturity securities $ 5,180,408 $ (91,871 ) $ 925,785 $ (115,966 ) $ 6,106,193 $ (207,837 ) Equity securities - - 105,507 (12,784 ) 105,507 (12,784 ) Total $ 5,180,408 $ (91,871 ) $ 1,031,292 $ (128,750 ) $ 6,211,700 $ (220,621 ) Duration of Unrealized Loss at December 31, 2016 By Maturity Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities Due in one year or less $ 178,281 $ (1,122 ) $ 78,153 $ (14,318 ) $ 256,434 $ (15,440 ) Due in one year through five years 2,123,113 (26,263 ) 538,130 (84,803 ) 2,661,243 (111,066 ) Due in five years through ten years 680,334 (22,555 ) 86,631 (8,754 ) 766,965 (31,309 ) Due after ten years 286,731 (15,682 ) 7,123 (1,221 ) 293,854 (16,903 ) Asset-backed securities 150,023 (565 ) 18,786 (721 ) 168,809 (1,286 ) Mortgage-backed securities 1,761,926 (25,684 ) 196,962 (6,149 ) 1,958,888 (31,833 ) Total fixed maturity securities $ 5,180,408 $ (91,871 ) $ 925,785 $ (115,966 ) $ 6,106,193 $ (207,837 ) The aggregate market value and gross unrealized losses related to investments in an unrealized loss position at December 31, 2016 were $ 6,211,700 220,621 1.1 91,871 85,078 115,966 112,132 no The components of net investment income are presented in the table below for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Fixed maturities $ 107,969 $ 100,752 $ 319,336 $ 306,128 Equity securities 8,590 9,905 25,701 31,967 Short-term investments and cash 974 475 2,439 1,220 Other invested assets Limited partnerships 23,315 17,077 54,373 33,922 Other 2,095 1,033 6,652 1,334 Gross investment income before adjustments 142,943 129,242 408,501 374,571 Funds held interest income (expense) 2,284 1,538 7,156 5,818 Future policy benefit reserve income (expense) (280 ) (517 ) (1,015 ) (1,243 ) Gross investment income 144,947 130,263 414,642 379,146 Investment expenses (7,974 ) (7,606 ) (20,872 ) (21,228 ) Net investment income $ 136,973 $ 122,657 $ 393,770 $ 357,918 The Company records results from limited partnership investments on the equity method of accounting with changes in value reported through net investment income. Due to the timing of receiving financial information from these partnerships, the results are generally reported on a one month or quarter lag. If the Company determines there has been a significant decline in value of a limited partnership during this lag period, a loss will be recorded in the period in which the Company identifies the decline. The Company had contractual commitments to invest up to an additional $ 663,222 The Company's other invested assets at September 30, 2017 and December 31, 2016 included $ 367,966 378,862 The components of net realized capital gains (losses) are presented in the table below for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Fixed maturity securities, market value: Other-than-temporary impairments $ (1,485 ) $ (867 ) $ (5,188 ) $ (31,130 ) Gains (losses) from sales 7,998 5,912 32,913 (7,670 ) Fixed maturity securities, fair value: Gains (losses) from sales - (1 ) - (1,855 ) Gains (losses) from fair value adjustments - 42 - 1,381 Equity securities, market value: Gains (losses) from sales - - (3,436 ) 65 Equity securities, fair value: Gains (losses) from sales (1,525 ) 5,850 3,796 (10,266 ) Gains (losses) from fair value adjustments 36,463 17,475 91,367 36,284 Sale of subsidiary - (28,032 ) - (28,032 ) Other invested assets 85 - 84 - Short-term investments gain (loss) (1 ) 1 (5 ) 2 Total net realized capital gains (losses) $ 41,535 $ 380 $ 119,531 $ (41,221 ) The Company recorded as net realized capital gains (losses) in the consolidated statements of operations and comprehensive income (loss) both fair value re-measurements and write-downs in the value of securities deemed to be impaired on an other-than-temporary basis as displayed in the table above. The Company had no other-than-temporary impaired securities where the impairment had both a credit and non-credit component. The proceeds and split between gross gains and losses, from sales of fixed maturity and equity securities, are presented in the table below for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Proceeds from sales of fixed maturity securities $ 700,728 $ 293,998 $ 1,691,937 $ 890,349 Gross gains from sales 13,743 15,028 46,321 32,674 Gross losses from sales (5,745 ) (9,117 ) (13,408 ) (42,199 ) Proceeds from sales of equity securities $ 57,861 $ 112,451 $ 334,889 $ 542,715 Gross gains from sales 2,258 7,308 14,351 14,040 Gross losses from sales (3,783 ) (1,458 ) (13,991 ) (24,241 )

Reserve For Losses, LAE And Fut

Reserve For Losses, LAE And Future Policy Benefit Reserve	9 Months Ended
	Sep. 30, 2017
Reserve For Losses LAE And Future Policy Benefit Reserve [Abstract]
Reserve For Losses LAE And Future Policy Benefit Reserve	4. RESERVE FOR LOSSES, LAE AND FUTURE POLICY BENEFIT RESERVE Activity in the reserve for losses and LAE is summarized for the periods indicated: Nine Months Ended Twelve Months Ended September 30, December 31, (Dollars in thousands) 2017 2016 Gross reserves at beginning of period $ 10,312,313 $ 9,951,798 Less reinsurance recoverables (990,862 ) (881,503 ) Net reserves at beginning of period 9,321,451 9,070,295 Incurred related to: Current year 3,843,434 3,434,964 Prior years (1,289 ) (295,335 ) Total incurred losses and LAE 3,842,145 3,139,629 Paid related to: Current year 948,897 745,642 Prior years 1,265,713 2,042,972 Total paid losses and LAE 2,214,610 2,788,614 Foreign exchange/translation adjustment 208,246 (99,859 ) Net reserves at end of period 11,157,232 9,321,451 Plus reinsurance recoverables 1,298,125 990,862 Gross reserves at end of period $ 12,455,357 $ 10,312,313 Current year incurred losses were $3,843,434 thousand for the nine months ended September 30, 2017 compared to $3,434,964 thousand for the full year 2016. The increase in current year incurred losses was primarily due to $ 1,443,746 307,263 Incurred prior years' reserves decreased by $1,289 thousand and $295,335 thousand for the nine months ended September 30, 2017 and for the twelve months ended December 31, 2016, respectively. The decrease for the twelve months ended December 31, 2016 was attributable to favorable development in the reinsurance segments of $ 468,749 53,909 60,000 16,720 43,280 173,414

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2017
Derivatives [Abstract]
Derivatives	5. DERIVATIVES The Company sold seven two One no The Company has five 2 S&P 500 index value were zero 3 397,561 2,519.36 no The Company has one 15 zero 3 41,134 7,372.76 no At September 30, 2017 and December 31, 2016, the fair value for these equity put options was $ 16,006 22,059 The fair value of the equity index put options can be found in the Company's consolidated balance sheets as follows: (Dollars in thousands) Derivatives not designated as Location of fair value At At hedging instruments in balance sheets September 30, 2017 December 31, 2016 Equity index put option contracts Equity index put option liability $ 16,006 $ 22,059 Total $ 16,006 $ 22,059 The change in fair value of the equity index put option contracts can be found in the Company's statement of operations and comprehensive income (loss) as follows: (Dollars in thousands) For the Three Months Ended For the Nine Months Ended Derivatives not designated as Location of gain (loss) in statements of September 30, September 30, hedging instruments operations and comprehensive income (loss) 2017 2016 2017 2016 Equity index put option contracts Net derivative gain (loss) $ 2,656 $ 6,510 $ 6,052 $ 5,486 Total $ 2,656 $ 6,510 $ 6,052 $ 5,486

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2017
Fair Value [Abstract]
Fair Value	6. FAIR VALUE GAAP guidance regarding fair value measurements address how companies should measure fair value when they are required to use fair value measures for recognition or disclosure purposes under GAAP and provides a common definition of fair value to be used throughout GAAP. It defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly fashion between market participants at the measurement date. In addition, it establishes a three-level valuation hierarchy for the disclosure of fair value measurements. The valuation hierarchy is based on the transparency of inputs to the valuation of an asset or liability. The level in the hierarchy within which a given fair value measurement falls is determined based on the lowest level input that is significant to the measurement, with Level 1 being the highest priority and Level 3 being the lowest priority. The levels in the hierarchy are defined as follows: Level 1: Inputs to the valuation methodology are observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in an active market; Level 2: Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument; Level 3: Inputs to the valuation methodology are unobservable and significant to the fair value measurement. The Company's fixed maturity and equity securities are primarily managed by third party investment asset managers. The investment asset managers obtain prices from nationally recognized pricing services. These services seek to utilize market data and observations in their evaluation process. They use pricing applications that vary by asset class and incorporate available market information and when fixed maturity securities do not trade on a daily basis the services will apply available information through processes such as benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. In addition, they use model processes, such as the Option Adjusted Spread model to develop prepayment and interest rate scenarios for securities that have prepayment features. In limited instances where prices are not provided by pricing services or in rare instances when a manager may not agree with the pricing service, price quotes on a non-binding basis are obtained from investment brokers. The investment asset managers do not make any changes to prices received from either the pricing services or the investment brokers. In addition, the investment asset managers have procedures in place to review the reasonableness of the prices from the service providers and may request verification of the prices. In addition, the Company continually performs analytical reviews of price changes and tests the prices on a random basis to an independent pricing source. No material variances were noted during these price validation procedures. In limited situations, where financial markets are inactive or illiquid, the Company may use its own assumptions about future cash flows and risk-adjusted discount rates to determine fair value. Due to the unavailability of prices for fifty-one private placement securities, the investment manager's valuation committee valued the fifty 105,987 one 51,965 forty-two 86,536 The Company internally manages a public equity portfolio which had a fair value at September 30, 2017 and December 31, 2016 of $ 361,608 256,041 Equity securities denominated in U.S. currency with quoted prices in active markets for identical assets are categorized as level 1 since the quoted prices are directly observable. Equity securities traded on foreign exchanges are categorized as level 2 due to the added input of a foreign exchange conversion rate to determine fair or market value. The Company uses foreign currency exchange rates published by nationally recognized sources. All categories of fixed maturity securities listed in the tables below are generally categorized as level 2, since a particular security may not have traded but the pricing services are able to use valuation models with observable market inputs such as interest rate yield curves and prices for similar fixed maturity securities in terms of issuer, maturity and seniority. For foreign government securities and foreign corporate securities, the fair values provided by the third party pricing services in local currencies, and where applicable, are converted to U.S. dollars using currency exchange rates from nationally recognized sources. The fixed maturities with fair values categorized as level 3 result when prices are not available from the nationally recognized pricing services. The asset managers will then obtain non-binding price quotes for the securities from brokers. The single broker quotes are provided by market makers or broker-dealers who are recognized as market participants in the markets in which they are providing the quotes. The prices received from brokers are reviewed for reasonableness by the third party asset managers and the Company. If the broker quotes are for foreign denominated securities, the quotes are converted to U.S. dollars using currency exchange rates from nationally recognized sources. In limited circumstances when broker prices are not available for private placements, the Company will value the securities using comparable market information. The composition and valuation inputs for the presented fixed maturities categories are as follows: · U.S. Treasury securities and obligations of U.S. government agencies and corporations are primarily comprised of U.S. Treasury bonds and the fair value is based on observable market inputs such as quoted prices, reported trades, quoted prices for similar issuances or benchmark yields; · Obligations of U.S. states and political subdivisions are comprised of state and municipal bond issuances and the fair values are based on observable market inputs such as quoted market prices, quoted prices for similar securities, benchmark yields and credit spreads; · Corporate securities are primarily comprised of U.S. corporate and public utility bond issuances and the fair values are based on observable market inputs such as quoted market prices, quoted prices for similar securities, benchmark yields and credit spreads; · Asset-backed and mortgage-backed securities fair values are based on observable inputs such as quoted prices, reported trades, quoted prices for similar issuances or benchmark yields and cash flow models using observable inputs such as prepayment speeds, collateral performance and default spreads; · Foreign government securities are comprised of global non-U.S. sovereign bond issuances and the fair values are based on observable market inputs such as quoted market prices, quoted prices for similar securities and models with observable inputs such as benchmark yields and credit spreads and then, where applicable, converted to U.S. dollars using an exchange rate from a nationally recognized source; · Foreign corporate securities are comprised of global non-U.S. corporate bond issuances and the fair values are based on observable market inputs such as quoted market prices, quoted prices for similar securities and models with observable inputs such as benchmark yields and credit spreads and then, where applicable, converted to U.S. dollars using an exchange rate from a nationally recognized source. The Company sold seven two The Company's liability for equity index put options is categorized as level 3 since there is no active market for these equity put options. The fair values for these options are calculated by the Company using an industry accepted pricing model, Black-Scholes. The model inputs and assumptions are: risk free interest rates, equity market indexes values, volatilities and dividend yields and duration. The model results are then adjusted for the Company's credit default swap rate. All of these inputs and assumptions are updated quarterly. One of the option contacts is in British Pound Sterling so the fair value for this contract is converted to U.S. dollars using an exchange rate from a nationally recognized source. The following table presents the fair value measurement levels for all assets and liabilities, which the Company has recorded at fair value (fair and market value) as of the periods indicated: Fair Value Measurement Using: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Assets Inputs Inputs (Dollars in thousands) September 30, 2017 (Level 1) (Level 2) (Level 3) Assets: Fixed maturities, market value U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,146,869 $ - $ 1,146,869 $ - Obligations of U.S. States and political subdivisions 671,842 - 671,842 - Corporate securities 5,676,162 - 5,522,128 154,034 Asset-backed securities 556,397 - 556,397 - Mortgage-backed securities Commercial 252,791 - 252,791 - Agency residential 2,380,329 - 2,380,329 - Non-agency residential 517 - 517 - Foreign government securities 1,329,433 - 1,329,433 - Foreign corporate securities 2,763,835 - 2,759,917 3,918 Total fixed maturities, market value 14,778,175 - 14,620,223 157,952 Equity securities, market value 127,425 112,015 15,410 - Equity securities, fair value 1,141,146 1,094,754 46,392 - Liabilities: Equity index put option contracts $ 16,006 $ - $ - $ 16,006 There were no The following table presents the fair value measurement levels for all assets and liabilities, which the Company has recorded at fair value (fair and market value) as of the periods indicated: Fair Value Measurement Using: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Assets Inputs Inputs (Dollars in thousands) December 31, 2016 (Level 1) (Level 2) (Level 3) Assets: Fixed maturities, market value U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,130,315 $ - $ 1,130,315 $ - Obligations of U.S. States and political subdivisions 729,984 - 729,984 - Corporate securities 5,155,281 - 5,090,084 65,197 Asset-backed securities 488,648 - 488,648 - Mortgage-backed securities Commercial 306,932 - 306,932 - Agency residential 2,405,469 - 2,405,469 - Non-agency residential 641 - 641 - Foreign government securities 1,258,160 - 1,258,160 - Foreign corporate securities 2,631,978 - 2,629,440 2,538 Total fixed maturities, market value 14,107,408 - 14,039,673 67,735 Equity securities, market value 119,067 105,507 13,560 - Equity securities, fair value 1,010,085 949,523 60,562 - Liabilities: Equity index put option contracts $ 22,059 $ - $ - $ 22,059 In addition, $ 70,657 18,801 The following tables present the activity under Level 3, fair value measurements using significant unobservable inputs by asset type, for the periods indicated: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Corporate Foreign Corporate Foreign (Dollars in thousands) Securities Corporate Total Securities Corporate Total Beginning balance $ 138,105 $ 3,151 $ 141,256 $ 65,197 $ 2,538 $ 67,735 Total gains or (losses) (realized/unrealized) Included in earnings 283 209 492 1,208 313 1,521 Included in other comprehensive income (loss) 18 (184 ) (166 ) 161 (184 ) (23 ) Purchases, issuances and settlements 15,628 742 16,370 87,468 1,251 88,719 Transfers in and/or (out) of Level 3 - - - - - - Ending balance $ 154,034 $ 3,918 $ 157,952 $ 154,034 $ 3,918 $ 157,952 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ - $ - $ - $ - $ - $ - (Some amounts may not reconcile due to rounding.) Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Corporate Foreign Corporate Foreign (Dollars in thousands) Securities CMBS Corporate Total Securities CMBS Corporate Total Beginning balance $ 32,410 $ - $ 2,021 $ 34,431 $ 3,933 $ - $ 1,593 $ 5,526 Total gains or (losses) (realized/unrealized) Included in earnings (12 ) - 27 15 (22 ) - (970 ) (992 ) Included in other comprehensive income (loss) (48 ) (38 ) (1,285 ) (1,371 ) (81 ) (38 ) 140 21 Purchases, issuances and settlements 25,877 (44 ) 2,231 28,064 54,397 (44 ) 2,231 56,584 Transfers in and/or (out) of Level 3 (1,932 ) 3,947 - 2,015 (1,932 ) 3,947 - 2,015 Ending balance $ 56,295 $ 3,865 $ 2,994 $ 63,154 $ 56,295 $ 3,865 $ 2,994 $ 63,154 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ - $ - $ - $ - $ - $ - $ (997 ) $ (997 ) (Some amounts may not reconcile due to rounding.) The net transfers to/(from) level 3, fair value measurements using significant unobservable inputs were $ 0 2,015 The following table presents the activity under Level 3, fair value measurements using significant unobservable inputs for equity index put option contracts, for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Liabilities: Balance, beginning of period $ 18,662 $ 41,729 $ 22,059 $ 40,705 Total (gains) or losses (realized/unrealized) Included in earnings (2,656 ) (6,510 ) (6,052 ) (5,486 ) Included in other comprehensive income (loss) - - - - Purchases, issuances and settlements - - - - Transfers in and/or (out) of Level 3 - - - - Balance, end of period $ 16,006 $ 35,219 $ 16,006 $ 35,219 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to liabilities still held at the reporting date $ - $ - $ - $ - (Some amounts may not reconcile due to rounding.)

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Common Share [Abstract]
Earnings Per Common Share	7. EARNINGS PER COMMON SHARE Basic earnings per share are calculated by dividing net income by the weighted average number of common shares outstanding. Diluted earnings per share reflect the potential dilution that would occur if options granted under various share-based compensation plans were exercised resulting in the issuance of common shares that would participate in the earnings of the entity. Net income (loss) per common share has been computed as per below, based upon weighted average common basic and dilutive shares outstanding. The dilutive calculation is not applicable for the three and nine months ended September 30, 2017 due to net losses. Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands, except per share amounts) 2017 2016 2017 2016 Net income (loss) per share: Numerator Net income (loss) $ (639,374 ) $ 295,394 $ (102,057 ) $ 622,772 Less: dividends declared-common shares and nonvested common shares (51,302 ) (47,463 ) (153,887 ) (144,299 ) Undistributed earnings (690,676 ) 247,932 (255,944 ) 478,472 Percentage allocated to common shareholders (1) 100.0 % 98.9 % 100.0 % 98.9 % (690,676 ) 245,248 (255,944 ) 473,372 Add: dividends declared-common shareholders 51,302 46,985 153,887 142,839 Numerator for basic and diluted earnings per common share $ (639,374 ) $ 292,233 $ (102,057 ) $ 616,211 Denominator Denominator for basic earnings per weighted-average common shares 40,638 41,101 40,597 41,626 Effect of dilutive securities: Options 245 284 255 305 Denominator for diluted earnings per adjusted weighted-average common shares 40,883 41,386 40,852 41,931 Per common share net income (loss) Basic $ (15.73 ) $ 7.11 $ (2.51 ) $ 14.80 Diluted $ (15.73 ) $ 7.06 $ (2.51 ) $ 14.70 (1) Basic weighted-average common shares outstanding 40,638 41,101 40,597 41,626 Basic weighted-average common shares outstanding and nonvested common shares expected to vest 40,638 41,551 40,597 42,074 Percentage allocated to common shareholders 100.0 % 98.9 % 100.0 % 98.9 % (Some amounts may not reconcile due to rounding.) There were no All outstanding options expire on or between February 20, 2018 and September 19, 2022.

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments And Contingencies [Abstract]
Commitments And Contingencies	8. COMMITMENTS AND CONTINGENCIES In the ordinary course of business, the Company is involved in lawsuits, arbitrations and other formal and informal dispute resolution procedures, the outcomes of which will determine the Company's rights and obligations under insurance and reinsurance agreements. In some disputes, the Company seeks to enforce its rights under an agreement or to collect funds owing to it. In other matters, the Company is resisting attempts by others to collect funds or enforce alleged rights. These disputes arise from time to time and are ultimately resolved through both informal and formal means, including negotiated resolution, arbitration and litigation. In all such matters, the Company believes that its positions are legally and commercially reasonable. The Company considers the statuses of these proceedings when determining its reserves for unpaid loss and loss adjustment expenses. Aside from litigation and arbitrations related to these insurance and reinsurance agreements, the Company is not a party to any other material litigation or arbitration. The Company has entered into separate annuity agreements with The Prudential Insurance of America ("The Prudential") and an additional unaffiliated life insurance company in which the Company has either purchased annuity contracts or become the assignee of annuity proceeds that are meant to settle claim payment obligations in the future. In both instances, the Company would become contingently liable if either The Prudential or the unaffiliated life insurance company were unable to make payments related to the respective annuity contract. The table below presents the estimated cost to replace all such annuities for which the Company was contingently liable for the periods indicated: At September 30, At December 31, (Dollars in thousands) 2017 2016 The Prudential $ 144,331 $ 146,507 Unaffiliated life insurance company 33,769 33,860

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2017
Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss)	9. OTHER COMPREHENSIVE INCOME (LOSS) The following tables present the components of comprehensive income (loss) in the consolidated statements of operations for the periods indicated: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (Dollars in thousands) Before Tax Tax Effect Net of Tax Before Tax Tax Effect Net of Tax Unrealized appreciation (depreciation) ("URA(D)") on securities - temporary $ (3,197 ) $ (2,835 ) $ (6,032 ) $ 18,844 $ 3,699 $ 22,543 URA(D) on securities - OTTI 306 55 361 (5,189 ) 1,391 (3,798 ) Reclassification of net realized losses (gains) included in net income (loss) (6,598 ) 1,061 (5,537 ) (24,373 ) 7,644 (16,729 ) Foreign currency translation adjustments 96,022 (18,458 ) 77,564 148,395 (23,271 ) 125,124 Benefit plan actuarial net gain (loss) - - - - - - Reclassification of benefit plan liability amortization included in net income (loss) 2,107 (738 ) 1,369 8,273 (2,896 ) 5,377 Total other comprehensive income (loss) $ 88,640 $ (20,915 ) $ 67,725 $ 145,950 $ (13,433 ) $ 132,517 Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Before Tax Tax Effect Net of Tax Before Tax Tax Effect Net of Tax Unrealized appreciation (depreciation) ("URA(D)") on securities - temporary $ (5,972 ) $ (2,079 ) $ (8,051 ) $ 295,311 $ (42,643 ) $ 252,668 URA(D) on securities - OTTI (1,836 ) 855 (981 ) 7,088 (1,470 ) 5,618 Reclassification of net realized losses (gains) included in net income (loss) (5,045 ) 1,823 (3,222 ) 38,734 (11,023 ) 27,711 Foreign currency translation adjustments 1,393 1,423 2,816 32,601 (14,962 ) 17,639 Benefit plan actuarial net gain (loss) - - - - - - Reclassification of benefit plan liability amortization included in net income (loss) 1,951 (683 ) 1,268 6,076 (2,127 ) 3,949 Total other comprehensive income (loss) $ (9,510 ) $ 1,340 $ (8,170 ) $ 379,809 $ (72,224 ) $ 307,585 The following table presents details of the amounts reclassified from AOCI for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, Affected line item within the statements of AOCI component 2017 2016 2017 2016 operations and comprehensive income (loss) (Dollars in thousands) URA(D) on securities $ (6,598 ) $ (5,045 ) $ (24,373 ) $ 38,734 Other net realized capital gains (losses) 1,061 1,823 7,644 (11,023 ) Income tax expense (benefit) $ (5,537 ) $ (3,222 ) $ (16,729 ) $ 27,711 Net income (loss) Benefit plan net gain (loss) $ 2,107 $ 1,951 $ 8,273 $ 6,076 Other underwriting expenses (738 ) (683 ) (2,896 ) (2,127 ) Income tax expense (benefit) $ 1,369 $ 1,268 $ 5,377 $ 3,949 Net income (loss) The following table presents the components of accumulated other comprehensive income (loss), net of tax, in the consolidated balance sheets for the periods indicated: Nine Months Ended Twelve Months Ended September 30, December 31, (Dollars in thousands) 2017 2016 Beginning balance of URA (D) on securities $ 115,558 $ 42,811 Current period change in URA (D) of investments - temporary 5,814 66,802 Current period change in URA (D) of investments - non-credit OTTI (3,798 ) 5,945 Ending balance of URA (D) on securities 117,574 115,558 Beginning balance of foreign currency translation adjustments (266,818 ) (211,477 ) Current period change in foreign currency translation adjustments 125,124 (55,341 ) Ending balance of foreign currency translation adjustments (141,694 ) (266,818 ) Beginning balance of benefit plan net gain (loss) (65,504 ) (63,089 ) Current period change in benefit plan net gain (loss) 5,377 (2,415 ) Ending balance of benefit plan net gain (loss) (60,127 ) (65,504 ) Ending balance of accumulated other comprehensive income (loss) $ (84,247 ) $ (216,764 )

Credit Facilities

Credit Facilities	9 Months Ended
	Sep. 30, 2017
Credit Facilities [Abstract]
Credit Facilities	10. CREDIT FACILITIES The Company has two 1,000,000 Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Credit facility interest and fees incurred $ 105 $ 35 $ 315 $ 618 The terms and outstanding amounts for each facility are discussed below: Group Credit Facility Effective May 26, 2016, Group, Everest Reinsurance (Bermuda), Ltd. ("Bermuda Re") and Everest International Reinsurance, Ltd. ("Everest International"), both direct subsidiaries of Group, entered into a five year, $ 800,000 800,000 two 200,000 0.5 1.0 600,000 The Group Credit Facility requires Group to maintain a debt to capital ratio of not greater than 0.35 5,370,979 25 25 5,723,052 (Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Wells Fargo Bank Group Credit Facility Tranche One $ 200,000 $ - $ 200,000 $ - Tranche Two 600,000 507,916 12/31/2017 600,000 478,233 12/31/2017 Total Wells Fargo Bank Group Credit Facility $ 800,000 $ 507,916 $ 800,000 $ 478,233 Bermuda Re Letter of Credit Facility Effective December 30, 2016, Bermuda Re renewed its letter of credit issuance facility with Citibank N.A. referred to as the "Bermuda Re Letter of Credit Facility", which commitment is reconfirmed annually with updated fees. The current renewal of the Bermuda Re Letter of Credit Facility provides for the issuance of up to $ 200,000 0.35 0.45 60 0.15 The following table summarizes the outstanding letters of credit for the periods indicated: (Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Citibank Bilateral Letter of Credit Agreement $ 200,000 $ 3,672 11/24/2017 $ 200,000 $ 4,058 2/28/2017 68,353 12/31/2017 3,672 11/24/2017 3,297 2/28/2018 69,404 12/31/2017 353 8/30/2018 269 8/30/2018 4,019 12/31/2018 1,163 12/31/2018 105,485 9/30/2021 93,180 12/30/2020 Total Citibank Bilateral Agreement $ 200,000 $ 185,179 $ 200,000 $ 171,746 Everest International Credit Facility Effective November 9, 2016 four 145,000 0.1 0.35 The Everest International Credit Facility requires Group to maintain a debt to capital ratio of not greater than 0.35 5,326,009 70 25 25 5,723,052 The following table summarizes the outstanding letters of credit for the periods indicated: (Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Lloyds Bank plc £ 145,000 £ 140,964 12/31/2020 £ 140,000 £ 130,606 12/31/2019 - - - - Total Lloyds Bank plc Credit Facility £ 145,000 £ 140,964 £ 140,000 £ 130,606

Collateralized Reinsurance And

Collateralized Reinsurance And Trust Agreements	9 Months Ended
	Sep. 30, 2017
Collateralized Reinsurance And Trust Agreements [Abstract]
Collateralized Reinsurance And Trust Agreements	11. COLLATERALIZED REINSURANCE AND TRUST AGREEMENTS Certain subsidiaries of Group have established trust agreements, which effectively use the Company's investments as collateral, as security for assumed losses payable to certain non-affiliated ceding companies. At September 30, 2017, the total amount on deposit in trust accounts was $ 794,469 The Company reinsures some of its catastrophe exposures with the segregated accounts of Mt. Logan Re. Mt. Logan Re is a Class 3 insurer registered in Bermuda effective February 27, 2013 under The Segregated Accounts Companies Act 2000 and 100 The following table summarizes the premiums and losses that are ceded by the Company to Mt. Logan Re segregated accounts and assumed by the Company from Mt. Logan Re segregated accounts. Three Months Ended Nine Months Ended September 30, September 30, Mt. Logan Re Segregated Accounts 2017 2016 2017 2016 (Dollars in thousands) Ceded written premiums 64,003 65,093 160,949 157,939 Ceded earned premiums 55,708 53,007 154,191 143,856 Ceded losses and LAE 197,395 8,725 241,792 38,459 Assumed written premiums 2,587 5,032 9,082 11,666 Assumed earned premiums 2,587 5,032 9,082 11,666 Assumed losses and LAE - - - - Each segregated account is permitted to assume net risk exposures equal to the amount of its available posted collateral, which in the aggregate was $ 832,679 932,243 50,935 58,955 On April 24, 2014, the Company entered into two 250,000 200,000 On November 18, 2014, the Company entered into a collateralized reinsurance agreement with Kilimanjaro to provide the Company with catastrophe reinsurance coverage. This agreement is a multi-year reinsurance contract which covers specified earthquake events. The agreement provides up to $ 500,000 On December 1, 2015 the Company entered into two 300,000 325,000 On April 13, 2017 the Company entered into six three four 225,000 400,000 325,000 three five 50,000 75,000 175,000 Recoveries under these collateralized reinsurance agreements with Kilimanjaro are primarily dependent on estimated industry level insured losses from covered events, as well as, the geographic location of the events. The estimated industry level of insured losses is obtained from published estimates by an independent recognized authority on insured property losses. As of September 30, 2017, none of the published insured loss estimates for the 2017 catastrophe events have exceeded the single event retentions under the terms of the agreements that would result in a recovery. In addition, the aggregation of the to date published insured loss estimates for the 2017 covered events have not exceeded the aggregated retentions for recovery. However, if the published estimates for insured losses for the covered 2017 events increase or if there are additional covered events during the remainder of 2017, the aggregate losses may exceed the aggregate event retentions under the agreements, resulting in a recovery. Kilimanjaro has financed the various property catastrophe reinsurance coverages by issuing catastrophe bonds to unrelated, external investors. On April 24, 2014, Kilimanjaro issued $ 450,000 500,000 625,000 950,000 300,000

Senior Notes

Senior Notes	9 Months Ended
	Sep. 30, 2017
Senior Notes [Abstract]
Senior Notes	12. SENIOR NOTES The table below displays Holdings' outstanding senior notes. Market value is based on quoted market prices, but due to limited trading activity, these senior notes are considered Level 2 in the fair value hierarchy. September 30, 2017 December 31, 2016 Consolidated Balance Consolidated Balance (Dollars in thousands) Date Issued Date Due Principal Amounts Sheet Amount Market Value Sheet Amount Market Value 4.868 06/05/2014 06/01/2044 400,000 $ 396,804 $ 420,008 $ 396,714 $ 383,612 On June 5, 2014, Holdings issued $400,000 thousand of 30 Interest expense incurred in connection with these senior notes is as follows for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Interest expense incurred $ 4,868 $ 4,868 $ 14,604 $ 14,604

Long Term Subordinated Notes

Long Term Subordinated Notes	9 Months Ended
	Sep. 30, 2017
Long Term Subordinated Notes [Abstract]
Long Term Subordinated Notes	13. LONG TERM SUBORDINATED NOTES The table below displays Holdings' outstanding fixed to floating rate long term subordinated notes. Market value is based on quoted market prices, but due to limited trading activity, these subordinated notes are considered Level 2 in the fair value hierarchy. Maturity Date September 30, 2017 December 31, 2016 Original Consolidated Balance Consolidated Balance (Dollars in thousands) Date Issued Principal Amount Scheduled Final Sheet Amount Market Value Sheet Amount Market Value 6.6 04/26/2007 $ 400,000 05/15/2037 05/01/2067 $ 236,536 $ 221,380 $ 236,462 $ 204,636 During the fixed rate interest period from May 3, 2007 May 14, 2017 6.6 November 15, 2007 3.70 Holdings may redeem the long term subordinated notes on or after May 15, 2017, in whole or in part at 100 May 1, 2047 5.40 October 15, 2014 4.868 June 1, 2044 On March 19, 2009, Group announced the commencement of a cash tender offer for any and all of the 6.60% fixed to floating rate long term subordinated notes. Upon expiration of the tender offer, the Company had reduced its outstanding debt by $ 161,441 Interest expense incurred in connection with these long term subordinated notes is as follows for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Interest expense incurred $ 2,240 $ 3,937 $ 9,210 $ 11,811

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Reporting	14. SEGMENT REPORTING The U.S. Reinsurance operation writes property and casualty reinsurance and specialty lines of business, including Marine, Aviation, Surety and Accident and Health ("A&H") business, on both a treaty and facultative basis, through reinsurance brokers, as well as directly with ceding companies primarily within the U.S. The International operation writes non-U.S. property and casualty reinsurance through Everest Re's branches in Canada and Singapore and through offices in Brazil, Miami and New Jersey. The Bermuda operation provides reinsurance and insurance to worldwide property and casualty markets through brokers and directly with ceding companies from its Bermuda office and reinsurance to the United Kingdom and European markets through its UK branch and Ireland Re. The Insurance operation writes property and casualty insurance directly and through brokers, surplus lines brokers and general agents within the U.S. and Canada. These segments are managed independently, but conform with corporate guidelines with respect to pricing, risk management, control of aggregate catastrophe exposures, capital, investments and support operations. Management generally monitors and evaluates the financial performance of these operating segments based upon their underwriting results. Underwriting results include earned premium less losses and loss adjustment expenses ("LAE") incurred, commission and brokerage expenses and other underwriting expenses. We measure our underwriting results using ratios, in particular loss, commission and brokerage and other underwriting expense ratios, which, respectively, divide incurred losses, commissions and brokerage and other underwriting expenses by premiums earned. For inter-affiliate reinsurance and business written through the Lloyd's Syndicate, business is generally reported within the segment in which the business was first produced, consistent with how the business is managed. The Company does not maintain separate balance sheet data for its operating segments. Accordingly, the Company does not review and evaluate the financial results of its operating segments based upon balance sheet data. The following tables present the underwriting results for the operating segments for the periods indicated: Three Months Ended Nine Months Ended U.S. Reinsurance September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 908,256 $ 654,770 $ 1,962,207 $ 1,597,005 Net written premiums 809,298 678,848 1,711,934 1,491,155 Premiums earned $ 649,772 $ 519,160 $ 1,609,790 $ 1,478,974 Incurred losses and LAE 925,436 276,272 1,455,123 732,306 Commission and brokerage 113,449 116,667 328,230 354,608 Other underwriting expenses 12,095 14,265 40,624 39,856 Underwriting gain (loss) $ (401,208 ) $ 111,956 $ (214,187 ) $ 352,204 Three Months Ended Nine Months Ended International September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 344,805 $ 348,812 $ 931,008 $ 925,028 Net written premiums 330,761 316,207 848,792 799,908 Premiums earned $ 305,951 $ 282,442 $ 841,348 $ 823,493 Incurred losses and LAE 563,082 122,181 895,071 531,580 Commission and brokerage 68,441 78,384 199,438 209,348 Other underwriting expenses 8,307 11,030 27,601 26,822 Underwriting gain (loss) $ (333,879 ) $ 70,847 $ (280,762 ) $ 55,743 Three Months Ended Nine Months Ended Bermuda September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 311,781 $ 245,995 $ 870,473 $ 612,657 Net written premiums 287,591 229,373 810,437 562,128 Premiums earned $ 267,488 $ 215,761 $ 766,051 $ 610,466 Incurred losses and LAE 301,315 127,236 595,052 348,586 Commission and brokerage 83,861 59,605 205,770 169,413 Other underwriting expenses 9,049 8,785 27,551 26,290 Underwriting gain (loss) $ (126,737 ) $ 20,135 $ (62,322 ) $ 66,177 Three Months Ended Nine Months Ended Insurance September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 480,060 $ 533,039 $ 1,483,807 $ 1,364,465 Net written premiums 370,439 340,216 1,179,873 1,047,863 Premiums earned $ 375,664 $ 354,111 $ 1,063,464 $ 966,268 Incurred losses and LAE 420,249 260,479 896,899 732,261 Commission and brokerage 67,362 54,889 181,900 146,684 Other underwriting expenses 43,694 44,483 132,125 129,782 Underwriting gain (loss) $ (155,641 ) $ (5,740 ) $ (147,460 ) $ (42,459 ) The following table reconciles the underwriting results for the operating segments to income before taxes as reported in the consolidated statements of operations and comprehensive income (loss) for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Underwriting gain (loss) $ (1,017,465 ) $ 197,198 $ (704,731 ) $ 431,665 Net investment income 136,973 122,657 393,770 357,918 Net realized capital gains (losses) 41,535 380 119,531 (41,221 ) Net derivative gain (loss) 2,656 6,510 6,052 5,486 Corporate expenses (5,932 ) (6,400 ) (21,308 ) (21,403 ) Interest, fee and bond issue cost amortization expense (7,266 ) (8,893 ) (24,289 ) (27,194 ) Other income (expense) (54,568 ) 9,435 (59,146 ) (20,998 ) Income (loss) before taxes $ (904,067 ) $ 320,887 $ (290,121 ) $ 684,253 The Company produces business in the U.S., Bermuda and internationally. The net income deriving from and assets residing in the individual foreign countries in which the Company writes business are not identifiable in the Company's financial records. Based on gross written premium, the table below presents the largest country, other than the U.S., in which the Company writes business, for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 United Kingdom gross written premium $ 204,774 $ 182,786 $ 580,559 $ 511,994 No other country represented more than 5

Share-Based Compensation Plans

Share-Based Compensation Plans	9 Months Ended
	Sep. 30, 2017
Share-Based Compensation Plans [Abstract]
Share-Based Compensation Plans	15. SHARE-BASED COMPENSATION PLANS For the three months ended September 30, 2017, share-based compensation awards granted were 3,855 September 6, 2017 230.52

Retirement Benefits

Retirement Benefits	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Retirement Benefits	16. RETIREMENT BENEFITS The Company maintains both qualified and non-qualified defined benefit pension plans and a retiree health plan for its U.S. employees employed prior to April 1, 2010. Net periodic benefit cost for U.S. employees included the following components for the periods indicated: Pension Benefits Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Service cost $ 2,737 $ 2,731 $ 9,335 $ 8,524 Interest cost 2,509 2,371 7,060 7,093 Expected return on plan assets (3,263 ) (2,789 ) (9,572 ) (7,757 ) Amortization of prior service cost - - - - Amortization of net (income) loss 2,091 1,984 8,172 6,012 Net periodic benefit cost $ 4,074 $ 4,297 $ 14,995 $ 13,872 Other Benefits Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Service cost $ 392 $ 354 $ 1,273 $ 1,230 Interest cost 296 252 793 844 Amortization of prior service cost (33 ) (33 ) (98 ) (33 ) Amortization of net (income) loss 48 - 199 96 Net periodic benefit cost $ 703 $ 573 $ 2,167 $ 2,137 (Some amounts may not reconcile due to rounding.) The Company contributed $ 10,000 30,000

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Taxes [Abstract]
Income Taxes	17. INCOME TAXES The Company is domiciled in Bermuda and has significant subsidiaries and/or branches in Canada, Ireland, Singapore, the United Kingdom, and the United States. The Company's Bermuda domiciled subsidiaries are exempt from income taxation under Bermuda law until 2035. The Company's non-Bermudian subsidiaries and branches are subject to income taxation at varying rates in their respective domiciles. The Company generally applies the estimated annual effective tax rate approach for calculating its tax provision for interim periods as prescribed by ASC 740-270, Interim Reporting. Under the estimated annual effective tax rate approach, the estimated annual effective tax rate is applied to the interim year-to-date pre-tax income/loss to determine the income tax expense or benefit for the year-to-date period. If the annual effective tax rate approach produces a year-to-date tax benefit which exceeds the amount which is estimated to be recoverable for the full year, then the tax benefit for the interim reporting period will be limited as prescribed under ASC 740-270 to the estimated recoverable based on the year-to-date result. The tax expense or benefit for the quarter represents the difference between the year-to-date tax expense or benefit for the current year-to-date period less such amount for the immediately preceding year-to-date period. Management considers the impact of all known events in its estimation of the Company's annual pre-tax income/loss and effective tax rate.

Dispositions

Dispositions	9 Months Ended
	Sep. 30, 2017
Dispositions [Abstract]
Dispositions	18. DISPOSITION On August 24, 2016, the Company sold Heartland, its crop Managing General Agent to CGB for $ 49,000 12,942

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	19. SUBSEQUENT EVENTS The Company has evaluated known recognized and non-recognized subsequent events. In October 2017, Hurricane Nate impacted the Southern United States and Central America and Hurricane Ophelia impacted Ireland, the United Kingdom and Northern Europe. Also, in October 2017, a number of wildfires affected California. Due to the recentness of these events, the Company is unable to estimate the amount of losses related to Hurricane Nate, Hurricane Ophelia or the California wildfires at this time. However, the Company anticipates that these events will adversely impact the fourth quarter 2017 financial results.

Basis Of Presentation (Tables)

Basis Of Presentation (Tables)	9 Months Ended
	Sep. 30, 2017
Basis Of Presentation[Abstract]
Schedule of Effect of Newly Adopted Accounting Policies, Cash Flow	Consolidated Statements of Cash Flows: Nine Months Ended September 30, 2016 Effect of adoption of As previously new accounting reported policy As adopted (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES: Change in other assets and liabilities, net $ (164,782 ) $ 10,017 $ (154,765 ) Net cash provided by (used in) operating activities 950,731 10,017 960,748 CASH FLOWS FROM FINANCING ACTIVITIES: Cost of shares withheld for taxes on settlements of share-based compensation awards - (10,017 ) (10,017 ) Net cash provided by (used in) financing activities (518,210 ) (10,017 ) (528,227 )

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments [Abstract]
Summary Of Unrealized Appreciation (Depreciation) Of Available For Sale, Fixed Maturity And Equity Security Investments	At September 30, 2017 Amortized Unrealized Unrealized Market OTTI in AOCI (Dollars in thousands) Cost Appreciation Depreciation Value (a) Fixed maturity securities U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,141,002 $ 12,475 $ (6,608 ) $ 1,146,869 $ - Obligations of U.S. states and political subdivisions 652,525 24,061 (4,744 ) 671,842 - Corporate securities 5,599,904 108,072 (31,814 ) 5,676,162 2,902 Asset-backed securities 555,451 1,390 (444 ) 556,397 - Mortgage-backed securities Commercial 253,154 1,462 (1,825 ) 252,791 - Agency residential 2,390,238 13,680 (23,589 ) 2,380,329 - Non-agency residential 519 42 (44 ) 517 - Foreign government securities 1,317,697 46,225 (34,489 ) 1,329,433 182 Foreign corporate securities 2,716,264 89,202 (41,631 ) 2,763,835 961 Total fixed maturity securities $ 14,626,754 $ 296,609 $ (145,188 ) $ 14,778,175 $ 4,045 Equity securities $ 128,116 $ 2,542 $ (3,233 ) $ 127,425 $ - At December 31, 2016 Amortized Unrealized Unrealized Market OTTI in AOCI (Dollars in thousands) Cost Appreciation Depreciation Value (a) Fixed maturity securities U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,115,208 $ 20,410 $ (5,303 ) $ 1,130,315 $ - Obligations of U.S. states and political subdivisions 723,938 18,016 (11,970 ) 729,984 - Corporate securities 5,059,388 131,651 (35,758 ) 5,155,281 7,936 Asset-backed securities 488,824 1,110 (1,286 ) 488,648 - Mortgage-backed securities Commercial 308,827 1,983 (3,878 ) 306,932 - Agency residential 2,415,901 17,478 (27,910 ) 2,405,469 - Non-agency residential 642 44 (45 ) 641 - Foreign government securities 1,254,175 61,226 (57,241 ) 1,258,160 115 Foreign corporate securities 2,565,710 130,714 (64,446 ) 2,631,978 1,184 Total fixed maturity securities $ 13,932,613 $ 382,632 $ (207,837 ) $ 14,107,408 $ 9,235 Equity securities $ 129,553 $ 2,298 $ (12,784 ) $ 119,067 $ - (a) Represents the amount of OTTI recognized in AOCI. Amount includes unrealized gains and losses on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date
Summary Of Amortized Cost And Market Value Of Fixed Maturity Securities, By Contractual Maturity	At September 30, 2017 At December 31, 2016 Amortized Market Amortized Market (Dollars in thousands) Cost Value Cost Value Fixed maturity securities – available for sale: Due in one year or less $ 1,091,257 $ 1,095,288 $ 956,945 $ 966,970 Due after one year through five years 7,267,248 7,334,494 6,769,585 6,870,056 Due after five years through ten years 2,096,762 2,124,265 2,020,215 2,052,733 Due after ten years 972,125 1,034,094 971,674 1,015,959 Asset-backed securities 555,451 556,397 488,824 488,648 Mortgage-backed securities: Commercial 253,154 252,791 308,827 306,932 Agency residential 2,390,238 2,380,329 2,415,901 2,405,469 Non-agency residential 519 517 642 641 Total fixed maturity securities $ 14,626,754 $ 14,778,175 $ 13,932,613 $ 14,107,408
Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Increase (decrease) during the period between the market value and cost of investments carried at market value, and deferred taxes thereon: Fixed maturity securities $ (13,993 ) $ (13,544 ) $ (18,184 ) $ 324,147 Fixed maturity securities, other-than-temporary impairment 306 (1,836 ) (5,189 ) 7,088 Equity securities 2,603 2,527 9,795 9,898 Other invested assets 1,595 - 2,860 - Change in unrealized appreciation (depreciation), pre-tax (9,489 ) (12,853 ) (10,718 ) 341,133 Deferred tax benefit (expense) (1,774 ) (256 ) 11,343 (53,666 ) Deferred tax benefit (expense), other-than-temporary impairment 55 855 1,391 (1,470 ) Change in unrealized appreciation (depreciation), net of deferred taxes, included in shareholders' equity $ (11,208 ) $ (12,254 ) $ 2,016 $ 285,997
Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Security Type	Duration of Unrealized Loss at September 30, 2017 By Security Type Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities - available for sale U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 376,128 $ (4,865 ) $ 53,039 $ (1,743 ) $ 429,167 $ (6,608 ) Obligations of U.S. states and political subdivisions 89,509 (2,104 ) 67,956 (2,640 ) 157,465 (4,744 ) Corporate securities 1,214,762 (20,914 ) 283,985 (10,900 ) 1,498,747 (31,814 ) Asset-backed securities 189,752 (369 ) 6,262 (75 ) 196,014 (444 ) Mortgage-backed securities Commercial 63,101 (540 ) 40,432 (1,285 ) 103,533 (1,825 ) Agency residential 1,345,113 (13,416 ) 450,890 (10,173 ) 1,796,003 (23,589 ) Non-agency residential - - 77 (44 ) 77 (44 ) Foreign government securities 385,494 (14,007 ) 258,478 (20,482 ) 643,972 (34,489 ) Foreign corporate securities 660,017 (17,136 ) 312,821 (24,495 ) 972,838 (41,631 ) Total fixed maturity securities $ 4,323,876 $ (73,351 ) $ 1,473,940 $ (71,837 ) $ 5,797,816 $ (145,188 ) Equity securities - - 112,015 (3,233 ) 112,015 (3,233 ) Total $ 4,323,876 $ (73,351 ) $ 1,585,955 $ (75,070 ) $ 5,909,831 $ (148,421 ) Duration of Unrealized Loss at December 31, 2016 By Security Type Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities - available for sale U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 638,740 $ (5,303 ) $ - $ - $ 638,740 $ (5,303 ) Obligations of U.S. states and political subdivisions 221,088 (11,486 ) 564 (484 ) 221,652 (11,970 ) Corporate securities 1,360,743 (24,023 ) 177,153 (11,735 ) 1,537,896 (35,758 ) Asset-backed securities 150,023 (565 ) 18,786 (721 ) 168,809 (1,286 ) Mortgage-backed securities Commercial 143,554 (3,223 ) 7,184 (655 ) 150,738 (3,878 ) Agency residential 1,618,372 (22,461 ) 189,665 (5,449 ) 1,808,037 (27,910 ) Non-agency residential - - 113 (45 ) 113 (45 ) Foreign government securities 360,289 (12,041 ) 236,820 (45,200 ) 597,109 (57,241 ) Foreign corporate securities 687,599 (12,769 ) 295,500 (51,677 ) 983,099 (64,446 ) Total fixed maturity securities $ 5,180,408 $ (91,871 ) $ 925,785 $ (115,966 ) $ 6,106,193 $ (207,837 ) Equity securities - - 105,507 (12,784 ) 105,507 (12,784 ) Total $ 5,180,408 $ (91,871 ) $ 1,031,292 $ (128,750 ) $ 6,211,700 $ (220,621 )
Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Contractual Maturity	Duration of Unrealized Loss at September 30, 2017 By Maturity Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities Due in one year or less $ 270,695 $ (848 ) $ 123,092 $ (13,069 ) $ 393,787 $ (13,917 ) Due in one year through five years 1,680,251 (31,686 ) 644,557 (37,591 ) 2,324,808 (69,277 ) Due in five years through ten years 639,836 (22,619 ) 136,548 (6,469 ) 776,384 (29,088 ) Due after ten years 135,128 (3,873 ) 72,082 (3,131 ) 207,210 (7,004 ) Asset-backed securities 189,752 (369 ) 6,262 (75 ) 196,014 (444 ) Mortgage-backed securities 1,408,214 (13,956 ) 491,399 (11,502 ) 1,899,613 (25,458 ) Total fixed maturity securities $ 4,323,876 $ (73,351 ) $ 1,473,940 $ (71,837 ) $ 5,797,816 $ (145,188 ) Duration of Unrealized Loss at December 31, 2016 By Maturity Less than 12 months Greater than 12 months Total Gross Gross Gross Unrealized Unrealized Unrealized (Dollars in thousands) Market Value Depreciation Market Value Depreciation Market Value Depreciation Fixed maturity securities Due in one year or less $ 178,281 $ (1,122 ) $ 78,153 $ (14,318 ) $ 256,434 $ (15,440 ) Due in one year through five years 2,123,113 (26,263 ) 538,130 (84,803 ) 2,661,243 (111,066 ) Due in five years through ten years 680,334 (22,555 ) 86,631 (8,754 ) 766,965 (31,309 ) Due after ten years 286,731 (15,682 ) 7,123 (1,221 ) 293,854 (16,903 ) Asset-backed securities 150,023 (565 ) 18,786 (721 ) 168,809 (1,286 ) Mortgage-backed securities 1,761,926 (25,684 ) 196,962 (6,149 ) 1,958,888 (31,833 ) Total fixed maturity securities $ 5,180,408 $ (91,871 ) $ 925,785 $ (115,966 ) $ 6,106,193 $ (207,837 )
Summary Of Components Of Net Investment Income	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Fixed maturities $ 107,969 $ 100,752 $ 319,336 $ 306,128 Equity securities 8,590 9,905 25,701 31,967 Short-term investments and cash 974 475 2,439 1,220 Other invested assets Limited partnerships 23,315 17,077 54,373 33,922 Other 2,095 1,033 6,652 1,334 Gross investment income before adjustments 142,943 129,242 408,501 374,571 Funds held interest income (expense) 2,284 1,538 7,156 5,818 Future policy benefit reserve income (expense) (280 ) (517 ) (1,015 ) (1,243 ) Gross investment income 144,947 130,263 414,642 379,146 Investment expenses (7,974 ) (7,606 ) (20,872 ) (21,228 ) Net investment income $ 136,973 $ 122,657 $ 393,770 $ 357,918
Summary Of Components Of Net Realized Capital Gains (Losses)	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Fixed maturity securities, market value: Other-than-temporary impairments $ (1,485 ) $ (867 ) $ (5,188 ) $ (31,130 ) Gains (losses) from sales 7,998 5,912 32,913 (7,670 ) Fixed maturity securities, fair value: Gains (losses) from sales - (1 ) - (1,855 ) Gains (losses) from fair value adjustments - 42 - 1,381 Equity securities, market value: Gains (losses) from sales - - (3,436 ) 65 Equity securities, fair value: Gains (losses) from sales (1,525 ) 5,850 3,796 (10,266 ) Gains (losses) from fair value adjustments 36,463 17,475 91,367 36,284 Sale of subsidiary - (28,032 ) - (28,032 ) Other invested assets 85 - 84 - Short-term investments gain (loss) (1 ) 1 (5 ) 2 Total net realized capital gains (losses) $ 41,535 $ 380 $ 119,531 $ (41,221 )
Summary Of Gross Gains (Losses) From Sales Of Fixed Maturity And Equity Securities	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Proceeds from sales of fixed maturity securities $ 700,728 $ 293,998 $ 1,691,937 $ 890,349 Gross gains from sales 13,743 15,028 46,321 32,674 Gross losses from sales (5,745 ) (9,117 ) (13,408 ) (42,199 ) Proceeds from sales of equity securities $ 57,861 $ 112,451 $ 334,889 $ 542,715 Gross gains from sales 2,258 7,308 14,351 14,040 Gross losses from sales (3,783 ) (1,458 ) (13,991 ) (24,241 )

Reserve For Losses, LAE And F29

Reserve For Losses, LAE And Future Policy Benefit Reserve (Tables)	9 Months Ended
	Sep. 30, 2017
Reserve For Losses LAE And Future Policy Benefit Reserve [Abstract]
Summary Of Activity In The Reserve For Losses And LAE	Nine Months Ended Twelve Months Ended September 30, December 31, (Dollars in thousands) 2017 2016 Gross reserves at beginning of period $ 10,312,313 $ 9,951,798 Less reinsurance recoverables (990,862 ) (881,503 ) Net reserves at beginning of period 9,321,451 9,070,295 Incurred related to: Current year 3,843,434 3,434,964 Prior years (1,289 ) (295,335 ) Total incurred losses and LAE 3,842,145 3,139,629 Paid related to: Current year 948,897 745,642 Prior years 1,265,713 2,042,972 Total paid losses and LAE 2,214,610 2,788,614 Foreign exchange/translation adjustment 208,246 (99,859 ) Net reserves at end of period 11,157,232 9,321,451 Plus reinsurance recoverables 1,298,125 990,862 Gross reserves at end of period $ 12,455,357 $ 10,312,313

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2017
Derivatives [Abstract]
Summary Of The Fair Value Of The Equity Index Put Options	(Dollars in thousands) Derivatives not designated as Location of fair value At At hedging instruments in balance sheets September 30, 2017 December 31, 2016 Equity index put option contracts Equity index put option liability $ 16,006 $ 22,059 Total $ 16,006 $ 22,059 The change in fair value of the equity index put option contracts can be found in the Company's statement of operations and comprehensive income (loss) as follows: (Dollars in thousands) For the Three Months Ended For the Nine Months Ended Derivatives not designated as Location of gain (loss) in statements of September 30, September 30, hedging instruments operations and comprehensive income (loss) 2017 2016 2017 2016 Equity index put option contracts Net derivative gain (loss) $ 2,656 $ 6,510 $ 6,052 $ 5,486 Total $ 2,656 $ 6,510 $ 6,052 $ 5,486

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value [Abstract]
Fair Value Measurement Levels For All Assets And Liabilities	Fair Value Measurement Using: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Assets Inputs Inputs (Dollars in thousands) September 30, 2017 (Level 1) (Level 2) (Level 3) Assets: Fixed maturities, market value U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,146,869 $ - $ 1,146,869 $ - Obligations of U.S. States and political subdivisions 671,842 - 671,842 - Corporate securities 5,676,162 - 5,522,128 154,034 Asset-backed securities 556,397 - 556,397 - Mortgage-backed securities Commercial 252,791 - 252,791 - Agency residential 2,380,329 - 2,380,329 - Non-agency residential 517 - 517 - Foreign government securities 1,329,433 - 1,329,433 - Foreign corporate securities 2,763,835 - 2,759,917 3,918 Total fixed maturities, market value 14,778,175 - 14,620,223 157,952 Equity securities, market value 127,425 112,015 15,410 - Equity securities, fair value 1,141,146 1,094,754 46,392 - Liabilities: Equity index put option contracts $ 16,006 $ - $ - $ 16,006 Fair Value Measurement Using: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Assets Inputs Inputs (Dollars in thousands) December 31, 2016 (Level 1) (Level 2) (Level 3) Assets: Fixed maturities, market value U.S. Treasury securities and obligations of U.S. government agencies and corporations $ 1,130,315 $ - $ 1,130,315 $ - Obligations of U.S. States and political subdivisions 729,984 - 729,984 - Corporate securities 5,155,281 - 5,090,084 65,197 Asset-backed securities 488,648 - 488,648 - Mortgage-backed securities Commercial 306,932 - 306,932 - Agency residential 2,405,469 - 2,405,469 - Non-agency residential 641 - 641 - Foreign government securities 1,258,160 - 1,258,160 - Foreign corporate securities 2,631,978 - 2,629,440 2,538 Total fixed maturities, market value 14,107,408 - 14,039,673 67,735 Equity securities, market value 119,067 105,507 13,560 - Equity securities, fair value 1,010,085 949,523 60,562 - Liabilities: Equity index put option contracts $ 22,059 $ - $ - $ 22,059
Activity Under Level 3, Fair Value Measurements Using Significant Unobservable Inputs By Asset Type	Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Corporate Foreign Corporate Foreign (Dollars in thousands) Securities Corporate Total Securities Corporate Total Beginning balance $ 138,105 $ 3,151 $ 141,256 $ 65,197 $ 2,538 $ 67,735 Total gains or (losses) (realized/unrealized) Included in earnings 283 209 492 1,208 313 1,521 Included in other comprehensive income (loss) 18 (184 ) (166 ) 161 (184 ) (23 ) Purchases, issuances and settlements 15,628 742 16,370 87,468 1,251 88,719 Transfers in and/or (out) of Level 3 - - - - - - Ending balance $ 154,034 $ 3,918 $ 157,952 $ 154,034 $ 3,918 $ 157,952 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ - $ - $ - $ - $ - $ - (Some amounts may not reconcile due to rounding.) Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Corporate Foreign Corporate Foreign (Dollars in thousands) Securities CMBS Corporate Total Securities CMBS Corporate Total Beginning balance $ 32,410 $ - $ 2,021 $ 34,431 $ 3,933 $ - $ 1,593 $ 5,526 Total gains or (losses) (realized/unrealized) Included in earnings (12 ) - 27 15 (22 ) - (970 ) (992 ) Included in other comprehensive income (loss) (48 ) (38 ) (1,285 ) (1,371 ) (81 ) (38 ) 140 21 Purchases, issuances and settlements 25,877 (44 ) 2,231 28,064 54,397 (44 ) 2,231 56,584 Transfers in and/or (out) of Level 3 (1,932 ) 3,947 - 2,015 (1,932 ) 3,947 - 2,015 Ending balance $ 56,295 $ 3,865 $ 2,994 $ 63,154 $ 56,295 $ 3,865 $ 2,994 $ 63,154 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ - $ - $ - $ - $ - $ - $ (997 ) $ (997 ) (Some amounts may not reconcile due to rounding.)
Fair Value Measurements Using Significant Unobservable Inputs For Equity Index Put Option Contracts	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Liabilities: Balance, beginning of period $ 18,662 $ 41,729 $ 22,059 $ 40,705 Total (gains) or losses (realized/unrealized) Included in earnings (2,656 ) (6,510 ) (6,052 ) (5,486 ) Included in other comprehensive income (loss) - - - - Purchases, issuances and settlements - - - - Transfers in and/or (out) of Level 3 - - - - Balance, end of period $ 16,006 $ 35,219 $ 16,006 $ 35,219 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to liabilities still held at the reporting date $ - $ - $ - $ - (Some amounts may not reconcile due to rounding.)

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Common Share [Abstract]
Schedule Of Net Income (Loss) Per Common Share	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands, except per share amounts) 2017 2016 2017 2016 Net income (loss) per share: Numerator Net income (loss) $ (639,374 ) $ 295,394 $ (102,057 ) $ 622,772 Less: dividends declared-common shares and nonvested common shares (51,302 ) (47,463 ) (153,887 ) (144,299 ) Undistributed earnings (690,676 ) 247,932 (255,944 ) 478,472 Percentage allocated to common shareholders (1) 100.0 % 98.9 % 100.0 % 98.9 % (690,676 ) 245,248 (255,944 ) 473,372 Add: dividends declared-common shareholders 51,302 46,985 153,887 142,839 Numerator for basic and diluted earnings per common share $ (639,374 ) $ 292,233 $ (102,057 ) $ 616,211 Denominator Denominator for basic earnings per weighted-average common shares 40,638 41,101 40,597 41,626 Effect of dilutive securities: Options 245 284 255 305 Denominator for diluted earnings per adjusted weighted-average common shares 40,883 41,386 40,852 41,931 Per common share net income (loss) Basic $ (15.73 ) $ 7.11 $ (2.51 ) $ 14.80 Diluted $ (15.73 ) $ 7.06 $ (2.51 ) $ 14.70 (1) Basic weighted-average common shares outstanding 40,638 41,101 40,597 41,626 Basic weighted-average common shares outstanding and nonvested common shares expected to vest 40,638 41,551 40,597 42,074 Percentage allocated to common shareholders 100.0 % 98.9 % 100.0 % 98.9 % (Some amounts may not reconcile due to rounding.)

Commitments And Contingencies (

Commitments And Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments And Contingencies [Abstract]
Summary Of Estimated Cost To Replace Annuities For Contingent Liability	At September 30, At December 31, (Dollars in thousands) 2017 2016 The Prudential $ 144,331 $ 146,507 Unaffiliated life insurance company 33,769 33,860

Other Comprehensive Income (L34

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2017
Other Comprehensive Income (Loss) [Abstract]
Components Of Comprehensive Income (Loss) In The Consolidated Statements Of Operations	Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (Dollars in thousands) Before Tax Tax Effect Net of Tax Before Tax Tax Effect Net of Tax Unrealized appreciation (depreciation) ("URA(D)") on securities - temporary $ (3,197 ) $ (2,835 ) $ (6,032 ) $ 18,844 $ 3,699 $ 22,543 URA(D) on securities - OTTI 306 55 361 (5,189 ) 1,391 (3,798 ) Reclassification of net realized losses (gains) included in net income (loss) (6,598 ) 1,061 (5,537 ) (24,373 ) 7,644 (16,729 ) Foreign currency translation adjustments 96,022 (18,458 ) 77,564 148,395 (23,271 ) 125,124 Benefit plan actuarial net gain (loss) - - - - - - Reclassification of benefit plan liability amortization included in net income (loss) 2,107 (738 ) 1,369 8,273 (2,896 ) 5,377 Total other comprehensive income (loss) $ 88,640 $ (20,915 ) $ 67,725 $ 145,950 $ (13,433 ) $ 132,517 Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Before Tax Tax Effect Net of Tax Before Tax Tax Effect Net of Tax Unrealized appreciation (depreciation) ("URA(D)") on securities - temporary $ (5,972 ) $ (2,079 ) $ (8,051 ) $ 295,311 $ (42,643 ) $ 252,668 URA(D) on securities - OTTI (1,836 ) 855 (981 ) 7,088 (1,470 ) 5,618 Reclassification of net realized losses (gains) included in net income (loss) (5,045 ) 1,823 (3,222 ) 38,734 (11,023 ) 27,711 Foreign currency translation adjustments 1,393 1,423 2,816 32,601 (14,962 ) 17,639 Benefit plan actuarial net gain (loss) - - - - - - Reclassification of benefit plan liability amortization included in net income (loss) 1,951 (683 ) 1,268 6,076 (2,127 ) 3,949 Total other comprehensive income (loss) $ (9,510 ) $ 1,340 $ (8,170 ) $ 379,809 $ (72,224 ) $ 307,585
Reclassification From Accumulated Other Comprehensive Income	Three Months Ended Nine Months Ended September 30, September 30, Affected line item within the statements of AOCI component 2017 2016 2017 2016 operations and comprehensive income (loss) (Dollars in thousands) URA(D) on securities $ (6,598 ) $ (5,045 ) $ (24,373 ) $ 38,734 Other net realized capital gains (losses) 1,061 1,823 7,644 (11,023 ) Income tax expense (benefit) $ (5,537 ) $ (3,222 ) $ (16,729 ) $ 27,711 Net income (loss) Benefit plan net gain (loss) $ 2,107 $ 1,951 $ 8,273 $ 6,076 Other underwriting expenses (738 ) (683 ) (2,896 ) (2,127 ) Income tax expense (benefit) $ 1,369 $ 1,268 $ 5,377 $ 3,949 Net income (loss)
Components Of Accumulated Other Comprehensive Income (Loss), Net Of Tax, In The Consolidated Balance Sheets	Nine Months Ended Twelve Months Ended September 30, December 31, (Dollars in thousands) 2017 2016 Beginning balance of URA (D) on securities $ 115,558 $ 42,811 Current period change in URA (D) of investments - temporary 5,814 66,802 Current period change in URA (D) of investments - non-credit OTTI (3,798 ) 5,945 Ending balance of URA (D) on securities 117,574 115,558 Beginning balance of foreign currency translation adjustments (266,818 ) (211,477 ) Current period change in foreign currency translation adjustments 125,124 (55,341 ) Ending balance of foreign currency translation adjustments (141,694 ) (266,818 ) Beginning balance of benefit plan net gain (loss) (65,504 ) (63,089 ) Current period change in benefit plan net gain (loss) 5,377 (2,415 ) Ending balance of benefit plan net gain (loss) (60,127 ) (65,504 ) Ending balance of accumulated other comprehensive income (loss) $ (84,247 ) $ (216,764 )

Credit Facilities (Tables)

Credit Facilities (Tables)	9 Months Ended
	Sep. 30, 2017
Line of Credit Facility [Line Items]
Summary Of Costs Incurred Connection With Credit Facilities	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Credit facility interest and fees incurred $ 105 $ 35 $ 315 $ 618
Wells Fargo Bank Group Credit Facility [Member]
Line of Credit Facility [Line Items]
Summary Of Outstanding Letters Of Credit And/Or Borrowings	(Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Wells Fargo Bank Group Credit Facility Tranche One $ 200,000 $ - $ 200,000 $ - Tranche Two 600,000 507,916 12/31/2017 600,000 478,233 12/31/2017 Total Wells Fargo Bank Group Credit Facility $ 800,000 $ 507,916 $ 800,000 $ 478,233
Citibank Bilateral Agreement [Member]
Line of Credit Facility [Line Items]
Summary Of Outstanding Letters Of Credit And/Or Borrowings	(Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Citibank Bilateral Letter of Credit Agreement $ 200,000 $ 3,672 11/24/2017 $ 200,000 $ 4,058 2/28/2017 68,353 12/31/2017 3,672 11/24/2017 3,297 2/28/2018 69,404 12/31/2017 353 8/30/2018 269 8/30/2018 4,019 12/31/2018 1,163 12/31/2018 105,485 9/30/2021 93,180 12/30/2020 Total Citibank Bilateral Agreement $ 200,000 $ 185,179 $ 200,000 $ 171,746
Lloyds Bank plc Credit Facility [Member]
Line of Credit Facility [Line Items]
Summary Of Outstanding Letters Of Credit And/Or Borrowings	(Dollars in thousands) At September 30, 2017 At December 31, 2016 Bank Commitment In Use Date of Expiry Commitment In Use Date of Expiry Lloyds Bank plc £ 145,000 £ 140,964 12/31/2020 £ 140,000 £ 130,606 12/31/2019 - - - - Total Lloyds Bank plc Credit Facility £ 145,000 £ 140,964 £ 140,000 £ 130,606

Collateralized Reinsurance An36

Collateralized Reinsurance And Trust Agreements (Tables)	9 Months Ended
	Sep. 30, 2017
Collateralized Reinsurance And Trust Agreements [Abstract]
Premiums And Losses Ceded By The Company To Affiliate	Three Months Ended Nine Months Ended September 30, September 30, Mt. Logan Re Segregated Accounts 2017 2016 2017 2016 (Dollars in thousands) Ceded written premiums 64,003 65,093 160,949 157,939 Ceded earned premiums 55,708 53,007 154,191 143,856 Ceded losses and LAE 197,395 8,725 241,792 38,459 Assumed written premiums 2,587 5,032 9,082 11,666 Assumed earned premiums 2,587 5,032 9,082 11,666 Assumed losses and LAE - - - -

Senior Notes (Tables)

Senior Notes (Tables)	9 Months Ended
	Sep. 30, 2017
Senior Notes [Abstract]
Schedule Of Outstanding Senior Notes	September 30, 2017 December 31, 2016 Consolidated Balance Consolidated Balance (Dollars in thousands) Date Issued Date Due Principal Amounts Sheet Amount Market Value Sheet Amount Market Value 4.868 06/05/2014 06/01/2044 400,000 $ 396,804 $ 420,008 $ 396,714 $ 383,612
Schedule Of Interest Expense Incurred In Connection With Senior Notes	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Interest expense incurred $ 4,868 $ 4,868 $ 14,604 $ 14,604

Long Term Subordinated Notes (T

Long Term Subordinated Notes (Tables)	9 Months Ended
	Sep. 30, 2017
Long Term Subordinated Notes [Abstract]
Schedule Of Outstanding Fixed To Floating Rate Long Term Subordinated Notes	Maturity Date September 30, 2017 December 31, 2016 Original Consolidated Balance Consolidated Balance (Dollars in thousands) Date Issued Principal Amount Scheduled Final Sheet Amount Market Value Sheet Amount Market Value 6.6 04/26/2007 $ 400,000 05/15/2037 05/01/2067 $ 236,536 $ 221,380 $ 236,462 $ 204,636
Schedule Of Interest Expense Incurred In Connection With Long Term Subordinated Notes	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Interest expense incurred $ 2,240 $ 3,937 $ 9,210 $ 11,811

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule Of Underwriting Results For Operating Segments	Three Months Ended Nine Months Ended U.S. Reinsurance September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 908,256 $ 654,770 $ 1,962,207 $ 1,597,005 Net written premiums 809,298 678,848 1,711,934 1,491,155 Premiums earned $ 649,772 $ 519,160 $ 1,609,790 $ 1,478,974 Incurred losses and LAE 925,436 276,272 1,455,123 732,306 Commission and brokerage 113,449 116,667 328,230 354,608 Other underwriting expenses 12,095 14,265 40,624 39,856 Underwriting gain (loss) $ (401,208 ) $ 111,956 $ (214,187 ) $ 352,204 Three Months Ended Nine Months Ended International September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 344,805 $ 348,812 $ 931,008 $ 925,028 Net written premiums 330,761 316,207 848,792 799,908 Premiums earned $ 305,951 $ 282,442 $ 841,348 $ 823,493 Incurred losses and LAE 563,082 122,181 895,071 531,580 Commission and brokerage 68,441 78,384 199,438 209,348 Other underwriting expenses 8,307 11,030 27,601 26,822 Underwriting gain (loss) $ (333,879 ) $ 70,847 $ (280,762 ) $ 55,743 Three Months Ended Nine Months Ended Bermuda September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 311,781 $ 245,995 $ 870,473 $ 612,657 Net written premiums 287,591 229,373 810,437 562,128 Premiums earned $ 267,488 $ 215,761 $ 766,051 $ 610,466 Incurred losses and LAE 301,315 127,236 595,052 348,586 Commission and brokerage 83,861 59,605 205,770 169,413 Other underwriting expenses 9,049 8,785 27,551 26,290 Underwriting gain (loss) $ (126,737 ) $ 20,135 $ (62,322 ) $ 66,177 Three Months Ended Nine Months Ended Insurance September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Gross written premiums $ 480,060 $ 533,039 $ 1,483,807 $ 1,364,465 Net written premiums 370,439 340,216 1,179,873 1,047,863 Premiums earned $ 375,664 $ 354,111 $ 1,063,464 $ 966,268 Incurred losses and LAE 420,249 260,479 896,899 732,261 Commission and brokerage 67,362 54,889 181,900 146,684 Other underwriting expenses 43,694 44,483 132,125 129,782 Underwriting gain (loss) $ (155,641 ) $ (5,740 ) $ (147,460 ) $ (42,459 )
Schedule Of Underwriting Results For Operating Segments To Income (Loss) Before Taxes	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Underwriting gain (loss) $ (1,017,465 ) $ 197,198 $ (704,731 ) $ 431,665 Net investment income 136,973 122,657 393,770 357,918 Net realized capital gains (losses) 41,535 380 119,531 (41,221 ) Net derivative gain (loss) 2,656 6,510 6,052 5,486 Corporate expenses (5,932 ) (6,400 ) (21,308 ) (21,403 ) Interest, fee and bond issue cost amortization expense (7,266 ) (8,893 ) (24,289 ) (27,194 ) Other income (expense) (54,568 ) 9,435 (59,146 ) (20,998 ) Income (loss) before taxes $ (904,067 ) $ 320,887 $ (290,121 ) $ 684,253
Schedule Of Gross Written Premiums Derived From Largest Non-U.S. Market	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 United Kingdom gross written premium $ 204,774 $ 182,786 $ 580,559 $ 511,994

Retirement Benefits (Tables)

Retirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Summary Of Pension Expense	Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Service cost $ 2,737 $ 2,731 $ 9,335 $ 8,524 Interest cost 2,509 2,371 7,060 7,093 Expected return on plan assets (3,263 ) (2,789 ) (9,572 ) (7,757 ) Amortization of prior service cost - - - - Amortization of net (income) loss 2,091 1,984 8,172 6,012 Net periodic benefit cost $ 4,074 $ 4,297 $ 14,995 $ 13,872 Other Benefits Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2017 2016 2017 2016 Service cost $ 392 $ 354 $ 1,273 $ 1,230 Interest cost 296 252 793 844 Amortization of prior service cost (33 ) (33 ) (98 ) (33 ) Amortization of net (income) loss 48 - 199 96 Net periodic benefit cost $ 703 $ 573 $ 2,167 $ 2,137 (Some amounts may not reconcile due to rounding.)

Basis Of Presentation (Schedule

Basis Of Presentation (Schedule of Effect of Newly Adopted Accounting Policies, Cash Flow) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (639,374)	$ 295,394	$ (102,057)	$ 622,772
Change in other assets and liabilities, net			(116,623)	(154,765)
Net cash provided by (used in) operating activities			1,044,218	960,748
CASH FLOWS FROM FINANCING ACTIVITIES:
Cost of shares withheld for taxes on settlements of share-based compensation awards			(12,707)	(10,017)
Net cash provided by (used in) financing activities			$ (172,244)	(528,227)
As Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Change in other assets and liabilities, net				(164,782)
Net cash provided by (used in) operating activities				950,731
CASH FLOWS FROM FINANCING ACTIVITIES:
Cost of shares withheld for taxes on settlements of share-based compensation awards
Net cash provided by (used in) financing activities				(518,210)
Effect Of Adoption Of New Accounting Policy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Change in other assets and liabilities, net				10,017
Net cash provided by (used in) operating activities				10,017
CASH FLOWS FROM FINANCING ACTIVITIES:
Cost of shares withheld for taxes on settlements of share-based compensation awards				(10,017)
Net cash provided by (used in) financing activities				$ (10,017)

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Percentage threshold that triggers a review of available for sale debt securities for declines in market value	80.00%
Aggregate market value of investments in unrealized loss position	$ 5,909,831		$ 6,211,700
Gross unrealized losses on investments in unrealized loss position	148,421		220,621
Fixed maturity securities, duration of unrealized loss, less than 12 months, gross unrealized depreciation	73,351		91,871
Fixed maturity securities, duration of unrealized loss, greater than 12 months, gross unrealized depreciation	75,070		128,750
Gross unrealized depreciation	0		0
Additional contractual commitments	663,222
Other invested assets	$ 1,487,519		1,333,129
Sales Revenue, Net [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage threshold of unrealized losses not exceeded by any one single issuer	5.00%	5.00%
Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Limited partnership financial reporting lag time, months	1 month
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Limited partnership financial reporting lag time, months	3 months
Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, duration of unrealized loss, less than 12 months, gross unrealized depreciation	$ 69,276		85,078
Fixed maturity securities, duration of unrealized loss, greater than 12 months, gross unrealized depreciation	67,753
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate market value of investments in unrealized loss position	5,797,816		6,106,193
Gross unrealized losses on investments in unrealized loss position	145,188		207,837
Fixed maturity securities, duration of unrealized loss, less than 12 months, gross unrealized depreciation	73,351		91,871
Fixed maturity securities, duration of unrealized loss, greater than 12 months, gross unrealized depreciation	$ 71,837		$ 115,966
Fixed Maturity Securities [Member] | Sales Revenue, Net [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage threshold of unrealized losses not exceeded by any one single issuer	0.40%		1.10%
Foreign Exchange Losses [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, duration of unrealized loss, greater than 12 months, gross unrealized depreciation			$ 112,132
Private Placement Liquidity Sweep [Member]
Schedule of Available-for-sale Securities [Line Items]
Other invested assets	$ 367,966		$ 378,862

Investments (Summary Of Unreali

Investments (Summary Of Unrealized Appreciation (Depreciation) Of Available For Sale, Fixed Maturity And Equity Security Investments) (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$ 14,626,754	$ 13,932,613
Unrealized Appreciation		296,609	382,632
Unrealized Depreciation		(145,188)	(207,837)
Market Value		14,778,175	14,107,408
OTTI in AOCI	[1]	4,045	9,235
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,141,002	1,115,208
Unrealized Appreciation		12,475	20,410
Unrealized Depreciation		(6,608)	(5,303)
Market Value		1,146,869	1,130,315
OTTI in AOCI	[1]
Obligations Of U.S. States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		652,525	723,938
Unrealized Appreciation		24,061	18,016
Unrealized Depreciation		(4,744)	(11,970)
Market Value		671,842	729,984
OTTI in AOCI	[1]
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		5,599,904	5,059,388
Unrealized Appreciation		108,072	131,651
Unrealized Depreciation		(31,814)	(35,758)
Market Value		5,676,162	5,155,281
OTTI in AOCI	[1]	2,902	7,936
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		555,451	488,824
Unrealized Appreciation		1,390	1,110
Unrealized Depreciation		(444)	(1,286)
Market Value		556,397	488,648
OTTI in AOCI	[1]
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		253,154	308,827
Unrealized Appreciation		1,462	1,983
Unrealized Depreciation		(1,825)	(3,878)
Market Value		252,791	306,932
OTTI in AOCI	[1]
Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,390,238	2,415,901
Unrealized Appreciation		13,680	17,478
Unrealized Depreciation		(23,589)	(27,910)
Market Value		2,380,329	2,405,469
OTTI in AOCI	[1]
Non-Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		519	642
Unrealized Appreciation		42	44
Unrealized Depreciation		(44)	(45)
Market Value		517	641
OTTI in AOCI	[1]
Foreign Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,317,697	1,254,175
Unrealized Appreciation		46,225	61,226
Unrealized Depreciation		(34,489)	(57,241)
Market Value		1,329,433	1,258,160
OTTI in AOCI	[1]	182	115
Foreign Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,716,264	2,565,710
Unrealized Appreciation		89,202	130,714
Unrealized Depreciation		(41,631)	(64,446)
Market Value		2,763,835	2,631,978
OTTI in AOCI	[1]	961	1,184
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		128,116	129,553
Unrealized Appreciation		2,542	2,298
Unrealized Depreciation		(3,233)	(12,784)
Market Value		127,425	119,067
OTTI in AOCI	[1]
[1]	Represents the amount of OTTI recognized in AOCI. Amount includes unrealized gains and losses on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date

Investments (Summary Of Amortiz

Investments (Summary Of Amortized Cost And Market Value Of Fixed Maturity Securities, By Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Amortized Cost	$ 14,626,754	$ 13,932,613
Fixed maturity securities - available for sale, Market Value	14,778,175	14,107,408
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Due in one year or less, Amortized Cost	1,091,257	956,945
Fixed maturity securities - available for sale, Due after one year through five years, Amortized Cost	7,267,248	6,769,585
Fixed maturity securities - available for sale, Due after five years through ten years, Amortized Cost	2,096,762	2,020,215
Fixed maturity securities - available for sale, Due after ten years, Amortized Cost	972,125	971,674
Fixed maturity securities - available for sale, Due in one year or less, Market Value	1,095,288	966,970
Fixed maturity securities - available for sale, Due after one year through five years, Market Value	7,334,494	6,870,056
Fixed maturity securities - available for sale, Due after five years through ten years, Market Value	2,124,265	2,052,733
Fixed maturity securities - available for sale, Due after ten years, Market Value	1,034,094	1,015,959
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Amortized Cost	555,451	488,824
Fixed maturity securities - available for sale, Market Value	556,397	488,648
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Amortized Cost	253,154	308,827
Fixed maturity securities - available for sale, Market Value	252,791	306,932
Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Amortized Cost	2,390,238	2,415,901
Fixed maturity securities - available for sale, Market Value	2,380,329	2,405,469
Non-Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities - available for sale, Amortized Cost	519	642
Fixed maturity securities - available for sale, Market Value	$ 517	$ 641

Investments (Summary Of Changes

Investments (Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ (9,489)	$ (12,853)	$ (10,718)	$ 341,133
Deferred tax benefit (expense)	(1,774)	(256)	11,343	(53,666)
Deferred tax benefit (expense), other-than-temporary impairment	55	855	1,391	(1,470)
Total URA(D) on securities arising during the period	(11,208)	(12,254)	2,016	285,997
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	(13,993)	(13,544)	(18,184)	324,147
Fixed Maturity Securities, Other-Than-Temporary Impairment [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	306	(1,836)	(5,189)	7,088
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	2,603	2,527	9,795	9,898
Other Invested Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ 1,595		$ 2,860

Investments (Summary Of Aggrega

Investments (Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Security Type) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	$ 4,323,876	$ 5,180,408
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(73,351)	(91,871)
Fixed maturity securities, Greater than 12 months, Market Value	1,585,955	1,031,292
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(75,070)	(128,750)
Fixed maturity securities, Total, Market Value	5,909,831	6,211,700
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(148,421)	(220,621)
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	4,323,876	5,180,408
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(73,351)	(91,871)
Fixed maturity securities, Greater than 12 months, Market Value	1,473,940	925,785
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(71,837)	(115,966)
Fixed maturity securities, Total, Market Value	5,797,816	6,106,193
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(145,188)	(207,837)
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	376,128	638,740
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(4,865)	(5,303)
Fixed maturity securities, Greater than 12 months, Market Value	53,039
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(1,743)
Fixed maturity securities, Total, Market Value	429,167	638,740
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(6,608)	(5,303)
Obligations Of U.S. States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	89,509	221,088
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(2,104)	(11,486)
Fixed maturity securities, Greater than 12 months, Market Value	67,956	564
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(2,640)	(484)
Fixed maturity securities, Total, Market Value	157,465	221,652
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(4,744)	(11,970)
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	1,214,762	1,360,743
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(20,914)	(24,023)
Fixed maturity securities, Greater than 12 months, Market Value	283,985	177,153
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(10,900)	(11,735)
Fixed maturity securities, Total, Market Value	1,498,747	1,537,896
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(31,814)	(35,758)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	189,752	150,023
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(369)	(565)
Fixed maturity securities, Greater than 12 months, Market Value	6,262	18,786
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(75)	(721)
Fixed maturity securities, Total, Market Value	196,014	168,809
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(444)	(1,286)
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	63,101	143,554
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(540)	(3,223)
Fixed maturity securities, Greater than 12 months, Market Value	40,432	7,184
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(1,285)	(655)
Fixed maturity securities, Total, Market Value	103,533	150,738
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(1,825)	(3,878)
Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	1,345,113	1,618,372
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(13,416)	(22,461)
Fixed maturity securities, Greater than 12 months, Market Value	450,890	189,665
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(10,173)	(5,449)
Fixed maturity securities, Total, Market Value	1,796,003	1,808,037
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(23,589)	(27,910)
Non-Agency Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation
Fixed maturity securities, Greater than 12 months, Market Value	77	113
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(44)	(45)
Fixed maturity securities, Total, Market Value	77	113
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(44)	(45)
Foreign Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	385,494	360,289
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(14,007)	(12,041)
Fixed maturity securities, Greater than 12 months, Market Value	258,478	236,820
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(20,482)	(45,200)
Fixed maturity securities, Total, Market Value	643,972	597,109
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(34,489)	(57,241)
Foreign Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	660,017	687,599
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(17,136)	(12,769)
Fixed maturity securities, Greater than 12 months, Market Value	312,821	295,500
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(24,495)	(51,677)
Fixed maturity securities, Total, Market Value	972,838	983,099
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(41,631)	(64,446)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation
Fixed maturity securities, Greater than 12 months, Market Value	112,015	105,507
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(3,233)	(12,784)
Fixed maturity securities, Total, Market Value	112,015	105,507
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	$ (3,233)	$ (12,784)

Investments (Summary Of Aggre47

Investments (Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	$ 4,323,876	$ 5,180,408
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(73,351)	(91,871)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	1,585,955	1,031,292
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(75,070)	(128,750)
Fixed maturity securities, Total, Market Value	5,909,831	6,211,700
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(148,421)	(220,621)
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	4,323,876	5,180,408
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(73,351)	(91,871)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	1,473,940	925,785
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(71,837)	(115,966)
Fixed maturity securities, Total, Market Value	5,797,816	6,106,193
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(145,188)	(207,837)
Due In One Year Or Less [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	270,695	178,281
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(848)	(1,122)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	123,092	78,153
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(13,069)	(14,318)
Fixed maturity securities, Total, Market Value	393,787	256,434
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(13,917)	(15,440)
Due In One Year Through Five Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	1,680,251	2,123,113
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(31,686)	(26,263)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	644,557	538,130
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(37,591)	(84,803)
Fixed maturity securities, Total, Market Value	2,324,808	2,661,243
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(69,277)	(111,066)
Due In Five Years Through Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	639,836	680,334
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(22,619)	(22,555)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	136,548	86,631
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(6,469)	(8,754)
Fixed maturity securities, Total, Market Value	776,384	766,965
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(29,088)	(31,309)
Due After Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	135,128	286,731
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(3,873)	(15,682)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	72,082	7,123
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(3,131)	(1,221)
Fixed maturity securities, Total, Market Value	207,210	293,854
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(7,004)	(16,903)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	189,752	150,023
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(369)	(565)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	6,262	18,786
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(75)	(721)
Fixed maturity securities, Total, Market Value	196,014	168,809
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	(444)	(1,286)
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	1,408,214	1,761,926
Fixed maturity securities, Duration of Unrealized loss, less than 12 months, Gross Unrealized Depreciation	(13,956)	(25,684)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	491,399	196,962
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(11,502)	(6,149)
Fixed maturity securities, Total, Market Value	1,899,613	1,958,888
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation, Total	$ (25,458)	$ (31,833)

Investments (Summary Of Compone

Investments (Summary Of Components Of Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 142,943	$ 129,242	$ 408,501	$ 374,571
Funds held interest income (expense)	2,284	1,538	7,156	5,818
Future policy benefit reserve income (expense)	(280)	(517)	(1,015)	(1,243)
Gross investment income	144,947	130,263	414,642	379,146
Investment expenses	(7,974)	(7,606)	(20,872)	(21,228)
Net investment income	136,973	122,657	393,770	357,918
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	107,969	100,752	319,336	306,128
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	8,590	9,905	25,701	31,967
Short-Term Investments And Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	974	475	2,439	1,220
Limited Partnerships [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	23,315	17,077	54,373	33,922
Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 2,095	$ 1,033	$ 6,652	$ 1,334

Investments (Summary Of Compo49

Investments (Summary Of Components Of Net Realized Capital Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary impairments	$ (1,485)	$ (867)	$ (5,188)	$ (31,130)
Sale of Subsidiary		(28,032)		(28,032)
Total net realized capital gains (losses)	41,535	380	119,531	(41,221)
Fixed Maturity Securities [Member] | Market Value [Member]
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary impairments	(1,485)	(867)	(5,188)	(31,130)
Gains (losses) from sales	7,998	5,912	32,913	(7,670)
Fixed Maturity Securities [Member] | Fair Value [Member]
Schedule of Available-for-sale Securities [Line Items]
Gains (losses) from sales		(1)		(1,855)
Gains (losses) from fair value adjustments		42		1,381
Equity Securities [Member] | Market Value [Member]
Schedule of Available-for-sale Securities [Line Items]
Gains (losses) from sales			(3,436)	65
Equity Securities [Member] | Fair Value [Member]
Schedule of Available-for-sale Securities [Line Items]
Gains (losses) from sales	(1,525)	5,850	3,796	(10,266)
Gains (losses) from fair value adjustments	36,463	17,475	91,367	36,284
Other Invested Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Gains (losses) from sales	85		84
Short-Term Investments And Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Gains (losses) from sales	$ (1)	$ 1	$ (5)	$ 2

Investments (Summary Of Gross G

Investments (Summary Of Gross Gains (Losses) From Sales Of Fixed Maturity And Equity Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of fixed maturity securities	$ 700,728	$ 293,998	$ 1,691,937	$ 890,349
Gross gains from sales	13,743	15,028	46,321	32,674
Gross losses from sales	(5,745)	(9,117)	(13,408)	(42,199)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of fixed maturity securities	57,861	112,451	334,889	542,715
Gross gains from sales	2,258	7,308	14,351	14,040
Gross losses from sales	$ (3,783)	$ (1,458)	$ (13,991)	$ (24,241)

Reserve For Losses, LAE And F51

Reserve For Losses, LAE And Future Policy Benefit Reserve (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in insurance business	$ (1,289)	$ (295,335)
Partially offset, related to development on A&E reserves		53,909
Case reserve established by the Company on direct excess insurance claims	12,455,357	10,312,313	$ 9,951,798
Property and Short-Tail Business [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in reinsurance business		468,749
Explosion, Port Of Tianjin, China [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in reinsurance business		43,280
Explosion, Port Of Tianjin, China [Member] | Estimated [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in reinsurance business		60,000
Explosion, Port Of Tianjin, China [Member] | Projected [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in reinsurance business		16,720
Construction Liability, Umbrella, and Workers Compenstion Reserves [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in reinsurance business		173,414
Catastrophe Losses [Member]
Reserve For Losses LAE And Future Policy Benefit Reserve [Line Items]
Increase (decrease) in insurance business	$ 1,443,746	$ 307,263

Reserve For Losses, LAE And F52

Reserve For Losses, LAE And Future Policy Benefit Reserve (Summary Of Activity In The Reserve For Losses And LAE) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Reserve For Losses LAE And Future Policy Benefit Reserve [Abstract]
Gross reserves at beginning of period	$ 10,312,313	$ 9,951,798
Less reinsurance recoverable	(1,298,125)	(990,862)	$ (881,503)
Net reserves at beginning of period	9,321,451	9,070,295
Incurred related to: Current year	3,843,434	3,434,964
Incurred related to: Prior years	(1,289)	(295,335)
Total incurred losses and LAE	3,842,145	3,139,629
Paid related to: Current year	948,897	745,642
Paid related to: Prior years	1,265,713	2,042,972
Total paid losses and LAE	2,214,610	2,788,614
Foreign exchange/translation adjustment	208,246	(99,859)
Net reserves at end of period	11,157,232	9,321,451
Plus reinsurance recoverable	1,298,125	990,862
Gross reserves at end of period	$ 12,455,357	$ 10,312,313

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details)	9 Months Ended
	Sep. 30, 2017USD ($)itemsecurity	Dec. 31, 2016USD ($)	Dec. 31, 2005security	Dec. 31, 2001security
Derivative [Line Items]
Number of equity index put option contracts	7		7	7
Number of equity indices | item	2
Equity index put option liability	$ 16,006,000	$ 22,059,000
Equity Index Put Option Contracts [Member]
Derivative [Line Items]
Number of equity index put option contracts | item	1
Equity index put option liability	$ 0
Equity Index Put Option Contracts [Member] | Fair Value [Member]
Derivative [Line Items]
Equity index put option liability	$ 16,006,000	$ 22,059,000
Standard & Poor's 500 Index [Member]
Derivative [Line Items]
Number of equity index put option contracts | security	5
Theoretical maximum payout occurs based on index value	$ 0
Discount factor	3.00%
Present value of theoretical maximum payouts	$ 397,561,000
Settlement amount if contracts had expired	$ 0
Equity Index If Contracts Had Expired | item	2,519.36
Standard & Poor's 500 Index [Member] | Maximum [Member]
Derivative [Line Items]
Estimates the probability of equity index put option contract will falling below the strike price on the exercise date	2.00%
FTSE 100 Index [Member]
Derivative [Line Items]
Number of equity index put option contracts | security	1
Theoretical maximum payout occurs based on index value	$ 0
Discount factor	3.00%
Present value of theoretical maximum payouts	$ 41,134,000
Settlement amount if contracts had expired	$ 0
Equity Index If Contracts Had Expired | item	7,372.76
FTSE 100 Index [Member] | Maximum [Member]
Derivative [Line Items]
Estimates the probability of equity index put option contract will falling below the strike price on the exercise date	15.00%

Derivatives (Summary Of The Fai

Derivatives (Summary Of The Fair Value Of The Equity Index Put Options) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Option Indexed to Issuer's Equity [Line Items]
Equity index put option liability	$ 16,006		$ 16,006		$ 22,059
Net derivative gain (loss)	2,656	$ 6,510	6,052	$ 5,486
Equity Index Put Option Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Option Indexed to Issuer's Equity [Line Items]
Equity index put option liability	16,006		16,006		$ 22,059
Net derivative gain (loss)	$ 2,656	$ 6,510	$ 6,052	$ 5,486

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)securityitem	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)securityitem	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)security	Dec. 31, 2005security	Dec. 31, 2001security
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of public equity portfolio	$ 361,608		$ 361,608		$ 256,041
Number of equity index put option contracts	7		7			7	7
Derivatives, Number Of Indices | item			2
Equity index put option liability	$ 16,006		$ 16,006		22,059
other invested assets	517,765		517,765		263,459
Transfers between level 1 and 2	0		0
Transfers from level 3		$ 2,015	0	$ 2,015
Accounting Standards Update 2015-07 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
other invested assets	$ 70,657		$ 70,657		$ 18,801
Unavailability Of Prices [Member] | Private Placement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of securities | security	50		50		42
Available-for-sale Securities	$ 105,987		$ 105,987		$ 86,536
Par Value [Member] | Unavailability Of Prices [Member] | Private Placement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of securities | security	1		1
Available-for-sale Securities	$ 51,965		$ 51,965
Equity Index Put Option Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of equity index put option contracts | item	1		1
Equity index put option liability	$ 0		$ 0
Equity Index Put Option Contracts [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity index put option liability	$ 16,006		$ 16,006		$ 22,059

Fair Value (Fair Value Measurem

Fair Value (Fair Value Measurement Levels For All Assets And Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	$ 14,778,175	$ 14,107,408
Equity securities, market value	127,425	119,067
Equity securities, fair value	1,141,146	1,010,085
Equity index put option contracts	16,006	22,059
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Equity securities, market value	112,015	105,507
Equity securities, fair value	1,094,754	949,523
Equity index put option contracts
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	14,620,223	14,039,673
Equity securities, market value	15,410	13,560
Equity securities, fair value	46,392	60,562
Equity index put option contracts
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	157,952	67,735
Equity securities, market value
Equity securities, fair value
Equity index put option contracts	16,006	22,059
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	1,146,869	1,130,315
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	1,146,869	1,130,315
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Obligations Of U.S. States And Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	671,842	729,984
Obligations Of U.S. States And Political Subdivisions [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Obligations Of U.S. States And Political Subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	671,842	729,984
Obligations Of U.S. States And Political Subdivisions [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	5,676,162	5,155,281
Corporate Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Corporate Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	5,522,128	5,090,084
Corporate Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	154,034	65,197
Asset-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	556,397	488,648
Asset-Backed Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Asset-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	556,397	488,648
Asset-Backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Commercial Mortgage-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	252,791	306,932
Commercial Mortgage-Backed Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Commercial Mortgage-Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	252,791	306,932
Commercial Mortgage-Backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Agency Residential [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	2,380,329	2,405,469
Agency Residential [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Agency Residential [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	2,380,329	2,405,469
Agency Residential [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Non-Agency Residential [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	517	641
Non-Agency Residential [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Non-Agency Residential [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	517	641
Non-Agency Residential [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Foreign Government Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	1,329,433	1,258,160
Foreign Government Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Foreign Government Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	1,329,433	1,258,160
Foreign Government Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Foreign Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	2,763,835	2,631,978
Foreign Corporate Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value
Foreign Corporate Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	2,759,917	2,629,440
Foreign Corporate Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities, market value	$ 3,918	$ 2,538

Fair Value (Activity Under Leve

Fair Value (Activity Under Level 3, Fair Value Measurements Using Significant Unobservable Inputs By Asset Type) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 141,256	$ 34,431	$ 67,735	$ 5,526
Total gains or (losses) (realized/unrealized) Included in earnings	492	15	1,521	(992)
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)	(166)	(1,371)	(23)	21
Purchases, issuances and settlements	16,370	28,064	88,719	56,584
Transfers in and/or (out) of Level 3		2,015	0	2,015
Ending balance	157,952	63,154	157,952	63,154
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date				(997)
Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	138,105	32,410	65,197	3,933
Total gains or (losses) (realized/unrealized) Included in earnings	283	(12)	1,208	(22)
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)	18	(48)	161	(81)
Purchases, issuances and settlements	15,628	25,877	87,468	54,397
Transfers in and/or (out) of Level 3		(1,932)		(1,932)
Ending balance	154,034	56,295	154,034	56,295
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)		(38)		(38)
Purchases, issuances and settlements		(44)		(44)
Transfers in and/or (out) of Level 3		3,947		3,947
Ending balance		3,865		3,865
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Foreign Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	3,151	2,021	2,538	1,593
Total gains or (losses) (realized/unrealized) Included in earnings	209	27	313	(970)
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)	(184)	(1,285)	(184)	140
Purchases, issuances and settlements	742	2,231	1,251	2,231
Transfers in and/or (out) of Level 3
Ending balance	3,918	2,994	3,918	2,994
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date				$ (997)

Fair Value (Fair Value Measur58

Fair Value (Fair Value Measurements Using Significant Unobservable Inputs For Equity Index Put Option Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value [Abstract]
Balance, beginning of period	$ 18,662	$ 41,729	$ 22,059	$ 40,705
Total (gains) or losses (realized/unrealized) Included in earnings	(2,656)	(6,510)	(6,052)	(5,486)
Total (gains) or losses (realized/unrealized) Included in other comprehensive income (loss)
Purchases, issuances and settlements
Transfers in and/or (out) of Level 3
Balance, end of period	16,006	35,219	16,006	35,219
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to liabilities still held at the reporting date

Earnings Per Common Share (Narr

Earnings Per Common Share (Narrative) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Common Share [Abstract]
Anti-dilutive options	0	0	0	0

Earnings Per Common Share (Sche

Earnings Per Common Share (Schedule Of Net Income (Loss) Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Common Share [Abstract]
Net income (loss)	$ (639,374)	$ 295,394	$ (102,057)	$ 622,772
Less: dividends declared-common shares and nonvested common shares	(51,302)	(47,463)	(153,887)	(144,299)
Undistributed earnings	$ (690,676)	$ 247,932	$ (255,944)	$ 478,472
Percentage allocated to common shareholders	100.00%	98.90%	100.00%	98.90%
Net income (loss) available to common stockholders, total	$ (690,676)	$ 245,248	$ (255,944)	$ 473,372
Add: dividends declared-common shareholders	51,302	46,985	153,887	142,839
Numerator for basic and diluted earnings per common share	$ (639,374)	$ 292,233	$ (102,057)	$ 616,211
Denominator for basic earnings per weighted-average common shares	40,638	41,101	40,597	41,626
Effect of dilutive securities: Options	245	284	255	305
Denominator for diluted earnings per adjusted weighted-average common shares	40,883	41,386	40,852	41,931
Basic	$ (15.73)	$ 7.11	$ (2.51)	$ 14.80
Diluted	$ (15.73)	$ 7.06	$ (2.51)	$ 14.70
Basic weighted-average common shares outstanding	40,638	41,101	40,597	41,626
Basic weighted-average common shares outstanding and nonvested common shares expected to vest	40,638	41,551	40,597	42,074

Commitments And Contingencies61

Commitments And Contingencies (Summary Of Estimated Cost To Replace Annuities For Contingent Liability) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
The Prudential [Member]
Loss Contingencies [Line Items]
Estimated cost to replace annuities	$ 144,331	$ 146,507
Unaffiliated Life Insurance Company [Member]
Loss Contingencies [Line Items]
Estimated cost to replace annuities	$ 33,769	$ 33,860

Other Comprehensive Income (L62

Other Comprehensive Income (Loss) (Components Of Comprehensive Income (Loss) In The Consolidated Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Before Tax	$ 88,640	$ (9,510)	$ 145,950	$ 379,809
Total, Tax Effect	(20,915)	1,340	(13,433)	(72,224)
Total, Net of Tax	67,725	(8,170)	132,517	307,585
URA(D) On Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before Tax	(3,197)	(5,972)	18,844	295,311
Tax Effect	(2,835)	(2,079)	3,699	(42,643)
Net of Tax	(6,032)	(8,051)	22,543	252,668
Reclassification, Before Tax	(6,598)	(5,045)	(24,373)	38,734
Reclassification, Tax Effect	1,061	1,823	7,644	(11,023)
Reclassification, Net of Tax	(5,537)	(3,222)	(16,729)	27,711
Total, Net of Tax			5,814		$ 66,802
URA(D) On Securities OTTI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before Tax	306	(1,836)	(5,189)	7,088
Tax Effect	55	855	1,391	(1,470)
Net of Tax	361	(981)	(3,798)	5,618
Total, Net of Tax			(3,798)		5,945
Foreign Currency Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before Tax	96,022	1,393	148,395	32,601
Tax Effect	(18,458)	1,423	(23,271)	(14,962)
Net of Tax	77,564	2,816	125,124	17,639
Total, Net of Tax			125,124		(55,341)
Benefit Plan Net Gain (Loss)[Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before Tax
Tax Effect
Net of Tax
Reclassification, Before Tax	2,107	1,951	8,273	6,076
Reclassification, Tax Effect	(738)	(683)	(2,896)	(2,127)
Reclassification, Net of Tax	$ 1,369	$ 1,268	5,377	$ 3,949
Total, Net of Tax			$ 5,377		$ (2,415)

Other Comprehensive Income (L63

Other Comprehensive Income (Loss) (Reclassification From Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized capital gains (losses)	$ 43,020	$ 1,247	$ 124,719	$ (10,091)
Income tax expense (benefit)	(264,693)	25,493	(188,064)	61,481
Net income (loss)	(639,374)	295,394	(102,057)	622,772
URA(D) On Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other underwriting expenses	(6,598)	(5,045)	(24,373)	38,734
Income tax expense (benefit)	1,061	1,823	7,644	(11,023)
Net income (loss)	(5,537)	(3,222)	(16,729)	27,711
URA(D) On Securities [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized capital gains (losses)	(6,598)	(5,045)	(24,373)	38,734
Income tax expense (benefit)	1,061	1,823	7,644	(11,023)
Net income (loss)	(5,537)	(3,222)	(16,729)	27,711
Benefit Plan Net Gain (Loss)[Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)	(738)	(683)	(2,896)	(2,127)
Other underwriting expenses	2,107	1,951	8,273	6,076
Income tax expense (benefit)	(738)	(683)	(2,896)	(2,127)
Net income (loss)	$ 1,369	$ 1,268	$ 5,377	$ 3,949

Other Comprehensive Income (L64

Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss), Net Of Tax, In The Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period			$ 8,075,396
Current period change	$ 67,725	$ (8,170)	132,517	$ 307,585
Balance, end of period	7,969,331	8,041,092	7,969,331	8,041,092	$ 8,075,396
URA(D) On Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period			115,558	42,811	42,811
Current period change			5,814		66,802
Balance, end of period	117,574		117,574		115,558
URA(D) On Securities OTTI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Current period change			(3,798)		5,945
Foreign Currency Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period			(266,818)	(211,477)	(211,477)
Current period change			125,124		(55,341)
Balance, end of period	(141,694)		(141,694)		(266,818)
Benefit Plan Net Gain (Loss)[Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period			(65,504)	(63,089)	(63,089)
Current period change			5,377		(2,415)
Balance, end of period	(60,127)		(60,127)		(65,504)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(151,972)	84,000	(216,764)	(231,755)	(231,755)
Current period change	67,725	(8,170)	132,517	307,585
Balance, end of period	$ (84,247)	$ 75,830	$ (84,247)	$ 75,830	$ (216,764)

Credit Facilities (Narrative) (

Credit Facilities (Narrative) (Details) £ in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017GBP (£)item	Dec. 31, 2015	Sep. 30, 2017USD ($)item	Dec. 31, 2016GBP (£)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of credit facility, number of facilities | item	2
Line of credit facility, commitment			$ 1,000,000
Wells Fargo Bank Group Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, number of tranches | item	2		2
Line of credit facility, term of credit facility	4 years
Line of credit facility, commitment			$ 800,000		$ 800,000
Line of credit facility, required minimum debt-to-capital ratio	0.35		0.35
Line of credit facility, required minimum net worth			$ 5,370,979
Percentage amount of consolidated net income required to be reserved to maintain compliance with facility covenants	25.00%
Percentage amount of increase in consolidated net worth from new issuance required to be reserved to maintain compliance with facility covenants	25.00%
Increase in reserves due to new issuance during the period required to maintain compliance with facility covenants			5,723,052
Wells Fargo Bank Group Credit Facility [Member] | Before Amended And Restated Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility, term of credit facility	5 years
Line of credit facility, commitment			800,000
Wells Fargo Bank Group Credit Facility Tranche One [Member]
Line of Credit Facility [Line Items]
Line of credit facility, commitment			200,000		200,000
Wells Fargo Bank Group Credit Facility Tranche One [Member] | Interest Rate Base Rate Option 1(b) [Member]
Line of Credit Facility [Line Items]
Line of credit facility, spread on variable rate basis	0.50%
Wells Fargo Bank Group Credit Facility Tranche One [Member] | Interest Rate Base Rate Option 1(c) [Member]
Line of Credit Facility [Line Items]
Line of credit facility, spread on variable rate basis	1.00%
Wells Fargo Bank Group Credit Facility Tranche Two [Member]
Line of Credit Facility [Line Items]
Line of credit facility, commitment			600,000
Citibank Holdings Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, term of credit facility	3 years
Citibank Bilateral Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility, commitment			$ 200,000		$ 200,000
Per annum commitment fee on undrawn credit	0.15%
Citibank Bilateral Agreement [Member] | Interest Rate Base Rate Option 1(a) [Member]
Line of Credit Facility [Line Items]
Percentage of interest on the principal amount of letters of credit issued	0.35%
Maximum term allowed to execute issued letters of credit	15 months
Citibank Bilateral Agreement [Member] | Interest Rate Base Rate Option 1(b) [Member]
Line of Credit Facility [Line Items]
Percentage of interest on the principal amount of issued extended tenor letters of credit	0.45%
Maximum term allowed to execute issued letters of credit	60 months
Everest International Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, required minimum debt-to-capital ratio	0.35		0.35
Line of credit facility, required minimum net worth			$ 5,326,009
Consolidated net worth, percentage		70.00%
Percentage amount of consolidated net income required to be reserved to maintain compliance with facility covenants	25.00%
Percentage amount of increase in consolidated net worth from new issuance required to be reserved to maintain compliance with facility covenants	25.00%
Increase in reserves due to new issuance during the period required to maintain compliance with facility covenants			$ 5,723,052
Lloyds Bank plc Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, initiation date	Nov. 9, 2016
Line of credit facility, term of credit facility	4 years
Line of credit facility, commitment | £	£ 145,000			£ 140,000
Percentage commitment fee per annum	0.10%
Per annum commitment fee on undrawn credit	0.35%

Credit Facilities (Summary Of C

Credit Facilities (Summary Of Costs Incurred Connection With Credit Facilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Credit Facilities [Abstract]
Credit facility interest and fees incurred	$ 105	$ 35	$ 315	$ 618

Credit Facilities (Summary Of O

Credit Facilities (Summary Of Outstanding Letters Of Credit And/Or Borrowings) (Details) £ in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017GBP (£)	Dec. 31, 2016GBP (£)	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Commitment			$ 1,000,000
Wells Fargo Bank Group Credit Facility Tranche One [Member]
Line of Credit Facility [Line Items]
Commitment			200,000	$ 200,000
In Use
Wells Fargo Bank Group Credit Facility Tranche Two Issuance One [Member]
Line of Credit Facility [Line Items]
Commitment			600,000	600,000
In Use			507,916	478,233
Date of Expiry	Dec. 31, 2017	Dec. 31, 2017
Wells Fargo Bank Group Credit Facility [Member]
Line of Credit Facility [Line Items]
Commitment			800,000	800,000
In Use			507,916	478,233
Citibank Bilateral Letter Of Credit Agreement One [Member]
Line of Credit Facility [Line Items]
Commitment			200,000	200,000
In Use			3,672	4,058
Date of Expiry	Nov. 24, 2017	Feb. 28, 2017
Citibank Bilateral Letter Of Credit Agreement Two [Member]
Line of Credit Facility [Line Items]
In Use			68,353	3,672
Date of Expiry	Dec. 31, 2017	Nov. 24, 2017
Citibank Bilateral Letter Of Credit Agreement Three [Member]
Line of Credit Facility [Line Items]
In Use			3,297	69,404
Date of Expiry	Feb. 28, 2018	Dec. 31, 2017
Citibank Bilateral Letter Of Credit Agreement Four [Member]
Line of Credit Facility [Line Items]
In Use			353	269
Date of Expiry	Aug. 30, 2018	Aug. 30, 2018
Citibank Bilateral Letter Of Credit Agreement Five [Member]
Line of Credit Facility [Line Items]
In Use			4,019	1,163
Date of Expiry	Dec. 31, 2018	Dec. 31, 2018
Citibank Bilateral Letter Of Credit Agreement Six [Member]
Line of Credit Facility [Line Items]
In Use			105,485	93,180
Date of Expiry	Sep. 30, 2021	Dec. 30, 2020
Citibank Bilateral Agreement [Member]
Line of Credit Facility [Line Items]
Commitment			200,000	200,000
In Use			$ 185,179	$ 171,746
Lloyds Bank PLC [Member]
Line of Credit Facility [Line Items]
Commitment | £	£ 145,000	£ 140,000
In Use | £	£ 140,964	£ 130,606
Date of Expiry	Dec. 31, 2020	Dec. 31, 2019
Lloyds Bank plc Credit Facility [Member]
Line of Credit Facility [Line Items]
Commitment | £	£ 145,000	£ 140,000
In Use | £	£ 140,964	£ 130,606

Collateralized Reinsurance An68

Collateralized Reinsurance And Trust Agreements (Narrative) (Details) $ in Thousands	Apr. 13, 2017USD ($)item	Dec. 01, 2015USD ($)item	Nov. 18, 2014USD ($)	Apr. 24, 2014USD ($)item	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Effects of Reinsurance [Line Items]
Amount on deposit in trust accounts					$ 794,469
Preferred shares invested
Kilimanjaro Re Limited [Member]
Effects of Reinsurance [Line Items]
Number of collateralized reinsurance agreements | item	6	2		2
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount			$ 500,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 1 Through 3 [Member]
Effects of Reinsurance [Line Items]
Number of collateralized reinsurance agreements | item	3
Reinsurance Contrants	4 years
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 4 Through 6 [Member]
Effects of Reinsurance [Line Items]
Number of collateralized reinsurance agreements | item	3
Reinsurance Contrants	5 years
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 1 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	$ 225,000	$ 300,000		$ 250,000
Catastrophe reinsurance bonds funded amount	950,000	625,000		450,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 2 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	400,000	$ 325,000		$ 200,000
Catastrophe reinsurance bonds funded amount	300,000		$ 500,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 3 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	325,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 4 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	50,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 5 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	75,000
Kilimanjaro Re Limited [Member] | Catastrophe Reinsurance Agreement 6 [Member]
Effects of Reinsurance [Line Items]
Reinsurance coverage amount	$ 175,000
Mt. Logan Re [Member]
Effects of Reinsurance [Line Items]
Percentage of voting common shares owned by Group					100.00%
Assumed net risk exposures					$ 832,679	932,243
Preferred shares invested					$ 50,935	$ 58,955

Collateralized Reinsurance An69

Collateralized Reinsurance And Trust Agreements (Premiums And Losses Ceded By The Company To Affiliate) (Details) - Mt. Logan Re Segregated Accounts [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Effects of Reinsurance [Line Items]
Ceded written premiums	$ 64,003	$ 65,093	$ 160,949	$ 157,939
Ceded earned premiums	55,708	53,007	154,191	143,856
Ceded losses and LAE	197,395	8,725	241,792	38,459
Assumed written premiums	2,587	5,032	9,082	11,666
Assumed earned premiums	2,587	5,032	9,082	11,666
Assumed losses and LAE

Senior Notes (Narrative) (Detai

Senior Notes (Narrative) (Details) - Senior Notes [Member] - 4.868% Senior notes due 6/1/2044 [Member] - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Date Issued	Jun. 5, 2014
Principal amounts	$ 400,000,000
Debt Instrument, Term	30 years
Debt instrument, stated interest rate	4.868%	4.868%
Maturity Date	Jun. 1, 2044

Senior Notes (Schedule Of Outst

Senior Notes (Schedule Of Outstanding Senior Notes) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Consolidated balance sheet amount	$ 396,804,000	$ 396,714,000
4.868% Senior notes due 6/1/2044 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	4.868%	4.868%
Date issued	Jun. 5, 2014
Date due	Jun. 1, 2044
Principal amounts	$ 400,000,000
Consolidated balance sheet amount	396,804,000	$ 396,714,000
Market value	$ 420,008,000	$ 383,612,000

Senior Notes (Schedule Of Inter

Senior Notes (Schedule Of Interest Expense Incurred In Connection With Senior Notes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Senior Notes [Abstract]
Interest expense incurred	$ 4,868	$ 4,868	$ 14,604	$ 14,604

Long Term Subordinated Notes (N

Long Term Subordinated Notes (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Redemption date	May 1, 2047
6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	6.60%	6.60%
Maturity Date	May 1, 2067
Reset quarterly interest rate	3.70%
Percentage of principal amount required for redemption	100.00%
Outstanding debt reduction	$ 161,441
Fixed Rate Interest Period [Member] | 6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	6.60%
Interest payment commencement date	Nov. 15, 2007
Interest basis, term of LIBOR rate	3 months
Interest basis, 3 month LIBOR plus number of basis points, reset quarterly	2.385%
Right to defer interest on one or more occasions for up to number of consecutive years	10 years
Fixed Rate Interest Period [Member] | 6.6 % Long Term Subordinated Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest payment date	May 3, 2007
Fixed Rate Interest Period [Member] | 6.6 % Long Term Subordinated Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest payment date	May 14, 2017
Floating Rate Interest Period [Member] | 6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Right to defer interest on one or more occasions for up to number of consecutive years	10 years
5.4% Senior notes due 10/15/2014 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	5.40%
Maturity Date	Oct. 15, 2014
4.868% Senior notes due 6/1/2044 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	4.868%	4.868%
Maturity Date	Jun. 1, 2044

Long Term Subordinated Notes (S

Long Term Subordinated Notes (Schedule Of Outstanding Fixed To Floating Rate Long Term Subordinated Notes) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Consolidated balance sheet amount	$ 236,536,000	$ 236,462,000
6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate	6.60%	6.60%
Date Issued	Apr. 26, 2007
Original Principal Amount	$ 400,000,000
Maturity Date	May 1, 2067
Consolidated balance sheet amount	$ 236,536,000	$ 236,462,000
Market value	$ 221,380,000	$ 204,636,000
Scheduled [Member] | 6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Maturity Date	May 15, 2037
Final [Member] | 6.6 % Long Term Subordinated Notes [Member]
Debt Instrument [Line Items]
Maturity Date	May 1, 2067

Long Term Subordinated Notes 75

Long Term Subordinated Notes (Schedule Of Interest Expense Incurred In Connection With Long Term Subordinated Notes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Long Term Subordinated Notes [Abstract]
Interest expense incurred	$ 2,240	$ 3,937	$ 9,210	$ 11,811

Segment Reporting (Schedule Of

Segment Reporting (Schedule Of Underwriting Results For Operating Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Premiums earned	$ 1,598,875	$ 1,371,474	$ 4,280,653	$ 3,879,201
Incurred losses and LAE	2,210,082	786,168	3,842,145	2,344,733
Commission and brokerage	333,113	309,545	915,338	880,053
Other underwriting expenses	73,145	78,563	227,901	222,750
U.S. Reinsurance [Member]
Segment Reporting Information [Line Items]
Gross written premiums	908,256	654,770	1,962,207	1,597,005
Net written premiums	809,298	678,848	1,711,934	1,491,155
Premiums earned	649,772	519,160	1,609,790	1,478,974
Incurred losses and LAE	925,436	276,272	1,455,123	732,306
Commission and brokerage	113,449	116,667	328,230	354,608
Other underwriting expenses	12,095	14,265	40,624	39,856
Underwriting gain (loss)	(401,208)	111,956	(214,187)	352,204
International [Member]
Segment Reporting Information [Line Items]
Gross written premiums	344,805	348,812	931,008	925,028
Net written premiums	330,761	316,207	848,792	799,908
Premiums earned	305,951	282,442	841,348	823,493
Incurred losses and LAE	563,082	122,181	895,071	531,580
Commission and brokerage	68,441	78,384	199,438	209,348
Other underwriting expenses	8,307	11,030	27,601	26,822
Underwriting gain (loss)	(333,879)	70,847	(280,762)	55,743
Bermuda [Member]
Segment Reporting Information [Line Items]
Gross written premiums	311,781	245,995	870,473	612,657
Net written premiums	287,591	229,373	810,437	562,128
Premiums earned	267,488	215,761	766,051	610,466
Incurred losses and LAE	301,315	127,236	595,052	348,586
Commission and brokerage	83,861	59,605	205,770	169,413
Other underwriting expenses	9,049	8,785	27,551	26,290
Underwriting gain (loss)	(126,737)	20,135	(62,322)	66,177
Insurance [Member]
Segment Reporting Information [Line Items]
Gross written premiums	480,060	533,039	1,483,807	1,364,465
Net written premiums	370,439	340,216	1,179,873	1,047,863
Premiums earned	375,664	354,111	1,063,464	966,268
Incurred losses and LAE	420,249	260,479	896,899	732,261
Commission and brokerage	67,362	54,889	181,900	146,684
Other underwriting expenses	43,694	44,483	132,125	129,782
Underwriting gain (loss)	$ (155,641)	$ (5,740)	$ (147,460)	$ (42,459)

Segment Reporting (Schedule O77

Segment Reporting (Schedule Of Underwriting Results For Operating Segments To Income (Loss) Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net investment income	$ 136,973	$ 122,657	$ 393,770	$ 357,918
Net realized capital gains (losses)	41,535	380	119,531	(41,221)
Net derivative gain (loss)	2,656	6,510	6,052	5,486
Corporate expenses	(5,932)	(6,400)	(21,308)	(21,403)
Interest, fee and bond issue cost amortization expense	(7,266)	(8,893)	(24,289)	(27,194)
Other income (expense)	(54,568)	9,435	(59,146)	(20,998)
INCOME (LOSS) BEFORE TAXES	(904,067)	320,887	(290,121)	684,253
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting gain (loss)	(1,017,465)	197,198	(704,731)	431,665
Net investment income	136,973	122,657	393,770	357,918
Net realized capital gains (losses)	41,535	380	119,531	(41,221)
Net derivative gain (loss)	2,656	6,510	6,052	5,486
Corporate expenses	(5,932)	(6,400)	(21,308)	(21,403)
Interest, fee and bond issue cost amortization expense	(7,266)	(8,893)	(24,289)	(27,194)
Other income (expense)	(54,568)	9,435	(59,146)	(20,998)
INCOME (LOSS) BEFORE TAXES	$ (904,067)	$ 320,887	$ (290,121)	$ 684,253

Segment Reporting (Schedule O78

Segment Reporting (Schedule Of Gross Written Premiums Derived From Largest Non-U.S. Market) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
United Kingdom Gross Written Premium [Member]
Segment Reporting Information [Line Items]
Gross written premiums	$ 204,774	$ 182,786	$ 580,559	$ 511,994

Share-Based Compensation Plans

Share-Based Compensation Plans (Narrative) (Details) - Restricted Shares [Member]	3 Months Ended
	Sep. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards granted | shares	3,855
Share-based compensation awards, grant date	Sep. 6, 2017
Share-based compensation awards, per option fair value | $ / shares	$ 230.520

Retirement Benefits (Summary Of

Retirement Benefits (Summary Of Pension Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Pension contributions	$ 10,000	$ 30,000	$ 10,000	$ 30,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,737	2,731	9,335	8,524
Interest cost	2,509	2,371	7,060	7,093
Expected return on plan assets	(3,263)	(2,789)	(9,572)	(7,757)
Amortization of net (income) loss	2,091	1,984	8,172	6,012
Net periodic benefit cost	4,074	4,297	14,995	13,872
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	392	354	1,273	1,230
Interest cost	296	252	793	844
Amortization of prior service cost	(33)	(33)	(98)	(33)
Amortization of net (income) loss	48		199	96
Net periodic benefit cost	$ 703	$ 573	$ 2,167	$ 2,137

Dispositions (Narrative) (Detai

Dispositions (Narrative) (Details) - Heartland Crop [Member] $ in Thousands	Aug. 24, 2016USD ($)
Proceeds from sale of business	$ 49,000
After-tax loss on sale	$ 12,942