Document_and_Entity_Informatio
| Document and Entity Information | 9 Months Ended | |
| Sep. 30, 2014 | Oct. 31, 2014 | |
| Document and Entity Information [Abstract] | ' | ' |
| Entity Registrant Name | 'BERKLEY W R CORP | ' |
| Entity Central Index Key | '0000011544 | ' |
| Current Fiscal Year End Date | '--12-31 | ' |
| Entity Filer Category | 'Large Accelerated Filer | ' |
| Document Type | '10-Q | ' |
| Document Period End Date | 30-Sep-14 | ' |
| Document Fiscal Year Focus | '2014 | ' |
| Document Fiscal Period Focus | 'Q3 | ' |
| Amendment Flag | 'false | ' |
| Entity Common Stock, Shares Outstanding | ' | 126,909,538 |
Consolidated_Balance_Sheet_Con
| Consolidated Balance Sheet Consolidated Balance Sheet (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Assets [Abstract] | ' | ' |
| Fixed maturity securities | $12,397,756 | $11,616,844 |
| Equity securities | 222,024 | 283,338 |
| Arbitrage trading account | 918,223 | 522,128 |
| Investment funds | 1,020,132 | 1,067,495 |
| Loans receivable | 343,300 | 343,583 |
| Real estate | 703,994 | 715,242 |
| Total investments | 15,605,429 | 14,548,630 |
| Cash and cash equivalents | 1,342,285 | 839,738 |
| Premiums and fees receivable | 1,681,674 | 1,557,480 |
| Due from reinsurers | 1,452,393 | 1,533,103 |
| Accrued investment income | 138,904 | 118,329 |
| Prepaid reinsurance premiums | 418,081 | 367,803 |
| Deferred policy acquisition costs | 492,500 | 452,101 |
| Property, furniture and equipment | 333,938 | 339,448 |
| Federal and foreign income taxes | 0 | 44,857 |
| Goodwill | 103,337 | 110,146 |
| Trading account receivables from brokers and clearing organizations | 0 | 304,936 |
| Other assets | 529,056 | 335,225 |
| Total assets | 22,097,597 | 20,551,796 |
| Liabilities: | ' | ' |
| Reserves for losses and loss expenses | 10,314,265 | 10,080,941 |
| Unearned premiums | 3,111,013 | 2,781,437 |
| Due to reinsurers | 255,430 | 276,755 |
| Trading account securities sold but not yet purchased | 159,537 | 162,278 |
| Payables to Broker-Dealers and Clearing Organizations | 95,681 | 0 |
| Federal and foreign income taxes | 17,618 | 0 |
| Other liabilities | 938,554 | 848,749 |
| Junior subordinated debentures | 339,995 | 339,800 |
| Senior notes and other debt | 2,122,030 | 1,692,442 |
| Total liabilities | 17,354,123 | 16,182,402 |
| Equity: | ' | ' |
| Authorized 5,000,000 shares; issued and outstanding - none | 0 | 0 |
| Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 126,907,538 and 132,233,167 shares, respectively | 47,024 | 47,024 |
| Additional paid-in capital | 982,104 | 967,440 |
| Retained earnings | 5,762,406 | 5,265,015 |
| Accumulated other comprehensive income | 273,545 | 189,391 |
| Treasury stock, at cost, 108,210,380 and 102,884,751 shares, respectively | 2,356,176 | 2,132,835 |
| Total stockholders’ equity | 4,708,903 | 4,336,035 |
| Noncontrolling interests | 34,571 | 33,359 |
| Total equity | 4,743,474 | 4,369,394 |
| Total liabilities and equity | $22,097,597 | $20,551,796 |
Consolidated_Balance_Sheet_Con1
| Consolidated Balance Sheet Consolidated Balance Sheet (Parenthetical) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Statement of Financial Position [Abstract] | ' | ' |
| Preferred stock, par value $.10 per share: | $0.10 | $0.10 |
| Preferred shares authorized | 5,000,000 | 5,000,000 |
| Preferred shares issued | 0 | 0 |
| Preferred shares outstanding | 0 | 0 |
| Common stock, par value $.20 per share: | $0.20 | $0.20 |
| Common shares authorized | 500,000,000 | 500,000,000 |
| Common shares issued | 127,613,325 | 132,233,167 |
| Common shares outstanding | 127,613,325 | 132,233,167 |
| Treasury stock issued at cost | 107,504,593 | 102,884,751 |
Consolidated_Statements_of_Ope
| Consolidated Statements of Operations (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, except Per Share data, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| REVENUES: | ' | ' | ' | ' |
| Net premiums written | $1,525,382 | $1,423,625 | $4,541,038 | $4,142,489 |
| Change in net unearned premiums | -64,578 | -94,763 | -298,977 | -298,993 |
| Net premiums earned | 1,460,804 | 1,328,862 | 4,242,061 | 3,843,496 |
| Net investment income | 179,225 | 125,634 | 486,665 | 405,300 |
| Insurance service fees | 26,345 | 26,121 | 81,970 | 80,509 |
| Net investment gains | 72,258 | 43,869 | 234,180 | 96,896 |
| Revenues from wholly-owned investees | 101,568 | 109,390 | 298,693 | 284,900 |
| Other income | 405 | 248 | 931 | 754 |
| Total revenues | 1,840,605 | 1,634,124 | 5,344,500 | 4,711,855 |
| OPERATING COSTS AND EXPENSES: | ' | ' | ' | ' |
| Losses and loss expenses | 887,123 | 798,276 | 2,576,996 | 2,348,425 |
| Other operating costs and expenses | 544,303 | 504,096 | 1,593,619 | 1,479,986 |
| Expenses from wholly-owned investees | 97,797 | 103,170 | 290,823 | 273,615 |
| Interest expense | 32,929 | 30,349 | 93,570 | 92,667 |
| Total operating costs and expenses | 1,562,152 | 1,435,891 | 4,555,008 | 4,194,693 |
| Income before income taxes | 278,453 | 198,233 | 789,492 | 517,162 |
| Income tax expense | -89,662 | -60,045 | -250,840 | -147,249 |
| Net income before noncontrolling interests | 188,791 | 138,188 | 538,652 | 369,913 |
| Noncontrolling interests | -252 | -1,214 | -479 | -367 |
| Net income to common stockholders | $188,539 | $136,974 | $538,173 | $369,546 |
| NET INCOME PER SHARE: | ' | ' | ' | ' |
| Basic | $1.48 | $1.01 | $4.20 | $2.72 |
| Diluted | $1.42 | $0.97 | $4.02 | $2.62 |
Consolidated_Statements_of_Com
| Consolidated Statements of Comprehensive Income Statement (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Net income before noncontrolling interests | $188,791 | $138,188 | $538,652 | $369,913 |
| Other comprehensive income (loss): | ' | ' | ' | ' |
| Change in unrealized currency translation adjustments | -49,380 | 44,328 | -28,590 | -25,451 |
| Change in unrealized investment gains (losses), net of taxes | -12,912 | -38,879 | 108,232 | -228,129 |
| Change in net pension asset, net of taxes | 2,020 | 1,814 | 4,631 | 5,442 |
| Other comprehensive income (loss) | -60,272 | 7,263 | 84,273 | -248,138 |
| Comprehensive income | 128,519 | 145,451 | 622,925 | 121,775 |
| Comprehensive (income) to the noncontrolling interest | -334 | -1,223 | -598 | -381 |
| Comprehensive income to common stockholders | $128,185 | $144,228 | $622,327 | $121,394 |
Consolidated_Statements_of_Sto
| Consolidated Statements of Stockholders' Equity Statement (USD $) | Total | Common stocks | Additional Paid-in Capital [Member] | Retained Earnings [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Accumulated Translation Adjustment [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Treasury Stock [Member] | Noncontrolling Interest [Member] |
| In Thousands, unless otherwise specified | ||||||||||
| Beginning and end of period at Dec. 31, 2012 | ' | $47,024 | $945,166 | $4,817,807 | $517,658 | ($36,676) | ($15,351) | ' | ($1,969,411) | $29,249 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Options exercised and restricted stock units issued, net of tax | ' | ' | -1,428 | ' | ' | ' | ' | ' | ' | ' |
| Restricted stock units expensed | ' | ' | 17,031 | ' | ' | ' | ' | ' | ' | ' |
| Stock issued to directors | ' | ' | 535 | ' | ' | ' | ' | ' | 597 | ' |
| Net income before noncontrolling interests | 369,913 | ' | ' | 369,546 | ' | ' | ' | ' | ' | 367 |
| Dividends | ' | ' | ' | -39,336 | ' | ' | ' | ' | ' | ' |
| Change in unrealized investment gains (losses), net of taxes | -228,129 | ' | ' | ' | -228,677 | ' | ' | ' | ' | ' |
| Unrealized gains on other-than-temporarily impaired securities | ' | ' | ' | ' | 534 | ' | ' | ' | ' | ' |
| Change in unrealized currency translation adjustments | -25,451 | ' | ' | ' | ' | -25,451 | ' | ' | ' | ' |
| Change in net pension asset, net of taxes | 5,442 | ' | ' | ' | ' | ' | 5,442 | ' | ' | ' |
| Stock exercised/vested | ' | ' | ' | ' | ' | ' | ' | ' | 1,434 | ' |
| Stock repurchased | ' | ' | ' | ' | ' | ' | ' | ' | -39,370 | ' |
| Stock issued to directors | ' | ' | 535 | ' | ' | ' | ' | ' | 597 | ' |
| Contributions | ' | ' | ' | ' | ' | ' | ' | ' | ' | -1,406 |
| Other comprehensive income (loss) | -248,138 | ' | ' | ' | ' | -25,451 | 5,442 | -248,138 | ' | 14 |
| End of period at Sep. 30, 2013 | ' | ' | 961,304 | 5,148,017 | 289,515 | -62,127 | -9,909 | 217,479 | -2,006,750 | 28,224 |
| Beginning and end of period at Jun. 30, 2013 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Net income before noncontrolling interests | 138,188 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in unrealized investment gains (losses), net of taxes | -38,879 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in unrealized currency translation adjustments | 44,328 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in net pension asset, net of taxes | 1,814 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Other comprehensive income (loss) | 7,263 | ' | ' | ' | ' | 44,328 | 1,814 | 7,263 | ' | ' |
| End of period at Sep. 30, 2013 | ' | ' | ' | ' | ' | -62,127 | -9,909 | 217,479 | ' | ' |
| Beginning and end of period at Dec. 31, 2013 | 4,369,394 | 47,024 | 967,440 | 5,265,015 | 256,566 | -60,524 | -6,651 | ' | -2,132,835 | 33,359 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Options exercised and restricted stock units issued, net of tax | ' | ' | -6,383 | ' | ' | ' | ' | ' | ' | ' |
| Restricted stock units expensed | ' | ' | 20,456 | ' | ' | ' | ' | ' | ' | ' |
| Stock issued to directors | ' | ' | 591 | ' | ' | ' | ' | ' | 594 | ' |
| Net income before noncontrolling interests | 538,652 | ' | ' | 538,173 | ' | ' | ' | ' | ' | 479 |
| Dividends | ' | ' | ' | -40,782 | ' | ' | ' | ' | ' | ' |
| Change in unrealized investment gains (losses), net of taxes | 108,232 | ' | ' | ' | 107,501 | ' | ' | ' | ' | ' |
| Unrealized gains on other-than-temporarily impaired securities | ' | ' | ' | ' | 612 | ' | ' | ' | ' | ' |
| Change in unrealized currency translation adjustments | -28,590 | ' | ' | ' | ' | -28,590 | ' | ' | ' | ' |
| Change in net pension asset, net of taxes | 4,631 | ' | ' | ' | ' | ' | 4,631 | ' | ' | ' |
| Stock exercised/vested | ' | ' | ' | ' | ' | ' | ' | ' | 6,384 | ' |
| Stock repurchased | ' | ' | ' | ' | ' | ' | ' | ' | -230,319 | ' |
| Stock issued to directors | ' | ' | 591 | ' | ' | ' | ' | ' | 594 | ' |
| Contributions | ' | ' | ' | ' | ' | ' | ' | ' | ' | 614 |
| Other comprehensive income (loss) | 84,273 | ' | ' | ' | ' | -28,590 | 4,631 | 84,273 | ' | 119 |
| End of period at Sep. 30, 2014 | 4,743,474 | ' | 982,104 | 5,762,406 | 364,679 | -89,114 | -2,020 | 273,545 | -2,356,176 | 34,571 |
| Beginning and end of period at Jun. 30, 2014 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Net income before noncontrolling interests | 188,791 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in unrealized investment gains (losses), net of taxes | -12,912 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in unrealized currency translation adjustments | -49,380 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Change in net pension asset, net of taxes | 2,020 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Other comprehensive income (loss) | -60,272 | ' | ' | ' | ' | -49,380 | 2,020 | -60,272 | ' | ' |
| End of period at Sep. 30, 2014 | $4,743,474 | ' | ' | ' | ' | ($89,114) | ($2,020) | $273,545 | ' | ' |
Consolidated_Statements_of_Cas
| Consolidated Statements of Cash Flows (USD $) | 9 Months Ended | |
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 |
| CASH FROM (USED IN) OPERATING ACTIVITIES: | ' | ' |
| Net income to common stockholders | $538,173 | $369,546 |
| Adjustments to reconcile net income to net cash from operating activities: | ' | ' |
| Net investment gains | -234,180 | -96,896 |
| Depreciation and amortization | 63,415 | 80,049 |
| Noncontrolling interests | 479 | 367 |
| Investment funds | -150,502 | -48,299 |
| Stock incentive plans | 21,549 | 18,163 |
| Change in: | ' | ' |
| Arbitrage trading account | 1,781 | -249 |
| Premiums and fees receivable | -125,319 | -161,660 |
| Reinsurance accounts | 12,967 | -168,863 |
| Deferred policy acquisition costs | -44,087 | -51,629 |
| Income taxes | 11,092 | -25,396 |
| Reserves for losses and loss expenses | 277,542 | 341,266 |
| Unearned premiums | 345,521 | 363,354 |
| Other | -143,645 | 6,942 |
| Net cash from operating activities | 574,786 | 626,695 |
| CASH USED IN INVESTING ACTIVITIES: | ' | ' |
| Proceeds from sale of fixed maturity securities | 546,970 | 891,357 |
| Proceeds from sale of equity securities | 109,928 | 222,396 |
| Distributions from (contributions to) investment funds | 285,233 | -57,812 |
| Proceeds from maturities and prepayments of fixed maturity securities | 1,887,252 | 2,244,665 |
| Purchase of fixed maturity securities | -3,098,477 | -3,198,204 |
| Purchase of equity securities | -28,606 | -184,829 |
| Additions to real estate | -253,007 | -47,279 |
| SEC Schedule III, Real Estate, Cost of Real Estate Sold | 343,723 | 0 |
| Change in loans receivable | 320 | -99,356 |
| Net additions to property, furniture and equipment | -30,797 | -49,425 |
| Change in balances due to security brokers | 68,411 | -37,554 |
| Gain (Loss) on Disposition of Business | 15,612 | -21,408 |
| Payment for business purchased, net of cash acquired | -65,423 | -38,556 |
| Net cash used in investing activities | -218,861 | -376,005 |
| CASH USED IN (FROM) FINANCING ACTIVITIES: | ' | ' |
| Repayment of senior notes and other debt | -1,829 | -463,600 |
| Proceeds from Issuance of Debt | 431,409 | 349,423 |
| Cash dividends to common stockholders | -40,784 | -39,336 |
| Purchase of common treasury shares | -236,703 | -39,370 |
| Other, net | 915 | 7,341 |
| Net cash used in (from) financing activities | 153,008 | -185,542 |
| Net impact on cash due to change in foreign exchange rates | -6,386 | -4,492 |
| Net change in cash and cash equivalents | 502,547 | 60,656 |
| Cash and cash equivalents at beginning of year | 839,738 | 905,670 |
| Cash and cash equivalents at end of period | $1,342,285 | $966,326 |
General_General
| General General | 9 Months Ended |
| Sep. 30, 2014 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | ' |
| Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] | ' |
| General | |
| The accompanying unaudited consolidated financial statements of W. R. Berkley Corporation and its subsidiaries (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all the information and notes required by GAAP for annual financial statements. The unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring items, which are necessary to present fairly the Company’s financial position and results of operations on a basis consistent with the prior audited consolidated financial statements. Operating results for interim periods are not necessarily indicative of the results that may be expected for the year. All significant intercompany accounts and transactions have been eliminated. The preparation of financial statements requires the use of management estimates. For further information related to a description of areas of judgment and estimates and other information necessary to understand the Company’s financial position and results of operations, refer to the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013. Reclassifications have been made in the 2013 financial statements as originally reported to conform to the presentation of the 2014 financial statements. | |
| The income tax provision has been computed based on the Company’s estimated annual effective tax rate. The effective tax rate for the quarter differs from the federal income tax rate of 35% principally because of tax-exempt investment income. |
Per_Share_Data_Per_Share_Data
| Per Share Data Per Share Data | 9 Months Ended | |||||||||||
| Sep. 30, 2014 | ||||||||||||
| Earnings Per Share [Abstract] | ' | |||||||||||
| Earnings Per Share | ' | |||||||||||
| Per Share Data | ||||||||||||
| The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted EPS is based upon the weighted average number of common and common equivalent shares outstanding during the period and is calculated using the treasury stock method for stock incentive plans. Common equivalent shares are excluded from the computation in periods in which they have an anti-dilutive effect. | ||||||||||||
| The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows: | ||||||||||||
| For the Three Months | For the Nine Months | |||||||||||
| Ended September 30, | Ended September 30, | |||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||
| Basic | 127,165 | 135,268 | 128,225 | 135,726 | ||||||||
| Diluted | 133,001 | 140,758 | 133,886 | 141,095 | ||||||||
Recent_Accounting_Pronouncemen
| Recent Accounting Pronouncements Recent Accounting Pronouncements | 9 Months Ended |
| Sep. 30, 2014 | |
| Accounting Policies [Abstract] | ' |
| Recent Accounting Pronouncements | ' |
| Recent Accounting Pronouncements | |
| In January 2014, the Financial Accounting Standards Board issued guidance relating to Accounting for Investments in Qualified Affordable Housing Projects. This guidance modified the amortization method on these investments and the statement of operations classification as pre-adoption amounts were presented in both pre-tax income and income tax expense while post adoption all impacts are recorded in income tax expense. The Company adopted this guidance effective January 1, 2014, and the impact of applying this guidance was immaterial. | |
| All recently issued but not yet effective accounting and reporting standards are either not applicable to the Company or are not expected to have a material impact on the Company. |
Acquistions_Acquisitions
| Acquistions Acquisitions | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Business Combinations [Abstract] | ' | |||||||
| Business Combination Disclosure | ' | |||||||
| Acquisitions/Dispositions | ||||||||
| In 2014, the Company acquired a specialty property and casualty insurance distribution company for $83 million. The fair values of the assets acquired and liabilities assumed have been estimated based on a preliminary valuation. The fair values of the assets and liabilities will be adjusted, as needed, following completion of a final valuation. | ||||||||
| In 2012, the Company acquired a 49% interest in a worldwide supplier of after-market original equipment manufacturer (OEM) parts, systems and custom logistic support services for military aircraft operations for $43 million. In 2013, the Company acquired the remaining 51% of this business for $43 million. The estimated useful lives of the intangible assets acquired range from 2 years to 15 years, with approximately $3 million having an indefinite life. | ||||||||
| In 2014, the Company sold an aviation-related business for $16 million. The business had a net carrying value of $15 million. | ||||||||
| The following table summarizes the estimated fair value of net assets acquired and liabilities assumed for business combinations completed in 2014 and 2013: | ||||||||
| September 30, | December 31, | |||||||
| (In thousands) | 2014 | 2013 | ||||||
| Cash and cash equivalents | $ | 17,456 | $ | 3,911 | ||||
| Real estate, furniture and equipment | 669 | 898 | ||||||
| Goodwill and other intangibles assets | 77,967 | 64,464 | ||||||
| Premium and service fee receivable | 20,178 | — | ||||||
| Other assets | — | 60,661 | ||||||
| Total assets acquired | 116,270 | 129,934 | ||||||
| Debt | — | (27,612 | ) | |||||
| Other liabilities assumed | (33,391 | ) | (17,076 | ) | ||||
| Net assets acquired | $ | 82,879 | $ | 85,246 | ||||
Statements_of_Comprehensive_In
| Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Notes) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity [Abstract] | ' | |||||||||||||||
| Comprehensive Income (Loss) | ' | |||||||||||||||
| Statement of Comprehensive Income (Loss) | ||||||||||||||||
| The following table presents the components of the changes in accumulated other comprehensive income (loss) ("AOCI"): | ||||||||||||||||
| (In thousands) | Unrealized Investment Gains (Losses) | Currency Translation Adjustments | Net Pension Asset | Accumulated Other Comprehensive Income (Loss) | ||||||||||||
| As of and for the nine months ended September 30, 2014: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 256,566 | $ | (60,524 | ) | $ | (6,651 | ) | $ | 189,391 | ||||||
| Other comprehensive income (loss) before reclassifications | 143,388 | (28,590 | ) | — | 114,798 | |||||||||||
| Amounts reclassified from AOCI | (35,156 | ) | — | 4,631 | (30,525 | ) | ||||||||||
| Other comprehensive income (loss) | 108,232 | (28,590 | ) | 4,631 | 84,273 | |||||||||||
| Unrealized investment gain (loss) related to non-controlling interest | (119 | ) | — | — | (119 | ) | ||||||||||
| End of period | $ | 364,679 | $ | (89,114 | ) | $ | (2,020 | ) | $ | 273,545 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (54,086 | ) | -1 | $ | — | $ | 7,125 | -2 | $ | (46,961 | ) | ||||
| Tax effect (3) | 18,930 | — | (2,494 | ) | 16,436 | |||||||||||
| After-tax amounts reclassified | $ | (35,156 | ) | $ | — | $ | 4,631 | $ | (30,525 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | 163,651 | $ | (28,590 | ) | $ | 7,125 | $ | 142,186 | |||||||
| Tax effect | (55,419 | ) | — | (2,494 | ) | (57,913 | ) | |||||||||
| Other comprehensive income (loss) | $ | 108,232 | $ | (28,590 | ) | $ | 4,631 | $ | 84,273 | |||||||
| As of and for the three months ended September 30, 2014: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 377,673 | $ | (39,734 | ) | $ | (4,040 | ) | $ | 333,899 | ||||||
| Other comprehensive income (loss) before reclassifications | 3,099 | (49,380 | ) | — | (46,281 | ) | ||||||||||
| Amounts reclassified from AOCI | (16,011 | ) | — | 2,020 | (13,991 | ) | ||||||||||
| Other comprehensive income (loss) | (12,912 | ) | (49,380 | ) | 2,020 | (60,272 | ) | |||||||||
| Unrealized investment gain (loss) related to non-controlling interest | (82 | ) | — | — | (82 | ) | ||||||||||
| End of period | $ | 364,679 | $ | (89,114 | ) | $ | (2,020 | ) | $ | 273,545 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (24,632 | ) | -1 | $ | — | $ | 3,108 | -2 | $ | (21,524 | ) | ||||
| Tax effect (3) | 8,621 | — | (1,088 | ) | 7,533 | |||||||||||
| After-tax amounts reclassified | $ | (16,011 | ) | $ | — | $ | 2,020 | $ | (13,991 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (25,029 | ) | $ | (49,380 | ) | $ | 3,108 | $ | (71,301 | ) | |||||
| Tax effect | 12,117 | — | (1,088 | ) | 11,029 | |||||||||||
| Other comprehensive income (loss) | $ | (12,912 | ) | $ | (49,380 | ) | $ | 2,020 | $ | (60,272 | ) | |||||
| Unrealized Investment Gains (Losses) | Currency Translation Adjustments | Net Pension Asset | Accumulated Other Comprehensive Income (Loss) | |||||||||||||
| (In thousands) | ||||||||||||||||
| As of and for the nine months ended September 30, 2013: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 517,658 | $ | (36,676 | ) | $ | (15,351 | ) | $ | 465,631 | ||||||
| Other comprehensive income (loss) before reclassifications | (172,276 | ) | (25,451 | ) | — | (197,727 | ) | |||||||||
| Amounts reclassified from AOCI | (55,853 | ) | — | 5,442 | (50,411 | ) | ||||||||||
| Other comprehensive income (loss) | (228,129 | ) | (25,451 | ) | 5,442 | (248,138 | ) | |||||||||
| Unrealized investment gain related to non-controlling interest | (14 | ) | — | — | (14 | ) | ||||||||||
| End of period | $ | 289,515 | $ | (62,127 | ) | $ | (9,909 | ) | $ | 217,479 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (85,928 | ) | -1 | $ | — | $ | 8,372 | -2 | $ | (77,556 | ) | ||||
| Tax effect (3) | 30,075 | — | (2,930 | ) | 27,145 | |||||||||||
| After-tax amounts reclassified | $ | (55,853 | ) | $ | — | $ | 5,442 | $ | (50,411 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (350,968 | ) | $ | (25,451 | ) | $ | 8,372 | $ | (368,047 | ) | |||||
| Tax effect | 122,839 | — | (2,930 | ) | 119,909 | |||||||||||
| Other comprehensive income (loss) | $ | (228,129 | ) | $ | (25,451 | ) | $ | 5,442 | $ | (248,138 | ) | |||||
| As of and for the three months ended September 30, 2013: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 328,403 | $ | (106,455 | ) | $ | (11,723 | ) | $ | 210,225 | ||||||
| Other comprehensive income (loss) before reclassifications | (10,331 | ) | 44,328 | — | 33,997 | |||||||||||
| Amounts reclassified from AOCI | (28,548 | ) | — | 1,814 | (26,734 | ) | ||||||||||
| Other comprehensive income (loss) | (38,879 | ) | 44,328 | 1,814 | 7,263 | |||||||||||
| Unrealized investment gain related to non-controlling interest | (9 | ) | — | — | (9 | ) | ||||||||||
| End of period | $ | 289,515 | $ | (62,127 | ) | $ | (9,909 | ) | $ | 217,479 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (43,920 | ) | -1 | $ | — | $ | 2,790 | -2 | $ | (41,130 | ) | ||||
| Tax effect (3) | 15,372 | — | (976 | ) | 14,396 | |||||||||||
| After-tax amounts reclassified | $ | (28,548 | ) | $ | — | $ | 1,814 | $ | (26,734 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (59,814 | ) | $ | 44,328 | $ | 2,790 | $ | (12,696 | ) | ||||||
| Tax effect | 20,935 | — | (976 | ) | 19,959 | |||||||||||
| Other comprehensive income (loss) | $ | (38,879 | ) | $ | 44,328 | $ | 1,814 | $ | 7,263 | |||||||
| _______________ | ||||||||||||||||
| (1) Net investment gains in the consolidated statements of income. | ||||||||||||||||
| (2) Other operating costs and expenses in the consolidated statements of income. | ||||||||||||||||
| (3) Income tax expense in the consolidated statements of income. | ||||||||||||||||
Statements_of_Cash_Flow_Statem
| Statements of Cash Flow Statements of Cash Flow | 9 Months Ended |
| Sep. 30, 2014 | |
| Supplemental Cash Flow Elements [Abstract] | ' |
| Cash Flow, Supplemental Disclosures | ' |
| Statements of Cash Flow | |
| Interest payments were $108,688,000 and $114,026,000 and income taxes paid were $238,030,000 and $176,632,000 in the nine months ended September 30, 2014 and 2013, respectively. |
Investments_In_Fixed_Maturity_
| Investments In Fixed Maturity Securities (Debt Securities [Member]) | 9 Months Ended | |||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||
| Debt Securities [Member] | ' | |||||||||||||||||||
| Schedule of Marketable Securities [Line Items] | ' | |||||||||||||||||||
| Investments In Fixed Maturity Securities | ' | |||||||||||||||||||
| Investments in Fixed Maturity Securities | ||||||||||||||||||||
| At September 30, 2014 and December 31, 2013, investments in fixed maturity securities were as follows: | ||||||||||||||||||||
| (In thousands) | Amortized | Gross Unrealized | Fair | Carrying | ||||||||||||||||
| Cost | Gains | Losses | Value | Value | ||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||
| Held to maturity: | ||||||||||||||||||||
| State and municipal | $ | 71,897 | $ | 16,991 | $ | — | $ | 88,888 | $ | 71,897 | ||||||||||
| Residential mortgage-backed | 24,300 | 2,901 | — | 27,201 | 24,300 | |||||||||||||||
| Corporate | 4,999 | 368 | — | 5,367 | 4,999 | |||||||||||||||
| Total held to maturity | 101,196 | 20,260 | — | 121,456 | 101,196 | |||||||||||||||
| Available for sale: | ||||||||||||||||||||
| U.S. government and government agency | 787,967 | 30,296 | (5,229 | ) | 813,034 | 813,034 | ||||||||||||||
| State and municipal | 3,958,141 | 226,746 | (4,819 | ) | 4,180,068 | 4,180,068 | ||||||||||||||
| Mortgage-backed securities: | ||||||||||||||||||||
| Residential (1) | 1,209,068 | 26,100 | (14,209 | ) | 1,220,959 | 1,220,959 | ||||||||||||||
| Commercial | 76,993 | 976 | (83 | ) | 77,886 | 77,886 | ||||||||||||||
| Corporate | 4,866,983 | 191,727 | (17,008 | ) | 5,041,702 | 5,041,702 | ||||||||||||||
| Foreign | 880,959 | 95,159 | (13,207 | ) | 962,911 | 962,911 | ||||||||||||||
| Total available for sale | 11,780,111 | 571,004 | (54,555 | ) | 12,296,560 | 12,296,560 | ||||||||||||||
| Total investments in fixed maturity securities | $ | 11,881,307 | $ | 591,264 | $ | (54,555 | ) | $ | 12,418,016 | $ | 12,397,756 | |||||||||
| December 31, 2013 | ||||||||||||||||||||
| Held to maturity: | ||||||||||||||||||||
| State and municipal | $ | 68,929 | $ | 11,172 | $ | — | $ | 80,101 | $ | 68,929 | ||||||||||
| Residential mortgage-backed | 27,393 | 3,311 | — | 30,704 | 27,393 | |||||||||||||||
| Corporate | 4,998 | 417 | — | 5,415 | 4,998 | |||||||||||||||
| Total held to maturity | 101,320 | 14,900 | — | 116,220 | 101,320 | |||||||||||||||
| Available for sale: | ||||||||||||||||||||
| U.S. government and government agency | 858,319 | 34,522 | (7,982 | ) | 884,859 | 884,859 | ||||||||||||||
| State and municipal | 4,085,791 | 162,330 | (29,837 | ) | 4,218,284 | 4,218,284 | ||||||||||||||
| Mortgage-backed securities: | ||||||||||||||||||||
| Residential (1) | 1,248,693 | 25,895 | (25,941 | ) | 1,248,647 | 1,248,647 | ||||||||||||||
| Commercial | 76,454 | 5,670 | (988 | ) | 81,136 | 81,136 | ||||||||||||||
| Corporate | 4,076,585 | 156,256 | (30,100 | ) | 4,202,741 | 4,202,741 | ||||||||||||||
| Foreign | 844,469 | 51,674 | (16,286 | ) | 879,857 | 879,857 | ||||||||||||||
| Total available for sale | 11,190,311 | 436,347 | (111,134 | ) | 11,515,524 | 11,515,524 | ||||||||||||||
| Total investments in fixed maturity securities | $ | 11,291,631 | $ | 451,247 | $ | (111,134 | ) | $ | 11,631,744 | $ | 11,616,844 | |||||||||
| ________________ | ||||||||||||||||||||
| -1 | Gross unrealized losses for residential mortgage-backed securities include $1,020,000 and $1,961,000 as of September 30, 2014 and December 31, 2013, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income. | |||||||||||||||||||
| The amortized cost and fair value of fixed maturity securities at September 30, 2014, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations. | ||||||||||||||||||||
| (In thousands) | Amortized | Fair Value | ||||||||||||||||||
| Cost | ||||||||||||||||||||
| Due in one year or less | $ | 889,062 | $ | 900,273 | ||||||||||||||||
| Due after one year through five years | 4,052,836 | 4,268,705 | ||||||||||||||||||
| Due after five years through ten years | 3,105,077 | 3,288,731 | ||||||||||||||||||
| Due after ten years | 2,523,971 | 2,634,261 | ||||||||||||||||||
| Mortgage-backed securities | 1,310,361 | 1,326,046 | ||||||||||||||||||
| Total | $ | 11,881,307 | $ | 12,418,016 | ||||||||||||||||
| At September 30, 2014, there were no investments, other than investments in United States government and government agency securities, which exceeded 10% of common stockholders’ equity. | ||||||||||||||||||||
Investments_in_Equity_Securiti
| Investments in Equity Securities (Equity securities available for sale) | 9 Months Ended | |||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||
| Equity securities available for sale | ' | |||||||||||||||||||
| Schedule of Available-for-sale Securities [Line Items] | ' | |||||||||||||||||||
| Investments in Equity Securities | ' | |||||||||||||||||||
| Investments in Equity Securities | ||||||||||||||||||||
| At September 30, 2014 and December 31, 2013, investments in equity securities were as follows: | ||||||||||||||||||||
| (In thousands) | Cost | Gross Unrealized | Fair | Carrying | ||||||||||||||||
| Gains | Losses | Value | Value | |||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||
| Common stocks | $ | 68,762 | $ | 11,742 | $ | (531 | ) | $ | 79,973 | $ | 79,973 | |||||||||
| Preferred stocks | 92,767 | 52,463 | (3,179 | ) | 142,051 | 142,051 | ||||||||||||||
| Total | $ | 161,529 | $ | 64,205 | $ | (3,710 | ) | $ | 222,024 | $ | 222,024 | |||||||||
| December 31, 2013 | ||||||||||||||||||||
| Common stocks | $ | 118,536 | $ | 42,239 | $ | — | $ | 160,775 | $ | 160,775 | ||||||||||
| Preferred stocks | 85,091 | 43,791 | (6,319 | ) | 122,563 | 122,563 | ||||||||||||||
| Total | $ | 203,627 | $ | 86,030 | $ | (6,319 | ) | $ | 283,338 | $ | 283,338 | |||||||||
Arbitrage_Trading_Account_Arbi
| Arbitrage Trading Account Arbitrage Trading Account | 9 Months Ended |
| Sep. 30, 2014 | |
| Investments, Debt and Equity Securities [Abstract] | ' |
| Arbitrage Trading Account | ' |
| Arbitrage Trading Account | |
| At September 30, 2014 and December 31, 2013, the carrying value of the arbitrage trading account was $918 million and $522 million, respectively. The primary focus of the trading account is merger arbitrage. Merger arbitrage is the business of investing in the securities of publicly held companies which are the targets in announced tender offers and mergers. Arbitrage investing differs from other types of investing in its focus on transactions and events believed likely to bring about a change in value over a relatively short time period (usually four months or less). The Company believes that this makes merger arbitrage investments less vulnerable to changes in general financial market conditions. |
Net_Investment_Income_Net_Inve
| Net Investment Income Net Investment Income | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Income Statement [Abstract] | ' | |||||||||||||||
| Net Investment Income | ' | |||||||||||||||
| Net Investment Income | ||||||||||||||||
| Net investment income consists of the following: | ||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Investment income earned on: | ||||||||||||||||
| Fixed maturity securities, including cash and cash equivalents and loans receivable | $ | 117,289 | $ | 104,033 | $ | 331,947 | $ | 333,072 | ||||||||
| Investment funds | 59,077 | 5,492 | 135,232 | 45,248 | ||||||||||||
| Arbitrage trading account | 47 | 11,738 | 12,508 | 14,265 | ||||||||||||
| Equity securities available for sale | 1,369 | 3,192 | 5,418 | 9,073 | ||||||||||||
| Real estate | 3,042 | 3,086 | 9,207 | 9,343 | ||||||||||||
| Gross investment income | 180,824 | 127,541 | 494,312 | 411,001 | ||||||||||||
| Investment expense | (1,599 | ) | (1,907 | ) | (7,647 | ) | (5,701 | ) | ||||||||
| Net investment income | $ | 179,225 | $ | 125,634 | $ | 486,665 | $ | 405,300 | ||||||||
Investment_Funds_Investment_Fu
| Investment Funds Investment Funds | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity Method Investments and Joint Ventures [Abstract] | ' | |||||||||||||||
| Net Investment Income | ' | |||||||||||||||
| Investment Funds | ||||||||||||||||
| Investment funds consist of the following: | ||||||||||||||||
| Carrying Value as of | Income from Investment Funds | |||||||||||||||
| September 30, | December 31, | For the Nine Months Ended September 30, | ||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Real estate | $ | 282,431 | $ | 378,435 | $ | 24,341 | $ | 5,777 | ||||||||
| Energy | 159,857 | 155,026 | 18,136 | 25,959 | ||||||||||||
| Arbitrage | 286,845 | 271,575 | 15,270 | 3,050 | ||||||||||||
| Other | 290,999 | 262,459 | 77,485 | 10,462 | ||||||||||||
| Total | $ | 1,020,132 | $ | 1,067,495 | $ | 135,232 | $ | 45,248 | ||||||||
| The Company's share of the earnings or losses of investment funds is generally reported on a one-quarter lag in order to facilitate the timely completion of the Company's consolidated financial statements. | ||||||||||||||||
Real_Estate_Real_Estate
| Real Estate Real Estate | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Real Estate [Abstract] | ' | |||||||
| Real Estate | ' | |||||||
| Real Estate | ||||||||
| Investment in real estate represents directly owned property held for investment, as follows: | ||||||||
| Carrying Value | ||||||||
| September 30, | December 31, | |||||||
| (In thousands) | 2014 | 2013 | ||||||
| Properties in operation | $ | 196,884 | $ | 283,393 | ||||
| Properties under development | 507,110 | 431,849 | ||||||
| Total | $ | 703,994 | $ | 715,242 | ||||
| Included in properties in operation are a long-term ground lease in Washington, D.C. and an office building in West Palm Beach, Florida. Properties in operation are net of accumulated depreciation and amortization of $68,000 and $17,827,000 as of September 30, 2014 and December 31, 2013, respectively. Related depreciation expense was $3,228,000 and $5,111,000 for the nine months ended September 30, 2014 and 2013, respectively. Future minimum rental income expected on operating leases relating to properties in operation is $2,820,000 in 2014, $11,360,000 in 2015, $11,379,000 in 2016, $11,420,000 in 2017, $10,750,000 in 2018 and $343,903,000 thereafter. | ||||||||
| The properties under development are an office building in London, a mixed-use project in Washington, D.C. and an office complex in New York City. | ||||||||
Loans_Receivable_Loans_Receiva
| Loans Receivable Loans Receivable | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Receivables [Abstract] | ' | |||||||
| Loans Receivable | ' | |||||||
| Loans Receivable | ||||||||
| Loans receivable are as follows: | ||||||||
| (In thousands) | September 30, 2014 | 31-Dec-13 | ||||||
| Amortized cost: | ||||||||
| Real estate loans | $ | 259,522 | $ | 282,357 | ||||
| Commercial loans | 83,778 | 61,226 | ||||||
| Total | $ | 343,300 | $ | 343,583 | ||||
| Fair value: | ||||||||
| Real estate loans | $ | 261,342 | $ | 284,017 | ||||
| Commercial loans | 85,280 | 62,729 | ||||||
| Total | $ | 346,622 | $ | 346,746 | ||||
| Valuation allowance: | ||||||||
| Specific | $ | 115 | $ | — | ||||
| General | 2,427 | 2,087 | ||||||
| Total | $ | 2,542 | $ | 2,087 | ||||
| For the Three Months | ||||||||
| Ended September 30, | ||||||||
| 2014 | 2013 | |||||||
| Increase (decrease) in valuation allowance | $ | (24 | ) | $ | 72 | |||
| Loans receivable charged off | — | — | ||||||
| For the Nine Months | ||||||||
| Ended September 30, | ||||||||
| 2014 | 2013 | |||||||
| Increase in valuation allowance | $ | 455 | $ | 137 | ||||
| Loans receivable charged off | — | — | ||||||
| Loans receivable in non-accrual status as of September 30, 2014 were $15.2 million resulting from the transfer of such loans to held-for-sale. There were no loans receivable in non-accrual status as of December 31, 2013. | ||||||||
| The Company monitors the performance of its loans receivable and assesses the ability of the borrower to pay principal and interest based upon loan structure, underlying property values, cash flow and related financial and operating performance of the property and market conditions. Loans receivable with a potential for default are further assessed using discounted cash flow analysis and comparable cost and sales methodologies, if appropriate. | ||||||||
| Real estate loans are secured by commercial real estate primarily located in Arizona, California, Hawaii, Illinois, New York, North Carolina, Texas and Virginia. Real estate loans generally earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) through August 2025. Commercial loans are with small business owners who have secured the related financing with the assets of the business. Commercial loans generally earn interest on a fixed basis and have varying maturities not exceeding 10 years. | ||||||||
| The Company utilizes an internal risk rating system to assign a risk to each of its real estate loans. The loan rating system takes into consideration credit quality indicators including loan to value ratios, which compare the outstanding loan amount to the estimated value of the property, the borrower’s financial condition and performance with respect to loan terms, the Company’s position in the capital structure, and the overall leverage in the capital structure. Based on this rating system, none of the real estate loans were considered to be impaired at September 30, 2014, and accordingly, the Company determined that a specific valuation allowance was not required. | ||||||||
Realized_And_Unrealized_Invest
| Realized And Unrealized Investment Gains (Losses) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Realized and Unrealized Investment Gains (Losses) [Abstract] | ' | |||||||||||||||
| Realized and Unrealized Investment Gains (Losses) | ' | |||||||||||||||
| Realized and Unrealized Investment Gains (Losses) | ||||||||||||||||
| Realized and unrealized investment gains (losses) are as follows: | ||||||||||||||||
| For the Three Months Ended September 30, | For the Nine Months Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Realized investment gains (losses): | ||||||||||||||||
| Fixed maturity securities: | ||||||||||||||||
| Gains | $ | 13,803 | $ | 19,500 | $ | 17,263 | $ | 39,643 | ||||||||
| Losses | (2,208 | ) | (739 | ) | (3,727 | ) | (12,205 | ) | ||||||||
| Equity securities available for sale | 9,729 | 25,158 | 39,310 | 58,489 | ||||||||||||
| Investment funds | 50,919 | (34 | ) | 95,675 | 11,003 | |||||||||||
| Real estate | 15 | — | 85,659 | — | ||||||||||||
| Other | — | (16 | ) | — | (34 | ) | ||||||||||
| Total | 72,258 | 43,869 | 234,180 | 96,896 | ||||||||||||
| Income tax expense | (25,290 | ) | (15,355 | ) | (81,963 | ) | (33,914 | ) | ||||||||
| Total after-tax realized investment gains | $ | 46,968 | $ | 28,514 | $ | 152,217 | $ | 62,982 | ||||||||
| Change in unrealized investment gains (losses): | ||||||||||||||||
| Fixed maturity securities | $ | 10,722 | $ | (46,004 | ) | $ | 190,242 | $ | (339,384 | ) | ||||||
| Previously impaired fixed maturity securities | 188 | 299 | 941 | 821 | ||||||||||||
| Equity securities available for sale | (27,548 | ) | (13,984 | ) | (19,215 | ) | (5,614 | ) | ||||||||
| Investment funds | (8,391 | ) | 3,926 | (8,317 | ) | (5,248 | ) | |||||||||
| Total change in unrealized investment gains (losses) | (25,029 | ) | (55,763 | ) | 163,651 | (349,425 | ) | |||||||||
| Income tax benefit (expense) | 12,117 | 16,884 | (55,419 | ) | 121,296 | |||||||||||
| Noncontrolling interests | (82 | ) | (9 | ) | (119 | ) | (14 | ) | ||||||||
| Total after-tax unrealized gains (losses) | $ | (12,994 | ) | $ | (38,888 | ) | $ | 108,113 | $ | (228,143 | ) | |||||
Securities_In_An_Unrealized_Lo
| Securities In An Unrealized Loss Position | 9 Months Ended | |||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||
| Investments [Abstract] | ' | |||||||||||||||||||||||
| Securities in Unrealized Loss Position | ' | |||||||||||||||||||||||
| Securities in an Unrealized Loss Position | ||||||||||||||||||||||||
| The following tables summarize all securities in an unrealized loss position at September 30, 2014 and December 31, 2013 by the length of time those securities have been continuously in an unrealized loss position: | ||||||||||||||||||||||||
| Less Than 12 Months | 12 Months or Greater | Total | ||||||||||||||||||||||
| (In thousands) | Fair Value | Gross | Fair Value | Gross | Fair Value | Gross | ||||||||||||||||||
| Unrealized | Unrealized | Unrealized | ||||||||||||||||||||||
| Losses | Losses | Losses | ||||||||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||||||
| U.S. government and government agency | $ | 131,471 | $ | 1,411 | $ | 85,253 | $ | 3,818 | $ | 216,724 | $ | 5,229 | ||||||||||||
| State and municipal | 111,019 | 743 | 175,757 | 4,076 | 286,776 | 4,819 | ||||||||||||||||||
| Mortgage-backed securities | 182,774 | 1,481 | 295,503 | 12,811 | 478,277 | 14,292 | ||||||||||||||||||
| Corporate | 1,068,868 | 3,983 | 269,171 | 13,025 | 1,338,039 | 17,008 | ||||||||||||||||||
| Foreign | 82,459 | 3,154 | 120,708 | 10,053 | 203,167 | 13,207 | ||||||||||||||||||
| Fixed maturity securities | 1,576,591 | 10,772 | 946,392 | 43,783 | 2,522,983 | 54,555 | ||||||||||||||||||
| Common stocks | 10,813 | 531 | — | — | 10,813 | 531 | ||||||||||||||||||
| Preferred stocks | 3,005 | 40 | 22,535 | 3,139 | 25,540 | 3,179 | ||||||||||||||||||
| Equity securities | 13,818 | 571 | 22,535 | 3,139 | 36,353 | 3,710 | ||||||||||||||||||
| Total | $ | 1,590,409 | $ | 11,343 | $ | 968,927 | $ | 46,922 | $ | 2,559,336 | $ | 58,265 | ||||||||||||
| December 31, 2013 | ||||||||||||||||||||||||
| U.S. government and government agency | $ | 260,882 | $ | 7,927 | $ | 2,163 | $ | 55 | $ | 263,045 | $ | 7,982 | ||||||||||||
| State and municipal | 899,613 | 24,503 | 87,345 | 5,334 | 986,958 | 29,837 | ||||||||||||||||||
| Mortgage-backed securities | 578,603 | 17,964 | 140,648 | 8,965 | 719,251 | 26,929 | ||||||||||||||||||
| Corporate | 1,013,373 | 17,066 | 105,074 | 13,034 | 1,118,447 | 30,100 | ||||||||||||||||||
| Foreign | 320,215 | 16,286 | — | — | 320,215 | 16,286 | ||||||||||||||||||
| Fixed maturity securities | 3,072,686 | 83,746 | 335,230 | 27,388 | 3,407,916 | 111,134 | ||||||||||||||||||
| Common stocks | — | — | — | — | — | — | ||||||||||||||||||
| Preferred stocks | 13,291 | 513 | 19,868 | 5,806 | 33,159 | 6,319 | ||||||||||||||||||
| Equity securities | 13,291 | 513 | 19,868 | 5,806 | 33,159 | 6,319 | ||||||||||||||||||
| Total | $ | 3,085,977 | $ | 84,259 | $ | 355,098 | $ | 33,194 | $ | 3,441,075 | $ | 117,453 | ||||||||||||
| Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2014 is presented in the table below. | ||||||||||||||||||||||||
| ($ in thousands) | Number of | Aggregate | Gross | |||||||||||||||||||||
| Securities | Fair Value | Unrealized | ||||||||||||||||||||||
| Loss | ||||||||||||||||||||||||
| Mortgage-backed securities | 9 | $ | 42,230 | $ | 1,611 | |||||||||||||||||||
| Corporate | 9 | 27,494 | 647 | |||||||||||||||||||||
| Foreign | — | — | — | |||||||||||||||||||||
| Total | 18 | $ | 69,724 | $ | 2,258 | |||||||||||||||||||
| For OTTI of fixed maturity securities that management does not intend to sell or, more likely than not, would not be required to sell, the portion of the decline in value considered to be due to credit factors is recognized in earnings and the portion of the decline in value considered to be due to non-credit factors is recognized in other comprehensive income. For the nine months ended September 30, 2014 and 2013, there were no changes in the portion of impairments recognized in earnings for those securities that have been impaired due to both credit factors and non-credit factors. | ||||||||||||||||||||||||
| The Company has evaluated its fixed maturity securities in an unrealized loss position and believes the unrealized losses are due primarily to temporary market and sector-related factors rather than to issuer-specific factors. None of these securities are delinquent or in default under financial covenants. Based on its assessment of these issuers, the Company expects them to continue to meet their contractual payment obligations as they become due and does not consider any of these securities to be OTTI. | ||||||||||||||||||||||||
| Preferred Stocks – At September 30, 2014, there were two preferred stocks in an unrealized loss position, with an aggregate fair value of $26 million and a gross unrealized loss of $3 million. Based upon management’s view of the underlying value of these securities, the Company does not consider these preferred stocks to be OTTI. | ||||||||||||||||||||||||
Fair_Value_Measurements_Fair_V
| Fair Value Measurements Fair Value Measurements | 9 Months Ended | |||||||||||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||||||||||||||||||
| Fair Value Disclosures | ' | |||||||||||||||||||||||||||||||
| Fair Value Measurements | ||||||||||||||||||||||||||||||||
| The Company’s fixed maturity and equity securities available for sale and its arbitrage trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for similar assets in active markets. Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs may only be used to measure fair value to the extent that observable inputs are not available. | ||||||||||||||||||||||||||||||||
| Because many fixed maturity securities do not trade on a daily basis, the Company utilizes pricing models and processes, which may include benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. Market inputs used to evaluate securities include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Quoted prices are often unavailable for recently issued securities, securities that are infrequently traded or securities that are only traded in private transactions. For publicly traded securities for which quoted prices are unavailable, the Company determines fair value based on independent broker quotations and other observable market data. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information. | ||||||||||||||||||||||||||||||||
| The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2014 and December 31, 2013 by level: | ||||||||||||||||||||||||||||||||
| (In thousands) | Total | Level 1 | Level 2 | Level 3 | ||||||||||||||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 813,034 | $ | — | $ | 813,034 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,180,068 | — | 4,180,068 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,298,845 | — | 1,298,845 | — | ||||||||||||||||||||||||||||
| Corporate | 5,041,702 | — | 5,017,702 | 24,000 | ||||||||||||||||||||||||||||
| Foreign government | 962,911 | — | 962,911 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 12,296,560 | — | 12,272,560 | 24,000 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 79,973 | 68,852 | — | 11,121 | ||||||||||||||||||||||||||||
| Preferred stocks | 142,051 | — | 138,313 | 3,738 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 222,024 | 68,852 | 138,313 | 14,859 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 918,223 | 237,310 | 676,896 | 4,017 | ||||||||||||||||||||||||||||
| Total | $ | 13,436,807 | $ | 306,162 | $ | 13,087,769 | $ | 42,876 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 159,537 | $ | 159,501 | $ | 5 | $ | 31 | ||||||||||||||||||||||||
| December 31, 2013 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 884,859 | $ | — | $ | 884,859 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,218,284 | — | 4,218,284 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,329,783 | — | 1,329,783 | — | ||||||||||||||||||||||||||||
| Corporate | 4,202,741 | — | 4,159,877 | 42,864 | ||||||||||||||||||||||||||||
| Foreign government | 879,857 | — | 879,857 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 11,515,524 | — | 11,472,660 | 42,864 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 160,775 | 159,537 | — | 1,238 | ||||||||||||||||||||||||||||
| Preferred stocks | 122,563 | — | 118,811 | 3,752 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 283,338 | 159,537 | 118,811 | 4,990 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 522,128 | 192,281 | 328,067 | 1,780 | ||||||||||||||||||||||||||||
| Total | $ | 12,320,990 | $ | 351,818 | $ | 11,919,538 | $ | 49,634 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 162,278 | $ | 162,126 | $ | 152 | $ | — | ||||||||||||||||||||||||
| There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2014 or during the year ended December 31, 2013. | ||||||||||||||||||||||||||||||||
| The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2014 and for the year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Gains (Losses) Included in | ||||||||||||||||||||||||||||||||
| (In thousands) | Beginning | Earnings | Other | Purchases | (Sales) | Maturities | Transfer in (out) | Ending | ||||||||||||||||||||||||
| Balance | Comprehensive | Balance | ||||||||||||||||||||||||||||||
| Income | ||||||||||||||||||||||||||||||||
| Nine months ended September 30, 2014: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 42,864 | $ | 49 | $ | (1,146 | ) | $ | 84 | $ | (15,244 | ) | $ | (2,607 | ) | $ | — | $ | 24,000 | |||||||||||||
| Total | 42,864 | 49 | (1,146 | ) | 84 | (15,244 | ) | (2,607 | ) | — | 24,000 | |||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,238 | — | (531 | ) | 11,343 | (929 | ) | — | — | 11,121 | ||||||||||||||||||||||
| Preferred stocks | 3,752 | 8 | — | 3,430 | (3,452 | ) | — | — | 3,738 | |||||||||||||||||||||||
| Total | 4,990 | 8 | (531 | ) | 14,773 | (4,381 | ) | — | — | 14,859 | ||||||||||||||||||||||
| Arbitrage trading account | 1,780 | 2,294 | — | 4,942 | (14,063 | ) | — | 9,064 | 4,017 | |||||||||||||||||||||||
| Total | $ | 49,634 | $ | 2,351 | $ | (1,677 | ) | $ | 19,799 | $ | (33,688 | ) | $ | (2,607 | ) | $ | 9,064 | $ | 42,876 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | — | $ | — | $ | — | $ | 31 | $ | — | $ | — | $ | — | $ | 31 | ||||||||||||||||
| Year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 59,065 | $ | 677 | $ | 309 | $ | 170 | $ | (4,753 | ) | $ | (12,604 | ) | $ | — | $ | 42,864 | ||||||||||||||
| Total | 59,065 | 677 | 309 | 170 | (4,753 | ) | (12,604 | ) | — | 42,864 | ||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,408 | — | — | — | (170 | ) | — | — | 1,238 | |||||||||||||||||||||||
| Preferred stocks | 621 | (299 | ) | — | 3,430 | — | — | — | 3,752 | |||||||||||||||||||||||
| Total | 2,029 | (299 | ) | — | 3,430 | (170 | ) | — | — | 4,990 | ||||||||||||||||||||||
| Arbitrage trading account | 928 | 1,458 | 730 | 824 | (853 | ) | — | (1,307 | ) | 1,780 | ||||||||||||||||||||||
| Total | $ | 62,022 | $ | 1,836 | $ | 1,039 | $ | 4,424 | $ | (5,776 | ) | $ | (12,604 | ) | $ | (1,307 | ) | $ | 49,634 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 20 | $ | (4 | ) | $ | — | $ | 4 | $ | (20 | ) | $ | — | $ | — | $ | — | ||||||||||||||
| During the nine months ended September 30, 2014, two securities were transferred into Level 3 where the quoted prices were no longer available. One of these securities was sold during the second quarter of 2014. There were no significant transfers in or out of Level 3 during the year ended December 31, 2013. | ||||||||||||||||||||||||||||||||
| Fair Value of Financial Instruments | ||||||||||||||||||||||||||||||||
| The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments: | ||||||||||||||||||||||||||||||||
| September 30, 2014 | December 31, 2013 | |||||||||||||||||||||||||||||||
| (In thousands) | Carrying Value | Fair Value | Carrying Value | Fair Value | ||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities | $ | 12,397,756 | $ | 12,418,016 | $ | 11,616,844 | $ | 11,631,744 | ||||||||||||||||||||||||
| Equity securities available for sale | 222,024 | 222,024 | 283,338 | 283,338 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 918,223 | 918,223 | 522,128 | 522,128 | ||||||||||||||||||||||||||||
| Loans receivable | 343,300 | 346,622 | 343,583 | 346,746 | ||||||||||||||||||||||||||||
| Cash and cash equivalents | 1,342,285 | 1,342,285 | 839,738 | 839,738 | ||||||||||||||||||||||||||||
| Trading account receivables from brokers and clearing organizations | — | — | 304,936 | 304,936 | ||||||||||||||||||||||||||||
| Due from broker | — | — | 17,735 | 17,735 | ||||||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Due to broker | 58,926 | 58,926 | 8,273 | 8,273 | ||||||||||||||||||||||||||||
| Trading account payable to brokers and clearing organizations | 95,681 | 95,681 | — | — | ||||||||||||||||||||||||||||
| Trading account securities sold but not yet purchased | 159,537 | 159,537 | 162,278 | 162,278 | ||||||||||||||||||||||||||||
| Junior subordinated debentures | 339,995 | 326,480 | 339,800 | 288,540 | ||||||||||||||||||||||||||||
| Senior notes and other debt | 2,122,030 | 2,341,816 | 1,692,442 | 1,861,898 | ||||||||||||||||||||||||||||
| The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the junior subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input. | ||||||||||||||||||||||||||||||||
Reinsurance_Reinsurance
| Reinsurance Reinsurance | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Insurance [Abstract] | ' | |||||||||||||||
| Reinsurance [Text Block] | ' | |||||||||||||||
| Reinsurance | ||||||||||||||||
| The following is a summary of reinsurance financial information: | ||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Written premiums: | ||||||||||||||||
| Direct | $ | 1,553,493 | $ | 1,415,775 | $ | 4,699,319 | $ | 4,221,370 | ||||||||
| Assumed | 225,863 | 251,331 | 657,704 | 695,293 | ||||||||||||
| Ceded | (253,974 | ) | (243,481 | ) | (815,985 | ) | (774,174 | ) | ||||||||
| Total net premiums written | $ | 1,525,382 | $ | 1,423,625 | $ | 4,541,038 | $ | 4,142,489 | ||||||||
| Earned premiums: | ||||||||||||||||
| Direct | $ | 1,505,738 | $ | 1,351,542 | $ | 4,336,463 | $ | 3,893,806 | ||||||||
| Assumed | 216,889 | 226,530 | 667,566 | 658,063 | ||||||||||||
| Ceded | (261,823 | ) | (249,210 | ) | (761,968 | ) | (708,373 | ) | ||||||||
| Total net premiums earned | $ | 1,460,804 | $ | 1,328,862 | $ | 4,242,061 | $ | 3,843,496 | ||||||||
| Ceded losses incurred | $ | 128,903 | $ | 186,504 | $ | 319,156 | $ | 439,415 | ||||||||
| The Company reinsures a portion of its insurance exposures in order to reduce its net liability on individual risks and catastrophe losses. The Company also cedes premiums to state assigned risk plans and captive insurance companies. Estimated amounts due from reinsurers are reported net of reserves for uncollectible reinsurance of $2 million as of September 30, 2014 and $1 million as of December 31, 2013. | ||||||||||||||||
Fair_Value_Of_Financial_Instru
| Fair Value Of Financial Instruments Fair Value of Financial Instruments (Notes) | 9 Months Ended | |||||||||||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||||||||||||||||||
| Fair Value Disclosures | ' | |||||||||||||||||||||||||||||||
| Fair Value Measurements | ||||||||||||||||||||||||||||||||
| The Company’s fixed maturity and equity securities available for sale and its arbitrage trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for similar assets in active markets. Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs may only be used to measure fair value to the extent that observable inputs are not available. | ||||||||||||||||||||||||||||||||
| Because many fixed maturity securities do not trade on a daily basis, the Company utilizes pricing models and processes, which may include benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. Market inputs used to evaluate securities include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Quoted prices are often unavailable for recently issued securities, securities that are infrequently traded or securities that are only traded in private transactions. For publicly traded securities for which quoted prices are unavailable, the Company determines fair value based on independent broker quotations and other observable market data. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information. | ||||||||||||||||||||||||||||||||
| The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2014 and December 31, 2013 by level: | ||||||||||||||||||||||||||||||||
| (In thousands) | Total | Level 1 | Level 2 | Level 3 | ||||||||||||||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 813,034 | $ | — | $ | 813,034 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,180,068 | — | 4,180,068 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,298,845 | — | 1,298,845 | — | ||||||||||||||||||||||||||||
| Corporate | 5,041,702 | — | 5,017,702 | 24,000 | ||||||||||||||||||||||||||||
| Foreign government | 962,911 | — | 962,911 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 12,296,560 | — | 12,272,560 | 24,000 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 79,973 | 68,852 | — | 11,121 | ||||||||||||||||||||||||||||
| Preferred stocks | 142,051 | — | 138,313 | 3,738 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 222,024 | 68,852 | 138,313 | 14,859 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 918,223 | 237,310 | 676,896 | 4,017 | ||||||||||||||||||||||||||||
| Total | $ | 13,436,807 | $ | 306,162 | $ | 13,087,769 | $ | 42,876 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 159,537 | $ | 159,501 | $ | 5 | $ | 31 | ||||||||||||||||||||||||
| December 31, 2013 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 884,859 | $ | — | $ | 884,859 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,218,284 | — | 4,218,284 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,329,783 | — | 1,329,783 | — | ||||||||||||||||||||||||||||
| Corporate | 4,202,741 | — | 4,159,877 | 42,864 | ||||||||||||||||||||||||||||
| Foreign government | 879,857 | — | 879,857 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 11,515,524 | — | 11,472,660 | 42,864 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 160,775 | 159,537 | — | 1,238 | ||||||||||||||||||||||||||||
| Preferred stocks | 122,563 | — | 118,811 | 3,752 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 283,338 | 159,537 | 118,811 | 4,990 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 522,128 | 192,281 | 328,067 | 1,780 | ||||||||||||||||||||||||||||
| Total | $ | 12,320,990 | $ | 351,818 | $ | 11,919,538 | $ | 49,634 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 162,278 | $ | 162,126 | $ | 152 | $ | — | ||||||||||||||||||||||||
| There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2014 or during the year ended December 31, 2013. | ||||||||||||||||||||||||||||||||
| The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2014 and for the year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Gains (Losses) Included in | ||||||||||||||||||||||||||||||||
| (In thousands) | Beginning | Earnings | Other | Purchases | (Sales) | Maturities | Transfer in (out) | Ending | ||||||||||||||||||||||||
| Balance | Comprehensive | Balance | ||||||||||||||||||||||||||||||
| Income | ||||||||||||||||||||||||||||||||
| Nine months ended September 30, 2014: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 42,864 | $ | 49 | $ | (1,146 | ) | $ | 84 | $ | (15,244 | ) | $ | (2,607 | ) | $ | — | $ | 24,000 | |||||||||||||
| Total | 42,864 | 49 | (1,146 | ) | 84 | (15,244 | ) | (2,607 | ) | — | 24,000 | |||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,238 | — | (531 | ) | 11,343 | (929 | ) | — | — | 11,121 | ||||||||||||||||||||||
| Preferred stocks | 3,752 | 8 | — | 3,430 | (3,452 | ) | — | — | 3,738 | |||||||||||||||||||||||
| Total | 4,990 | 8 | (531 | ) | 14,773 | (4,381 | ) | — | — | 14,859 | ||||||||||||||||||||||
| Arbitrage trading account | 1,780 | 2,294 | — | 4,942 | (14,063 | ) | — | 9,064 | 4,017 | |||||||||||||||||||||||
| Total | $ | 49,634 | $ | 2,351 | $ | (1,677 | ) | $ | 19,799 | $ | (33,688 | ) | $ | (2,607 | ) | $ | 9,064 | $ | 42,876 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | — | $ | — | $ | — | $ | 31 | $ | — | $ | — | $ | — | $ | 31 | ||||||||||||||||
| Year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 59,065 | $ | 677 | $ | 309 | $ | 170 | $ | (4,753 | ) | $ | (12,604 | ) | $ | — | $ | 42,864 | ||||||||||||||
| Total | 59,065 | 677 | 309 | 170 | (4,753 | ) | (12,604 | ) | — | 42,864 | ||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,408 | — | — | — | (170 | ) | — | — | 1,238 | |||||||||||||||||||||||
| Preferred stocks | 621 | (299 | ) | — | 3,430 | — | — | — | 3,752 | |||||||||||||||||||||||
| Total | 2,029 | (299 | ) | — | 3,430 | (170 | ) | — | — | 4,990 | ||||||||||||||||||||||
| Arbitrage trading account | 928 | 1,458 | 730 | 824 | (853 | ) | — | (1,307 | ) | 1,780 | ||||||||||||||||||||||
| Total | $ | 62,022 | $ | 1,836 | $ | 1,039 | $ | 4,424 | $ | (5,776 | ) | $ | (12,604 | ) | $ | (1,307 | ) | $ | 49,634 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 20 | $ | (4 | ) | $ | — | $ | 4 | $ | (20 | ) | $ | — | $ | — | $ | — | ||||||||||||||
| During the nine months ended September 30, 2014, two securities were transferred into Level 3 where the quoted prices were no longer available. One of these securities was sold during the second quarter of 2014. There were no significant transfers in or out of Level 3 during the year ended December 31, 2013. | ||||||||||||||||||||||||||||||||
| Fair Value of Financial Instruments | ||||||||||||||||||||||||||||||||
| The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments: | ||||||||||||||||||||||||||||||||
| September 30, 2014 | December 31, 2013 | |||||||||||||||||||||||||||||||
| (In thousands) | Carrying Value | Fair Value | Carrying Value | Fair Value | ||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities | $ | 12,397,756 | $ | 12,418,016 | $ | 11,616,844 | $ | 11,631,744 | ||||||||||||||||||||||||
| Equity securities available for sale | 222,024 | 222,024 | 283,338 | 283,338 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 918,223 | 918,223 | 522,128 | 522,128 | ||||||||||||||||||||||||||||
| Loans receivable | 343,300 | 346,622 | 343,583 | 346,746 | ||||||||||||||||||||||||||||
| Cash and cash equivalents | 1,342,285 | 1,342,285 | 839,738 | 839,738 | ||||||||||||||||||||||||||||
| Trading account receivables from brokers and clearing organizations | — | — | 304,936 | 304,936 | ||||||||||||||||||||||||||||
| Due from broker | — | — | 17,735 | 17,735 | ||||||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Due to broker | 58,926 | 58,926 | 8,273 | 8,273 | ||||||||||||||||||||||||||||
| Trading account payable to brokers and clearing organizations | 95,681 | 95,681 | — | — | ||||||||||||||||||||||||||||
| Trading account securities sold but not yet purchased | 159,537 | 159,537 | 162,278 | 162,278 | ||||||||||||||||||||||||||||
| Junior subordinated debentures | 339,995 | 326,480 | 339,800 | 288,540 | ||||||||||||||||||||||||||||
| Senior notes and other debt | 2,122,030 | 2,341,816 | 1,692,442 | 1,861,898 | ||||||||||||||||||||||||||||
| The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the junior subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input. | ||||||||||||||||||||||||||||||||
Restricted_Stock_Units_Restric
| Restricted Stock Units Restricted Stock Units (Notes) | 9 Months Ended | ||||||
| Sep. 30, 2014 | |||||||
| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | ' | ||||||
| Restricted Stock Units | ' | ||||||
| Restricted Stock Units | |||||||
| Pursuant to its stock incentive plan, the Company may issue restricted stock units (RSUs) to employees of the Company and its subsidiaries. The RSUs generally vest five years from the award date and are subject to other vesting and forfeiture provisions contained in the award agreement. RSUs are expensed pro-ratably over the vesting period. RSU expenses were $20 million and $16 million for the nine months ended September 30, 2014 and 2013, respectively. A summary of RSUs issued in the nine months ended September 30, 2014 and 2013 follows: | |||||||
| ($ in thousands) | Units | Fair Value | |||||
| Nine months ended September 30, | |||||||
| 2014 | 1,135,900 | $ | 50,791 | ||||
| 2013 | 93,150 | $ | 3,957 | ||||
Litigation_and_Contingent_Liab
| Litigation and Contingent Liabilities Litigation and Contingent Liabilities | 9 Months Ended |
| Sep. 30, 2014 | |
| Commitments and Contingencies Disclosure [Abstract] | ' |
| Commitments and Contingencies Disclosure [Text Block] | ' |
| Litigation and Contingent Liabilities | |
| In the ordinary course of business, the Company is subject to disputes, litigation and arbitration arising from its insurance and reinsurance businesses. These matters are generally related to insurance and reinsurance claims and are considered in the establishment of loss and loss expense reserves. In addition, the Company may also become involved in legal actions which seek extra-contractual damages, punitive damages or penalties, including claims alleging bad faith in handling of insurance claims. The Company expects its ultimate liability with respect to such matters will not be material to its financial condition. However, adverse outcomes on such matters are possible, from time to time, and could be material to the Company’s results of operations in any particular financial reporting period. |
Industry_Segments
| Industry Segments | 9 Months Ended | |||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||
| Segment Reporting [Abstract] | ' | |||||||||||||||||||||||
| Industry Segments | ' | |||||||||||||||||||||||
| Business Segments | ||||||||||||||||||||||||
| The Company’s financial results are presented for the following reportable business segments, plus a corporate segment: | ||||||||||||||||||||||||
| • | Insurance-Domestic - commercial insurance business, including excess and surplus lines and admitted lines, primarily throughout the United States; | |||||||||||||||||||||||
| • | Insurance-International - insurance business primarily in the United Kingdom, Continental Europe, South America, Canada, Scandinavia, and Australia; and | |||||||||||||||||||||||
| • | Reinsurance-Global - reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Continental Europe, Australia, and the Asia-Pacific Region. | |||||||||||||||||||||||
| The accounting policies of the segments are the same as those described in the summary of significant accounting policies. Income tax expense and benefits are calculated based upon the Company’s overall effective tax rate. | ||||||||||||||||||||||||
| Summary financial information about the Company's business segments is presented in the following tables: | ||||||||||||||||||||||||
| Revenues | ||||||||||||||||||||||||
| (In thousands) | Earned | Investment | Other | Total | Pre-Tax | Net | ||||||||||||||||||
| Premiums | Income | Income | Income | |||||||||||||||||||||
| (Loss) | (Loss) to Common Stockholders | |||||||||||||||||||||||
| Three months ended September 30, 2014: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 1,093,554 | $ | 125,792 | $ | 26,408 | $ | 1,245,754 | $ | 228,359 | $ | 154,718 | ||||||||||||
| Insurance-International | 205,529 | 19,957 | — | 225,486 | 12,603 | 9,217 | ||||||||||||||||||
| Reinsurance-Global | 161,721 | 26,916 | — | 188,637 | 29,005 | 20,207 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 6,560 | 101,910 | 108,470 | (63,772 | ) | (42,571 | ) | ||||||||||||||||
| Net investment gains | — | — | 72,258 | 72,258 | 72,258 | 46,968 | ||||||||||||||||||
| Total | $ | 1,460,804 | $ | 179,225 | $ | 200,576 | $ | 1,840,605 | $ | 278,453 | $ | 188,539 | ||||||||||||
| Three months ended September 30, 2013: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 958,994 | $ | 94,071 | $ | 26,125 | $ | 1,079,190 | $ | 172,177 | $ | 118,183 | ||||||||||||
| Insurance-International | 189,054 | 11,151 | — | 200,205 | 16,129 | 11,225 | ||||||||||||||||||
| Reinsurance-Global | 180,814 | 20,121 | — | 200,935 | 24,559 | 17,300 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 291 | 109,634 | 109,925 | (58,501 | ) | (38,248 | ) | ||||||||||||||||
| Net investment gains | — | — | 43,869 | 43,869 | 43,869 | 28,514 | ||||||||||||||||||
| Total | $ | 1,328,862 | $ | 125,634 | $ | 179,628 | $ | 1,634,124 | $ | 198,233 | $ | 136,974 | ||||||||||||
| Nine months ended September 30, 2014: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 3,138,806 | $ | 347,002 | $ | 82,159 | $ | 3,567,967 | $ | 607,399 | $ | 414,588 | ||||||||||||
| Insurance-International | 592,721 | 47,885 | — | 640,606 | 41,860 | 29,938 | ||||||||||||||||||
| Reinsurance-Global | 510,534 | 72,102 | — | 582,636 | 86,945 | 60,624 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 19,676 | 299,435 | 319,111 | (180,892 | ) | (119,194 | ) | ||||||||||||||||
| Net investment gains | — | — | 234,180 | 234,180 | 234,180 | 152,217 | ||||||||||||||||||
| Total | $ | 4,242,061 | $ | 486,665 | $ | 615,774 | $ | 5,344,500 | $ | 789,492 | $ | 538,173 | ||||||||||||
| Nine months ended September 30, 2013: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 2,769,369 | $ | 299,430 | $ | 80,513 | $ | 3,149,312 | $ | 465,861 | $ | 324,069 | ||||||||||||
| Insurance-International | 540,365 | 36,383 | — | 576,748 | 51,094 | 35,794 | ||||||||||||||||||
| Reinsurance-Global | 533,762 | 65,656 | — | 599,418 | 87,252 | 61,375 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 3,831 | 285,650 | 289,481 | (183,941 | ) | (114,674 | ) | ||||||||||||||||
| Net investment gains | — | — | 96,896 | 96,896 | 96,896 | 62,982 | ||||||||||||||||||
| Total | $ | 3,843,496 | $ | 405,300 | $ | 463,059 | $ | 4,711,855 | $ | 517,162 | $ | 369,546 | ||||||||||||
| (1) Corporate and eliminations represent corporate revenues and expenses that are not allocated to business segments. | ||||||||||||||||||||||||
| Identifiable assets by segment are as follows: | ||||||||||||||||||||||||
| (In thousands) | September 30, 2014 | 31-Dec-13 | ||||||||||||||||||||||
| Insurance-Domestic | $ | 16,074,387 | $ | 15,247,807 | ||||||||||||||||||||
| Insurance-International | 1,915,322 | 1,516,310 | ||||||||||||||||||||||
| Reinsurance-Global | 2,801,268 | 3,103,193 | ||||||||||||||||||||||
| Corporate and eliminations | 1,306,620 | 684,486 | ||||||||||||||||||||||
| Total | $ | 22,097,597 | $ | 20,551,796 | ||||||||||||||||||||
| Net premiums earned by major line of business are as follows: | ||||||||||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||||||||||
| Insurance-Domestic: | ||||||||||||||||||||||||
| Other liability | $ | 368,818 | $ | 314,878 | $ | 1,070,525 | $ | 917,910 | ||||||||||||||||
| Workers’ compensation | 291,297 | 252,220 | 824,541 | 722,422 | ||||||||||||||||||||
| Short-tail lines | 222,561 | 199,181 | 642,833 | 570,868 | ||||||||||||||||||||
| Commercial automobile | 134,197 | 125,942 | 385,667 | 361,964 | ||||||||||||||||||||
| Professional liability | 76,681 | 66,773 | 215,240 | 196,205 | ||||||||||||||||||||
| Total | 1,093,554 | 958,994 | 3,138,806 | 2,769,369 | ||||||||||||||||||||
| Insurance-International: | ||||||||||||||||||||||||
| Other liability | 27,705 | 18,457 | 70,036 | 48,745 | ||||||||||||||||||||
| Workers’ compensation | 18,012 | 20,847 | 52,578 | 65,482 | ||||||||||||||||||||
| Short-tail lines | 100,417 | 92,213 | 303,119 | 248,637 | ||||||||||||||||||||
| Commercial automobile | 29,076 | 30,898 | 86,318 | 97,929 | ||||||||||||||||||||
| Professional liability | 30,319 | 26,639 | 80,670 | 79,572 | ||||||||||||||||||||
| Total | 205,529 | 189,054 | 592,721 | 540,365 | ||||||||||||||||||||
| Reinsurance-Global: | ||||||||||||||||||||||||
| Casualty | 122,741 | 128,127 | 372,894 | 371,571 | ||||||||||||||||||||
| Property | 38,980 | 52,687 | 137,640 | 162,191 | ||||||||||||||||||||
| Total | 161,721 | 180,814 | 510,534 | 533,762 | ||||||||||||||||||||
| Total | $ | 1,460,804 | $ | 1,328,862 | $ | 4,242,061 | $ | 3,843,496 | ||||||||||||||||
Per_Share_Data_Tables
| Per Share Data (Tables) | 9 Months Ended | |||||||||||
| Sep. 30, 2014 | ||||||||||||
| Earnings Per Share [Abstract] | ' | |||||||||||
| Schedule of Weighted Average Number of Shares [Table Text Block] | ' | |||||||||||
| The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows: | ||||||||||||
| For the Three Months | For the Nine Months | |||||||||||
| Ended September 30, | Ended September 30, | |||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||
| Basic | 127,165 | 135,268 | 128,225 | 135,726 | ||||||||
| Diluted | 133,001 | 140,758 | 133,886 | 141,095 | ||||||||
Acquistions_Acquisitions_Table
| Acquistions Acquisitions (Tables) | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Business Combinations [Abstract] | ' | |||||||
| Summary of fair value of net assets acquired and liabilities assumed | ' | |||||||
| The following table summarizes the estimated fair value of net assets acquired and liabilities assumed for business combinations completed in 2014 and 2013: | ||||||||
| September 30, | December 31, | |||||||
| (In thousands) | 2014 | 2013 | ||||||
| Cash and cash equivalents | $ | 17,456 | $ | 3,911 | ||||
| Real estate, furniture and equipment | 669 | 898 | ||||||
| Goodwill and other intangibles assets | 77,967 | 64,464 | ||||||
| Premium and service fee receivable | 20,178 | — | ||||||
| Other assets | — | 60,661 | ||||||
| Total assets acquired | 116,270 | 129,934 | ||||||
| Debt | — | (27,612 | ) | |||||
| Other liabilities assumed | (33,391 | ) | (17,076 | ) | ||||
| Net assets acquired | $ | 82,879 | $ | 85,246 | ||||
Statements_of_Comprehensive_In1
| Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity [Abstract] | ' | |||||||||||||||
| Components of changes in accumulated other comprehensive income (loss) | ' | |||||||||||||||
| The following table presents the components of the changes in accumulated other comprehensive income (loss) ("AOCI"): | ||||||||||||||||
| (In thousands) | Unrealized Investment Gains (Losses) | Currency Translation Adjustments | Net Pension Asset | Accumulated Other Comprehensive Income (Loss) | ||||||||||||
| As of and for the nine months ended September 30, 2014: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 256,566 | $ | (60,524 | ) | $ | (6,651 | ) | $ | 189,391 | ||||||
| Other comprehensive income (loss) before reclassifications | 143,388 | (28,590 | ) | — | 114,798 | |||||||||||
| Amounts reclassified from AOCI | (35,156 | ) | — | 4,631 | (30,525 | ) | ||||||||||
| Other comprehensive income (loss) | 108,232 | (28,590 | ) | 4,631 | 84,273 | |||||||||||
| Unrealized investment gain (loss) related to non-controlling interest | (119 | ) | — | — | (119 | ) | ||||||||||
| End of period | $ | 364,679 | $ | (89,114 | ) | $ | (2,020 | ) | $ | 273,545 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (54,086 | ) | -1 | $ | — | $ | 7,125 | -2 | $ | (46,961 | ) | ||||
| Tax effect (3) | 18,930 | — | (2,494 | ) | 16,436 | |||||||||||
| After-tax amounts reclassified | $ | (35,156 | ) | $ | — | $ | 4,631 | $ | (30,525 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | 163,651 | $ | (28,590 | ) | $ | 7,125 | $ | 142,186 | |||||||
| Tax effect | (55,419 | ) | — | (2,494 | ) | (57,913 | ) | |||||||||
| Other comprehensive income (loss) | $ | 108,232 | $ | (28,590 | ) | $ | 4,631 | $ | 84,273 | |||||||
| As of and for the three months ended September 30, 2014: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 377,673 | $ | (39,734 | ) | $ | (4,040 | ) | $ | 333,899 | ||||||
| Other comprehensive income (loss) before reclassifications | 3,099 | (49,380 | ) | — | (46,281 | ) | ||||||||||
| Amounts reclassified from AOCI | (16,011 | ) | — | 2,020 | (13,991 | ) | ||||||||||
| Other comprehensive income (loss) | (12,912 | ) | (49,380 | ) | 2,020 | (60,272 | ) | |||||||||
| Unrealized investment gain (loss) related to non-controlling interest | (82 | ) | — | — | (82 | ) | ||||||||||
| End of period | $ | 364,679 | $ | (89,114 | ) | $ | (2,020 | ) | $ | 273,545 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (24,632 | ) | -1 | $ | — | $ | 3,108 | -2 | $ | (21,524 | ) | ||||
| Tax effect (3) | 8,621 | — | (1,088 | ) | 7,533 | |||||||||||
| After-tax amounts reclassified | $ | (16,011 | ) | $ | — | $ | 2,020 | $ | (13,991 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (25,029 | ) | $ | (49,380 | ) | $ | 3,108 | $ | (71,301 | ) | |||||
| Tax effect | 12,117 | — | (1,088 | ) | 11,029 | |||||||||||
| Other comprehensive income (loss) | $ | (12,912 | ) | $ | (49,380 | ) | $ | 2,020 | $ | (60,272 | ) | |||||
| Unrealized Investment Gains (Losses) | Currency Translation Adjustments | Net Pension Asset | Accumulated Other Comprehensive Income (Loss) | |||||||||||||
| (In thousands) | ||||||||||||||||
| As of and for the nine months ended September 30, 2013: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 517,658 | $ | (36,676 | ) | $ | (15,351 | ) | $ | 465,631 | ||||||
| Other comprehensive income (loss) before reclassifications | (172,276 | ) | (25,451 | ) | — | (197,727 | ) | |||||||||
| Amounts reclassified from AOCI | (55,853 | ) | — | 5,442 | (50,411 | ) | ||||||||||
| Other comprehensive income (loss) | (228,129 | ) | (25,451 | ) | 5,442 | (248,138 | ) | |||||||||
| Unrealized investment gain related to non-controlling interest | (14 | ) | — | — | (14 | ) | ||||||||||
| End of period | $ | 289,515 | $ | (62,127 | ) | $ | (9,909 | ) | $ | 217,479 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (85,928 | ) | -1 | $ | — | $ | 8,372 | -2 | $ | (77,556 | ) | ||||
| Tax effect (3) | 30,075 | — | (2,930 | ) | 27,145 | |||||||||||
| After-tax amounts reclassified | $ | (55,853 | ) | $ | — | $ | 5,442 | $ | (50,411 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (350,968 | ) | $ | (25,451 | ) | $ | 8,372 | $ | (368,047 | ) | |||||
| Tax effect | 122,839 | — | (2,930 | ) | 119,909 | |||||||||||
| Other comprehensive income (loss) | $ | (228,129 | ) | $ | (25,451 | ) | $ | 5,442 | $ | (248,138 | ) | |||||
| As of and for the three months ended September 30, 2013: | ||||||||||||||||
| Changes in AOCI | ||||||||||||||||
| Beginning of period | $ | 328,403 | $ | (106,455 | ) | $ | (11,723 | ) | $ | 210,225 | ||||||
| Other comprehensive income (loss) before reclassifications | (10,331 | ) | 44,328 | — | 33,997 | |||||||||||
| Amounts reclassified from AOCI | (28,548 | ) | — | 1,814 | (26,734 | ) | ||||||||||
| Other comprehensive income (loss) | (38,879 | ) | 44,328 | 1,814 | 7,263 | |||||||||||
| Unrealized investment gain related to non-controlling interest | (9 | ) | — | — | (9 | ) | ||||||||||
| End of period | $ | 289,515 | $ | (62,127 | ) | $ | (9,909 | ) | $ | 217,479 | ||||||
| Amounts reclassified from AOCI | ||||||||||||||||
| Pre-tax | $ | (43,920 | ) | -1 | $ | — | $ | 2,790 | -2 | $ | (41,130 | ) | ||||
| Tax effect (3) | 15,372 | — | (976 | ) | 14,396 | |||||||||||
| After-tax amounts reclassified | $ | (28,548 | ) | $ | — | $ | 1,814 | $ | (26,734 | ) | ||||||
| Other comprehensive income (loss) | ||||||||||||||||
| Pre-tax | $ | (59,814 | ) | $ | 44,328 | $ | 2,790 | $ | (12,696 | ) | ||||||
| Tax effect | 20,935 | — | (976 | ) | 19,959 | |||||||||||
| Other comprehensive income (loss) | $ | (38,879 | ) | $ | 44,328 | $ | 1,814 | $ | 7,263 | |||||||
| _______________ | ||||||||||||||||
| (1) Net investment gains in the consolidated statements of income. | ||||||||||||||||
| (2) Other operating costs and expenses in the consolidated statements of income. | ||||||||||||||||
| (3) Income tax expense in the consolidated statements of income. | ||||||||||||||||
Investments_In_Fixed_Maturity_1
| Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Tables) | 9 Months Ended | |||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||
| Schedule of Marketable Securities [Line Items] | ' | |||||||||||||||||||
| Amortized cost and fair value of fixed maturity securities by contractual maturity | ' | |||||||||||||||||||
| The amortized cost and fair value of fixed maturity securities at September 30, 2014, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations. | ||||||||||||||||||||
| (In thousands) | Amortized | Fair Value | ||||||||||||||||||
| Cost | ||||||||||||||||||||
| Due in one year or less | $ | 889,062 | $ | 900,273 | ||||||||||||||||
| Due after one year through five years | 4,052,836 | 4,268,705 | ||||||||||||||||||
| Due after five years through ten years | 3,105,077 | 3,288,731 | ||||||||||||||||||
| Due after ten years | 2,523,971 | 2,634,261 | ||||||||||||||||||
| Mortgage-backed securities | 1,310,361 | 1,326,046 | ||||||||||||||||||
| Total | $ | 11,881,307 | $ | 12,418,016 | ||||||||||||||||
| Debt Securities [Member] | ' | |||||||||||||||||||
| Schedule of Marketable Securities [Line Items] | ' | |||||||||||||||||||
| Schedule of investments in fixed maturity securities | ' | |||||||||||||||||||
| At September 30, 2014 and December 31, 2013, investments in fixed maturity securities were as follows: | ||||||||||||||||||||
| (In thousands) | Amortized | Gross Unrealized | Fair | Carrying | ||||||||||||||||
| Cost | Gains | Losses | Value | Value | ||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||
| Held to maturity: | ||||||||||||||||||||
| State and municipal | $ | 71,897 | $ | 16,991 | $ | — | $ | 88,888 | $ | 71,897 | ||||||||||
| Residential mortgage-backed | 24,300 | 2,901 | — | 27,201 | 24,300 | |||||||||||||||
| Corporate | 4,999 | 368 | — | 5,367 | 4,999 | |||||||||||||||
| Total held to maturity | 101,196 | 20,260 | — | 121,456 | 101,196 | |||||||||||||||
| Available for sale: | ||||||||||||||||||||
| U.S. government and government agency | 787,967 | 30,296 | (5,229 | ) | 813,034 | 813,034 | ||||||||||||||
| State and municipal | 3,958,141 | 226,746 | (4,819 | ) | 4,180,068 | 4,180,068 | ||||||||||||||
| Mortgage-backed securities: | ||||||||||||||||||||
| Residential (1) | 1,209,068 | 26,100 | (14,209 | ) | 1,220,959 | 1,220,959 | ||||||||||||||
| Commercial | 76,993 | 976 | (83 | ) | 77,886 | 77,886 | ||||||||||||||
| Corporate | 4,866,983 | 191,727 | (17,008 | ) | 5,041,702 | 5,041,702 | ||||||||||||||
| Foreign | 880,959 | 95,159 | (13,207 | ) | 962,911 | 962,911 | ||||||||||||||
| Total available for sale | 11,780,111 | 571,004 | (54,555 | ) | 12,296,560 | 12,296,560 | ||||||||||||||
| Total investments in fixed maturity securities | $ | 11,881,307 | $ | 591,264 | $ | (54,555 | ) | $ | 12,418,016 | $ | 12,397,756 | |||||||||
| December 31, 2013 | ||||||||||||||||||||
| Held to maturity: | ||||||||||||||||||||
| State and municipal | $ | 68,929 | $ | 11,172 | $ | — | $ | 80,101 | $ | 68,929 | ||||||||||
| Residential mortgage-backed | 27,393 | 3,311 | — | 30,704 | 27,393 | |||||||||||||||
| Corporate | 4,998 | 417 | — | 5,415 | 4,998 | |||||||||||||||
| Total held to maturity | 101,320 | 14,900 | — | 116,220 | 101,320 | |||||||||||||||
| Available for sale: | ||||||||||||||||||||
| U.S. government and government agency | 858,319 | 34,522 | (7,982 | ) | 884,859 | 884,859 | ||||||||||||||
| State and municipal | 4,085,791 | 162,330 | (29,837 | ) | 4,218,284 | 4,218,284 | ||||||||||||||
| Mortgage-backed securities: | ||||||||||||||||||||
| Residential (1) | 1,248,693 | 25,895 | (25,941 | ) | 1,248,647 | 1,248,647 | ||||||||||||||
| Commercial | 76,454 | 5,670 | (988 | ) | 81,136 | 81,136 | ||||||||||||||
| Corporate | 4,076,585 | 156,256 | (30,100 | ) | 4,202,741 | 4,202,741 | ||||||||||||||
| Foreign | 844,469 | 51,674 | (16,286 | ) | 879,857 | 879,857 | ||||||||||||||
| Total available for sale | 11,190,311 | 436,347 | (111,134 | ) | 11,515,524 | 11,515,524 | ||||||||||||||
| Total investments in fixed maturity securities | $ | 11,291,631 | $ | 451,247 | $ | (111,134 | ) | $ | 11,631,744 | $ | 11,616,844 | |||||||||
| ________________ | ||||||||||||||||||||
| -1 | Gross unrealized losses for residential mortgage-backed securities include $1,020,000 and $1,961,000 as of September 30, 2014 and December 31, 2013, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income. | |||||||||||||||||||
Investments_in_Equity_Securiti1
| Investments in Equity Securities Investments in Equity Securities (Tables) (Equity securities available for sale) | 9 Months Ended | |||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||
| Equity securities available for sale | ' | |||||||||||||||||||
| Schedule of Available-for-sale Securities [Line Items] | ' | |||||||||||||||||||
| Schedule of Investments in Equity Securities | ' | |||||||||||||||||||
| At September 30, 2014 and December 31, 2013, investments in equity securities were as follows: | ||||||||||||||||||||
| (In thousands) | Cost | Gross Unrealized | Fair | Carrying | ||||||||||||||||
| Gains | Losses | Value | Value | |||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||
| Common stocks | $ | 68,762 | $ | 11,742 | $ | (531 | ) | $ | 79,973 | $ | 79,973 | |||||||||
| Preferred stocks | 92,767 | 52,463 | (3,179 | ) | 142,051 | 142,051 | ||||||||||||||
| Total | $ | 161,529 | $ | 64,205 | $ | (3,710 | ) | $ | 222,024 | $ | 222,024 | |||||||||
| December 31, 2013 | ||||||||||||||||||||
| Common stocks | $ | 118,536 | $ | 42,239 | $ | — | $ | 160,775 | $ | 160,775 | ||||||||||
| Preferred stocks | 85,091 | 43,791 | (6,319 | ) | 122,563 | 122,563 | ||||||||||||||
| Total | $ | 203,627 | $ | 86,030 | $ | (6,319 | ) | $ | 283,338 | $ | 283,338 | |||||||||
Net_Investment_Income_Tables
| Net Investment Income (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Net Investment Income [Abstract] | ' | |||||||||||||||
| Schedule of Net Investment Income | ' | |||||||||||||||
| Net investment income consists of the following: | ||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Investment income earned on: | ||||||||||||||||
| Fixed maturity securities, including cash and cash equivalents and loans receivable | $ | 117,289 | $ | 104,033 | $ | 331,947 | $ | 333,072 | ||||||||
| Investment funds | 59,077 | 5,492 | 135,232 | 45,248 | ||||||||||||
| Arbitrage trading account | 47 | 11,738 | 12,508 | 14,265 | ||||||||||||
| Equity securities available for sale | 1,369 | 3,192 | 5,418 | 9,073 | ||||||||||||
| Real estate | 3,042 | 3,086 | 9,207 | 9,343 | ||||||||||||
| Gross investment income | 180,824 | 127,541 | 494,312 | 411,001 | ||||||||||||
| Investment expense | (1,599 | ) | (1,907 | ) | (7,647 | ) | (5,701 | ) | ||||||||
| Net investment income | $ | 179,225 | $ | 125,634 | $ | 486,665 | $ | 405,300 | ||||||||
Investment_Funds_Investment_Fu1
| Investment Funds Investment Funds (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity Method Investments and Joint Ventures [Abstract] | ' | |||||||||||||||
| Schedule of Net Investment Funds | ' | |||||||||||||||
| Investment funds consist of the following: | ||||||||||||||||
| Carrying Value as of | Income from Investment Funds | |||||||||||||||
| September 30, | December 31, | For the Nine Months Ended September 30, | ||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Real estate | $ | 282,431 | $ | 378,435 | $ | 24,341 | $ | 5,777 | ||||||||
| Energy | 159,857 | 155,026 | 18,136 | 25,959 | ||||||||||||
| Arbitrage | 286,845 | 271,575 | 15,270 | 3,050 | ||||||||||||
| Other | 290,999 | 262,459 | 77,485 | 10,462 | ||||||||||||
| Total | $ | 1,020,132 | $ | 1,067,495 | $ | 135,232 | $ | 45,248 | ||||||||
Real_Estate_Real_Estate_Tables
| Real Estate Real Estate (Tables) | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Real Estate [Abstract] | ' | |||||||
| Schedule of Real Estate Investments | ' | |||||||
| Investment in real estate represents directly owned property held for investment, as follows: | ||||||||
| Carrying Value | ||||||||
| September 30, | December 31, | |||||||
| (In thousands) | 2014 | 2013 | ||||||
| Properties in operation | $ | 196,884 | $ | 283,393 | ||||
| Properties under development | 507,110 | 431,849 | ||||||
| Total | $ | 703,994 | $ | 715,242 | ||||
Loans_Receivable_Loans_Receiva1
| Loans Receivable Loans Receivable (Tables) | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Receivables [Abstract] | ' | |||||||
| Schedule of Loans Receivable | ' | |||||||
| Loans receivable are as follows: | ||||||||
| (In thousands) | September 30, 2014 | 31-Dec-13 | ||||||
| Amortized cost: | ||||||||
| Real estate loans | $ | 259,522 | $ | 282,357 | ||||
| Commercial loans | 83,778 | 61,226 | ||||||
| Total | $ | 343,300 | $ | 343,583 | ||||
| Fair value: | ||||||||
| Real estate loans | $ | 261,342 | $ | 284,017 | ||||
| Commercial loans | 85,280 | 62,729 | ||||||
| Total | $ | 346,622 | $ | 346,746 | ||||
| Valuation allowance: | ||||||||
| Specific | $ | 115 | $ | — | ||||
| General | 2,427 | 2,087 | ||||||
| Total | $ | 2,542 | $ | 2,087 | ||||
| For the Three Months | ||||||||
| Ended September 30, | ||||||||
| 2014 | 2013 | |||||||
| Increase (decrease) in valuation allowance | $ | (24 | ) | $ | 72 | |||
| Loans receivable charged off | — | — | ||||||
| For the Nine Months | ||||||||
| Ended September 30, | ||||||||
| 2014 | 2013 | |||||||
| Increase in valuation allowance | $ | 455 | $ | 137 | ||||
| Loans receivable charged off | — | — | ||||||
Realized_And_Unrealized_Invest1
| Realized And Unrealized Investment Gains (Losses) (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Realized and Unrealized Investment Gains (Losses) [Abstract] | ' | |||||||||||||||
| Realized and Unrealized Investment Gains (Losses) | ' | |||||||||||||||
| Realized and unrealized investment gains (losses) are as follows: | ||||||||||||||||
| For the Three Months Ended September 30, | For the Nine Months Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Realized investment gains (losses): | ||||||||||||||||
| Fixed maturity securities: | ||||||||||||||||
| Gains | $ | 13,803 | $ | 19,500 | $ | 17,263 | $ | 39,643 | ||||||||
| Losses | (2,208 | ) | (739 | ) | (3,727 | ) | (12,205 | ) | ||||||||
| Equity securities available for sale | 9,729 | 25,158 | 39,310 | 58,489 | ||||||||||||
| Investment funds | 50,919 | (34 | ) | 95,675 | 11,003 | |||||||||||
| Real estate | 15 | — | 85,659 | — | ||||||||||||
| Other | — | (16 | ) | — | (34 | ) | ||||||||||
| Total | 72,258 | 43,869 | 234,180 | 96,896 | ||||||||||||
| Income tax expense | (25,290 | ) | (15,355 | ) | (81,963 | ) | (33,914 | ) | ||||||||
| Total after-tax realized investment gains | $ | 46,968 | $ | 28,514 | $ | 152,217 | $ | 62,982 | ||||||||
| Unrealized Gain (Loss) on Investments | ' | |||||||||||||||
| Change in unrealized investment gains (losses): | ||||||||||||||||
| Fixed maturity securities | $ | 10,722 | $ | (46,004 | ) | $ | 190,242 | $ | (339,384 | ) | ||||||
| Previously impaired fixed maturity securities | 188 | 299 | 941 | 821 | ||||||||||||
| Equity securities available for sale | (27,548 | ) | (13,984 | ) | (19,215 | ) | (5,614 | ) | ||||||||
| Investment funds | (8,391 | ) | 3,926 | (8,317 | ) | (5,248 | ) | |||||||||
| Total change in unrealized investment gains (losses) | (25,029 | ) | (55,763 | ) | 163,651 | (349,425 | ) | |||||||||
| Income tax benefit (expense) | 12,117 | 16,884 | (55,419 | ) | 121,296 | |||||||||||
| Noncontrolling interests | (82 | ) | (9 | ) | (119 | ) | (14 | ) | ||||||||
| Total after-tax unrealized gains (losses) | $ | (12,994 | ) | $ | (38,888 | ) | $ | 108,113 | $ | (228,143 | ) | |||||
Securities_In_An_Unrealized_Lo1
| Securities In An Unrealized Loss Position Securities In An Unrealized Loss Position (Tables) | 9 Months Ended | |||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||
| Statement of Financial Position [Abstract] | ' | |||||||||||||||||||||||
| Securities in an unrealized loss position | ' | |||||||||||||||||||||||
| The following tables summarize all securities in an unrealized loss position at September 30, 2014 and December 31, 2013 by the length of time those securities have been continuously in an unrealized loss position: | ||||||||||||||||||||||||
| Less Than 12 Months | 12 Months or Greater | Total | ||||||||||||||||||||||
| (In thousands) | Fair Value | Gross | Fair Value | Gross | Fair Value | Gross | ||||||||||||||||||
| Unrealized | Unrealized | Unrealized | ||||||||||||||||||||||
| Losses | Losses | Losses | ||||||||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||||||
| U.S. government and government agency | $ | 131,471 | $ | 1,411 | $ | 85,253 | $ | 3,818 | $ | 216,724 | $ | 5,229 | ||||||||||||
| State and municipal | 111,019 | 743 | 175,757 | 4,076 | 286,776 | 4,819 | ||||||||||||||||||
| Mortgage-backed securities | 182,774 | 1,481 | 295,503 | 12,811 | 478,277 | 14,292 | ||||||||||||||||||
| Corporate | 1,068,868 | 3,983 | 269,171 | 13,025 | 1,338,039 | 17,008 | ||||||||||||||||||
| Foreign | 82,459 | 3,154 | 120,708 | 10,053 | 203,167 | 13,207 | ||||||||||||||||||
| Fixed maturity securities | 1,576,591 | 10,772 | 946,392 | 43,783 | 2,522,983 | 54,555 | ||||||||||||||||||
| Common stocks | 10,813 | 531 | — | — | 10,813 | 531 | ||||||||||||||||||
| Preferred stocks | 3,005 | 40 | 22,535 | 3,139 | 25,540 | 3,179 | ||||||||||||||||||
| Equity securities | 13,818 | 571 | 22,535 | 3,139 | 36,353 | 3,710 | ||||||||||||||||||
| Total | $ | 1,590,409 | $ | 11,343 | $ | 968,927 | $ | 46,922 | $ | 2,559,336 | $ | 58,265 | ||||||||||||
| December 31, 2013 | ||||||||||||||||||||||||
| U.S. government and government agency | $ | 260,882 | $ | 7,927 | $ | 2,163 | $ | 55 | $ | 263,045 | $ | 7,982 | ||||||||||||
| State and municipal | 899,613 | 24,503 | 87,345 | 5,334 | 986,958 | 29,837 | ||||||||||||||||||
| Mortgage-backed securities | 578,603 | 17,964 | 140,648 | 8,965 | 719,251 | 26,929 | ||||||||||||||||||
| Corporate | 1,013,373 | 17,066 | 105,074 | 13,034 | 1,118,447 | 30,100 | ||||||||||||||||||
| Foreign | 320,215 | 16,286 | — | — | 320,215 | 16,286 | ||||||||||||||||||
| Fixed maturity securities | 3,072,686 | 83,746 | 335,230 | 27,388 | 3,407,916 | 111,134 | ||||||||||||||||||
| Common stocks | — | — | — | — | — | — | ||||||||||||||||||
| Preferred stocks | 13,291 | 513 | 19,868 | 5,806 | 33,159 | 6,319 | ||||||||||||||||||
| Equity securities | 13,291 | 513 | 19,868 | 5,806 | 33,159 | 6,319 | ||||||||||||||||||
| Total | $ | 3,085,977 | $ | 84,259 | $ | 355,098 | $ | 33,194 | $ | 3,441,075 | $ | 117,453 | ||||||||||||
| Non-Investment Grade Fixed Maturity Securities | ' | |||||||||||||||||||||||
| Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2014 is presented in the table below. | ||||||||||||||||||||||||
| ($ in thousands) | Number of | Aggregate | Gross | |||||||||||||||||||||
| Securities | Fair Value | Unrealized | ||||||||||||||||||||||
| Loss | ||||||||||||||||||||||||
| Mortgage-backed securities | 9 | $ | 42,230 | $ | 1,611 | |||||||||||||||||||
| Corporate | 9 | 27,494 | 647 | |||||||||||||||||||||
| Foreign | — | — | — | |||||||||||||||||||||
| Total | 18 | $ | 69,724 | $ | 2,258 | |||||||||||||||||||
Fair_Value_Measurements_Tables
| Fair Value Measurements (Tables) | 9 Months Ended | |||||||||||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||||||||||||||||||
| Assets And Liabilities Measured At Fair value, On A Recurring Basis | ' | |||||||||||||||||||||||||||||||
| The following tables present the assets and liabilities measured at fair value, on a recurring basis, as of September 30, 2014 and December 31, 2013 by level: | ||||||||||||||||||||||||||||||||
| (In thousands) | Total | Level 1 | Level 2 | Level 3 | ||||||||||||||||||||||||||||
| September 30, 2014 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 813,034 | $ | — | $ | 813,034 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,180,068 | — | 4,180,068 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,298,845 | — | 1,298,845 | — | ||||||||||||||||||||||||||||
| Corporate | 5,041,702 | — | 5,017,702 | 24,000 | ||||||||||||||||||||||||||||
| Foreign government | 962,911 | — | 962,911 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 12,296,560 | — | 12,272,560 | 24,000 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 79,973 | 68,852 | — | 11,121 | ||||||||||||||||||||||||||||
| Preferred stocks | 142,051 | — | 138,313 | 3,738 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 222,024 | 68,852 | 138,313 | 14,859 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 918,223 | 237,310 | 676,896 | 4,017 | ||||||||||||||||||||||||||||
| Total | $ | 13,436,807 | $ | 306,162 | $ | 13,087,769 | $ | 42,876 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 159,537 | $ | 159,501 | $ | 5 | $ | 31 | ||||||||||||||||||||||||
| December 31, 2013 | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturity securities available for sale: | ||||||||||||||||||||||||||||||||
| U.S. government and government agency | $ | 884,859 | $ | — | $ | 884,859 | $ | — | ||||||||||||||||||||||||
| State and municipal | 4,218,284 | — | 4,218,284 | — | ||||||||||||||||||||||||||||
| Mortgage-backed securities | 1,329,783 | — | 1,329,783 | — | ||||||||||||||||||||||||||||
| Corporate | 4,202,741 | — | 4,159,877 | 42,864 | ||||||||||||||||||||||||||||
| Foreign government | 879,857 | — | 879,857 | — | ||||||||||||||||||||||||||||
| Total fixed maturity securities available for sale | 11,515,524 | — | 11,472,660 | 42,864 | ||||||||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 160,775 | 159,537 | — | 1,238 | ||||||||||||||||||||||||||||
| Preferred stocks | 122,563 | — | 118,811 | 3,752 | ||||||||||||||||||||||||||||
| Total equity securities available for sale | 283,338 | 159,537 | 118,811 | 4,990 | ||||||||||||||||||||||||||||
| Arbitrage trading account | 522,128 | 192,281 | 328,067 | 1,780 | ||||||||||||||||||||||||||||
| Total | $ | 12,320,990 | $ | 351,818 | $ | 11,919,538 | $ | 49,634 | ||||||||||||||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 162,278 | $ | 162,126 | $ | 152 | $ | — | ||||||||||||||||||||||||
| Summarize Changes In Level 3 Assets | ' | |||||||||||||||||||||||||||||||
| The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2014 and for the year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Gains (Losses) Included in | ||||||||||||||||||||||||||||||||
| (In thousands) | Beginning | Earnings | Other | Purchases | (Sales) | Maturities | Transfer in (out) | Ending | ||||||||||||||||||||||||
| Balance | Comprehensive | Balance | ||||||||||||||||||||||||||||||
| Income | ||||||||||||||||||||||||||||||||
| Nine months ended September 30, 2014: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 42,864 | $ | 49 | $ | (1,146 | ) | $ | 84 | $ | (15,244 | ) | $ | (2,607 | ) | $ | — | $ | 24,000 | |||||||||||||
| Total | 42,864 | 49 | (1,146 | ) | 84 | (15,244 | ) | (2,607 | ) | — | 24,000 | |||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,238 | — | (531 | ) | 11,343 | (929 | ) | — | — | 11,121 | ||||||||||||||||||||||
| Preferred stocks | 3,752 | 8 | — | 3,430 | (3,452 | ) | — | — | 3,738 | |||||||||||||||||||||||
| Total | 4,990 | 8 | (531 | ) | 14,773 | (4,381 | ) | — | — | 14,859 | ||||||||||||||||||||||
| Arbitrage trading account | 1,780 | 2,294 | — | 4,942 | (14,063 | ) | — | 9,064 | 4,017 | |||||||||||||||||||||||
| Total | $ | 49,634 | $ | 2,351 | $ | (1,677 | ) | $ | 19,799 | $ | (33,688 | ) | $ | (2,607 | ) | $ | 9,064 | $ | 42,876 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | — | $ | — | $ | — | $ | 31 | $ | — | $ | — | $ | — | $ | 31 | ||||||||||||||||
| Year ended December 31, 2013: | ||||||||||||||||||||||||||||||||
| Assets: | ||||||||||||||||||||||||||||||||
| Fixed maturities available for sale: | ||||||||||||||||||||||||||||||||
| Corporate | $ | 59,065 | $ | 677 | $ | 309 | $ | 170 | $ | (4,753 | ) | $ | (12,604 | ) | $ | — | $ | 42,864 | ||||||||||||||
| Total | 59,065 | 677 | 309 | 170 | (4,753 | ) | (12,604 | ) | — | 42,864 | ||||||||||||||||||||||
| Equity securities available for sale: | ||||||||||||||||||||||||||||||||
| Common stocks | 1,408 | — | — | — | (170 | ) | — | — | 1,238 | |||||||||||||||||||||||
| Preferred stocks | 621 | (299 | ) | — | 3,430 | — | — | — | 3,752 | |||||||||||||||||||||||
| Total | 2,029 | (299 | ) | — | 3,430 | (170 | ) | — | — | 4,990 | ||||||||||||||||||||||
| Arbitrage trading account | 928 | 1,458 | 730 | 824 | (853 | ) | — | (1,307 | ) | 1,780 | ||||||||||||||||||||||
| Total | $ | 62,022 | $ | 1,836 | $ | 1,039 | $ | 4,424 | $ | (5,776 | ) | $ | (12,604 | ) | $ | (1,307 | ) | $ | 49,634 | |||||||||||||
| Liabilities: | ||||||||||||||||||||||||||||||||
| Securities sold but not yet purchased | $ | 20 | $ | (4 | ) | $ | — | $ | 4 | $ | (20 | ) | $ | — | $ | — | $ | — | ||||||||||||||
Reinsurance_Tables
| Reinsurance (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Reinsurance Disclosures [Abstract] | ' | |||||||||||||||
| Reinsurance Financial Information | ' | |||||||||||||||
| The following is a summary of reinsurance financial information: | ||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||
| Written premiums: | ||||||||||||||||
| Direct | $ | 1,553,493 | $ | 1,415,775 | $ | 4,699,319 | $ | 4,221,370 | ||||||||
| Assumed | 225,863 | 251,331 | 657,704 | 695,293 | ||||||||||||
| Ceded | (253,974 | ) | (243,481 | ) | (815,985 | ) | (774,174 | ) | ||||||||
| Total net premiums written | $ | 1,525,382 | $ | 1,423,625 | $ | 4,541,038 | $ | 4,142,489 | ||||||||
| Earned premiums: | ||||||||||||||||
| Direct | $ | 1,505,738 | $ | 1,351,542 | $ | 4,336,463 | $ | 3,893,806 | ||||||||
| Assumed | 216,889 | 226,530 | 667,566 | 658,063 | ||||||||||||
| Ceded | (261,823 | ) | (249,210 | ) | (761,968 | ) | (708,373 | ) | ||||||||
| Total net premiums earned | $ | 1,460,804 | $ | 1,328,862 | $ | 4,242,061 | $ | 3,843,496 | ||||||||
| Ceded losses incurred | $ | 128,903 | $ | 186,504 | $ | 319,156 | $ | 439,415 | ||||||||
Recovered_Sheet1
| Fair Value of Financial Instruments (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||
| Carrying Amounts And Estimated Fair Values Of Financial Instruments | ' | |||||||||||||||
| The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments: | ||||||||||||||||
| September 30, 2014 | December 31, 2013 | |||||||||||||||
| (In thousands) | Carrying Value | Fair Value | Carrying Value | Fair Value | ||||||||||||
| Assets: | ||||||||||||||||
| Fixed maturity securities | $ | 12,397,756 | $ | 12,418,016 | $ | 11,616,844 | $ | 11,631,744 | ||||||||
| Equity securities available for sale | 222,024 | 222,024 | 283,338 | 283,338 | ||||||||||||
| Arbitrage trading account | 918,223 | 918,223 | 522,128 | 522,128 | ||||||||||||
| Loans receivable | 343,300 | 346,622 | 343,583 | 346,746 | ||||||||||||
| Cash and cash equivalents | 1,342,285 | 1,342,285 | 839,738 | 839,738 | ||||||||||||
| Trading account receivables from brokers and clearing organizations | — | — | 304,936 | 304,936 | ||||||||||||
| Due from broker | — | — | 17,735 | 17,735 | ||||||||||||
| Liabilities: | ||||||||||||||||
| Due to broker | 58,926 | 58,926 | 8,273 | 8,273 | ||||||||||||
| Trading account payable to brokers and clearing organizations | 95,681 | 95,681 | — | — | ||||||||||||
| Trading account securities sold but not yet purchased | 159,537 | 159,537 | 162,278 | 162,278 | ||||||||||||
| Junior subordinated debentures | 339,995 | 326,480 | 339,800 | 288,540 | ||||||||||||
| Senior notes and other debt | 2,122,030 | 2,341,816 | 1,692,442 | 1,861,898 | ||||||||||||
Restricted_Stock_Units_Tables
| Restricted Stock Units (Tables) | 9 Months Ended | ||||||
| Sep. 30, 2014 | |||||||
| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | ' | ||||||
| Summary Of Restricted Stock Units Issued | ' | ||||||
| A summary of RSUs issued in the nine months ended September 30, 2014 and 2013 follows: | |||||||
| ($ in thousands) | Units | Fair Value | |||||
| Nine months ended September 30, | |||||||
| 2014 | 1,135,900 | $ | 50,791 | ||||
| 2013 | 93,150 | $ | 3,957 | ||||
Industry_Segments_Tables
| Industry Segments (Tables) | 9 Months Ended | |||||||||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||||||||
| Segment Reporting [Abstract] | ' | |||||||||||||||||||||||
| Financial Information Of Company Operating Segments | ' | |||||||||||||||||||||||
| Revenues | ||||||||||||||||||||||||
| (In thousands) | Earned | Investment | Other | Total | Pre-Tax | Net | ||||||||||||||||||
| Premiums | Income | Income | Income | |||||||||||||||||||||
| (Loss) | (Loss) to Common Stockholders | |||||||||||||||||||||||
| Three months ended September 30, 2014: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 1,093,554 | $ | 125,792 | $ | 26,408 | $ | 1,245,754 | $ | 228,359 | $ | 154,718 | ||||||||||||
| Insurance-International | 205,529 | 19,957 | — | 225,486 | 12,603 | 9,217 | ||||||||||||||||||
| Reinsurance-Global | 161,721 | 26,916 | — | 188,637 | 29,005 | 20,207 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 6,560 | 101,910 | 108,470 | (63,772 | ) | (42,571 | ) | ||||||||||||||||
| Net investment gains | — | — | 72,258 | 72,258 | 72,258 | 46,968 | ||||||||||||||||||
| Total | $ | 1,460,804 | $ | 179,225 | $ | 200,576 | $ | 1,840,605 | $ | 278,453 | $ | 188,539 | ||||||||||||
| Three months ended September 30, 2013: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 958,994 | $ | 94,071 | $ | 26,125 | $ | 1,079,190 | $ | 172,177 | $ | 118,183 | ||||||||||||
| Insurance-International | 189,054 | 11,151 | — | 200,205 | 16,129 | 11,225 | ||||||||||||||||||
| Reinsurance-Global | 180,814 | 20,121 | — | 200,935 | 24,559 | 17,300 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 291 | 109,634 | 109,925 | (58,501 | ) | (38,248 | ) | ||||||||||||||||
| Net investment gains | — | — | 43,869 | 43,869 | 43,869 | 28,514 | ||||||||||||||||||
| Total | $ | 1,328,862 | $ | 125,634 | $ | 179,628 | $ | 1,634,124 | $ | 198,233 | $ | 136,974 | ||||||||||||
| Nine months ended September 30, 2014: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 3,138,806 | $ | 347,002 | $ | 82,159 | $ | 3,567,967 | $ | 607,399 | $ | 414,588 | ||||||||||||
| Insurance-International | 592,721 | 47,885 | — | 640,606 | 41,860 | 29,938 | ||||||||||||||||||
| Reinsurance-Global | 510,534 | 72,102 | — | 582,636 | 86,945 | 60,624 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 19,676 | 299,435 | 319,111 | (180,892 | ) | (119,194 | ) | ||||||||||||||||
| Net investment gains | — | — | 234,180 | 234,180 | 234,180 | 152,217 | ||||||||||||||||||
| Total | $ | 4,242,061 | $ | 486,665 | $ | 615,774 | $ | 5,344,500 | $ | 789,492 | $ | 538,173 | ||||||||||||
| Nine months ended September 30, 2013: | ||||||||||||||||||||||||
| Insurance-Domestic | $ | 2,769,369 | $ | 299,430 | $ | 80,513 | $ | 3,149,312 | $ | 465,861 | $ | 324,069 | ||||||||||||
| Insurance-International | 540,365 | 36,383 | — | 576,748 | 51,094 | 35,794 | ||||||||||||||||||
| Reinsurance-Global | 533,762 | 65,656 | — | 599,418 | 87,252 | 61,375 | ||||||||||||||||||
| Corporate and eliminations (1) | — | 3,831 | 285,650 | 289,481 | (183,941 | ) | (114,674 | ) | ||||||||||||||||
| Net investment gains | — | — | 96,896 | 96,896 | 96,896 | 62,982 | ||||||||||||||||||
| Total | $ | 3,843,496 | $ | 405,300 | $ | 463,059 | $ | 4,711,855 | $ | 517,162 | $ | 369,546 | ||||||||||||
| (1) Corporate and eliminations represent corporate revenues and expenses that are not allocated to business segments. | ||||||||||||||||||||||||
| Identifiable Assets By Segment | ' | |||||||||||||||||||||||
| Identifiable assets by segment are as follows: | ||||||||||||||||||||||||
| (In thousands) | September 30, 2014 | 31-Dec-13 | ||||||||||||||||||||||
| Insurance-Domestic | $ | 16,074,387 | $ | 15,247,807 | ||||||||||||||||||||
| Insurance-International | 1,915,322 | 1,516,310 | ||||||||||||||||||||||
| Reinsurance-Global | 2,801,268 | 3,103,193 | ||||||||||||||||||||||
| Corporate and eliminations | 1,306,620 | 684,486 | ||||||||||||||||||||||
| Total | $ | 22,097,597 | $ | 20,551,796 | ||||||||||||||||||||
| Net Premiums Earned By Major Line Of Business | ' | |||||||||||||||||||||||
| Net premiums earned by major line of business are as follows: | ||||||||||||||||||||||||
| For the Three Months | For the Nine Months | |||||||||||||||||||||||
| Ended September 30, | Ended September 30, | |||||||||||||||||||||||
| (In thousands) | 2014 | 2013 | 2014 | 2013 | ||||||||||||||||||||
| Insurance-Domestic: | ||||||||||||||||||||||||
| Other liability | $ | 368,818 | $ | 314,878 | $ | 1,070,525 | $ | 917,910 | ||||||||||||||||
| Workers’ compensation | 291,297 | 252,220 | 824,541 | 722,422 | ||||||||||||||||||||
| Short-tail lines | 222,561 | 199,181 | 642,833 | 570,868 | ||||||||||||||||||||
| Commercial automobile | 134,197 | 125,942 | 385,667 | 361,964 | ||||||||||||||||||||
| Professional liability | 76,681 | 66,773 | 215,240 | 196,205 | ||||||||||||||||||||
| Total | 1,093,554 | 958,994 | 3,138,806 | 2,769,369 | ||||||||||||||||||||
| Insurance-International: | ||||||||||||||||||||||||
| Other liability | 27,705 | 18,457 | 70,036 | 48,745 | ||||||||||||||||||||
| Workers’ compensation | 18,012 | 20,847 | 52,578 | 65,482 | ||||||||||||||||||||
| Short-tail lines | 100,417 | 92,213 | 303,119 | 248,637 | ||||||||||||||||||||
| Commercial automobile | 29,076 | 30,898 | 86,318 | 97,929 | ||||||||||||||||||||
| Professional liability | 30,319 | 26,639 | 80,670 | 79,572 | ||||||||||||||||||||
| Total | 205,529 | 189,054 | 592,721 | 540,365 | ||||||||||||||||||||
| Reinsurance-Global: | ||||||||||||||||||||||||
| Casualty | 122,741 | 128,127 | 372,894 | 371,571 | ||||||||||||||||||||
| Property | 38,980 | 52,687 | 137,640 | 162,191 | ||||||||||||||||||||
| Total | 161,721 | 180,814 | 510,534 | 533,762 | ||||||||||||||||||||
| Total | $ | 1,460,804 | $ | 1,328,862 | $ | 4,242,061 | $ | 3,843,496 | ||||||||||||||||
General_General_Details
| General General (Details) | 9 Months Ended |
| Sep. 30, 2014 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | ' |
| Federal Income Tax Rate | 35.00% |
Per_Share_Data_Weighted_Averag
| Per Share Data (Weighted Average Number of Common Shares Used In the Computation of Basic and Diluted Earnings per Share) (Details) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Earnings Per Share [Abstract] | ' | ' | ' | ' |
| Basic (shares) | 127,165 | 135,268 | 128,225 | 135,726 |
| Diluted (shares) | 133,001 | 140,758 | 133,886 | 141,095 |
Acquistions_Acquisitions_Detai
| Acquistions Acquisitions (Details) (USD $) | 1 Months Ended | 12 Months Ended | ||
| Jan. 31, 2013 | Dec. 31, 2012 | Sep. 30, 2014 | Dec. 31, 2013 | |
| Business Acquisition [Line Items] | ' | ' | ' | ' |
| Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds | ' | ' | $16,000,000 | ' |
| Assets of Disposal Group, Including Discontinued Operation | ' | ' | 15,000,000 | ' |
| Goodwill | ' | ' | 103,337,000 | 110,146,000 |
| Premiums and fees receivable | ' | ' | 1,681,674,000 | 1,557,480,000 |
| After Market Original Equipment Manufacturer | ' | ' | ' | ' |
| Business Acquisition [Line Items] | ' | ' | ' | ' |
| Business Acquisition, Transaction Costs | ' | ' | 83,000,000 | ' |
| Cash and cash equivalents | ' | ' | 17,456,000 | 3,911,000 |
| Real estate, furniture and equipment | ' | ' | 669,000 | 898,000 |
| Goodwill and other intangibles assets | ' | ' | 77,967,000 | 64,464,000 |
| Premiums and fees receivable | ' | ' | 20,178,000 | 0 |
| Other assets | ' | ' | 0 | 60,661,000 |
| Total assets acquired | ' | ' | 116,270,000 | 129,934,000 |
| Debt | ' | ' | 0 | -27,612,000 |
| Other liabilities assumed | ' | ' | -33,391,000 | -17,076,000 |
| Net assets acquired | ' | ' | 82,879,000 | 85,246,000 |
| Business Acquisition, Percentage of Voting Interests Acquired | 51.00% | 49.00% | ' | ' |
| Business Combination, Consideration Transferred | $43,000,000 | $43,000,000 | ' | ' |
Acquistions_Intangibles_Detail
| Acquistions Intangibles (Details) (After Market Original Equipment Manufacturer, USD $) | 1 Months Ended | 9 Months Ended | 12 Months Ended |
| In Millions, unless otherwise specified | Jan. 31, 2013 | Sep. 30, 2014 | Dec. 31, 2012 |
| Business Acquisition [Line Items] | ' | ' | ' |
| Percentage acquired | 51.00% | ' | 49.00% |
| Purchase amount | $43 | ' | $43 |
| Acquired Indefinite-lived Intangible Assets | ' | $3 | ' |
| Minimum | ' | ' | ' |
| Business Acquisition [Line Items] | ' | ' | ' |
| Amortization of Acquired Intangible Assets | ' | '2 years | ' |
| Maximum | ' | ' | ' |
| Business Acquisition [Line Items] | ' | ' | ' |
| Amortization of Acquired Intangible Assets | ' | '15 years | ' |
Statements_of_Comprehensive_In2
| Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||||||||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Mar. 31, 2014 | Mar. 31, 2013 | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Beginning of Period | ' | ' | $189,391 | ' | ' | ' | ||||
| Other comprehensive income (loss) | -60,272 | 7,263 | 84,273 | -248,138 | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), End of Period | 273,545 | ' | 273,545 | ' | ' | ' | ||||
| Net investment gains | 72,258 | 43,869 | 234,180 | 96,896 | ' | ' | ||||
| Income before income taxes | 278,453 | 198,233 | 789,492 | 517,162 | ' | ' | ||||
| Income before taxes | 544,303 | 504,096 | 1,593,619 | 1,479,986 | ' | ' | ||||
| Tax effect | -89,662 | -60,045 | -250,840 | -147,249 | ' | ' | ||||
| After-tax amounts reclassified | 188,791 | 138,188 | 538,652 | 369,913 | ' | ' | ||||
| Unrealized investment gains, pre-tax | -25,029 | -59,814 | 163,651 | -350,968 | ' | ' | ||||
| Unrealized investment gains, tax effect | 12,117 | 20,935 | -55,419 | 122,839 | ' | ' | ||||
| Unrealized investment gains, after-tax amounts | -12,912 | -38,879 | 108,232 | -228,129 | ' | ' | ||||
| Currency translation adjustment, pre-tax | -49,380 | 44,328 | -28,590 | -25,451 | ' | ' | ||||
| Currency translation adjustment, tax effect | 0 | 0 | 0 | 0 | ' | ' | ||||
| Change in unrealized currency translation adjustments | -49,380 | 44,328 | -28,590 | -25,451 | ' | ' | ||||
| Net pension asset, pre-tax | 3,108 | 2,790 | 7,125 | 8,372 | ' | ' | ||||
| Net pension asset, tax effect | -1,088 | -976 | -2,494 | -2,930 | ' | ' | ||||
| Net pension asset, after-tax amounts | 2,020 | 1,814 | 4,631 | 5,442 | ' | ' | ||||
| Other comprehensive income (loss), pre-tax | -71,301 | -12,696 | 142,186 | -368,047 | ' | ' | ||||
| Other comprehensive income (loss), tax effect | 11,029 | 19,959 | -57,913 | 119,909 | ' | ' | ||||
| Accumulated Net Unrealized Investment Gain (Loss) [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Beginning of Period | ' | ' | 256,566 | 517,658 | 377,673 | 328,403 | ||||
| Other comprehensive income (loss) before reclassifications | 3,099 | -10,331 | 143,388 | -172,276 | ' | ' | ||||
| Amounts reclassified from AOCI | -16,011 | -28,548 | -35,156 | -55,853 | ' | ' | ||||
| Other comprehensive income (loss) | -12,912 | -38,879 | 108,232 | -228,129 | ' | ' | ||||
| Unrealized investment gain related to non-controlling interest | -82 | -9 | -119 | -14 | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), End of Period | 364,679 | 289,515 | 364,679 | 289,515 | 377,673 | 328,403 | ||||
| Currency Translation Adjustments [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Beginning of Period | ' | ' | -60,524 | -36,676 | -39,734 | -106,455 | ||||
| Other comprehensive income (loss) before reclassifications | -49,380 | 44,328 | -28,590 | -25,451 | ' | ' | ||||
| Amounts reclassified from AOCI | 0 | 0 | 0 | 0 | ' | ' | ||||
| Other comprehensive income (loss) | -49,380 | 44,328 | -28,590 | -25,451 | ' | ' | ||||
| Unrealized investment gain related to non-controlling interest | 0 | 0 | 0 | 0 | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), End of Period | -89,114 | -62,127 | -89,114 | -62,127 | -39,734 | -106,455 | ||||
| Change in unrealized currency translation adjustments | ' | ' | -28,590 | -25,451 | ' | ' | ||||
| Net Pension Asset [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Beginning of Period | ' | ' | -6,651 | -15,351 | -4,040 | -11,723 | ||||
| Other comprehensive income (loss) before reclassifications | 0 | 0 | 0 | 0 | ' | ' | ||||
| Amounts reclassified from AOCI | 2,020 | 1,814 | 4,631 | 5,442 | ' | ' | ||||
| Other comprehensive income (loss) | 2,020 | 1,814 | 4,631 | 5,442 | ' | ' | ||||
| Unrealized investment gain related to non-controlling interest | 0 | 0 | 0 | 0 | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), End of Period | -2,020 | -9,909 | -2,020 | -9,909 | -4,040 | -11,723 | ||||
| Accumulated Other Comprehensive Income (Loss) [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Beginning of Period | ' | ' | 189,391 | 465,631 | 333,899 | 210,225 | ||||
| Other comprehensive income (loss) before reclassifications | -46,281 | 33,997 | 114,798 | -197,727 | ' | ' | ||||
| Amounts reclassified from AOCI | -13,991 | -26,734 | -30,525 | -50,411 | ' | ' | ||||
| Other comprehensive income (loss) | -60,272 | 7,263 | 84,273 | -248,138 | ' | ' | ||||
| Unrealized investment gain related to non-controlling interest | -82 | -9 | -119 | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), End of Period | 273,545 | 217,479 | 273,545 | 217,479 | 333,899 | 210,225 | ||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Net investment gains | -24,632 | [1] | -43,920 | -54,086 | [1] | -85,928 | [1] | ' | ' | |
| Tax effect | 8,621 | [2] | 15,372 | [2] | 18,930 | [2] | 30,075 | [2] | ' | ' |
| After-tax amounts reclassified | -16,011 | -28,548 | -35,156 | -55,853 | ' | ' | ||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency Translation Adjustments [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Income before income taxes | 0 | 0 | 0 | 0 | ' | ' | ||||
| Tax effect | 0 | [2] | 0 | [2] | 0 | [2] | 0 | [2] | ' | ' |
| After-tax amounts reclassified | 0 | 0 | 0 | 0 | ' | ' | ||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension Asset [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Income before taxes | 3,108 | [3] | 2,790 | 7,125 | [3] | 8,372 | [3] | ' | ' | |
| Tax effect | -1,088 | [2] | -976 | [2] | -2,494 | [2] | -2,930 | [2] | ' | ' |
| After-tax amounts reclassified | 2,020 | 1,814 | 4,631 | 5,442 | ' | ' | ||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | ' | ' | ' | ' | ' | ' | ||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] | ' | ' | ' | ' | ' | ' | ||||
| Income before income taxes | -21,524 | -41,130 | -46,961 | -77,556 | ' | ' | ||||
| Tax effect | 7,533 | [2] | 14,396 | [2] | 16,436 | [2] | 27,145 | [2] | ' | ' |
| After-tax amounts reclassified | ($13,991) | ($26,734) | ($30,525) | ($50,411) | ' | ' | ||||
| [1] | Net investment gains in the consolidated statements of | |||||||||
| [2] | Income tax expense in the consolidated statements of income. | |||||||||
| [3] | Other operating costs and expenses in the consolidated statements of income. | |||||||||
Statements_of_Cash_Flow_Detail
| Statements of Cash Flow (Details) (USD $) | 9 Months Ended | |
| Sep. 30, 2014 | Sep. 30, 2013 | |
| Supplemental Cash Flow Information [Abstract] | ' | ' |
| Interest payments | $108,688,000 | $114,026,000 |
| Income taxes paid | $238,030,000 | $176,632,000 |
Investments_In_Fixed_Maturity_2
| Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Investments in fixed maturity securities) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total held to maturity, Amortized Cost | $101,196,000 | $101,320,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Gain | 20,260,000 | 14,900,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Loss | 0 | 0 | ||
| Total held to maturity, Fair Value | 121,456,000 | 116,220,000 | ||
| Total held to maturity, Carrying Value | 101,196,000 | 101,320,000 | ||
| Total available for sale, Amortized Cost | 11,780,111,000 | 11,190,311,000 | ||
| Total available for sale, Gross Unrealized Gains | 571,004,000 | 436,347,000 | ||
| Total available for sale, Gross Unrealized Losses | -54,555,000 | -111,134,000 | ||
| Total available for sale, Fair Value | 12,296,560,000 | 11,515,524,000 | ||
| Total available for sale, Carrying Value | 12,296,560,000 | 11,515,524,000 | ||
| Total investments in fixed maturity securities, Amortized Value | 11,881,307,000 | 11,291,631,000 | ||
| Total investments in fixed maturity securities, Gross Unrealized Gains | 591,264,000 | 451,247,000 | ||
| Total investments in fixed maturity securities, Gross Unrealized Losses | -54,555,000 | -111,134,000 | ||
| Total investments in fixed maturity securities, Fair Value | 12,418,016,000 | 11,631,744,000 | ||
| Total investments in fixed maturity securities, Carrying Value | 12,397,756,000 | 11,616,844,000 | ||
| Minimum ownership of Common stockholders equity | 10.00% | ' | ||
| Foreign government | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 880,959,000 | 844,469,000 | ||
| Total available for sale, Gross Unrealized Gains | 95,159,000 | 51,674,000 | ||
| Total available for sale, Gross Unrealized Losses | -13,207,000 | -16,286,000 | ||
| Total available for sale, Fair Value | 962,911,000 | 879,857,000 | ||
| Total available for sale, Carrying Value | 962,911,000 | 879,857,000 | ||
| Commercial Mortgage Backed Securities [Member] | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 76,993,000 | 76,454,000 | ||
| Total available for sale, Gross Unrealized Gains | 976,000 | 5,670,000 | ||
| Total available for sale, Gross Unrealized Losses | -83,000 | -988,000 | ||
| Total available for sale, Fair Value | 77,886,000 | 81,136,000 | ||
| Total available for sale, Carrying Value | 77,886,000 | 81,136,000 | ||
| U.S. government and government agency | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 787,967,000 | 858,319,000 | ||
| Total available for sale, Gross Unrealized Gains | 30,296,000 | 34,522,000 | ||
| Total available for sale, Gross Unrealized Losses | -5,229,000 | -7,982,000 | ||
| Total available for sale, Fair Value | 813,034,000 | 884,859,000 | ||
| Total available for sale, Carrying Value | 813,034,000 | 884,859,000 | ||
| Residential Mortgage Backed Securities [Member] | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 1,209,068,000 | [1] | 1,248,693,000 | [1] |
| Total available for sale, Gross Unrealized Gains | 26,100,000 | [1] | 25,895,000 | [1] |
| Total available for sale, Gross Unrealized Losses | -14,209,000 | [1] | -25,941,000 | [1] |
| Total available for sale, Fair Value | 1,220,959,000 | [1] | 1,248,647,000 | [1] |
| Total available for sale, Carrying Value | 1,220,959,000 | [1] | 1,248,647,000 | [1] |
| Non-credit portion of other-than-temporary impairments (OTTI) | 1,020,000 | 1,961,000 | ||
| Corporate Debt Securities [Member] | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 4,866,983,000 | 4,076,585,000 | ||
| Total available for sale, Gross Unrealized Gains | 191,727,000 | 156,256,000 | ||
| Total available for sale, Gross Unrealized Losses | -17,008,000 | -30,100,000 | ||
| Total available for sale, Fair Value | 5,041,702,000 | 4,202,741,000 | ||
| Total available for sale, Carrying Value | 5,041,702,000 | 4,202,741,000 | ||
| State and municipal | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total available for sale, Amortized Cost | 3,958,141,000 | 4,085,791,000 | ||
| Total available for sale, Gross Unrealized Gains | 226,746,000 | 162,330,000 | ||
| Total available for sale, Gross Unrealized Losses | -4,819,000 | -29,837,000 | ||
| Total available for sale, Fair Value | 4,180,068,000 | 4,218,284,000 | ||
| Total available for sale, Carrying Value | 4,180,068,000 | 4,218,284,000 | ||
| State and municipal | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total held to maturity, Amortized Cost | 71,897,000 | 68,929,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Gain | 16,991,000 | 11,172,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Loss | 0 | 0 | ||
| Total held to maturity, Fair Value | 88,888,000 | 80,101,000 | ||
| Total held to maturity, Carrying Value | 71,897,000 | 68,929,000 | ||
| Residential Mortgage Backed Securities [Member] | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total held to maturity, Amortized Cost | 24,300,000 | 27,393,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Gain | 2,901,000 | 3,311,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Loss | 0 | 0 | ||
| Total held to maturity, Fair Value | 27,201,000 | 30,704,000 | ||
| Total held to maturity, Carrying Value | 24,300,000 | 27,393,000 | ||
| Corporate Debt Securities [Member] | ' | ' | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' | ||
| Total held to maturity, Amortized Cost | 4,999,000 | 4,998,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Gain | 368,000 | 417,000 | ||
| Held to Maturity Securities Accumulated Unrecognized Holding Loss | 0 | 0 | ||
| Total held to maturity, Fair Value | 5,367,000 | 5,415,000 | ||
| Total held to maturity, Carrying Value | $4,999,000 | $4,998,000 | ||
| [1] | Gross unrealized losses for residential mortgage-backed securities include $1,020,000 and $1,961,000 as of September 30, 2014 and December 31, 2013, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTIâ€) recognized in accumulated other comprehensive income. | |||
Investments_In_Fixed_Maturity_3
| Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Amortized cost and fair value of fixed maturity securities) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Investments, Debt and Equity Securities [Abstract] | ' | ' |
| Amortized Cost, Due in one year or less | $889,062 | ' |
| Amortized Cost, Due after one year through five years | 4,052,836 | ' |
| Amortized Cost, Due after five years through ten years | 3,105,077 | ' |
| Amortized Cost, Due after ten years | 2,523,971 | ' |
| Amortized Cost, Mortgaged-backed securities | 1,310,361 | ' |
| Total investments in fixed maturity securities, Amortized Value | 11,881,307 | 11,291,631 |
| Fair Value, Due in one year or less | 900,273 | ' |
| Fair Value, Due after one year through five years | 4,268,705 | ' |
| Fair Value, Due after five years through ten years | 3,288,731 | ' |
| Fair Value, Due after ten years | 2,634,261 | ' |
| Fair Value, Mortgage-backed securities | 1,326,046 | ' |
| Total investments in fixed maturity securities, Fair Value | $12,418,016 | $11,631,744 |
Investments_in_Equity_Securiti2
| Investments in Equity Securities (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Cost | $161,529 | $203,627 |
| Gross Unrealized, Gains | 64,205 | 86,030 |
| Gross Unrealized, Losses | -3,710 | -6,319 |
| Carrying and fair value of equity securities | 222,024 | 283,338 |
| Common stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Cost | 68,762 | 118,536 |
| Gross Unrealized, Gains | 11,742 | 42,239 |
| Gross Unrealized, Losses | -531 | 0 |
| Carrying and fair value of equity securities | 79,973 | 160,775 |
| Preferred stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Cost | 92,767 | 85,091 |
| Gross Unrealized, Gains | 52,463 | 43,791 |
| Gross Unrealized, Losses | -3,179 | -6,319 |
| Carrying and fair value of equity securities | $142,051 | $122,563 |
Arbitrage_Trading_Account_Deta
| Arbitrage Trading Account (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Trading Securities [Abstract] | ' | ' |
| Arbitrage trading account | $918,223 | $522,128 |
Net_Investment_Income_Net_Inve1
| Net Investment Income Net Investment Income (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | $180,824 | $127,541 | $494,312 | $411,001 |
| Investment expense | -1,599 | -1,907 | -7,647 | -5,701 |
| Net investment income | 179,225 | 125,634 | 486,665 | 405,300 |
| Fixed maturity securities, including cash and cash equivalents and loans receivable | ' | ' | ' | ' |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | 117,289 | 104,033 | 331,947 | 333,072 |
| Investment funds | ' | ' | ' | ' |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | 59,077 | 5,492 | 135,232 | 45,248 |
| Arbitrage trading account | ' | ' | ' | ' |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | 47 | 11,738 | 12,508 | 14,265 |
| Equity securities available for sale | ' | ' | ' | ' |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | 1,369 | 3,192 | 5,418 | 9,073 |
| Real estate | ' | ' | ' | ' |
| Net Investment Income [Line Items] | ' | ' | ' | ' |
| Investment income | $3,042 | $3,086 | $9,207 | $9,343 |
Investment_Funds_Investment_Fu2
| Investment Funds Investment Funds (Details) (USD $) | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 |
| Schedule of Equity Method Investments [Line Items] | ' | ' | ' |
| Investment funds | $1,020,132 | ' | $1,067,495 |
| Income from Investment Funds | 135,232 | 45,248 | ' |
| Real estate | ' | ' | ' |
| Schedule of Equity Method Investments [Line Items] | ' | ' | ' |
| Investment funds | 282,431 | ' | 378,435 |
| Income from Investment Funds | 24,341 | 5,777 | ' |
| Energy | ' | ' | ' |
| Schedule of Equity Method Investments [Line Items] | ' | ' | ' |
| Investment funds | 159,857 | ' | 155,026 |
| Income from Investment Funds | 18,136 | 25,959 | ' |
| Arbitrage | ' | ' | ' |
| Schedule of Equity Method Investments [Line Items] | ' | ' | ' |
| Investment funds | 286,845 | ' | 271,575 |
| Income from Investment Funds | 15,270 | 3,050 | ' |
| Other | ' | ' | ' |
| Schedule of Equity Method Investments [Line Items] | ' | ' | ' |
| Investment funds | 290,999 | ' | 262,459 |
| Income from Investment Funds | $77,485 | $10,462 | ' |
Real_Estate_Real_Estate_Detail
| Real Estate Real Estate (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Real Estate [Abstract] | ' | ' |
| Properties in operation | $196,884 | $283,393 |
| Properties under development | 507,110 | 431,849 |
| Total | 703,994 | 715,242 |
| Real Estate Investment Property, Accumulated Depreciation | $68 | $17,827 |
Real_Estate_Real_Estate_Detail1
| Real Estate Real Estate (Details 1) (USD $) | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 |
| Real Estate [Abstract] | ' | ' | ' |
| Accumulated depreciation and amortization on properties | $68 | ' | $17,827 |
| Real estate depreciation expense | 3,228 | 5,111 | ' |
| Lease future minimum payments 2014 | 2,820 | ' | ' |
| Lease future minimum payments 2015 | 11,360 | ' | ' |
| Lease future minimum payments 2016 | 11,379 | ' | ' |
| Lease future minimum payments 2016 | 11,420 | ' | ' |
| Lease future minimum payments 2014 | 10,750 | ' | ' |
| Lease future minimum payments after 2017 | $343,903 | ' | ' |
Loans_Receivable_Details
| Loans Receivable (Details) (USD $) | 3 Months Ended | 9 Months Ended | |||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | |
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ' | ' | ' | ' | ' |
| Financing Receivable, Recorded Investment, Nonaccrual Status | $15,200,000 | ' | $15,200,000 | ' | ' |
| Loans and Leases Receivable, Gross | 343,300,000 | ' | 343,300,000 | ' | 343,583,000 |
| Loans receivable | 346,622,000 | ' | 346,622,000 | ' | 346,746,000 |
| Valuation allowance, specific | 115,000 | ' | 115,000 | ' | 0 |
| Valuation allowance, general | 2,427,000 | ' | 2,427,000 | ' | 2,087,000 |
| Valuation allowance of loans receivable | 2,542,000 | ' | 2,542,000 | ' | 2,087,000 |
| Decrease in valuation allowance | -24,000 | 72,000 | 455,000 | 137,000 | ' |
| Loans receivable charged off | 0 | 0 | 0 | 0 | ' |
| Real Estate | ' | ' | ' | ' | ' |
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ' | ' | ' | ' | ' |
| Loans and Leases Receivable, Gross | 259,522,000 | ' | 259,522,000 | ' | 282,357,000 |
| Loans receivable | 261,342,000 | ' | 261,342,000 | ' | 284,017,000 |
| Commercial | ' | ' | ' | ' | ' |
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ' | ' | ' | ' | ' |
| Loans and Leases Receivable, Gross | 83,778,000 | ' | 83,778,000 | ' | 61,226,000 |
| Loans receivable | $85,280,000 | ' | $85,280,000 | ' | $62,729,000 |
Realized_And_Unrealized_Invest2
| Realized And Unrealized Investment Gains Realized and Unrealized Investment Gains (Loss) (Realized and unrealized investmetns gains(losses)) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Investments, Debt and Equity Securities [Abstract] | ' | ' | ' | ' |
| Fixed maturity securities, gains | $13,803 | $19,500 | $17,263 | $39,643 |
| Fixed maturity securities, losses | -2,208 | -739 | -3,727 | -12,205 |
| Equity securities available for sale | 9,729 | 25,158 | 39,310 | 58,489 |
| Investment funds | 50,919 | -34 | 95,675 | 11,003 |
| Real Estate Realized Gain (Loss) on Disposal | 15 | 0 | 85,659 | 0 |
| Other | 0 | -16 | 0 | -34 |
| Realized Gain (Loss) on Investments, Including Equity Method Investments, Excluding Other than Temporary Impairments and Allowances | 72,258 | 43,869 | 234,180 | 96,896 |
| Net investment gains | 72,258 | 43,869 | 234,180 | 96,896 |
| Income tax expense | -25,290 | -15,355 | -81,963 | -33,914 |
| Total after-tax realized investment gains | $46,968 | $28,514 | $152,217 | $62,982 |
Recovered_Sheet2
| Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Realized and Unrealized Investment Gains Losses [Line Items] | ' | ' | ' | ' |
| Change in unrealized gains (losses) before income taxes and noncontrolling interests | ($25,029) | ($55,763) | $163,651 | ($349,425) |
| Income tax benefit (expense) | 12,117 | 16,884 | -55,419 | 121,296 |
| Noncontrolling interests | -82 | -9 | -119 | -14 |
| Total change in unrealized gains | -12,994 | -38,888 | 108,113 | -228,143 |
| Debt Securities [Member] | ' | ' | ' | ' |
| Realized and Unrealized Investment Gains Losses [Line Items] | ' | ' | ' | ' |
| Change in unrealized gains (losses) before income taxes and noncontrolling interests | 10,722 | -46,004 | 190,242 | -339,384 |
| Debt Securities Previously Impaired [Member] | ' | ' | ' | ' |
| Realized and Unrealized Investment Gains Losses [Line Items] | ' | ' | ' | ' |
| Change in unrealized gains (losses) before income taxes and noncontrolling interests | 188 | 299 | 941 | 821 |
| Equity securities available for sale | ' | ' | ' | ' |
| Realized and Unrealized Investment Gains Losses [Line Items] | ' | ' | ' | ' |
| Change in unrealized gains (losses) before income taxes and noncontrolling interests | -27,548 | -13,984 | -19,215 | -5,614 |
| Investment funds | ' | ' | ' | ' |
| Realized and Unrealized Investment Gains Losses [Line Items] | ' | ' | ' | ' |
| Change in unrealized gains (losses) before income taxes and noncontrolling interests | ($8,391) | $3,926 | ($8,317) | ($5,248) |
Securities_In_An_Unrealized_Lo2
| Securities In An Unrealized Loss Position Securities in an Unrealized Loss Position (Securities in an Unrealized Loss Position) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | $1,590,409 | $3,085,977 |
| Gross Unrealized Losses, Less than 12 Months | 11,343 | 84,259 |
| Fair Value, 12 Months or Greater | 968,927 | 355,098 |
| Gross Unrealized Losses, 12 Months or Greater | 46,922 | 33,194 |
| Fair Value, Total | 2,559,336 | 3,441,075 |
| Gross Unrealized Losses, Total | 58,265 | 117,453 |
| U.S. government and government agency | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 131,471 | 260,882 |
| Gross Unrealized Losses, Less than 12 Months | 1,411 | 7,927 |
| Fair Value, 12 Months or Greater | 85,253 | 2,163 |
| Gross Unrealized Losses, 12 Months or Greater | 3,818 | 55 |
| Fair Value, Total | 216,724 | 263,045 |
| Gross Unrealized Losses, Total | 5,229 | 7,982 |
| State and municipal | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 111,019 | 899,613 |
| Gross Unrealized Losses, Less than 12 Months | 743 | 24,503 |
| Fair Value, 12 Months or Greater | 175,757 | 87,345 |
| Gross Unrealized Losses, 12 Months or Greater | 4,076 | 5,334 |
| Fair Value, Total | 286,776 | 986,958 |
| Gross Unrealized Losses, Total | 4,819 | 29,837 |
| Mortgage-backed securities | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 182,774 | 578,603 |
| Gross Unrealized Losses, Less than 12 Months | 1,481 | 17,964 |
| Fair Value, 12 Months or Greater | 295,503 | 140,648 |
| Gross Unrealized Losses, 12 Months or Greater | 12,811 | 8,965 |
| Fair Value, Total | 478,277 | 719,251 |
| Gross Unrealized Losses, Total | 14,292 | 26,929 |
| Corporate Debt Securities [Member] | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 1,068,868 | 1,013,373 |
| Gross Unrealized Losses, Less than 12 Months | 3,983 | 17,066 |
| Fair Value, 12 Months or Greater | 269,171 | 105,074 |
| Gross Unrealized Losses, 12 Months or Greater | 13,025 | 13,034 |
| Fair Value, Total | 1,338,039 | 1,118,447 |
| Gross Unrealized Losses, Total | 17,008 | 30,100 |
| Foreign government | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 82,459 | 320,215 |
| Gross Unrealized Losses, Less than 12 Months | 3,154 | 16,286 |
| Fair Value, 12 Months or Greater | 120,708 | 0 |
| Gross Unrealized Losses, 12 Months or Greater | 10,053 | 0 |
| Fair Value, Total | 203,167 | 320,215 |
| Gross Unrealized Losses, Total | 13,207 | 16,286 |
| Debt Securities [Member] | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 1,576,591 | 3,072,686 |
| Gross Unrealized Losses, Less than 12 Months | 10,772 | 83,746 |
| Fair Value, 12 Months or Greater | 946,392 | 335,230 |
| Gross Unrealized Losses, 12 Months or Greater | 43,783 | 27,388 |
| Fair Value, Total | 2,522,983 | 3,407,916 |
| Gross Unrealized Losses, Total | 54,555 | 111,134 |
| Common stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 10,813 | 0 |
| Gross Unrealized Losses, Less than 12 Months | 531 | 0 |
| Fair Value, 12 Months or Greater | 0 | 0 |
| Gross Unrealized Losses, 12 Months or Greater | 0 | 0 |
| Fair Value, Total | 10,813 | 0 |
| Gross Unrealized Losses, Total | 531 | 0 |
| Preferred stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 3,005 | 13,291 |
| Gross Unrealized Losses, Less than 12 Months | 40 | 513 |
| Fair Value, 12 Months or Greater | 22,535 | 19,868 |
| Gross Unrealized Losses, 12 Months or Greater | 3,139 | 5,806 |
| Fair Value, Total | 25,540 | 33,159 |
| Gross Unrealized Losses, Total | 3,179 | 6,319 |
| Equity securities available for sale | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Fair Value, Less than 12 Months | 13,818 | 13,291 |
| Gross Unrealized Losses, Less than 12 Months | 571 | 513 |
| Fair Value, 12 Months or Greater | 22,535 | 19,868 |
| Gross Unrealized Losses, 12 Months or Greater | 3,139 | 5,806 |
| Fair Value, Total | 36,353 | 33,159 |
| Gross Unrealized Losses, Total | $3,710 | $6,319 |
Securities_In_An_Unrealized_Lo3
| Securities In An Unrealized Loss Position Non-Investment Grade Fixed Maturity Securities (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | $2,559,336 | $3,441,075 |
| Mortgage-backed securities | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 478,277 | 719,251 |
| Corporate Debt Securities [Member] | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 1,338,039 | 1,118,447 |
| State and municipal | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 286,776 | 986,958 |
| Foreign government | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 203,167 | 320,215 |
| Noninvestment Grade Investments at Loss Less than 5 Million | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Number of Securities | 18 | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 69,724 | ' |
| Gross Unrealized Loss | 2,258 | ' |
| Noninvestment Grade Investments at Loss Less than 5 Million | Mortgage-backed securities | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Number of Securities | 9 | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 42,230 | ' |
| Gross Unrealized Loss | 1,611 | ' |
| Noninvestment Grade Investments at Loss Less than 5 Million | Corporate Debt Securities [Member] | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Number of Securities | 9 | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 27,494 | ' |
| Gross Unrealized Loss | 647 | ' |
| Noninvestment Grade Investments at Loss Less than 5 Million | Foreign government | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Number of Securities | 0 | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 0 | ' |
| Gross Unrealized Loss | $0 | ' |
Securities_In_An_Unrealized_Lo4
| Securities In An Unrealized Loss Position Securities In An Unrealized Loss Position (Narrative) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | $2,559,336 | $3,441,075 |
| Gross Unrealized Losses | 58,265 | 117,453 |
| Preferred stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 25,540 | 33,159 |
| Gross Unrealized Losses | 3,179 | 6,319 |
| Preferred stocks | Noninvestment Grade Investments [Member] | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Number of Securities | 2 | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 26,000 | ' |
| Gross Unrealized Losses | 3,000 | ' |
| Common stocks | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Aggregate fair value of securities in a continuous unrealized loss position | 10,813 | 0 |
| Gross Unrealized Losses | $531 | $0 |
Fair_Value_Measurements_Assets
| Fair Value Measurements (Assets and Liabilities Measured At Fair Value, On a Recurring Basis) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | $12,296,560 | $11,515,524 |
| Equity securities | 222,024 | 283,338 |
| Arbitrage trading account | 918,223 | 522,128 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Equity securities | 68,852 | 159,537 |
| Assets, fair value disclosure | 306,162 | 351,818 |
| Arbitrage trading account | 237,310 | 192,281 |
| Securities sold but not yet purchased | 159,501 | 162,126 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | State and municipal | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | Corporate | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | Foreign government | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | Common stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 68,852 | 159,537 |
| Level 1 | Fair Value, Measurements, Recurring [Member] | Preferred stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 0 | 0 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 12,272,560 | 11,472,660 |
| Equity securities | 138,313 | 118,811 |
| Assets, fair value disclosure | 13,087,769 | 11,919,538 |
| Arbitrage trading account | 676,896 | 328,067 |
| Securities sold but not yet purchased | 5 | 152 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 813,034 | 884,859 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | State and municipal | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 4,180,068 | 4,218,284 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 1,298,845 | 1,329,783 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | Corporate | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 5,017,702 | 4,159,877 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | Foreign government | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 962,911 | 879,857 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | Common stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 0 | 0 |
| Level 2 | Fair Value, Measurements, Recurring [Member] | Preferred stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 138,313 | 118,811 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 24,000 | 42,864 |
| Equity securities | 14,859 | 4,990 |
| Assets, fair value disclosure | 42,876 | 49,634 |
| Arbitrage trading account | 4,017 | 1,780 |
| Securities sold but not yet purchased | 31 | 0 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | State and municipal | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | Corporate | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 24,000 | 42,864 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | Foreign government | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 0 | 0 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | Common stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 11,121 | 1,238 |
| Level 3 | Fair Value, Measurements, Recurring [Member] | Preferred stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 3,738 | 3,752 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 12,296,560 | 11,515,524 |
| Equity securities | 222,024 | 283,338 |
| Assets, fair value disclosure | 13,436,807 | 12,320,990 |
| Arbitrage trading account | 918,223 | 522,128 |
| Securities sold but not yet purchased | 159,537 | 162,278 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 813,034 | 884,859 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | State and municipal | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 4,180,068 | 4,218,284 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 1,298,845 | 1,329,783 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | Corporate | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 5,041,702 | 4,202,741 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | Foreign government | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Fixed maturity securities | 962,911 | 879,857 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | Common stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | 79,973 | 160,775 |
| Fair Value | Fair Value, Measurements, Recurring [Member] | Preferred stocks | ' | ' |
| Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items] | ' | ' |
| Equity securities | $142,051 | $122,563 |
Fair_Value_Measurements_Fair_V1
| Fair Value Measurements Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) (Level 3, USD $) | 9 Months Ended | 12 Months Ended |
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Dec. 31, 2013 |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | $49,634 | $62,022 |
| Assets, earnings | 2,351 | 1,836 |
| Assets, other comprehensive income | -1,677 | 1,039 |
| Assets, purchases | 19,799 | 4,424 |
| Assets, (sales) | -33,688 | -5,776 |
| Assets, maturities | 2,607 | 12,604 |
| Assets, transfers in | 9,064 | -1,307 |
| Assets, ending balance | 42,876 | 49,634 |
| Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Liabilities, beginning balance | 0 | 20 |
| Liabilities, earnings | 0 | -4 |
| Liabilities, other comprehensive income | 0 | 0 |
| Liabilities, purchases | 31 | 4 |
| Liabilities, (sales) | 0 | -20 |
| Liabilities, maturities | 0 | 0 |
| Liabilities, transfers in | 0 | 0 |
| Liabilities, ending balance | 31 | 0 |
| Equity securities available for sale | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 4,990 | 2,029 |
| Assets, earnings | 8 | -299 |
| Assets, other comprehensive income | -531 | 0 |
| Assets, purchases | 14,773 | 3,430 |
| Assets, (sales) | -4,381 | -170 |
| Assets, maturities | ' | ' |
| Assets, transfers in | 0 | 0 |
| Assets, ending balance | 14,859 | 4,990 |
| Preferred stocks | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 3,752 | 621 |
| Assets, earnings | 8 | -299 |
| Assets, other comprehensive income | 0 | 0 |
| Assets, purchases | 3,430 | 3,430 |
| Assets, (sales) | -3,452 | 0 |
| Assets, maturities | ' | ' |
| Assets, transfers in | 0 | 0 |
| Assets, ending balance | 3,738 | 3,752 |
| Common stocks | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 1,238 | 1,408 |
| Assets, earnings | 0 | 0 |
| Assets, other comprehensive income | -531 | 0 |
| Assets, purchases | 11,343 | 0 |
| Assets, (sales) | -929 | -170 |
| Assets, maturities | ' | ' |
| Assets, transfers in | 0 | 0 |
| Assets, ending balance | 11,121 | 1,238 |
| Debt Securities [Member] | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 42,864 | 59,065 |
| Assets, earnings | 49 | 677 |
| Assets, other comprehensive income | -1,146 | 309 |
| Assets, purchases | 84 | 170 |
| Assets, (sales) | -15,244 | -4,753 |
| Assets, maturities | 2,607 | 12,604 |
| Assets, transfers in | 0 | 0 |
| Assets, ending balance | 24,000 | 42,864 |
| Corporate Debt Securities [Member] | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 42,864 | 59,065 |
| Assets, earnings | 49 | 677 |
| Assets, other comprehensive income | -1,146 | 309 |
| Assets, purchases | 84 | 170 |
| Assets, (sales) | -15,244 | -4,753 |
| Assets, maturities | 2,607 | 12,604 |
| Assets, transfers in | 0 | 0 |
| Assets, ending balance | 24,000 | 42,864 |
| Trading Assets, Excluding Debt and Equity Securities [Member] | ' | ' |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ' | ' |
| Assets, beginning balance | 1,780 | 928 |
| Assets, earnings | 2,294 | 1,458 |
| Assets, other comprehensive income | 0 | 730 |
| Assets, purchases | 4,942 | 824 |
| Assets, (sales) | -14,063 | -853 |
| Assets, maturities | ' | ' |
| Assets, transfers in | 9,064 | -1,307 |
| Assets, ending balance | $4,017 | $1,780 |
Reinsurance_Reinsurance_Detail
| Reinsurance Reinsurance (Details) (USD $) | 3 Months Ended | 9 Months Ended | |||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | |
| Premiums Written | ' | ' | ' | ' | ' |
| Written premiums, direct | $1,553,493,000 | $1,415,775,000 | $4,699,319,000 | $4,221,370,000 | ' |
| Written premiums, assumed | 225,863,000 | 251,331,000 | 657,704,000 | 695,293,000 | ' |
| Written premiums, ceded | -253,974,000 | -243,481,000 | -815,985,000 | -774,174,000 | ' |
| Total net premiums written | 1,525,382,000 | 1,423,625,000 | 4,541,038,000 | 4,142,489,000 | ' |
| Premiums Earned | ' | ' | ' | ' | ' |
| Earned premiums, direct | 1,505,738,000 | 1,351,542,000 | 4,336,463,000 | 3,893,806,000 | ' |
| Earned premiums, assumed | 216,889,000 | 226,530,000 | 667,566,000 | 658,063,000 | ' |
| Earned premiums, ceded | -261,823,000 | -249,210,000 | -761,968,000 | -708,373,000 | ' |
| Net premiums earned | 1,460,804,000 | 1,328,862,000 | 4,242,061,000 | 3,843,496,000 | ' |
| Ceded losses incurred | 128,903,000 | 186,504,000 | 319,156,000 | 439,415,000 | ' |
| Uncollectible reinsurance | $2,000,000 | ' | $2,000,000 | ' | $1,000,000 |
Fair_Value_of_Financial_Instru1
| Fair Value of Financial Instruments (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Assets: | ' | ' |
| Arbitrage trading account | $918,223 | $522,128 |
| Loans receivable | 346,622 | 346,746 |
| Payables to Broker-Dealers and Clearing Organizations | 95,681 | 0 |
| Carrying Value | ' | ' |
| Assets: | ' | ' |
| Fixed maturity securities | 12,397,756 | 11,616,844 |
| Equity securities available for sale | 222,024 | 283,338 |
| Arbitrage trading account | 918,223 | 522,128 |
| Loans receivable | 343,300 | 343,583 |
| Cash and cash equivalents | 1,342,285 | 839,738 |
| Trading account receivables from brokers and clearing organizations | 0 | 304,936 |
| Due from broker | 0 | 17,735 |
| Due from broker fair value | 58,926 | 8,273 |
| Liabilities: | ' | ' |
| Trading account securities sold but not yet purchased | 159,537 | 162,278 |
| Junior subordinated debentures | 339,995 | 339,800 |
| Senior notes and other debt | 2,122,030 | 1,692,442 |
| Fair Value | ' | ' |
| Assets: | ' | ' |
| Fixed maturity securities | 12,418,016 | 11,631,744 |
| Equity securities available for sale | 222,024 | 283,338 |
| Arbitrage trading account | 918,223 | 522,128 |
| Loans receivable | 346,622 | 346,746 |
| Cash and cash equivalents | 1,342,285 | 839,738 |
| Trading account receivables from brokers and clearing organizations | 0 | 304,936 |
| Due from broker | 0 | 17,735 |
| Liabilities: | ' | ' |
| Trading account securities sold but not yet purchased | 159,537 | 162,278 |
| Junior subordinated debentures | 326,480 | 288,540 |
| Senior notes and other debt | $2,341,816 | $1,861,898 |
Restricted_Stock_Units_Summary
| Restricted Stock Units (Summary of Restricted Stock Units Issued) (Details) (USD $) | 9 Months Ended | |
| Sep. 30, 2014 | Sep. 30, 2013 | |
| Share-Based Compensation Arrangement by Share-based Payment Award [Line Item] | ' | ' |
| Share based compensation expense | $20,000,000 | $16,000,000 |
| Restricted Stock [Member] | ' | ' |
| Share-Based Compensation Arrangement by Share-based Payment Award [Line Item] | ' | ' |
| Award vesting period | '5 years | ' |
| Restricted Stock Units | 1,135,900 | 93,150 |
| Restricted Stock Units, Fair Value | $50,791,000 | $3,957,000 |
Industry_Segments_Financial_In
| Industry Segments (Financial Information of Company Operating Segments) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||||||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | $1,460,804 | $1,328,862 | $4,242,061 | $3,843,496 | ||||
| Investment Income and Funds | 179,225 | 125,634 | 486,665 | 405,300 | ||||
| Other Revenues | 200,576 | 179,628 | 615,774 | 463,059 | ||||
| Total revenues | 1,840,605 | 1,634,124 | 5,344,500 | 4,711,855 | ||||
| Pre-Tax Income (Loss) | 278,453 | 198,233 | 789,492 | 517,162 | ||||
| Net Income (Loss) | 188,539 | 136,974 | 538,173 | 369,546 | ||||
| Net investment gains | 72,258 | 43,869 | 234,180 | 96,896 | ||||
| Net investment gains, net of tax | 46,968 | 28,514 | 152,217 | 62,982 | ||||
| Intersegment Eliminations and Corporate, Non-Segment [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 0 | [1] | 0 | [1] | 0 | [1] | 0 | [1] |
| Investment Income and Funds | 6,560 | [1] | 291 | [1] | 19,676 | [1] | 3,831 | [1] |
| Other Revenues | 101,910 | [1] | 109,634 | [1] | 299,435 | [1] | 285,650 | [1] |
| Total revenues | 108,470 | [1] | 109,925 | [1] | 319,111 | [1] | 289,481 | [1] |
| Pre-Tax Income (Loss) | -63,772 | [1] | -58,501 | [1] | -180,892 | [1] | -183,941 | [1] |
| Net Income (Loss) | -42,571 | [1] | -38,248 | [1] | -119,194 | [1] | -114,674 | [1] |
| Insurance-Domestic Segment [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 1,093,554 | 958,994 | 3,138,806 | 2,769,369 | ||||
| Insurance-Domestic Segment [Member] | Operating Segments [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 1,093,554 | 958,994 | 3,138,806 | 2,769,369 | ||||
| Investment Income and Funds | 125,792 | 94,071 | 347,002 | 299,430 | ||||
| Other Revenues | 26,408 | 26,125 | 82,159 | 80,513 | ||||
| Total revenues | 1,245,754 | 1,079,190 | 3,567,967 | 3,149,312 | ||||
| Pre-Tax Income (Loss) | 228,359 | 172,177 | 607,399 | 465,861 | ||||
| Net Income (Loss) | 154,718 | 118,183 | 414,588 | 324,069 | ||||
| Insurance-International Segment [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 205,529 | 189,054 | 592,721 | 540,365 | ||||
| Insurance-International Segment [Member] | Operating Segments [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 205,529 | 189,054 | 592,721 | 540,365 | ||||
| Investment Income and Funds | 19,957 | 11,151 | 47,885 | 36,383 | ||||
| Other Revenues | 0 | 0 | 0 | 0 | ||||
| Total revenues | 225,486 | 200,205 | 640,606 | 576,748 | ||||
| Pre-Tax Income (Loss) | 12,603 | 16,129 | 41,860 | 51,094 | ||||
| Net Income (Loss) | 9,217 | 11,225 | 29,938 | 35,794 | ||||
| Reinsurance-Global Segment [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 161,721 | 180,814 | 510,534 | 533,762 | ||||
| Reinsurance-Global Segment [Member] | Operating Segments [Member] | ' | ' | ' | ' | ||||
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ||||
| Earned Premiums | 161,721 | 180,814 | 510,534 | 533,762 | ||||
| Investment Income and Funds | 26,916 | 20,121 | 72,102 | 65,656 | ||||
| Other Revenues | 0 | 0 | 0 | 0 | ||||
| Total revenues | 188,637 | 200,935 | 582,636 | 599,418 | ||||
| Pre-Tax Income (Loss) | 29,005 | 24,559 | 86,945 | 87,252 | ||||
| Net Income (Loss) | $20,207 | $17,300 | $60,624 | $61,375 | ||||
| [1] | {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjM4NjFmYzZjMTM2ZDRmNmM4MzNjZmI3ODA4NzQ5ZTI3fFRleHRTZWxlY3Rpb246Q0MyODI3RTBEMkI0NTZENkFGM0I2RDUzRTY3RjZGRDYM} | |||||||
Industry_Segments_Identifiable
| Industry Segments (Identifiable Assets by Segment) (Details) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 | ||
| In Thousands, unless otherwise specified | ||||
| Segment Reporting, Asset Reconciling Item [Line Items] | ' | ' | ||
| Consolidated Assets | $22,097,597 | $20,551,796 | ||
| Operating Segments [Member] | Reinsurance-Global Segment [Member] | ' | ' | ||
| Segment Reporting, Asset Reconciling Item [Line Items] | ' | ' | ||
| Consolidated Assets | 2,801,268 | 3,103,193 | ||
| Operating Segments [Member] | Insurance-International Segment [Member] | ' | ' | ||
| Segment Reporting, Asset Reconciling Item [Line Items] | ' | ' | ||
| Consolidated Assets | 1,915,322 | 1,516,310 | ||
| Operating Segments [Member] | Insurance-Domestic Segment [Member] | ' | ' | ||
| Segment Reporting, Asset Reconciling Item [Line Items] | ' | ' | ||
| Consolidated Assets | 16,074,387 | 15,247,807 | ||
| Intersegment Eliminations and Corporate, Non-Segment [Member] | ' | ' | ||
| Segment Reporting, Asset Reconciling Item [Line Items] | ' | ' | ||
| Consolidated Assets | $1,306,620 | [1] | $684,486 | [1] |
| [1] | {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjM4NjFmYzZjMTM2ZDRmNmM4MzNjZmI3ODA4NzQ5ZTI3fFRleHRTZWxlY3Rpb246Q0MyODI3RTBEMkI0NTZENkFGM0I2RDUzRTY3RjZGRDYM} | |||
Industry_Segments_Industry_Seg
| Industry Segments Industry Segments (Net Premiums Earned By Major Line of Business) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | $1,460,804 | $1,328,862 | $4,242,061 | $3,843,496 | ||
| Insurance-Domestic Segment [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 1,093,554 | 958,994 | 3,138,806 | 2,769,369 | ||
| Insurance-Domestic Segment [Member] | Other Insurance Liabilities [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 368,818 | 314,878 | 1,070,525 | 917,910 | ||
| Insurance-Domestic Segment [Member] | Workers' Compensation [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 291,297 | 252,220 | 824,541 | 722,422 | ||
| Insurance-Domestic Segment [Member] | Property [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 222,561 | 199,181 | 642,833 | [1] | 570,868 | [1] |
| Insurance-Domestic Segment [Member] | Commercial Automobile [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 134,197 | 125,942 | 385,667 | 361,964 | ||
| Insurance-Domestic Segment [Member] | Products Liability [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 76,681 | 66,773 | 215,240 | 196,205 | ||
| Insurance-International Segment [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 205,529 | 189,054 | 592,721 | 540,365 | ||
| Insurance-International Segment [Member] | Other Insurance Liabilities [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 27,705 | 18,457 | 70,036 | 48,745 | ||
| Insurance-International Segment [Member] | Workers' Compensation [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 18,012 | 20,847 | 52,578 | 65,482 | ||
| Insurance-International Segment [Member] | Property [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 100,417 | 92,213 | 303,119 | [1] | 248,637 | [1] |
| Insurance-International Segment [Member] | Commercial Automobile [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 29,076 | 30,898 | 86,318 | 97,929 | ||
| Insurance-International Segment [Member] | Products Liability [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 30,319 | 26,639 | 80,670 | 79,572 | ||
| Reinsurance-Global Segment [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 161,721 | 180,814 | 510,534 | 533,762 | ||
| Reinsurance-Global Segment [Member] | Property [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | 38,980 | 52,687 | 137,640 | 162,191 | ||
| Reinsurance-Global Segment [Member] | Casualty [Member] | ' | ' | ' | ' | ||
| Revenue from External Customer [Line Items] | ' | ' | ' | ' | ||
| Premiums Earned, Net | $122,741 | $128,127 | $372,894 | $371,571 | ||
| [1] | For the Three Months For the Nine Months Ended September 30, Ended September 30,(In thousands)2014 2013 2014 2013 Insurance-Domestic: Other liability$368,818 $314,878 $1,070,525 $917,910Workers’ compensation291,297 252,220 824,541 722,422Short-tail lines 222,561 199,181 642,833 570,868Commercial automobile134,197 125,942 385,667 361,964Professional liability76,681 66,773 215,240 196,205Total1,093,554 958,994 3,138,806 2,769,369 Insurance-International: Other liability27,705 18,457 70,036 48,745Workers’ compensation18,012 20,847 52,578 65,482Short-tail lines100,417 92,213 303,119 248,637Commercial automobile29,076 30,898 86,318 97,929Professional liability30,319 26,639 80,670 79,572Total205,529 189,054 592,721 540,365 Reinsurance-Global: Casualty122,741 128,127 372,894 371,571Property38,980 52,687 137,640 162,191Total161,721 180,814 510,534 533,762 Total$1,460,804 $1,328,862 $4,242,061 $3,843,496 | |||||