W. R. Berkley (WRB) 10-Q 3 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 29, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	1-15202
Entity Registrant Name	W. R. BERKLEY CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-1867895
Entity Address, Address Line One	475 Steamboat Road
Entity Address, City or Town	Greenwich
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06830
City Area Code	(203)
Local Phone Number	629-3000
Title of 12(b) Security	Common Stock, par value $.20 per share
Trading Symbol	WRB
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		178,003,807
Entity Central Index Key	0000011544
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
5.625% Subordinated Debentures due 2053
Entity Information [Line Items]
Title of 12(b) Security	5.625% Subordinated Debentures due 2053
Trading Symbol	WRB-PB
Security Exchange Name	NYSE
5.90% Subordinated Debentures due 2056
Entity Information [Line Items]
Title of 12(b) Security	5.90% Subordinated Debentures due 2056
Trading Symbol	WRB-PC
Security Exchange Name	NYSE
5.75% Subordinated Debentures due 2056
Entity Information [Line Items]
Title of 12(b) Security	5.75% Subordinated Debentures due 2056
Trading Symbol	WRB-PD
Security Exchange Name	NYSE
5.70% Subordinated Debentures due 2058
Entity Information [Line Items]
Title of 12(b) Security	5.70% Subordinated Debentures due 2058
Trading Symbol	WRB-PE
Security Exchange Name	NYSE
5.10% Subordinated Debentures due 2059
Entity Information [Line Items]
Title of 12(b) Security	5.10% Subordinated Debentures due 2059
Trading Symbol	WRB-PF
Security Exchange Name	NYSE

Consolidated Balance Sheets Con

Consolidated Balance Sheets Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Investments:
Fixed maturity securities (amortized cost of $13,019,378 and $13,976,647; allowance for expected credit losses of $46,441 at June 30, 2020)	$ 13,281,085	$ 14,180,961
Real estate	2,072,772	2,105,950
Investment funds	1,159,237	1,213,535
Arbitrage trading account	580,950	400,809
Equity securities	362,265	480,620
Loans receivable (net of allowance for expected credit losses of $8,719 at June 30, 2020)	82,134	91,799
Total investments	17,538,443	18,473,674
Cash and cash equivalents	2,430,826	1,023,710
Premiums and fees receivable (net of allowance for expected credit losses of $22,106 at June 30, 2020)	2,186,964	1,997,186
Due from reinsurers (net of allowance for expected credit losses of $7,175 at June 30, 2020)	2,273,638	2,133,683
Deferred policy acquisition costs	547,958	517,364
Prepaid reinsurance premiums	608,913	567,595
Trading account receivables from brokers and clearing organizations	254,230	423,543
Property, furniture and equipment	414,335	422,091
Goodwill	169,652	169,652
Accrued investment income	128,616	138,789
Other assets	769,717	762,743
Total assets	27,323,292	26,630,030
Liabilities:
Reserves for losses and loss expenses	13,088,904	12,583,249
Unearned premiums	3,902,913	3,656,507
Due to reinsurers	424,806	360,314
Trading account securities sold but not yet purchased	20,814	36,143
Federal and foreign income taxes	10,921	4,308
Other liabilities	1,104,896	1,244,888
Senior notes and other debt	1,725,449	1,427,575
Subordinated debentures	1,199,198	1,198,704
Total liabilities	21,477,901	20,511,688
Equity:
Perferred stock, par value $.10 per share: Authorized 5,000,000 shares; issued and outstanding - none	0	0
Common stock, par value $.20 per share: Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 177,930,502 and 183,411,907 shares, respectively	70,535	70,535
Additional paid-in capital	1,076,043	1,056,042
Retained earnings	7,927,280	7,932,372
Accumulated other comprehensive loss	(249,350)	(257,299)
Treasury stock, at cost, 174,745,998 and 169,264,857 shares, respectively	(3,023,392)	(2,726,711)
Total stockholders’ equity	5,801,116	6,074,939
Noncontrolling interests	44,275	43,403
Total equity	5,845,391	6,118,342
Total liabilities and equity	$ 27,323,292	$ 26,630,030

Consolidated Balance Sheets C_2

Consolidated Balance Sheets Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturity securities, allowance for credit loss	$ 46,441
Fixed maturity securities, amortized cost	13,019,378	$ 13,976,647
Cumulative effect adjustment resulting from changes in accounting principles	8,719	2,146
Cumulative effect adjustment resulting from changes in accounting principles	22,106	19,823
Reinsurance recoverable, allowance for credit loss	$ 7,175	$ 690
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock issued (in shares)	5,000,000	5,000,000
Preferred stock outstanding (in shares)	0	0
Common stock, par value (in dollar per share)	$ 0.20	$ 0.20
Common shares authorized (in shares)	750,000,000	750,000,000
Common shares issued (in shares)	177,930,502	183,411,907
Common shares outstanding (in shares)	177,930,502	183,411,907
Treasury stock issued at cost (in shares)	174,745,998	169,264,857

Consolidated Statements Income

Consolidated Statements Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
REVENUES:
Net premiums written	$ 1,739,818	$ 1,743,464	$ 3,585,664	$ 3,453,065
Change in net unearned premiums	(62,903)	(96,623)	(217,331)	(213,368)
Net premiums earned	1,676,915	1,646,841	3,368,333	3,239,697
Net investment income	85,431	188,333	260,194	346,587
Net realized and unrealized gains (losses) on investments	61,653	73,574	(81,632)	142,226
Change in allowance for expected credit losses on investments	16,232	0	(17,657)	0
Net investment gains (losses)	77,885	73,574	(99,289)	142,226
Revenues from non-insurance businesses	75,742	89,297	169,471	181,124
Insurance service fees	19,870	22,446	45,621	47,759
Other income	183	2,893	2,305	3,013
Total revenues	1,936,026	2,023,384	3,746,635	3,960,406
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	1,135,126	1,028,830	2,242,379	2,017,479
Other operating costs and expenses	580,840	591,828	1,159,173	1,179,916
Expenses from non-insurance businesses	76,238	88,272	170,996	178,397
Interest expense	38,373	40,718	75,105	81,439
Total operating costs and expenses	1,830,577	1,749,648	3,647,653	3,457,231
Income before income taxes	105,449	273,736	98,982	503,175
Income tax expense	(33,793)	(56,309)	(30,852)	(104,134)
Net income before noncontrolling interests	71,656	217,427	68,130	399,041
Noncontrolling interests	(396)	(718)	(1,288)	(1,610)
Net income to common stockholders	$ 71,260	$ 216,709	$ 66,842	$ 397,431
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 0.38	$ 1.14	$ 0.36	$ 2.09
Diluted (in dollar per share)	$ 0.38	$ 1.12	$ 0.35	$ 2.06

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$ 71,656	$ 217,427	$ 68,130	$ 399,041
Other comprehensive income (loss):
Change in unrealized currency translation adjustments	21,447	(14,492)	(76,747)	5,268
Change in unrealized investment gains, net of taxes	318,725	118,649	59,743	244,424
Other comprehensive income (loss)	340,172	104,157	(17,004)	249,692
Comprehensive income	411,828	321,584	51,126	648,733
Noncontrolling interests	(395)	(748)	(1,289)	(1,592)
Comprehensive income to common stockholders	$ 411,433	$ 320,836	$ 49,837	$ 647,141

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated Other Comprehensive Income (Loss)	Unrealized investment gain	Currency Translation Adjustments	Treasury stock	Noncontrolling interest	Cumulative effect adjustment resulting from changes in accounting principlesRetained earnings	Cumulative effect adjustment resulting from changes in accounting principlesAccumulated Other Comprehensive Income (Loss)	Cumulative effect adjustment resulting from changes in accounting principlesUnrealized investment gain	Cumulative effect adjustment resulting from changes in accounting principlesCurrency Translation Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment resulting from changes in accounting principles		$ 70,535	$ 1,039,633	$ 7,558,619	$ (510,470)	$ (91,491)	$ (418,979)	$ (2,720,466)	$ 41,947	$ 0		$ 0
Beginning of period at Dec. 31, 2018		70,535	1,039,633	7,558,619	(510,470)	(91,491)	(418,979)	(2,720,466)	41,947	0		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(2,504)
Restricted stock units expensed			21,287
Cumulative effect adjustment resulting from changes in accounting principles		70,535	1,058,416	7,826,015	(510,470)	152,915	(413,711)	(2,717,410)	43,318	0		0
Net income before noncontrolling interests	$ 399,041			397,431					1,610
Dividends ($0.12, $0.61, $0.23 and $0.71 per share, respectively)				(130,035)
Change in unrealized gains on securities without an allowance for expected credit losses	244,424					244,393
Change in unrealized gains on securities with an allowance for expected credit losses						13
Net change in period	5,268						5,268
Stock exercised/vested								3,056
Stock repurchased								0
Distributions									(221)
Other comprehensive (loss) income, net of tax	$ 249,692				249,692		5,268		(18)
End of period at Jun. 30, 2019			1,058,416	7,826,015	(260,796)	152,915	(413,711)	(2,717,410)	43,318
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.71
Cumulative effect adjustment resulting from changes in accounting principles		70,535	1,053,372	7,721,039	(364,983)	34,236	(399,219)	(2,720,011)	42,844	0		0
Beginning of period at Mar. 31, 2019		70,535	1,053,372	7,721,039	(364,983)	34,236	(399,219)	(2,720,011)	42,844	0		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(2,049)
Restricted stock units expensed			7,093
Cumulative effect adjustment resulting from changes in accounting principles		70,535	1,058,416	7,826,015	(364,983)	152,915	(413,711)	(2,717,410)	43,318	0		0
Net income before noncontrolling interests	$ 217,427			216,709					718
Dividends ($0.12, $0.61, $0.23 and $0.71 per share, respectively)				(111,733)
Change in unrealized gains on securities without an allowance for expected credit losses	118,649					118,597
Change in unrealized gains on securities with an allowance for expected credit losses						82
Net change in period	(14,492)						(14,492)
Stock exercised/vested								2,601
Stock repurchased								0
Distributions									(274)
Other comprehensive (loss) income, net of tax	$ 104,157				104,157		(14,492)		30
End of period at Jun. 30, 2019			1,058,416	7,826,015	(260,796)	152,915	(413,711)	(2,717,410)	43,318
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.61
Cumulative effect adjustment resulting from changes in accounting principles			1,058,416	7,826,015	(260,796)	152,915	(413,711)	(2,717,410)	43,318
Cumulative effect adjustment resulting from changes in accounting principles	$ 6,118,342	70,535	1,056,042	7,932,372	(257,299)	124,514	(381,813)	(2,726,711)	43,403	(30,514)	$ 24,952	24,952	$ 0
Beginning of period at Dec. 31, 2019	6,118,342	70,535	1,056,042	7,932,372	(257,299)	124,514	(381,813)	(2,726,711)	43,403	(30,514)	24,952	24,952	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(3,386)
Restricted stock units expensed			23,387
Cumulative effect adjustment resulting from changes in accounting principles	6,118,342	70,535	1,076,043	7,927,280	(257,299)	209,210	(458,560)	(3,023,392)	44,275	(30,514)	$ 24,952	24,952	$ 0
Net income before noncontrolling interests	68,130			66,842					1,288
Dividends ($0.12, $0.61, $0.23 and $0.71 per share, respectively)				(41,420)
Change in unrealized gains on securities without an allowance for expected credit losses	59,743					34,753
Change in unrealized gains on securities with an allowance for expected credit losses						24,991
Net change in period	(76,747)						(76,747)
Stock exercised/vested								2,221
Stock repurchased								(298,902)
Distributions									(417)
Other comprehensive (loss) income, net of tax	(17,004)				(17,004)		(76,747)		1
End of period at Jun. 30, 2020	$ 5,845,391		1,076,043	7,927,280	(249,350)	209,210	(458,560)	(3,023,392)	44,275
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.23
Cumulative effect adjustment resulting from changes in accounting principles		70,535	1,063,084	7,877,371	(589,521)	(109,514)	(480,007)	(2,927,994)	44,069	0		0
Beginning of period at Mar. 31, 2020		70,535	1,063,084	7,877,371	(589,521)	(109,514)	(480,007)	(2,927,994)	44,069	0		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			1,204
Restricted stock units expensed			11,755
Cumulative effect adjustment resulting from changes in accounting principles	$ 5,845,391	$ 70,535	1,076,043	7,927,280	(589,521)	209,210	(458,560)	(3,023,392)	44,275	$ 0		$ 0
Net income before noncontrolling interests	71,656			71,260					396
Dividends ($0.12, $0.61, $0.23 and $0.71 per share, respectively)				(21,351)
Change in unrealized gains on securities without an allowance for expected credit losses	318,725					295,274
Change in unrealized gains on securities with an allowance for expected credit losses						23,450
Net change in period	21,447						21,447
Stock exercised/vested								883
Stock repurchased								(96,281)
Distributions									(189)
Other comprehensive (loss) income, net of tax	340,172				340,172		21,447		(1)
End of period at Jun. 30, 2020	$ 5,845,391		1,076,043	7,927,280	(249,350)	209,210	(458,560)	(3,023,392)	44,275
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.12
Cumulative effect adjustment resulting from changes in accounting principles	$ 5,845,391		$ 1,076,043	$ 7,927,280	$ (249,350)	$ 209,210	$ (458,560)	$ (3,023,392)	$ 44,275

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FROM OPERATING ACTIVITIES:
Net income to common stockholders	$ 66,842	$ 397,431
Adjustments to reconcile net income to net cash from operating activities:
Net investment losses (gains)	99,289	(142,226)
Depreciation and amortization	64,065	51,289
Noncontrolling interests	1,288	1,610
Investment funds	16,975	(58,251)
Stock incentive plans	25,731	27,340
Change in:
Arbitrage trading account	(26,158)	(14,797)
Premiums and fees receivable	(204,203)	(223,771)
Reinsurance accounts	(118,849)	(112,681)
Deferred policy acquisition costs	(31,478)	(23,632)
Income taxes	9,387	2,759
Reserves for losses and loss expenses	525,785	350,981
Unearned premiums	259,237	254,010
Other	(108,060)	(107,416)
Net cash from operating activities	579,851	402,646
CASH FROM INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	3,194,333	1,320,079
Proceeds from sale of equity securities	67,122	39,103
Distributions from (contributions to) investment funds	67,234	(2,896)
Proceeds from maturities and prepayments of fixed maturity securities	1,859,392	1,490,772
Purchase of fixed maturity securities	(4,189,664)	(2,633,251)
Purchase of equity securities	(35,591)	(41,849)
Real estate purchased	(30,178)	(117,773)
Change in loans receivable	963	140
Net purchases of property, furniture and equipment	(23,006)	(10,804)
Change in balances due to security brokers	(24,382)	19,096
Other	85	0
Net cash from investing activities	886,308	62,617
CASH USED IN FINANCING ACTIVITIES:
Repayment of senior notes and other debt	(1,160)	0
Net proceeds from issuance of debt	298,447	0
Cash dividends to common stockholders	(41,420)	(18,302)
Purchase of common treasury shares	(298,902)	0
Other, net	(4,140)	(5,548)
Net cash used in financing activities	(47,175)	(23,850)
Net impact on cash due to change in foreign exchange rates	(11,868)	(841)
Net change in cash and cash equivalents	1,407,116	440,572
Cash and cash equivalents at beginning of year	1,023,710	817,602
Cash and cash equivalents at end of period	$ 2,430,826	$ 1,258,174

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Consolidated Statements of Comprehensive Income	Consolidated Statements of Comprehensive Income The following table presents the components of the changes in accumulated other comprehensive (loss) income ("AOCI"): (In thousands) Unrealized Investment Gains Currency Translation Adjustments Accumulated Other Comprehensive As of and for the six months ended June 30, 2020 Changes in AOCI Beginning of period $ 124,514 $ (381,813) $ (257,299) Cumulative effect adjustment resulting from changes in accounting principles 24,952 — 24,952 Restated beginning of period 149,466 (381,813) (232,347) Other comprehensive income (loss) before reclassifications 36,986 (76,747) (39,761) Amounts reclassified from AOCI 22,757 — 22,757 Other comprehensive income (loss) 59,743 (76,747) (17,004) Unrealized investment loss related to noncontrolling interest 1 — 1 End of period $ 209,210 $ (458,560) $ (249,350) Amounts reclassified from AOCI Pre-tax $ 28,806 (1) $ — $ 28,806 Tax effect (6,049) (2) — (6,049) After-tax amounts reclassified $ 22,757 $ — $ 22,757 Other comprehensive income (loss) Pre-tax $ 62,777 $ (76,747) $ (13,970) Tax effect (3,034) — (3,034) Other comprehensive income (loss) $ 59,743 $ (76,747) $ (17,004) As of and for the three months ended June 30, 2020 Changes in AOCI Beginning of period $ (109,514) $ (480,007) $ (589,521) Other comprehensive income before reclassifications 335,518 21,447 356,965 Amounts reclassified from AOCI (16,793) — (16,793) Other comprehensive income 318,725 21,447 340,172 Unrealized investment gain related to noncontrolling interest (1) — (1) Ending balance $ 209,210 $ (458,560) $ (249,350) Amounts reclassified from AOCI Pre-tax $ (21,257) (1) $ — $ (21,257) Tax effect 4,464 (2) — 4,464 After-tax amounts reclassified $ (16,793) $ — $ (16,793) Other comprehensive income Pre-tax $ 395,624 $ 21,447 $ 417,071 Tax effect (76,899) — (76,899) Other comprehensive income $ 318,725 $ 21,447 $ 340,172 As of and for the six months ended June 30, 2019 Changes in AOCI Beginning of period $ (91,491) $ (418,979) $ (510,470) Other comprehensive gain before reclassifications 245,615 5,268 250,883 Amounts reclassified from AOCI (1,191) — (1,191) Other comprehensive gain 244,424 5,268 249,692 Unrealized investment gain related to noncontrolling interest (18) — (18) End of period $ 152,915 $ (413,711) $ (260,796) Amounts reclassified from AOCI Pre-tax $ (1,508) (1) $ — $ (1,508) Tax effect 317 (2) — 317 After-tax amounts reclassified $ (1,191) $ — $ (1,191) Other comprehensive income Pre-tax $ 316,331 $ 5,268 $ 321,599 Tax effect (71,907) — (71,907) Other comprehensive income $ 244,424 $ 5,268 $ 249,692 As of and for the three months ended June 30, 2019 Changes in AOCI Beginning of period $ 34,236 $ (399,219) $ (364,983) Other comprehensive income (loss) before reclassifications 118,475 (14,492) 103,983 Amounts reclassified from AOCI 174 — 174 Other comprehensive income (loss) 118,649 (14,492) 104,157 Unrealized investment loss related to noncontrolling interest 30 — 30 Ending balance $ 152,915 $ (413,711) $ (260,796) Amounts reclassified from AOCI Pre-tax $ 220 (1) $ — $ 220 Tax effect (46) (2) — (46) After-tax amounts reclassified $ 174 $ — $ 174 Other comprehensive income (loss) Pre-tax $ 147,072 $ (14,492) $ 132,580 Tax effect (28,423) — (28,423) Other comprehensive income (loss) $ 118,649 $ (14,492) $ 104,157 ____________ (1) Net investment gains (losses) in the consolidated statements of income. (2) Income tax expense in the consolidated statements of income.

Statements of Cash Flows

Statements of Cash Flows	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Statements of Cash Flows	Statements of Cash Flows        Interest payments were $73,056,000 and $77,672,000 for the six months ended June 30, 2020 and 2019, respectively. No income tax was paid for the six months ended June 30, 2020 and $82,800,000 was paid for the six months ended June 30, 2019.

Net Investment Income

Net Investment Income	6 Months Ended
	Jun. 30, 2020
Net Investment Income [Abstract]
Net Investment Income	Net Investment Income Net investment income consisted of the following: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Investment income (losses) earned on: Fixed maturity securities, including cash and cash equivalents and loans receivable $ 105,843 $ 128,903 $ 233,861 $ 261,022 Investment funds (57,552) 46,840 (16,975) 58,251 Arbitrage trading account 31,304 7,199 32,442 17,784 Real estate 5,045 5,174 11,141 9,481 Equity securities 2,726 1,303 4,288 2,591 Gross investment income 87,366 189,419 264,757 349,129 Investment expense (1,935) (1,086) (4,563) (2,542) Net investment income $ 85,431 $ 188,333 $ 260,194 $ 346,587

Consolidated Statements of Co_3

Consolidated Statements of Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Components of changes in accumulated other comprehensive income (loss)	The following table presents the components of the changes in accumulated other comprehensive (loss) income ("AOCI"): (In thousands) Unrealized Investment Gains Currency Translation Adjustments Accumulated Other Comprehensive As of and for the six months ended June 30, 2020 Changes in AOCI Beginning of period $ 124,514 $ (381,813) $ (257,299) Cumulative effect adjustment resulting from changes in accounting principles 24,952 — 24,952 Restated beginning of period 149,466 (381,813) (232,347) Other comprehensive income (loss) before reclassifications 36,986 (76,747) (39,761) Amounts reclassified from AOCI 22,757 — 22,757 Other comprehensive income (loss) 59,743 (76,747) (17,004) Unrealized investment loss related to noncontrolling interest 1 — 1 End of period $ 209,210 $ (458,560) $ (249,350) Amounts reclassified from AOCI Pre-tax $ 28,806 (1) $ — $ 28,806 Tax effect (6,049) (2) — (6,049) After-tax amounts reclassified $ 22,757 $ — $ 22,757 Other comprehensive income (loss) Pre-tax $ 62,777 $ (76,747) $ (13,970) Tax effect (3,034) — (3,034) Other comprehensive income (loss) $ 59,743 $ (76,747) $ (17,004) As of and for the three months ended June 30, 2020 Changes in AOCI Beginning of period $ (109,514) $ (480,007) $ (589,521) Other comprehensive income before reclassifications 335,518 21,447 356,965 Amounts reclassified from AOCI (16,793) — (16,793) Other comprehensive income 318,725 21,447 340,172 Unrealized investment gain related to noncontrolling interest (1) — (1) Ending balance $ 209,210 $ (458,560) $ (249,350) Amounts reclassified from AOCI Pre-tax $ (21,257) (1) $ — $ (21,257) Tax effect 4,464 (2) — 4,464 After-tax amounts reclassified $ (16,793) $ — $ (16,793) Other comprehensive income Pre-tax $ 395,624 $ 21,447 $ 417,071 Tax effect (76,899) — (76,899) Other comprehensive income $ 318,725 $ 21,447 $ 340,172 As of and for the six months ended June 30, 2019 Changes in AOCI Beginning of period $ (91,491) $ (418,979) $ (510,470) Other comprehensive gain before reclassifications 245,615 5,268 250,883 Amounts reclassified from AOCI (1,191) — (1,191) Other comprehensive gain 244,424 5,268 249,692 Unrealized investment gain related to noncontrolling interest (18) — (18) End of period $ 152,915 $ (413,711) $ (260,796) Amounts reclassified from AOCI Pre-tax $ (1,508) (1) $ — $ (1,508) Tax effect 317 (2) — 317 After-tax amounts reclassified $ (1,191) $ — $ (1,191) Other comprehensive income Pre-tax $ 316,331 $ 5,268 $ 321,599 Tax effect (71,907) — (71,907) Other comprehensive income $ 244,424 $ 5,268 $ 249,692 As of and for the three months ended June 30, 2019 Changes in AOCI Beginning of period $ 34,236 $ (399,219) $ (364,983) Other comprehensive income (loss) before reclassifications 118,475 (14,492) 103,983 Amounts reclassified from AOCI 174 — 174 Other comprehensive income (loss) 118,649 (14,492) 104,157 Unrealized investment loss related to noncontrolling interest 30 — 30 Ending balance $ 152,915 $ (413,711) $ (260,796) Amounts reclassified from AOCI Pre-tax $ 220 (1) $ — $ 220 Tax effect (46) (2) — (46) After-tax amounts reclassified $ 174 $ — $ 174 Other comprehensive income (loss) Pre-tax $ 147,072 $ (14,492) $ 132,580 Tax effect (28,423) — (28,423) Other comprehensive income (loss) $ 118,649 $ (14,492) $ 104,157 ____________ (1) Net investment gains (losses) in the consolidated statements of income. (2) Income tax expense in the consolidated statements of income.

Net Investment Income (Tables)

Net Investment Income (Tables)	6 Months Ended
	Jun. 30, 2020
Net Investment Income [Abstract]
Schedule of Net Investment Income	Net investment income consisted of the following: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Investment income (losses) earned on: Fixed maturity securities, including cash and cash equivalents and loans receivable $ 105,843 $ 128,903 $ 233,861 $ 261,022 Investment funds (57,552) 46,840 (16,975) 58,251 Arbitrage trading account 31,304 7,199 32,442 17,784 Real estate 5,045 5,174 11,141 9,481 Equity securities 2,726 1,303 4,288 2,591 Gross investment income 87,366 189,419 264,757 349,129 Investment expense (1,935) (1,086) (4,563) (2,542) Net investment income $ 85,431 $ 188,333 $ 260,194 $ 346,587

Fixed Maturity Securities In An

Fixed Maturity Securities In An Unrealized Loss Position (Tables)	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Securities in an unrealized loss position	The following tables summarize all fixed maturity securities in an unrealized loss position at June 30, 2020 and December 31, 2019 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 Gross Fair Gross Fair Gross June 30, 2020 U.S. government and government agency $ 42,279 $ 49 $ 20 $ — $ 42,299 $ 49 State and municipal 237,515 2,444 24,899 798 262,414 3,242 Mortgage-backed securities 55,367 1,458 57,184 360 112,551 1,818 Asset-backed securities 1,290,764 32,060 653,128 51,212 1,943,892 83,272 Corporate 531,733 34,588 49,806 7,154 581,539 41,742 Foreign government 78,803 5,786 38,726 27,157 117,529 32,943 Fixed maturity securities $ 2,236,461 $ 76,385 $ 823,763 $ 86,681 $ 3,060,224 $ 163,066 December 31, 2019 U.S. government and government agency $ 83,837 $ 618 $ 53,089 $ 857 $ 136,926 $ 1,475 State and municipal 365,184 4,245 127,210 1,682 492,394 5,927 Mortgage-backed securities 301,358 2,281 180,148 3,220 481,506 5,501 Asset-backed securities 755,259 2,307 774,508 19,183 1,529,767 21,490 Corporate 307,367 3,148 121,470 5,172 428,837 8,320 Foreign government 164,536 32,028 107,266 61,645 271,802 93,673 Fixed maturity securities $ 1,977,541 $ 44,627 $ 1,363,691 $ 91,759 $ 3,341,232 $ 136,386
Non-Investment Grade Fixed Maturity Securities	A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at June 30, 2020 is presented in the table below: ($ in thousands) Number of Aggregate Gross Foreign government 14 $ 52,126 $ 32,429 Corporate 18 47,404 9,320 Mortgage-backed securities 12 6,348 340 Asset-backed securities 2 279 6 Total 46 $ 106,157 $ 42,095

Consolidated Statements of Co_4

Consolidated Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			$ 6,118,342
Other comprehensive income (loss)	$ 340,172	$ 104,157	(17,004)	$ 249,692
End of period	5,845,391		5,845,391
Net realized and unrealized gains (losses) on investments	61,653	73,574	(81,632)	142,226
Income before income taxes	105,449	273,736	98,982	503,175
Tax effect	(33,793)	(56,309)	(30,852)	(104,134)
Net income before noncontrolling interests	71,656	217,427	68,130	399,041
Total change in unrealized investment gains	395,624	147,071	62,777	316,331
Net change in period	21,447	(14,492)	(76,747)	5,268
Other comprehensive income (loss), pre-tax	417,071	132,580	(13,970)	321,599
Other comprehensive income (loss), tax effect	(76,899)	(28,423)	(3,034)	(71,907)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(589,521)	(364,983)	(257,299)	(510,470)
Other comprehensive income (loss) before reclassifications	356,965	103,983	(39,761)	250,883
Amounts reclassified from AOCI	(16,793)	174	22,757	(1,191)
Other comprehensive income (loss)	340,172	104,157	(17,004)	249,692
Unrealized investment gain related to noncontrolling interest	(1)	30	1	(18)
End of period	(249,350)	(260,796)	(249,350)	(260,796)
Accumulated Other Comprehensive Income (Loss) | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	(21,257)	220	28,806	(1,508)
Tax effect	4,464	(46)	(6,049)	317
Net income before noncontrolling interests	(16,793)	174	22,757	(1,191)
Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(109,514)	34,236	124,514	(91,491)
Other comprehensive income (loss) before reclassifications	335,518	118,475	36,986	245,615
Amounts reclassified from AOCI	(16,793)	174	22,757	(1,191)
Other comprehensive income (loss)	318,725	118,649	59,743	244,424
Unrealized investment gain related to noncontrolling interest	(1)	30	1	(18)
End of period	209,210	152,915	209,210	152,915
Total change in unrealized investment gains	395,624	147,072	62,777	316,331
Unrealized investment gains, tax effect	(76,899)	(28,423)	(3,034)	(71,907)
Unrealized investment gains (losses), after-tax amounts	318,725	118,649	59,743	244,424
Unrealized Investment Gains (Losses) | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net realized and unrealized gains (losses) on investments	(21,257)	220	28,806	(1,508)
Tax effect	4,464	(46)	(6,049)	317
Net income before noncontrolling interests	(16,793)	174	22,757	(1,191)
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(480,007)	(399,219)	(381,813)	(418,979)
Other comprehensive income (loss) before reclassifications	21,447	(14,492)	(76,747)	5,268
Amounts reclassified from AOCI	0	0	0	0
Other comprehensive income (loss)	21,447	(14,492)	(76,747)	5,268
Unrealized investment gain related to noncontrolling interest	0	0	0	0
End of period	(458,560)	(413,711)	(458,560)	(413,711)
Currency translation adjustment, pre-tax	21,447	(14,492)	(76,747)	5,268
Currency translation adjustment, tax effect	0	0	0	0
Net change in period	21,447	(14,492)	(76,747)	5,268
Currency Translation Adjustments | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	0	0	0	0
Tax effect	0	0	0	0
Net income before noncontrolling interests	$ 0	$ 0	0	$ 0
Cumulative effect adjustment resulting from changes in accounting principles | Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			24,952
Cumulative effect adjustment resulting from changes in accounting principles | Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			24,952
Cumulative effect adjustment resulting from changes in accounting principles | Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			0
Cumulative Effect, Period Of Adoption, Adjusted Balance | Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			(232,347)
Cumulative Effect, Period Of Adoption, Adjusted Balance | Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			149,466
Cumulative Effect, Period Of Adoption, Adjusted Balance | Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			$ (381,813)

Net Investment Income (Details)

Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net Investment Income [Line Items]
Gross investment income	$ 87,366	$ 189,419	$ 264,757	$ 349,129
Investment expense	(1,935)	(1,086)	(4,563)	(2,542)
Net investment income	85,431	188,333	260,194	346,587
Fixed maturity securities, including cash and cash equivalents and loans receivable
Net Investment Income [Line Items]
Gross investment income	105,843	128,903	233,861	261,022
Investment funds
Net Investment Income [Line Items]
Gross investment income	(57,552)	46,840	(16,975)	58,251
Arbitrage trading account
Net Investment Income [Line Items]
Gross investment income	31,304	7,199	32,442	17,784
Real estate
Net Investment Income [Line Items]
Gross investment income	5,045	5,174	11,141	9,481
Equity securities
Net Investment Income [Line Items]
Gross investment income	$ 2,726	$ 1,303	$ 4,288	$ 2,591

Fixed Maturity Securities In _2

Fixed Maturity Securities In An Unrealized Loss Position (Securities in an Unrealized Loss Position) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 2,236,461	$ 1,977,541
Gross Unrealized Losses, Less than 12 Months	76,385	44,627
Fair Value, 12 Months or Greater	823,763	1,363,691
Gross Unrealized Losses, 12 Months or Greater	86,681	91,759
Fair Value, Total	3,060,224	3,341,232
Gross Unrealized Losses, Total	163,066	136,386
U.S. government and government agency
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	42,279	83,837
Gross Unrealized Losses, Less than 12 Months	49	618
Fair Value, 12 Months or Greater	20	53,089
Gross Unrealized Losses, 12 Months or Greater	0	857
Fair Value, Total	42,299	136,926
Gross Unrealized Losses, Total	49	1,475
State and municipal
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	237,515	365,184
Gross Unrealized Losses, Less than 12 Months	2,444	4,245
Fair Value, 12 Months or Greater	24,899	127,210
Gross Unrealized Losses, 12 Months or Greater	798	1,682
Fair Value, Total	262,414	492,394
Gross Unrealized Losses, Total	3,242	5,927
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	55,367	301,358
Gross Unrealized Losses, Less than 12 Months	1,458	2,281
Fair Value, 12 Months or Greater	57,184	180,148
Gross Unrealized Losses, 12 Months or Greater	360	3,220
Fair Value, Total	112,551	481,506
Gross Unrealized Losses, Total	1,818	5,501
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	1,290,764	755,259
Gross Unrealized Losses, Less than 12 Months	32,060	2,307
Fair Value, 12 Months or Greater	653,128	774,508
Gross Unrealized Losses, 12 Months or Greater	51,212	19,183
Fair Value, Total	1,943,892	1,529,767
Gross Unrealized Losses, Total	83,272	21,490
Corporate
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	531,733	307,367
Gross Unrealized Losses, Less than 12 Months	34,588	3,148
Fair Value, 12 Months or Greater	49,806	121,470
Gross Unrealized Losses, 12 Months or Greater	7,154	5,172
Fair Value, Total	581,539	428,837
Gross Unrealized Losses, Total	41,742	8,320
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	78,803	164,536
Gross Unrealized Losses, Less than 12 Months	5,786	32,028
Fair Value, 12 Months or Greater	38,726	107,266
Gross Unrealized Losses, 12 Months or Greater	27,157	61,645
Fair Value, Total	117,529	271,802
Gross Unrealized Losses, Total	$ 32,943	$ 93,673

General

General	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General         The unaudited consolidated financial statements, which include the accounts of W. R. Berkley Corporation and its subsidiaries (the “Company”), have been prepared on the basis of 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 in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the revenues and expenses reflected during the reporting period. For further information related to 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, 2019.         The income tax provision has been computed based on the Company’s estimated annual effective tax rate. The effective income tax rate differs from the federal income tax rate of 21%

Per Share Data

Per Share Data	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Per Share Data	Per Share Data The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period (including 7,575,168 and 7,389,781 common shares held in a grantor trust as of June 30, 2020 and 2019, respectively). The common shares held in the grantor trust are for delivery upon settlement of vested but mandatorily deferred restricted stock units ("RSUs"). Shares held by the grantor trust do not affect diluted shares outstanding since the shares deliverable under vested RSUs were already included in diluted shares outstanding. Diluted EPS is based upon the weighted average number of basic 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 Six Months (In thousands) 2020 2019 2020 2019 Basic 185,979 190,512 188,133 190,456 Diluted 187,862 193,059 190,078 192,804

Recent Accounting Pronouncement

Recent Accounting Pronouncements and Accounting Policies	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Recent Accounting Pronouncements and Accounting Policies	Recent Accounting Pronouncements and Accounting Policies Recently adopted accounting pronouncements: In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments - Credit Losses, which amended the accounting guidance for credit losses on financial instruments. The updated guidance amended the current other-than-temporary impairment model for available for sale debt securities by requiring the recognition of impairments relating to expected credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. This guidance also applies a new current expected credit loss model for determining credit-related impairments for financial instruments measured at amortized cost, such as reinsurance recoverables. The updated guidance was effective for reporting periods beginning after December 15, 2019. The adoption of this guidance on January 1, 2020 resulted in the recognition of an allowance for expected credit losses in connection with operating assets (premiums and fees receivable and due from reinsurers) of $5.7 million (net of tax) and a corresponding cumulative effect adjustment that decreased common stockholders' equity. Certain investments (primarily fixed maturity securities available for sale) established an allowance for expected credit loss of $24.8 million (net of tax), with a cumulative effect adjustment decreasing retained earnings by $24.8 million (net of tax) and increasing accumulated other comprehensive (loss) income ("AOCI") by $25.0 million (net of tax), resulting in $0.2 million net impact to total common stockholders' equity. All other accounting and reporting standards that have become effective in 2020 were either not applicable to the Company or their adoption did not have a material impact on the Company. Accounting and reporting standards that are not yet effective: 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. Accounting policies: The following accounting policies have been updated to reflect the Company's adoption of Financial Instruments - Credit Losses as described above. Revenue recognition (related to premiums and fees receivable) Insurance premiums are recognized as written at the inception of the policy. Reinsurance premiums are estimated based upon information received from ceding companies, and subsequent differences from such estimates are recorded in the period they are determined. Insurance and reinsurance premiums are primarily earned on a pro rata basis over the policy term. Fees for services are earned over the period that the services are provided. Premiums and fees receivable are reported net of an allowance for expected credit losses with the allowance being estimated based on current and future expected conditions, historical loss data and specific identification of collectability concerns where applicable. Changes in the allowance are reported within other operating costs and expenses. Reinsurance ceded (related to due from reinsurers) The unearned portion of premiums ceded to reinsurers is reported as prepaid reinsurance premiums and earned ratably over the policy term. The estimated amounts of reinsurance recoverable on unpaid losses are reported as due from reinsurers. To the extent any reinsurer does not meet its obligations under reinsurance agreements, the Company must discharge its liability. Amounts due from reinsurers are reflected net of funds held where the right of offset is present. The Company has provided an allowance for expected credit losses for estimated uncollectible reinsurance. The allowance is estimated based on the composition of the recoverable balance, considering reinsurer credit ratings, collateral received from financial institutions and funds withheld arrangements, length of collection periods, probability of default methodology, and specific identification of collectability concerns. Changes in the allowance are reported within losses and loss expenses. Investments For available for sale securities in an unrealized loss position where the Company intends to sell, or it is more likely than not that it will be required to sell the security before recovery in value, the amortized cost basis is written down to fair value through net investment gains. For available for sale securities in an unrealized loss position where the Company does not intend to sell, or it is more likely than not that it will not be required to sell the security before recovery in value, the Company evaluates whether the decline in fair value has resulted from credit losses or all other factors (non-credit factors). In making this assessment, the Company considers the extent to which fair value is less than amortized cost, changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, an allowance for expected credit losses is recorded for the credit loss through net investment gains, limited by the amount that the fair value is less than the amortized cost basis. The allowance is adjusted for any change in expected credit losses and subsequent recoveries through net investment gains. The impairment related to non-credit factors is recognized in other comprehensive income. For financial assets carried at amortized cost, which includes held to maturity securities and loans receivable, the Company estimates an allowance for expected credit losses based on relevant information about past events, including historical loss experience, current conditions and forecasts that affect the expected collectability of the amortized cost of the financial asset. The allowance for expected credit losses is presented as a reduction to amortized cost of the financial asset in the consolidated balance sheet and changes to the estimate for expected credit losses are recognized through net investment gains. The Company’s credit assessment of allowance for expected credit losses uses a third party model for available for sale and held to maturity securities, as well as loans receivable. The allowance for expected credit losses is generally based on the performance of the underlying collateral under various economic and default scenarios that involve subjective judgments and estimates by management. Modeling these securities involves various factors, such as projected default rates, the nature and realizable value of the collateral, if any, the ability of the issuer to make scheduled payments, historical performance and other relevant economic and performance factors. A discounted cash flow analysis is used to ascertain the amount of the allowance for expected credit losses, if any. In general, the model reverts to the rating-level long-term average marginal default rates based on 10 years of historical data, beyond the forecast period. For other inputs, the model in most cases reverts to the baseline long-term assumptions linearly over 5 years beyond the forecast period. The long-term assumptions are based on the historical averages. The Company reports accrued investment income separately from fixed maturity securities, and has elected not to measure an allowance for expected credit losses for accrued investment income. Accrued investment income is written off through net investment income at the time the issuer of the bond defaults or is expected to default on payments.

Investments In Fixed Maturity S

Investments In Fixed Maturity Securities	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Investments In Fixed Maturity Securities	Investments in Fixed Maturity Securities At June 30, 2020 and December 31, 2019, investments in fixed maturity securities were as follows: (In thousands) Amortized Allowance for Expected Credit Losses (1) Gross Unrealized Fair Carrying Gains Losses June 30, 2020 Held to maturity: State and municipal $ 71,640 $ (948) $ 14,137 $ — $ 84,829 $ 70,692 Residential mortgage-backed 7,385 — 1,176 — 8,561 7,385 Total held to maturity 79,025 (948) 15,313 — 93,390 78,077 Available for sale: U.S. government and government agency 670,032 — 23,784 (49) 693,767 693,767 State and municipal: Special revenue 2,153,909 — 82,603 (1,551) 2,234,961 2,234,961 State general obligation 350,228 — 31,192 (810) 380,610 380,610 Pre-refunded 299,333 — 20,944 (130) 320,147 320,147 Corporate backed 224,649 — 8,581 (500) 232,730 232,730 Local general obligation 394,105 — 42,393 (251) 436,247 436,247 Total state and municipal 3,422,224 — 185,713 (3,242) 3,604,695 3,604,695 Mortgage-backed securities: Residential 913,065 — 32,241 (1,019) 944,287 944,287 Commercial 211,987 — 6,370 (799) 217,558 217,558 Total mortgage-backed securities 1,125,052 — 38,611 (1,818) 1,161,845 1,161,845 Asset-backed 3,170,931 — 10,539 (83,272) 3,098,198 3,098,198 Corporate: Industrial 1,922,336 (724) 101,976 (24,466) 1,999,122 1,999,122 Financial 1,399,238 — 49,596 (17,130) 1,431,704 1,431,704 Utilities 293,279 — 29,582 (146) 322,715 322,715 Other 18,655 — 385 — 19,040 19,040 Total corporate 3,633,508 (724) 181,539 (41,742) 3,772,581 3,772,581 Foreign government 918,606 (44,769) 31,028 (32,943) 871,922 871,922 Total available for sale 12,940,353 (45,493) 471,214 (163,066) 13,203,008 13,203,008 Total investments in fixed maturity securities $ 13,019,378 $ (46,441) $ 486,527 $ (163,066) $ 13,296,398 $ 13,281,085 ____________ (1) Represents the amount of impairment that has resulted from credit-related factors. The change in the allowance for expected credit losses, excluding the cumulative effect adjustment resulting from changes in accounting principles, is recognized in the consolidated statements of income. Amount excludes unrealized losses relating to non-credit factors. (In thousands) Amortized Gross Unrealized Fair Carrying Gains Losses December 31, 2019 Held to maturity: State and municipal $ 70,312 $ 13,000 $ — $ 83,312 $ 70,312 Residential mortgage-backed 8,371 994 — 9,365 8,371 Total held to maturity 78,683 13,994 — 92,677 78,683 Available for sale: U.S. government and government agency 775,157 13,249 (1,475) 786,931 786,931 State and municipal: Special revenue 2,343,209 64,586 (4,152) 2,403,643 2,403,643 State general obligation 359,298 22,074 (97) 381,275 381,275 Pre-refunded 364,571 20,342 (128) 384,785 384,785 Corporate backed 255,230 7,232 (903) 261,559 261,559 Local general obligation 432,333 32,684 (647) 464,370 464,370 Total state and municipal 3,754,641 146,918 (5,927) 3,895,632 3,895,632 Mortgage-backed securities: Residential 1,298,145 23,230 (5,155) 1,316,220 1,316,220 Commercial 304,506 5,214 (346) 309,374 309,374 Total mortgage-backed securities 1,602,651 28,444 (5,501) 1,625,594 1,625,594 Asset-backed 2,802,588 9,532 (21,490) 2,790,630 2,790,630 Corporate: Industrial 2,260,073 72,900 (3,800) 2,329,173 2,329,173 Financial 1,447,589 37,681 (4,118) 1,481,152 1,481,152 Utilities 325,762 15,281 (402) 340,641 340,641 Other 5,219 230 — 5,449 5,449 Total corporate 4,038,643 126,092 (8,320) 4,156,415 4,156,415 Foreign government 924,284 16,465 (93,673) 847,076 847,076 Total available for sale 13,897,964 340,700 (136,386) 14,102,278 14,102,278 Total investments in fixed maturity securities $ 13,976,647 $ 354,694 $ (136,386) $ 14,194,955 $ 14,180,961 The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the six months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at January 1, 2020 $ — Cumulative effect adjustment resulting from changes in accounting principles 69 Provision for expected credit losses 879 Allowance for expected credit losses at June 30, 2020 $ 948 The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the three months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at April 1, 2020 $ 107 Provision for expected credit losses 841 Allowance for expected credit losses at June 30, 2020 $ 948 The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the six months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at January 1, 2020 $ — $ — $ — Cumulative effect adjustment resulting from changes in accounting principles 35,645 — 35,645 Expected credit losses on securities for which credit losses were not previously recorded 12,494 6,797 19,291 Expected credit losses on securities for which credit losses were previously recorded 547 (3,758) (3,211) Reduction due to disposals (3,917) (2,315) (6,232) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493 The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the three months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at April 1, 2020 $ 60,920 $ 6,436 $ 67,356 Expected credit losses on securities for which credit losses were not previously recorded — 361 361 Expected credit losses on securities for which credit losses were previously recorded (15,822) (3,758) (19,580) Reduction due to disposals (329) (2,315) (2,644) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493 During the six months ended June 30, 2020, the Company increased the allowance for expected credit losses utilizing its credit loss assessment process and inputs used in its credit loss model, primarily due to the negative impact to the financial markets caused by COVID-19. As a result, the Company recognized an initial allowance for expected credit losses on securities that previously did not have an allowance, and increased the allowance for expected credit losses on existing securities due to higher default rate and lower recovery rate assumptions. Improved market pricing and credit ratings at June 30, 2020 compared to March 31, 2020 led to a decrease in the allowance for expected credit losses during the three months ended June 30, 2020. The amortized cost and fair value of fixed maturity securities at June 30, 2020, 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 Due in one year or less $ 852,249 $ 832,105 Due after one year through five years 5,021,482 5,151,442 Due after five years through ten years 3,148,884 3,297,837 Due after ten years 2,863,378 2,844,608 Mortgage-backed securities 1,132,437 1,170,406 Total $ 13,018,430 $ 13,296,398 ________________ (1) Amortized cost is reduced by the allowance for expected credit losses of $948 thousand related to held to maturity securities.

Investments in Equity Securitie

Investments in Equity Securities	6 Months Ended
	Jun. 30, 2020
Debt Securities, Available-for-sale [Line Items]
Investments in Equity Securities	Investments in Fixed Maturity Securities At June 30, 2020 and December 31, 2019, investments in fixed maturity securities were as follows: (In thousands) Amortized Allowance for Expected Credit Losses (1) Gross Unrealized Fair Carrying Gains Losses June 30, 2020 Held to maturity: State and municipal $ 71,640 $ (948) $ 14,137 $ — $ 84,829 $ 70,692 Residential mortgage-backed 7,385 — 1,176 — 8,561 7,385 Total held to maturity 79,025 (948) 15,313 — 93,390 78,077 Available for sale: U.S. government and government agency 670,032 — 23,784 (49) 693,767 693,767 State and municipal: Special revenue 2,153,909 — 82,603 (1,551) 2,234,961 2,234,961 State general obligation 350,228 — 31,192 (810) 380,610 380,610 Pre-refunded 299,333 — 20,944 (130) 320,147 320,147 Corporate backed 224,649 — 8,581 (500) 232,730 232,730 Local general obligation 394,105 — 42,393 (251) 436,247 436,247 Total state and municipal 3,422,224 — 185,713 (3,242) 3,604,695 3,604,695 Mortgage-backed securities: Residential 913,065 — 32,241 (1,019) 944,287 944,287 Commercial 211,987 — 6,370 (799) 217,558 217,558 Total mortgage-backed securities 1,125,052 — 38,611 (1,818) 1,161,845 1,161,845 Asset-backed 3,170,931 — 10,539 (83,272) 3,098,198 3,098,198 Corporate: Industrial 1,922,336 (724) 101,976 (24,466) 1,999,122 1,999,122 Financial 1,399,238 — 49,596 (17,130) 1,431,704 1,431,704 Utilities 293,279 — 29,582 (146) 322,715 322,715 Other 18,655 — 385 — 19,040 19,040 Total corporate 3,633,508 (724) 181,539 (41,742) 3,772,581 3,772,581 Foreign government 918,606 (44,769) 31,028 (32,943) 871,922 871,922 Total available for sale 12,940,353 (45,493) 471,214 (163,066) 13,203,008 13,203,008 Total investments in fixed maturity securities $ 13,019,378 $ (46,441) $ 486,527 $ (163,066) $ 13,296,398 $ 13,281,085 ____________ (1) Represents the amount of impairment that has resulted from credit-related factors. The change in the allowance for expected credit losses, excluding the cumulative effect adjustment resulting from changes in accounting principles, is recognized in the consolidated statements of income. Amount excludes unrealized losses relating to non-credit factors. (In thousands) Amortized Gross Unrealized Fair Carrying Gains Losses December 31, 2019 Held to maturity: State and municipal $ 70,312 $ 13,000 $ — $ 83,312 $ 70,312 Residential mortgage-backed 8,371 994 — 9,365 8,371 Total held to maturity 78,683 13,994 — 92,677 78,683 Available for sale: U.S. government and government agency 775,157 13,249 (1,475) 786,931 786,931 State and municipal: Special revenue 2,343,209 64,586 (4,152) 2,403,643 2,403,643 State general obligation 359,298 22,074 (97) 381,275 381,275 Pre-refunded 364,571 20,342 (128) 384,785 384,785 Corporate backed 255,230 7,232 (903) 261,559 261,559 Local general obligation 432,333 32,684 (647) 464,370 464,370 Total state and municipal 3,754,641 146,918 (5,927) 3,895,632 3,895,632 Mortgage-backed securities: Residential 1,298,145 23,230 (5,155) 1,316,220 1,316,220 Commercial 304,506 5,214 (346) 309,374 309,374 Total mortgage-backed securities 1,602,651 28,444 (5,501) 1,625,594 1,625,594 Asset-backed 2,802,588 9,532 (21,490) 2,790,630 2,790,630 Corporate: Industrial 2,260,073 72,900 (3,800) 2,329,173 2,329,173 Financial 1,447,589 37,681 (4,118) 1,481,152 1,481,152 Utilities 325,762 15,281 (402) 340,641 340,641 Other 5,219 230 — 5,449 5,449 Total corporate 4,038,643 126,092 (8,320) 4,156,415 4,156,415 Foreign government 924,284 16,465 (93,673) 847,076 847,076 Total available for sale 13,897,964 340,700 (136,386) 14,102,278 14,102,278 Total investments in fixed maturity securities $ 13,976,647 $ 354,694 $ (136,386) $ 14,194,955 $ 14,180,961 The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the six months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at January 1, 2020 $ — Cumulative effect adjustment resulting from changes in accounting principles 69 Provision for expected credit losses 879 Allowance for expected credit losses at June 30, 2020 $ 948 The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the three months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at April 1, 2020 $ 107 Provision for expected credit losses 841 Allowance for expected credit losses at June 30, 2020 $ 948 The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the six months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at January 1, 2020 $ — $ — $ — Cumulative effect adjustment resulting from changes in accounting principles 35,645 — 35,645 Expected credit losses on securities for which credit losses were not previously recorded 12,494 6,797 19,291 Expected credit losses on securities for which credit losses were previously recorded 547 (3,758) (3,211) Reduction due to disposals (3,917) (2,315) (6,232) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493 The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the three months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at April 1, 2020 $ 60,920 $ 6,436 $ 67,356 Expected credit losses on securities for which credit losses were not previously recorded — 361 361 Expected credit losses on securities for which credit losses were previously recorded (15,822) (3,758) (19,580) Reduction due to disposals (329) (2,315) (2,644) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493 During the six months ended June 30, 2020, the Company increased the allowance for expected credit losses utilizing its credit loss assessment process and inputs used in its credit loss model, primarily due to the negative impact to the financial markets caused by COVID-19. As a result, the Company recognized an initial allowance for expected credit losses on securities that previously did not have an allowance, and increased the allowance for expected credit losses on existing securities due to higher default rate and lower recovery rate assumptions. Improved market pricing and credit ratings at June 30, 2020 compared to March 31, 2020 led to a decrease in the allowance for expected credit losses during the three months ended June 30, 2020. The amortized cost and fair value of fixed maturity securities at June 30, 2020, 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 Due in one year or less $ 852,249 $ 832,105 Due after one year through five years 5,021,482 5,151,442 Due after five years through ten years 3,148,884 3,297,837 Due after ten years 2,863,378 2,844,608 Mortgage-backed securities 1,132,437 1,170,406 Total $ 13,018,430 $ 13,296,398 ________________ (1) Amortized cost is reduced by the allowance for expected credit losses of $948 thousand related to held to maturity securities.
Equity securities
Debt Securities, Available-for-sale [Line Items]
Investments in Equity Securities	Investments in Equity Securities At June 30, 2020 and December 31, 2019, investments in equity securities were as follows: (In thousands) Cost Gross Unrealized Fair Carrying Gains Losses June 30, 2020 Common stocks $ 144,674 $ 5,739 $ (33,445) $ 116,968 $ 116,968 Preferred stocks 174,621 79,440 (8,764) 245,297 245,297 Total $ 319,295 $ 85,179 $ (42,209) $ 362,265 $ 362,265 December 31, 2019 Common stocks $ 175,928 $ 16,967 $ (26,090) $ 166,805 $ 166,805 Preferred stocks 169,171 148,243 (3,599) 313,815 313,815 Total $ 345,099 $ 165,210 $ (29,689) $ 480,620 $ 480,620

Arbitrage Trading Account

Arbitrage Trading Account	6 Months Ended
	Jun. 30, 2020
Debt Securities, Trading, and Equity Securities, FV-NI [Abstract]
Arbitrage Trading Account	Arbitrage Trading Account At June 30, 2020 and December 31, 2019, the fair and carrying values of the arbitrage trading account were $581 million and $401 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 uses put options and call options in order to mitigate the impact of potential changes in market conditions on the merger arbitrage trading account. These options are reported at fair value. As of June 30, 2020, the fair value of long option contracts outstanding was $202 thousand (notional amount of $5.2 million) and the fair value of short option contracts outstanding was $88 thousand (notional amount of $3.9 million). Other than with respect to the use of these trading account securities, the Company does not make use of derivatives.

Investment Funds

Investment Funds	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investment Funds	Investment Funds The Company evaluates whether it is an investor in a variable interest entity ("VIE"). Such entities do not have sufficient equity at risk to finance their activities without additional subordinated financial support, or the equity investors, as a group, do not have the characteristics of a controlling financial interest (primary beneficiary). The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose, and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE and on an ongoing basis. The Company is not the primary beneficiary in any of its investment funds, and accordingly, carries its interests in investment funds under the equity method of accounting. The Company’s maximum exposure to loss with respect to these investments is limited to the carrying amount reported on the Company’s consolidated balance sheet and its unfunded commitments, which were $145 million as of June 30, 2020. Investment funds consisted of the following: Carrying Value as of Income (Loss) from June 30, December 31, For the Six Months (In thousands) 2020 2019 2020 2019 Real estate $ 313,781 $ 412,275 $ 4,021 $ 13,078 Financial services 345,175 280,705 (6,881) 23,297 Energy 129,031 156,869 (20,968) (6,422) Transportation 142,840 147,034 (4,627) 9,536 Other funds 228,410 216,652 11,480 18,762 Total $ 1,159,237 $ 1,213,535 $ (16,975) $ 58,251 The Company's share of the earnings or losses from investment funds is generally reported on a one-quarter lag in order to facilitate the timely completion of the Company's consolidated financial statements. Accordingly, losses from investment funds for the second quarter of 2020 reflects the adverse impact from the disruption in global financial markets associated with COVID-19 during the first quarter of 2020.

Real Estate

Real Estate	6 Months Ended
	Jun. 30, 2020
Real Estate [Abstract]
Real Estate	Real Estate Investment in real estate represents directly owned property held for investment, as follows: Carrying Value June 30, December 31, (In thousands) 2020 2019 Properties in operation $ 1,623,579 $ 1,351,249 Properties under development 449,193 754,701 Total $ 2,072,772 $ 2,105,950 As of June 30, 2020, properties in operation included a long-term ground lease in Washington, D.C., a hotel in Memphis, Tennessee, two office complexes in New York City, office buildings in West Palm Beach and Palm Beach, Florida, an office building in London, and the completed portion of a mixed-use project in Washington D.C.. Properties in operation are net of accumulated depreciation and amortization of $72,036,000 and $59,832,000 as of June 30, 2020 and December 31, 2019, respectively. Related depreciation expense was $13,776,000 and $8,931,000 for the six months ended June 30, 2020 and 2019, respectively. Future minimum rental income expected on operating leases relating to properties in operation is $39,127,419 in 2020, $81,060,656 in 2021, $81,637,432 in 2022, $75,278,181 in 2023, $73,040,940 in 2024, $69,300,988 in 2025 and $660,961,934 thereafter. The Company borrowed $101,750,000 through a non-recourse loan secured by the West Palm Beach office building in 2018. The loan matures in November 2028 and carries a fixed interest rate of 4.21%. The carrying value does not reflect the outstanding financing, which is reflected within senior notes and other debt on the Company's consolidated balance sheet.

Loans Receivable

Loans Receivable	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Loans Receivable	Loans Receivable At June 30, 2020 and December 31, 2019, loans receivable are as follows: (In thousands) June 30, December 31, Amortized cost (net of allowance for expected credit losses): Real estate loans $ 49,770 $ 58,541 Commercial loans 32,364 33,258 Total $ 82,134 $ 91,799 Fair value: Real estate loans $ 54,088 $ 59,853 Commercial loans 32,364 34,760 Total $ 86,452 $ 94,613 The real estate loans are secured by commercial real estate primarily located in New York. These loans generally earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) through August 2025. The commercial loans are with small business owners who have secured the related financing with the assets of the business. Commercial loans primarily earn interest on a fixed basis and have varying maturities generally not exceeding 10 years. Loans receivable in non-accrual status were both $0.2 million as of June 30, 2020 and December 31, 2019. The following table presents the rollforward of the allowance for expected credit losses for loans receivable for the six months ended June 30, 2020: Real Estate Loans Commercial Loans Total (In thousands) Allowance for expected credit losses at January 1, 2020 $ 1,502 $ 644 $ 2,146 Cumulative effect adjustment resulting from changes in accounting principles (905) 548 (357) Provision for expected credit losses 3,721 3,209 6,930 Allowance for expected credit losses at June 30, 2020 $ 4,318 $ 4,401 $ 8,719 The following table presents the rollforward of the allowance for expected credit losses for loans receivable for the three months ended June 30, 2020: Real Estate Loans Commercial Loans Total (In thousands) Allowance for expected credit losses at April 1, 2020 $ 1,435 $ 2,493 $ 3,928 Provision for expected credit losses 2,883 1,908 4,791 Allowance for expected credit losses at June 30, 2020 $ 4,318 $ 4,401 $ 8,719 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.

Net Investment Gains (Losses)

Net Investment Gains (Losses)	6 Months Ended
	Jun. 30, 2020
Realized and Unrealized Investment Gains (Losses) [Abstract]
Net Investment Gains (Losses)	Net Investment Gains (Losses) Net investment gains (losses) are as follows: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Net investment gains (losses): Fixed maturity securities: Gains $ 14,844 $ 3,157 $ 19,775 $ 8,403 Losses (9,234) (3,377) (14,081) (6,895) Equity securities (1): Net realized gains (losses) on investment sales 5,727 (6) 5,727 23,339 Change in unrealized gains (losses) 61,914 69,418 (92,552) 111,496 Investment funds 913 41 31,096 58 Real estate (2) (7,137) 3,021 (7,824) 5,767 Loans receivable — — — (970) Other (5,374) 1,320 (23,773) 1,028 Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses 61,653 73,574 (81,632) 142,226 Change in allowance for expected credit losses on investments (3): Fixed maturity securities 21,023 — (10,727) — Loans receivable (4,791) — (6,930) — Change in allowance for expected credit losses on investments 16,232 — (17,657) — Net investment gains (losses) 77,885 73,574 (99,289) 142,226 Income tax (expense) benefit (18,098) (15,451) 22,476 (29,867) After-tax net investment gains (losses) $ 59,787 $ 58,123 $ (76,813) $ 112,359 Change in unrealized investment gains on available for sale securities: Fixed maturity securities without allowance for expected credit losses $ 369,615 $ 146,629 $ 43,199 $ 321,123 Fixed maturity securities with allowance for expected credit losses 23,450 81 24,991 12 Investment funds 4,212 5,762 (3,434) 7,552 Other (1,653) (5,401) (1,979) (12,356) Total change in unrealized investment gains 395,624 147,071 62,777 316,331 Income tax expense (76,899) (28,422) (3,034) (71,907) Noncontrolling interests (1) 30 1 (18) After-tax change in unrealized investment gains of available for sale securities $ 318,724 $ 118,679 $ 59,744 $ 244,406 ______________________ (1) The net realized gains or losses on investment sales represent the total gains or losses from the purchase dates of the equity securities. The change in unrealized gains consists of two components: (i) the reversal of the gain or loss recognized in previous periods on equity securities sold and (ii) the change in unrealized gain or loss resulting from mark-to-market adjustments on equity securities still held. (2) For the three and six months ended June 30, 2020, net investment losses on real estate includes an allowance of $8 million. (3) The inclusion of the allowance for expected credit losses on investments commenced January 1, 2020 due to the adoption of ASU 2016-13. See Note 3 for more details.

Fixed Maturity Securities In _3

Fixed Maturity Securities In An Unrealized Loss Position	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Fixed Maturity Securities In An Unrealized Loss Position	Fixed Maturity Securities in an Unrealized Loss Position The following tables summarize all fixed maturity securities in an unrealized loss position at June 30, 2020 and December 31, 2019 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 Gross Fair Gross Fair Gross June 30, 2020 U.S. government and government agency $ 42,279 $ 49 $ 20 $ — $ 42,299 $ 49 State and municipal 237,515 2,444 24,899 798 262,414 3,242 Mortgage-backed securities 55,367 1,458 57,184 360 112,551 1,818 Asset-backed securities 1,290,764 32,060 653,128 51,212 1,943,892 83,272 Corporate 531,733 34,588 49,806 7,154 581,539 41,742 Foreign government 78,803 5,786 38,726 27,157 117,529 32,943 Fixed maturity securities $ 2,236,461 $ 76,385 $ 823,763 $ 86,681 $ 3,060,224 $ 163,066 December 31, 2019 U.S. government and government agency $ 83,837 $ 618 $ 53,089 $ 857 $ 136,926 $ 1,475 State and municipal 365,184 4,245 127,210 1,682 492,394 5,927 Mortgage-backed securities 301,358 2,281 180,148 3,220 481,506 5,501 Asset-backed securities 755,259 2,307 774,508 19,183 1,529,767 21,490 Corporate 307,367 3,148 121,470 5,172 428,837 8,320 Foreign government 164,536 32,028 107,266 61,645 271,802 93,673 Fixed maturity securities $ 1,977,541 $ 44,627 $ 1,363,691 $ 91,759 $ 3,341,232 $ 136,386 Substantially all of the securities in an unrealized loss position are rated investment grade, except for the securities in the foreign government classification. In general, fair value in all classifications were negatively affected by market disruptions caused by COVID-19. A significant amount of the unrealized loss on foreign government securities is the result of changes in currency exchange rates. A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at June 30, 2020 is presented in the table below: ($ in thousands) Number of Aggregate Gross Foreign government 14 $ 52,126 $ 32,429 Corporate 18 47,404 9,320 Mortgage-backed securities 12 6,348 340 Asset-backed securities 2 279 6 Total 46 $ 106,157 $ 42,095 For fixed maturity securities that management does not intend to sell or to be required to sell, the portion of the decline in value that is considered to be due to credit factors is recognized in earnings, and the portion of the decline in value that is considered to be due to non-credit factors is recognized in other comprehensive income.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company’s fixed maturity available for sale securities, equity securities 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, as follows: Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 - Quoted prices for similar assets or valuations based on inputs that are observable. Level 3 - Estimates of fair value based on internal pricing methodologies using unobservable inputs. Unobservable inputs are only used to measure fair value to the extent that observable inputs are not available. Substantially all of the Company’s fixed maturity securities were priced by independent pricing services. The prices provided by the independent pricing services are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The pricing services may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs are available for each security evaluation on any given day. The pricing services used by the Company have indicated that they will only produce an estimate of fair value if objectively verifiable information is available. The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness and periodically performs independent price tests of a sample of securities to ensure proper valuation. If prices from independent pricing services are not available for fixed maturity securities, the Company estimates the fair value. For Level 2 securities, the Company utilizes pricing models and processes which may include benchmark yields, sector groupings, matrix pricing, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, bids, offers and reference data. Where broker quotes are used, the Company generally requests two or more quotes and sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes received from brokers. 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. For Level 3 securities, the Company generally uses a discounted cash flow model to estimate the fair value of fixed maturity securities. The cash flow models are based upon assumptions as to prevailing credit spreads, interest rate and interest rate volatility, time to maturity and subordination levels. Projected cash flows are discounted at rates that are adjusted to reflect illiquidity, where appropriate. The following tables present the assets and liabilities measured at fair value on a recurring basis as of June 30, 2020 and December 31, 2019 by level: (In thousands) Total Level 1 Level 2 Level 3 June 30, 2020 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 693,767 $ — $ 693,767 $ — State and municipal 3,604,695 — 3,604,695 — Mortgage-backed securities 1,161,845 — 1,161,845 — Asset-backed securities 3,098,198 — 3,098,198 — Corporate 3,772,581 — 3,772,581 — Foreign government 871,922 — 871,922 — Total fixed maturity securities available for sale 13,203,008 — 13,203,008 — Equity securities: Common stocks 116,968 110,072 — 6,896 Preferred stocks 245,297 — 238,792 6,505 Total equity securities 362,265 110,072 238,792 13,401 Arbitrage trading account 580,950 393,067 187,883 — Total $ 14,146,223 $ 503,139 $ 13,629,683 $ 13,401 Liabilities: Trading account securities sold but not yet purchased $ 20,814 $ 20,814 $ — $ — December 31, 2019 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 786,931 $ — $ 786,931 $ — State and municipal 3,895,632 — 3,895,632 — Mortgage-backed securities 1,625,594 — 1,625,594 — Asset-backed securities 2,790,630 — 2,790,630 — Corporate 4,156,415 — 4,156,415 — Foreign government 847,076 — 847,076 — Total fixed maturity securities available for sale 14,102,278 — 14,102,278 — Equity securities: Common stocks 166,805 157,752 — 9,053 Preferred stocks 313,815 — 307,310 6,505 Total equity securities 480,620 157,752 307,310 15,558 Arbitrage trading account 400,809 381,061 19,748 — Total $ 14,983,707 $ 538,813 $ 14,429,336 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 36,143 $ 36,143 $ — $ — The following tables summarize changes in Level 3 assets and liabilities for the six months ended June 30, 2020 and for the year ended December 31, 2019: Gains (Losses) Included in: (In thousands) Beginning Earnings (Losses) Other Impairments Purchases (Sales) Paydowns / Maturities Transfers In / (Out) Ending Six Months Ended June 30, 2020 Assets: Equity securities: Common stocks $ 9,053 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 6,896 Preferred stocks 6,505 — — — — — — — 6,505 Total $ 15,558 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 13,401 Year Ended Assets: Fixed maturities securities available for sale: Asset-backed securities $ 99 $ (26) $ 61 $ — $ — $ (134) $ — $ — $ — Total 99 (26) 61 — — (134) — — — Equity securities: Common stocks 8,596 2,005 — — (1,548) — — 9,053 Preferred stocks 3,945 (42) — — 2,602 — — — 6,505 Total 12,541 1,963 — — 2,602 (1,548) — — 15,558 Arbitrage trading account 17,308 (8,731) — — 14,767 (38,233) — 14,889 — Total $ 29,948 $ (6,794) $ 61 $ — $ 17,369 $ (39,915) $ — $ 14,889 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 793 $ 133 $ — $ — $ 7,609 $ (8,535) $ — $ — $ — For the quarter ended June 30, 2020, there were no securities transferred into or out of Level 3. For the year ended December 31, 2019, there were two common stocks transferred into Level 3 in the arbitrage trading account where publicly traded prices were no longer available, and both were sold by year end. The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments: June 30, 2020 December 31, 2019 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Assets: Fixed maturity securities $ 13,281,085 $ 13,296,398 $ 14,180,961 $ 14,194,955 Equity securities 362,265 362,265 480,620 480,620 Arbitrage trading account 580,950 580,950 400,809 400,809 Loans receivable 82,134 86,452 91,799 94,613 Cash and cash equivalents 2,430,826 2,430,826 1,023,710 1,023,710 Trading account receivables from brokers and clearing organizations 254,230 254,230 423,543 423,543 Due from broker 993 993 — — Liabilities: Due to broker — — 27,116 27,116 Trading account securities sold but not yet purchased 20,814 20,814 36,143 36,143 Subordinated debentures 1,199,198 1,219,704 1,198,704 1,274,088 Senior notes and other debt 1,725,449 1,935,507 1,427,575 1,582,290

Reserves for Loss and Loss Expe

Reserves for Loss and Loss Expenses	6 Months Ended
	Jun. 30, 2020
Insurance [Abstract]
Reserves for Loss and Loss Expenses	Reserves for Loss and Loss Expenses The Company's reserves for losses and loss expenses are comprised of case reserves and incurred but not reported liabilities ("IBNR"). When a claim is reported, a case reserve is established for the estimated ultimate payment based upon known information about the claim. As more information about the claim becomes available over time, case reserves are adjusted up or down as appropriate. Reserves are also established on an aggregate basis to provide for IBNR liabilities and expected loss reserve development on reported claims. Loss reserves included in the Company’s financial statements represent management’s best estimates based upon an actuarially derived point estimate and other considerations. The Company uses a variety of actuarial techniques and methods to derive an actuarial point estimate for each operating unit. These methods include paid loss development, incurred loss development, paid and incurred Bornhuetter-Ferguson methods and frequency and severity methods. In circumstances where one actuarial method is considered more credible than the others, that method is used to set the point estimate. The actuarial point estimate may also be based on a judgmental weighting of estimates produced from each of the methods considered. Industry loss experience is used to supplement the Company’s own data in selecting “tail factors” in areas where the Company’s own data is limited. The actuarial data is analyzed by line of business, coverage and accident or policy year, as appropriate, for each operating unit. The establishment of the actuarially derived loss reserve point estimate also includes consideration of qualitative factors that may affect the ultimate losses. These qualitative considerations include, among others, the impact of re-underwriting initiatives, changes in the mix of business, changes in distribution sources and changes in policy terms and conditions. The key assumptions used to arrive at the best estimate of loss reserves are the expected loss ratios, rate of loss cost inflation, and reported and paid loss emergence patterns. Expected loss ratios represent management’s expectation of losses at the time the business is priced and written, before any actual claims experience has emerged. This expectation is a significant determinant of the estimate of loss reserves for recently written business where there is little paid or incurred loss data to consider. Expected loss ratios are generally derived from historical loss ratios adjusted for the impact of rate changes, loss cost trends and known changes in the type of risks underwritten. Expected loss ratios are estimated for each key line of business within each operating unit. Expected loss cost inflation is particularly important for the long-tail lines, such as excess casualty, and claims with a high medical component, such as workers’ compensation. Reported and paid loss emergence patterns are used to project current reported or paid loss amounts to their ultimate settlement value. Loss development factors are based on the historical emergence patterns of paid and incurred losses, and are derived from the Company’s own experience and industry data. The paid loss emergence pattern is also significant to excess and assumed workers’ compensation reserves because those reserves are discounted to their estimated present value based upon such estimated payout patterns. Loss frequency and severity are measures of loss activity that are considered in determining the key assumptions described in our discussion of loss and loss expense reserves, including expected loss ratios, rate of loss cost inflation and reported and paid loss emergence patterns. Loss frequency is a measure of the number of claims per unit of insured exposure, and loss severity is a measure of the average size of claims. Factors affecting loss frequency include the effectiveness of loss controls and safety programs and changes in economic activity or weather patterns. Factors affecting loss severity include changes in policy limits, retentions, rate of inflation and judicial interpretations. Another factor affecting estimates of loss frequency and severity is the loss reporting lag, which is the period of time between the occurrence of a loss and the date the loss is reported to the Company. The length of the loss reporting lag affects our ability to accurately predict loss frequency (loss frequencies are more predictable for lines with short reporting lags) as well as the amount of reserves needed for incurred but not reported losses (less IBNR is required for lines with short reporting lags). As a result, loss reserves for lines with short reporting lags are likely to have less variation from initial loss estimates. For lines with short reporting lags, which include commercial automobile, primary workers’ compensation, other liability (claims-made) and property business, the key assumption is the loss emergence pattern used to project ultimate loss estimates from known losses paid or reported to date. For lines of business with long reporting lags, which include other liability (occurrence), products liability, excess workers’ compensation and liability reinsurance, the key assumption is the expected loss ratio since there is often little paid or incurred loss data to consider. Historically, the Company has experienced less variation from its initial loss estimates for lines of businesses with short reporting lags than for lines of business with long reporting lags. The key assumptions used in calculating the most recent estimate of the loss reserves are reviewed each quarter and adjusted, to the extent necessary, to reflect the latest reported loss data, current trends and other factors observed. The table below provides a reconciliation of the beginning and ending reserve balances: June 30, (In thousands) 2020 2019 Net reserves at beginning of period $ 10,697,998 $ 10,248,883 Cumulative effect adjustment resulting from changes in accounting principles 5,927 — Restated net reserves at beginning of period 10,703,925 10,248,883 Net provision for losses and loss expenses: Claims occurring during the current year (1) 2,222,671 1,980,138 Increase in estimates for claims occurring in prior years (2) (3) 2,050 16,764 Loss reserve discount accretion 17,658 20,577 Total 2,242,379 2,017,479 Net payments for claims: Current year 289,154 548,589 Prior years 1,545,471 1,200,906 Total 1,834,625 1,749,495 Foreign currency translation (45,572) (2,228) Net reserves at end of period 11,066,107 10,514,639 Ceded reserves at end of period 2,022,797 1,805,639 Gross reserves at end of period $ 13,088,904 $ 12,320,278 _______________________________________ (1) Claims occurring during the current year are net of loss reserve discounts of $5 million and $11 million for the six months ended June 30, 2020 and 2019, respectively. (2) The change in estimates for claims occurring in prior years is net of loss reserve discount. On an undiscounted basis, the estimates for claims occurring in prior years decreased by $8 million and increased by $9 million for the six months ended June 30, 2020 and 2019, respectively. (3) For certain retrospectively rated insurance policies and reinsurance agreements, reserve development is offset by additional or return premiums. Favorable development, net of additional and return premiums, was $7 million and $14 million for the six months ended June 30, 2020 and 2019, respectively. The ongoing COVID-19 global pandemic has impacted, and will likely continue to impact, the Company’s results through its effect on claim frequency and severity. Loss cost trends have been impacted and will likely be further impacted by COVID-19-related claims in certain lines of business, as well as by other effects of COVID-19 associated with economic conditions, inflation, and social distancing and work from home rules, for example. Although it is still too early to determine, to date, it appears that the losses incurred due to COVID-19-related claims have been partially offset by lower claim frequency in certain lines of our businesses, including commercial auto. However, given the continuing nature of the pandemic, the impact of COVID-19 could ultimately increase or decrease overall loss cost trends and is likely to have differing impacts on the Company's different lines of business. For certain lines of business, such as contingency and event cancellation, the Company has received reported claims related to COVID-19, and it expects additional claims to be reported in the future. The Company has also received claims for other short-tailed lines related to business interruption and film production delays. Further, for workers’ compensation, nearly one-third of the states have enacted rules, legislation or administrative orders creating a presumption that certain “essential” workers who contract COVID-19 did so through the course of their employment. Several other states are considering similar actions, including with varying definitions of “essential” workers. While the ultimate impact of these presumptions are unknown at this time, the Company believes that such state actions will likely increase workers’ compensation claims with respect to workers deemed “essential,” although this impact may be partially offset by lower workers’ compensation claim frequency with respect to non-essential workers. The Company has estimated the potential COVID-19 impact to its workers’ compensation, contingency and event cancellation, and other lines of business under a number of possible scenarios, however, due to COVID-19’s evolving impact and the limited amount of available data, there is a high degree of uncertainty around the Company’s COVID-19 reserves. In addition, several states (and international jurisdictions), through regulation, legislation and/or judicial action, continue to seek to expand policy coverage terms beyond the policy’s intended coverage, including, for example, but not limited to, property coverages, where there are attempts to extend business interruption coverage where there is no physical damage or loss to property, and attempts to disregard policy exclusions for communicable disease. Accordingly, losses arising from these actions, and the other factors described above, could exceed the Company’s reserves established for those related policies. For the six months ended June 30, 2020, the Company has recognized losses for COVID-19-related claims activity, net of reinsurance, of approximately $143 million, of which $102 million relates to the Insurance segment and $41 million relates to the Reinsurance & Monoline Excess segment. Of the $143 million of COVID-19-related losses, $37 million are reported losses and $106 million is booked as IBNR. During the six months ended June 30, 2020, favorable prior year development (net of additional and return premiums) of $7.0 million included $11.9 million of favorable development for the Insurance segment, partially offset by $4.9 million of adverse development for the Reinsurance & Monoline Excess segment. The overall favorable development for the Insurance segment was primarily attributable to favorable development on workers’ compensation business, partially offset by adverse development on professional liability business. The favorable workers’ compensation development was spread across many accident years, including prior to 2010, but was especially significant in accident year 2019. The favorable workers’ compensation development reflects a continuation of the benign loss cost trends experienced during recent years, particularly the favorable claim frequency trends (i.e., number of reported claims per unit of exposure). Our ongoing workers’ compensation claims management efforts, including active medical case management and use of networks and specialty vendors to control medical and pharmaceutical benefit costs, have also added to the favorable workers’ compensation prior year development. The adverse professional liability development was concentrated in accident years 2016 through 2018 and predominately resulted from a greater than expected number of large losses being reported in the period in two niches of our professional liability business. The adverse development for the Reinsurance & Monoline Excess segment was mainly driven by non-proportional reinsurance assumed liability business written in the U.K., primarily from accident years 2014 through 2018. The development was driven by a greater than expected number of reported large losses during the period. During the six months ended June 30, 2019, favorable prior year development (net of additional and return premiums) of $13.6 million included $17.2 million of favorable development for the Insurance segment, offset by $3.6 million of adverse development for the Reinsurance & Monoline Excess segment. The overall favorable development for the Insurance segment was primarily attributable to favorable development on workers’ compensation business, partially offset by adverse development on other liability business, commercial auto liability business, and medical malpractice business. The favorable workers’compensation development was spread across many accident years, including prior to 2009, but was most significant in accident years 2015 through 2018. The favorable workers’ compensation development reflects a continuation of the benign loss cost trends experienced during recent years, particularly the favorable claim frequency trends (i.e., number of reported claims per unit of exposure). The adverse other liability development was mainly related to accident years 2014 through 2016. It was driven by a higher than expected number of large losses being reported in the period, including both general liability and professional liability losses. The adverse commercial auto liability development was primarily related to accident year 2018, and was driven by a greater than expected number of large losses during the period. The adverse medical malpractice development was primarily related to accident years 2013 through 2016, and stemmed from a discontinued book of business at one of our operating units. The adverse development for the Reinsurance & Monoline Excess segment was mainly driven by U.S. casualty facultative business from accident years 2009 and prior related to construction projects.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value Measurements The Company’s fixed maturity available for sale securities, equity securities 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, as follows: Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 - Quoted prices for similar assets or valuations based on inputs that are observable. Level 3 - Estimates of fair value based on internal pricing methodologies using unobservable inputs. Unobservable inputs are only used to measure fair value to the extent that observable inputs are not available. Substantially all of the Company’s fixed maturity securities were priced by independent pricing services. The prices provided by the independent pricing services are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The pricing services may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs are available for each security evaluation on any given day. The pricing services used by the Company have indicated that they will only produce an estimate of fair value if objectively verifiable information is available. The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness and periodically performs independent price tests of a sample of securities to ensure proper valuation. If prices from independent pricing services are not available for fixed maturity securities, the Company estimates the fair value. For Level 2 securities, the Company utilizes pricing models and processes which may include benchmark yields, sector groupings, matrix pricing, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, bids, offers and reference data. Where broker quotes are used, the Company generally requests two or more quotes and sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes received from brokers. 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. For Level 3 securities, the Company generally uses a discounted cash flow model to estimate the fair value of fixed maturity securities. The cash flow models are based upon assumptions as to prevailing credit spreads, interest rate and interest rate volatility, time to maturity and subordination levels. Projected cash flows are discounted at rates that are adjusted to reflect illiquidity, where appropriate. The following tables present the assets and liabilities measured at fair value on a recurring basis as of June 30, 2020 and December 31, 2019 by level: (In thousands) Total Level 1 Level 2 Level 3 June 30, 2020 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 693,767 $ — $ 693,767 $ — State and municipal 3,604,695 — 3,604,695 — Mortgage-backed securities 1,161,845 — 1,161,845 — Asset-backed securities 3,098,198 — 3,098,198 — Corporate 3,772,581 — 3,772,581 — Foreign government 871,922 — 871,922 — Total fixed maturity securities available for sale 13,203,008 — 13,203,008 — Equity securities: Common stocks 116,968 110,072 — 6,896 Preferred stocks 245,297 — 238,792 6,505 Total equity securities 362,265 110,072 238,792 13,401 Arbitrage trading account 580,950 393,067 187,883 — Total $ 14,146,223 $ 503,139 $ 13,629,683 $ 13,401 Liabilities: Trading account securities sold but not yet purchased $ 20,814 $ 20,814 $ — $ — December 31, 2019 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 786,931 $ — $ 786,931 $ — State and municipal 3,895,632 — 3,895,632 — Mortgage-backed securities 1,625,594 — 1,625,594 — Asset-backed securities 2,790,630 — 2,790,630 — Corporate 4,156,415 — 4,156,415 — Foreign government 847,076 — 847,076 — Total fixed maturity securities available for sale 14,102,278 — 14,102,278 — Equity securities: Common stocks 166,805 157,752 — 9,053 Preferred stocks 313,815 — 307,310 6,505 Total equity securities 480,620 157,752 307,310 15,558 Arbitrage trading account 400,809 381,061 19,748 — Total $ 14,983,707 $ 538,813 $ 14,429,336 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 36,143 $ 36,143 $ — $ — The following tables summarize changes in Level 3 assets and liabilities for the six months ended June 30, 2020 and for the year ended December 31, 2019: Gains (Losses) Included in: (In thousands) Beginning Earnings (Losses) Other Impairments Purchases (Sales) Paydowns / Maturities Transfers In / (Out) Ending Six Months Ended June 30, 2020 Assets: Equity securities: Common stocks $ 9,053 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 6,896 Preferred stocks 6,505 — — — — — — — 6,505 Total $ 15,558 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 13,401 Year Ended Assets: Fixed maturities securities available for sale: Asset-backed securities $ 99 $ (26) $ 61 $ — $ — $ (134) $ — $ — $ — Total 99 (26) 61 — — (134) — — — Equity securities: Common stocks 8,596 2,005 — — (1,548) — — 9,053 Preferred stocks 3,945 (42) — — 2,602 — — — 6,505 Total 12,541 1,963 — — 2,602 (1,548) — — 15,558 Arbitrage trading account 17,308 (8,731) — — 14,767 (38,233) — 14,889 — Total $ 29,948 $ (6,794) $ 61 $ — $ 17,369 $ (39,915) $ — $ 14,889 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 793 $ 133 $ — $ — $ 7,609 $ (8,535) $ — $ — $ — For the quarter ended June 30, 2020, there were no securities transferred into or out of Level 3. For the year ended December 31, 2019, there were two common stocks transferred into Level 3 in the arbitrage trading account where publicly traded prices were no longer available, and both were sold by year end. The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments: June 30, 2020 December 31, 2019 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Assets: Fixed maturity securities $ 13,281,085 $ 13,296,398 $ 14,180,961 $ 14,194,955 Equity securities 362,265 362,265 480,620 480,620 Arbitrage trading account 580,950 580,950 400,809 400,809 Loans receivable 82,134 86,452 91,799 94,613 Cash and cash equivalents 2,430,826 2,430,826 1,023,710 1,023,710 Trading account receivables from brokers and clearing organizations 254,230 254,230 423,543 423,543 Due from broker 993 993 — — Liabilities: Due to broker — — 27,116 27,116 Trading account securities sold but not yet purchased 20,814 20,814 36,143 36,143 Subordinated debentures 1,199,198 1,219,704 1,198,704 1,274,088 Senior notes and other debt 1,725,449 1,935,507 1,427,575 1,582,290

Premiums and Reinsurance Relate

Premiums and Reinsurance Related Information	6 Months Ended
	Jun. 30, 2020
Insurance [Abstract]
Premiums and Reinsurance Related Information	Premiums and Reinsurance Related Information The following is a summary of insurance and reinsurance financial information: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Written premiums: Direct $ 1,892,359 $ 1,883,032 $ 3,856,848 $ 3,712,847 Assumed 239,887 206,828 506,769 423,243 Ceded (392,428) (346,396) (777,953) (683,025) Total net premiums written $ 1,739,818 $ 1,743,464 $ 3,585,664 $ 3,453,065 Earned premiums: Direct $ 1,804,844 $ 1,773,437 $ 3,634,558 $ 3,497,047 Assumed 232,996 198,661 461,210 386,852 Ceded (360,925) (325,257) (727,435) (644,202) Total net premiums earned $ 1,676,915 $ 1,646,841 $ 3,368,333 $ 3,239,697 Ceded losses and loss expenses incurred $ 232,873 $ 239,267 $ 468,055 $ 412,314 Ceded commissions earned $ 85,593 $ 73,092 $ 166,638 $ 144,109 The following table presents the rollforward of the allowance for expected credit losses for premiums and fees receivable for the six months ended June 30, 2020: (In thousands) Allowance for expected credit losses at January 1, 2020 $ 19,823 Cumulative effect adjustment resulting from changes in accounting principles 1,270 Provision for expected credit losses 1,013 Allowance for expected credit losses at June 30, 2020 $ 22,106 The following table presents the rollforward of the allowance for expected credit losses for premiums and fees receivable for the three months ended June 30, 2020: (In thousands) Allowance for expected credit losses at April 1, 2020 $ 21,524 Provision for expected credit losses 582 Allowance for expected credit losses at June 30, 2020 $ 22,106 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 an allowance for expected credit losses. The following table presents the rollforward of the allowance for expected credit losses associated with due from reinsurers for the six months ended June 30, 2020: (In thousands) Allowance for expected credit losses at January 1, 2020 $ 690 Cumulative effect adjustment resulting from changes in accounting principles 5,927 Provision for expected credit losses 558 Allowance for expected credit losses at June 30, 2020 $ 7,175 The following table presents the rollforward of the allowance for expected credit losses associated with due from reinsurers for the three months ended June 30, 2020: (In thousands) Allowance for expected credit losses at April 1, 2020 $ 6,800 Provision for expected credit losses 375 Allowance for expected credit losses at June 30, 2020 $ 7,175

Restricted Stock Units

Restricted Stock Units	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [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 three ($ in thousands) Units Fair Value 2020 724 $ 57 2019 5,141 $ 308

Litigation and Contingent Liabi

Litigation and Contingent Liabilities	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingent Liabilities	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.

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	Leases Lessees are required to recognize a right-of-use asset and a lease liability for leases with terms of more than 12 months on the balance sheet. All leases disclosed within this footnote are classified as operating leases. Recognized right-of-use asset and lease liability are reported within other assets and other liabilities, respectively, in the consolidated balance sheet. Lease expense is reported in other operating costs and expenses in the consolidated statement of income and accounted for on a straight-line basis over the lease term. To determine the discount rate used to calculate present value of future minimum lease payments, the Company uses its incremental borrowing rate during the lease commencement period in line with the respective lease duration. In certain cases, the Company has the option to renew the lease. Lease renewal future payments are included in the present value of the future minimum lease payments when the Company determines it is reasonably certain to renew. The main leases entered into by the Company are for office space used by the Company’s operating units across the world. Additionally, the Company, to a lesser extent, has equipment leases mainly for office equipment. Further information relating to operating lease expense and other operating lease information are as follows: For the Three Months Ended For the Six Months Ended (In thousands) 2020 2019 2020 2019 Leases: Lease cost $ 10,878 $ 10,680 $ 22,114 $ 22,235 Cash paid for amounts included in the measurement of lease liabilities reported in operating cash flows $ 11,479 $ 11,132 $ 22,309 $ 22,789 Right-of-use assets obtained in exchange for new lease liabilities $ 2,682 $ 2,918 $ 4,294 $ 7,884 As of June 30, ($ in thousands) 2020 2019 Right-of-use assets $ 180,011 $ 179,984 Lease liabilities $ 219,444 $ 209,107 Weighted-average remaining lease term 6.8 years 6.6 years Weighted-average discount rate 5.94 % 5.97 % Contractual maturities of the Company’s future minimum lease payments are as follows: (In thousands) June 30, 2020 Contractual Maturities: 2020 $ 24,525 2021 45,891 2022 41,509 2023 37,649 2024 31,401 Thereafter 78,745 Total undiscounted future minimum lease payments 259,720 Less: Discount impact (40,276) Total lease liability $ 219,444

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Business Segments	Business Segments The Company’s reportable segments include the following two business segments, plus a corporate segment: • Insurance - predominantly commercial insurance business, including excess and surplus lines, admitted lines and specialty personal lines throughout the United States, as well as insurance business in the United Kingdom, Continental Europe, South America, Canada, Mexico, Scandinavia, Asia and Australia. • Reinsurance & Monoline Excess - reinsurance business on a facultative and treaty basis, primarily in the United States, the United Kingdom, Continental Europe, Australia, the Asia-Pacific Region and South Africa, as well as operations that solely retain risk on an excess basis. 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 reporting segments is presented in the following tables. Income (loss) before income taxes by segment includes allocated investment income. Identifiable assets by segment are those assets used in or allocated to the operation of each segment. Revenues (In thousands) Earned Investment Other Total (2) Pre-Tax Income (Loss) Net Income (Loss) to Common Stockholders Three months ended June 30, 2020 Insurance $ 1,465,044 $ 44,105 $ 8,018 $ 1,517,167 $ 76,546 $ 48,607 Reinsurance & Monoline Excess 211,871 23,461 — 235,332 12,566 10,689 Corporate, other and eliminations (3) — 17,865 87,777 105,642 (61,548) (47,823) Net investment gains — — 77,885 77,885 77,885 59,787 Total $ 1,676,915 $ 85,431 $ 173,680 $ 1,936,026 $ 105,449 $ 71,260 Three months ended June 30, 2019 Insurance $ 1,475,184 $ 132,403 $ 13,687 $ 1,621,274 $ 225,871 $ 179,241 Reinsurance & Monoline Excess 171,657 44,449 — 216,106 52,635 41,864 Corporate, other and eliminations (3) — 11,481 100,949 112,430 (78,344) (62,519) Net investment gains — — 73,574 73,574 73,574 58,123 Total $ 1,646,841 $ 188,333 $ 188,210 $ 2,023,384 $ 273,736 $ 216,709 Six months ended June 30, 2020 Insurance $ 2,949,999 $ 167,564 $ 16,490 $ 3,134,053 $ 252,493 $ 185,467 Reinsurance & Monoline Excess 418,334 61,171 — 479,505 49,080 39,877 Corporate, other and eliminations (3) — 31,459 200,907 232,366 (103,302) (81,689) Net investment losses — — (99,289) (99,289) (99,289) (76,813) Total $ 3,368,333 $ 260,194 $ 118,108 $ 3,746,635 $ 98,982 $ 66,842 Six Months Ended June 30, 2019 Insurance $ 2,902,218 $ 232,444 $ 26,931 $ 3,161,593 $ 410,387 $ 325,234 Reinsurance & Monoline Excess 337,479 84,023 — 421,502 97,490 77,389 Corporate, other and eliminations (3) — 30,120 204,965 235,085 (146,928) (117,551) Net investment gains — — 142,226 142,226 142,226 112,359 Total $ 3,239,697 $ 346,587 $ 374,122 $ 3,960,406 $ 503,175 $ 397,431 _________________ (1) Certain amounts included in earned premiums of each segment are related to inter-segment transactions. (2) Revenues for Insurance from foreign countries for the three months ended June 30, 2020 and 2019 were $149 million and $179 million, respectively, and for the six months ended June 30, 2020 and 2019 were $317 million and $349 million, respectively. Revenues for Reinsurance & Monoline Excess from foreign countries for the three months ended June 30, 2020 and 2019 were $65 million and $62 million, respectively, and for the six months ended June 30, 2020 and 2019 were $134 million and $121 million, respectively. (3) Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments. Identifiable Assets (In thousands) June 30, December 31, Insurance $ 20,422,642 $ 20,005,802 Reinsurance & Monoline Excess 4,559,313 4,710,819 Corporate, other and eliminations 2,341,337 1,913,409 Consolidated $ 27,323,292 $ 26,630,030 Net premiums earned by major line of business are as follows: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Insurance: Other liability $ 544,465 $ 505,621 $ 1,091,594 $ 996,282 Short-tail lines (1) 295,968 305,852 591,446 594,943 Workers' compensation 278,699 330,510 580,299 657,186 Commercial automobile 190,335 188,278 379,978 369,203 Professional liability 155,577 144,923 306,682 284,604 Total Insurance 1,465,044 1,475,184 2,949,999 2,902,218 Reinsurance & Monoline Excess: Casualty reinsurance 130,459 95,109 253,190 185,939 Monoline excess (2) 41,062 39,400 83,224 78,381 Property reinsurance 40,350 37,148 81,920 73,159 Total Reinsurance & Monoline Excess 211,871 171,657 418,334 337,479 Total $ 1,676,915 $ 1,646,841 $ 3,368,333 $ 3,239,697 ______________ (1) Short-tail lines include commercial multi-peril (non-liability), inland marine, accident and health, fidelity and surety, boiler and machinery and other lines.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements and Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Per Share Data	Per Share Data        The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period (including 7,575,168 and 7,389,781 common shares held in a grantor trust as of June 30, 2020 and 2019, respectively). The common shares held in the grantor trust are for delivery upon settlement of vested but mandatorily deferred restricted stock units ("RSUs"). Shares held by the grantor trust do not affect diluted shares outstanding since the shares deliverable under vested RSUs were already included in diluted shares outstanding. Diluted EPS is based upon the weighted average number of basic 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
Recent Accounting Pronouncements	Recent Accounting Pronouncements and Accounting Policies Recently adopted accounting pronouncements: In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments - Credit Losses, which amended the accounting guidance for credit losses on financial instruments. The updated guidance amended the current other-than-temporary impairment model for available for sale debt securities by requiring the recognition of impairments relating to expected credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. This guidance also applies a new current expected credit loss model for determining credit-related impairments for financial instruments measured at amortized cost, such as reinsurance recoverables. The updated guidance was effective for reporting periods beginning after December 15, 2019. The adoption of this guidance on January 1, 2020 resulted in the recognition of an allowance for expected credit losses in connection with operating assets (premiums and fees receivable and due from reinsurers) of $5.7 million (net of tax) and a corresponding cumulative effect adjustment that decreased common stockholders' equity. Certain investments (primarily fixed maturity securities available for sale) established an allowance for expected credit loss of $24.8 million (net of tax), with a cumulative effect adjustment decreasing retained earnings by $24.8 million (net of tax) and increasing accumulated other comprehensive (loss) income ("AOCI") by $25.0 million (net of tax), resulting in $0.2 million net impact to total common stockholders' equity. All other accounting and reporting standards that have become effective in 2020 were either not applicable to the Company or their adoption did not have a material impact on the Company. Accounting and reporting standards that are not yet effective: 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.

Per Share Data (Tables)

Per Share Data (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Weighted average number of common shares	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 Six Months (In thousands) 2020 2019 2020 2019 Basic 185,979 190,512 188,133 190,456 Diluted 187,862 193,059 190,078 192,804

Investments in Fixed Maturity_2

Investments in Fixed Maturity Securities (Tables)	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in fixed maturity securities	At June 30, 2020 and December 31, 2019, investments in fixed maturity securities were as follows: (In thousands) Amortized Allowance for Expected Credit Losses (1) Gross Unrealized Fair Carrying Gains Losses June 30, 2020 Held to maturity: State and municipal $ 71,640 $ (948) $ 14,137 $ — $ 84,829 $ 70,692 Residential mortgage-backed 7,385 — 1,176 — 8,561 7,385 Total held to maturity 79,025 (948) 15,313 — 93,390 78,077 Available for sale: U.S. government and government agency 670,032 — 23,784 (49) 693,767 693,767 State and municipal: Special revenue 2,153,909 — 82,603 (1,551) 2,234,961 2,234,961 State general obligation 350,228 — 31,192 (810) 380,610 380,610 Pre-refunded 299,333 — 20,944 (130) 320,147 320,147 Corporate backed 224,649 — 8,581 (500) 232,730 232,730 Local general obligation 394,105 — 42,393 (251) 436,247 436,247 Total state and municipal 3,422,224 — 185,713 (3,242) 3,604,695 3,604,695 Mortgage-backed securities: Residential 913,065 — 32,241 (1,019) 944,287 944,287 Commercial 211,987 — 6,370 (799) 217,558 217,558 Total mortgage-backed securities 1,125,052 — 38,611 (1,818) 1,161,845 1,161,845 Asset-backed 3,170,931 — 10,539 (83,272) 3,098,198 3,098,198 Corporate: Industrial 1,922,336 (724) 101,976 (24,466) 1,999,122 1,999,122 Financial 1,399,238 — 49,596 (17,130) 1,431,704 1,431,704 Utilities 293,279 — 29,582 (146) 322,715 322,715 Other 18,655 — 385 — 19,040 19,040 Total corporate 3,633,508 (724) 181,539 (41,742) 3,772,581 3,772,581 Foreign government 918,606 (44,769) 31,028 (32,943) 871,922 871,922 Total available for sale 12,940,353 (45,493) 471,214 (163,066) 13,203,008 13,203,008 Total investments in fixed maturity securities $ 13,019,378 $ (46,441) $ 486,527 $ (163,066) $ 13,296,398 $ 13,281,085 ____________ (1) Represents the amount of impairment that has resulted from credit-related factors. The change in the allowance for expected credit losses, excluding the cumulative effect adjustment resulting from changes in accounting principles, is recognized in the consolidated statements of income. Amount excludes unrealized losses relating to non-credit factors. (In thousands) Amortized Gross Unrealized Fair Carrying Gains Losses December 31, 2019 Held to maturity: State and municipal $ 70,312 $ 13,000 $ — $ 83,312 $ 70,312 Residential mortgage-backed 8,371 994 — 9,365 8,371 Total held to maturity 78,683 13,994 — 92,677 78,683 Available for sale: U.S. government and government agency 775,157 13,249 (1,475) 786,931 786,931 State and municipal: Special revenue 2,343,209 64,586 (4,152) 2,403,643 2,403,643 State general obligation 359,298 22,074 (97) 381,275 381,275 Pre-refunded 364,571 20,342 (128) 384,785 384,785 Corporate backed 255,230 7,232 (903) 261,559 261,559 Local general obligation 432,333 32,684 (647) 464,370 464,370 Total state and municipal 3,754,641 146,918 (5,927) 3,895,632 3,895,632 Mortgage-backed securities: Residential 1,298,145 23,230 (5,155) 1,316,220 1,316,220 Commercial 304,506 5,214 (346) 309,374 309,374 Total mortgage-backed securities 1,602,651 28,444 (5,501) 1,625,594 1,625,594 Asset-backed 2,802,588 9,532 (21,490) 2,790,630 2,790,630 Corporate: Industrial 2,260,073 72,900 (3,800) 2,329,173 2,329,173 Financial 1,447,589 37,681 (4,118) 1,481,152 1,481,152 Utilities 325,762 15,281 (402) 340,641 340,641 Other 5,219 230 — 5,449 5,449 Total corporate 4,038,643 126,092 (8,320) 4,156,415 4,156,415 Foreign government 924,284 16,465 (93,673) 847,076 847,076 Total available for sale 13,897,964 340,700 (136,386) 14,102,278 14,102,278 Total investments in fixed maturity securities $ 13,976,647 $ 354,694 $ (136,386) $ 14,194,955 $ 14,180,961
Debt Securities, Held-to-maturity, Allowance for Credit Loss	The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the six months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at January 1, 2020 $ — Cumulative effect adjustment resulting from changes in accounting principles 69 Provision for expected credit losses 879 Allowance for expected credit losses at June 30, 2020 $ 948 The following table presents the rollforward of the allowance for expected credit losses for held to maturity securities for the three months ended June 30, 2020: State and Municipal (In thousands) Allowance for expected credit losses at April 1, 2020 $ 107 Provision for expected credit losses 841 Allowance for expected credit losses at June 30, 2020 $ 948
Debt Securities, Available-for-sale, Allowance for Credit Loss	The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the six months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at January 1, 2020 $ — $ — $ — Cumulative effect adjustment resulting from changes in accounting principles 35,645 — 35,645 Expected credit losses on securities for which credit losses were not previously recorded 12,494 6,797 19,291 Expected credit losses on securities for which credit losses were previously recorded 547 (3,758) (3,211) Reduction due to disposals (3,917) (2,315) (6,232) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493 The following table presents the rollforward of the allowance for expected credit losses for available for sale securities for the three months ended June 30, 2020: Foreign Government Corporate Total (In thousands) Allowance for expected credit losses at April 1, 2020 $ 60,920 $ 6,436 $ 67,356 Expected credit losses on securities for which credit losses were not previously recorded — 361 361 Expected credit losses on securities for which credit losses were previously recorded (15,822) (3,758) (19,580) Reduction due to disposals (329) (2,315) (2,644) Allowance for expected credit losses at June 30, 2020 $ 44,769 $ 724 $ 45,493
Amortized cost and fair value of fixed maturity securities by contractual maturity	The amortized cost and fair value of fixed maturity securities at June 30, 2020, 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 Due in one year or less $ 852,249 $ 832,105 Due after one year through five years 5,021,482 5,151,442 Due after five years through ten years 3,148,884 3,297,837 Due after ten years 2,863,378 2,844,608 Mortgage-backed securities 1,132,437 1,170,406 Total $ 13,018,430 $ 13,296,398 ________________

Investments in Equity Securit_2

Investments in Equity Securities (Tables)	6 Months Ended
	Jun. 30, 2020
Equity securities
Debt Securities, Available-for-sale [Line Items]
Schedule of Investments in Equity Securities	At June 30, 2020 and December 31, 2019, investments in equity securities were as follows: (In thousands) Cost Gross Unrealized Fair Carrying Gains Losses June 30, 2020 Common stocks $ 144,674 $ 5,739 $ (33,445) $ 116,968 $ 116,968 Preferred stocks 174,621 79,440 (8,764) 245,297 245,297 Total $ 319,295 $ 85,179 $ (42,209) $ 362,265 $ 362,265 December 31, 2019 Common stocks $ 175,928 $ 16,967 $ (26,090) $ 166,805 $ 166,805 Preferred stocks 169,171 148,243 (3,599) 313,815 313,815 Total $ 345,099 $ 165,210 $ (29,689) $ 480,620 $ 480,620

Investment Funds (Tables)

Investment Funds (Tables)	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Investment Funds	Investment funds consisted of the following: Carrying Value as of Income (Loss) from June 30, December 31, For the Six Months (In thousands) 2020 2019 2020 2019 Real estate $ 313,781 $ 412,275 $ 4,021 $ 13,078 Financial services 345,175 280,705 (6,881) 23,297 Energy 129,031 156,869 (20,968) (6,422) Transportation 142,840 147,034 (4,627) 9,536 Other funds 228,410 216,652 11,480 18,762 Total $ 1,159,237 $ 1,213,535 $ (16,975) $ 58,251

Real Estate (Tables)

Real Estate (Tables)	6 Months Ended
	Jun. 30, 2020
Real Estate [Abstract]
Schedule of Real Estate Investments	Investment in real estate represents directly owned property held for investment, as follows: Carrying Value June 30, December 31, (In thousands) 2020 2019 Properties in operation $ 1,623,579 $ 1,351,249 Properties under development 449,193 754,701 Total $ 2,072,772 $ 2,105,950

Loans Receivable Loans Receivab

Loans Receivable Loans Receivable (Tables)	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Schedule of Loans Receivable	oans receivable are as follows: (In thousands) June 30, December 31, Amortized cost (net of allowance for expected credit losses): Real estate loans $ 49,770 $ 58,541 Commercial loans 32,364 33,258 Total $ 82,134 $ 91,799 Fair value: Real estate loans $ 54,088 $ 59,853 Commercial loans 32,364 34,760 Total $ 86,452 $ 94,613
Financing Receivable, Allowance for Credit Loss	The following table presents the rollforward of the allowance for expected credit losses for loans receivable for the six months ended June 30, 2020: Real Estate Loans Commercial Loans Total (In thousands) Allowance for expected credit losses at January 1, 2020 $ 1,502 $ 644 $ 2,146 Cumulative effect adjustment resulting from changes in accounting principles (905) 548 (357) Provision for expected credit losses 3,721 3,209 6,930 Allowance for expected credit losses at June 30, 2020 $ 4,318 $ 4,401 $ 8,719 The following table presents the rollforward of the allowance for expected credit losses for loans receivable for the three months ended June 30, 2020: Real Estate Loans Commercial Loans Total (In thousands) Allowance for expected credit losses at April 1, 2020 $ 1,435 $ 2,493 $ 3,928 Provision for expected credit losses 2,883 1,908 4,791 Allowance for expected credit losses at June 30, 2020 $ 4,318 $ 4,401 $ 8,719

Net Investment Gains (Losses) (

Net Investment Gains (Losses) (Tables)	6 Months Ended
	Jun. 30, 2020
Realized and Unrealized Investment Gains (Losses) [Abstract]
Realized And Unrealized Investment Gains (Losses)	Net investment gains (losses) are as follows: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Net investment gains (losses): Fixed maturity securities: Gains $ 14,844 $ 3,157 $ 19,775 $ 8,403 Losses (9,234) (3,377) (14,081) (6,895) Equity securities (1): Net realized gains (losses) on investment sales 5,727 (6) 5,727 23,339 Change in unrealized gains (losses) 61,914 69,418 (92,552) 111,496 Investment funds 913 41 31,096 58 Real estate (2) (7,137) 3,021 (7,824) 5,767 Loans receivable — — — (970) Other (5,374) 1,320 (23,773) 1,028 Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses 61,653 73,574 (81,632) 142,226 Change in allowance for expected credit losses on investments (3): Fixed maturity securities 21,023 — (10,727) — Loans receivable (4,791) — (6,930) — Change in allowance for expected credit losses on investments 16,232 — (17,657) — Net investment gains (losses) 77,885 73,574 (99,289) 142,226 Income tax (expense) benefit (18,098) (15,451) 22,476 (29,867) After-tax net investment gains (losses) $ 59,787 $ 58,123 $ (76,813) $ 112,359 Change in unrealized investment gains on available for sale securities: Fixed maturity securities without allowance for expected credit losses $ 369,615 $ 146,629 $ 43,199 $ 321,123 Fixed maturity securities with allowance for expected credit losses 23,450 81 24,991 12 Investment funds 4,212 5,762 (3,434) 7,552 Other (1,653) (5,401) (1,979) (12,356) Total change in unrealized investment gains 395,624 147,071 62,777 316,331 Income tax expense (76,899) (28,422) (3,034) (71,907) Noncontrolling interests (1) 30 1 (18) After-tax change in unrealized investment gains of available for sale securities $ 318,724 $ 118,679 $ 59,744 $ 244,406 ______________________ (1) The net realized gains or losses on investment sales represent the total gains or losses from the purchase dates of the equity securities. The change in unrealized gains consists of two components: (i) the reversal of the gain or loss recognized in previous periods on equity securities sold and (ii) the change in unrealized gain or loss resulting from mark-to-market adjustments on equity securities still held. (2) For the three and six months ended June 30, 2020, net investment losses on real estate includes an allowance of $8 million. (3) The inclusion of the allowance for expected credit losses on investments commenced January 1, 2020 due to the adoption of ASU 2016-13. See Note 3 for more details.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020 and December 31, 2019 by level: (In thousands) Total Level 1 Level 2 Level 3 June 30, 2020 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 693,767 $ — $ 693,767 $ — State and municipal 3,604,695 — 3,604,695 — Mortgage-backed securities 1,161,845 — 1,161,845 — Asset-backed securities 3,098,198 — 3,098,198 — Corporate 3,772,581 — 3,772,581 — Foreign government 871,922 — 871,922 — Total fixed maturity securities available for sale 13,203,008 — 13,203,008 — Equity securities: Common stocks 116,968 110,072 — 6,896 Preferred stocks 245,297 — 238,792 6,505 Total equity securities 362,265 110,072 238,792 13,401 Arbitrage trading account 580,950 393,067 187,883 — Total $ 14,146,223 $ 503,139 $ 13,629,683 $ 13,401 Liabilities: Trading account securities sold but not yet purchased $ 20,814 $ 20,814 $ — $ — December 31, 2019 Assets: Fixed maturity securities available for sale: U.S. government and government agency $ 786,931 $ — $ 786,931 $ — State and municipal 3,895,632 — 3,895,632 — Mortgage-backed securities 1,625,594 — 1,625,594 — Asset-backed securities 2,790,630 — 2,790,630 — Corporate 4,156,415 — 4,156,415 — Foreign government 847,076 — 847,076 — Total fixed maturity securities available for sale 14,102,278 — 14,102,278 — Equity securities: Common stocks 166,805 157,752 — 9,053 Preferred stocks 313,815 — 307,310 6,505 Total equity securities 480,620 157,752 307,310 15,558 Arbitrage trading account 400,809 381,061 19,748 — Total $ 14,983,707 $ 538,813 $ 14,429,336 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 36,143 $ 36,143 $ — $ —
Summarize Changes In Level 3 Assets	The following tables summarize changes in Level 3 assets and liabilities for the six months ended June 30, 2020 and for the year ended December 31, 2019: Gains (Losses) Included in: (In thousands) Beginning Earnings (Losses) Other Impairments Purchases (Sales) Paydowns / Maturities Transfers In / (Out) Ending Six Months Ended June 30, 2020 Assets: Equity securities: Common stocks $ 9,053 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 6,896 Preferred stocks 6,505 — — — — — — — 6,505 Total $ 15,558 $ (1,091) $ — $ — $ — $ (1,066) $ — $ — $ 13,401 Year Ended Assets: Fixed maturities securities available for sale: Asset-backed securities $ 99 $ (26) $ 61 $ — $ — $ (134) $ — $ — $ — Total 99 (26) 61 — — (134) — — — Equity securities: Common stocks 8,596 2,005 — — (1,548) — — 9,053 Preferred stocks 3,945 (42) — — 2,602 — — — 6,505 Total 12,541 1,963 — — 2,602 (1,548) — — 15,558 Arbitrage trading account 17,308 (8,731) — — 14,767 (38,233) — 14,889 — Total $ 29,948 $ (6,794) $ 61 $ — $ 17,369 $ (39,915) $ — $ 14,889 $ 15,558 Liabilities: Trading account securities sold but not yet purchased $ 793 $ 133 $ — $ — $ 7,609 $ (8,535) $ — $ — $ —

Reserves for Loss and Loss Ex_2

Reserves for Loss and Loss Expenses (Tables)	6 Months Ended
	Jun. 30, 2020
Insurance [Abstract]
Reserve Balances	The table below provides a reconciliation of the beginning and ending reserve balances: June 30, (In thousands) 2020 2019 Net reserves at beginning of period $ 10,697,998 $ 10,248,883 Cumulative effect adjustment resulting from changes in accounting principles 5,927 — Restated net reserves at beginning of period 10,703,925 10,248,883 Net provision for losses and loss expenses: Claims occurring during the current year (1) 2,222,671 1,980,138 Increase in estimates for claims occurring in prior years (2) (3) 2,050 16,764 Loss reserve discount accretion 17,658 20,577 Total 2,242,379 2,017,479 Net payments for claims: Current year 289,154 548,589 Prior years 1,545,471 1,200,906 Total 1,834,625 1,749,495 Foreign currency translation (45,572) (2,228) Net reserves at end of period 11,066,107 10,514,639 Ceded reserves at end of period 2,022,797 1,805,639 Gross reserves at end of period $ 13,088,904 $ 12,320,278 _______________________________________ (1) Claims occurring during the current year are net of loss reserve discounts of $5 million and $11 million for the six months ended June 30, 2020 and 2019, respectively. (2) The change in estimates for claims occurring in prior years is net of loss reserve discount. On an undiscounted basis, the estimates for claims occurring in prior years decreased by $8 million and increased by $9 million for the six months ended June 30, 2020 and 2019, respectively. (3) For certain retrospectively rated insurance policies and reinsurance agreements, reserve development is offset by additional or return premiums. Favorable development, net of additional and return premiums, was $7 million and $14 million for the six months ended June 30, 2020 and 2019, respectively.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2020
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: June 30, 2020 December 31, 2019 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Assets: Fixed maturity securities $ 13,281,085 $ 13,296,398 $ 14,180,961 $ 14,194,955 Equity securities 362,265 362,265 480,620 480,620 Arbitrage trading account 580,950 580,950 400,809 400,809 Loans receivable 82,134 86,452 91,799 94,613 Cash and cash equivalents 2,430,826 2,430,826 1,023,710 1,023,710 Trading account receivables from brokers and clearing organizations 254,230 254,230 423,543 423,543 Due from broker 993 993 — — Liabilities: Due to broker — — 27,116 27,116 Trading account securities sold but not yet purchased 20,814 20,814 36,143 36,143 Subordinated debentures 1,199,198 1,219,704 1,198,704 1,274,088 Senior notes and other debt 1,725,449 1,935,507 1,427,575 1,582,290

Premiums and Reinsurance Rela_2

Premiums and Reinsurance Related Information (Tables)	6 Months Ended
	Jun. 30, 2020
Insurance [Abstract]
Reinsurance Financial Information	The following is a summary of insurance and reinsurance financial information: For the Three Months For the Six Months (In thousands) 2020 2019 2020 2019 Written premiums: Direct $ 1,892,359 $ 1,883,032 $ 3,856,848 $ 3,712,847 Assumed 239,887 206,828 506,769 423,243 Ceded (392,428) (346,396) (777,953) (683,025) Total net premiums written $ 1,739,818 $ 1,743,464 $ 3,585,664 $ 3,453,065 Earned premiums: Direct $ 1,804,844 $ 1,773,437 $ 3,634,558 $ 3,497,047 Assumed 232,996 198,661 461,210 386,852 Ceded (360,925) (325,257) (727,435) (644,202) Total net premiums earned $ 1,676,915 $ 1,646,841 $ 3,368,333 $ 3,239,697 Ceded losses and loss expenses incurred $ 232,873 $ 239,267 $ 468,055 $ 412,314 Ceded commissions earned $ 85,593 $ 73,092 $ 166,638 $ 144,109
Premium receivable, allowance for credit loss	The following table presents the rollforward of the allowance for expected credit losses for premiums and fees receivable for the six months ended June 30, 2020: (In thousands) Allowance for expected credit losses at January 1, 2020 $ 19,823 Cumulative effect adjustment resulting from changes in accounting principles 1,270 Provision for expected credit losses 1,013 Allowance for expected credit losses at June 30, 2020 $ 22,106 The following table presents the rollforward of the allowance for expected credit losses for premiums and fees receivable for the three months ended June 30, 2020: (In thousands) Allowance for expected credit losses at April 1, 2020 $ 21,524 Provision for expected credit losses 582 Allowance for expected credit losses at June 30, 2020 $ 22,106
Reinsurance Recoverable, Allowance for Credit Loss	The following table presents the rollforward of the allowance for expected credit losses associated with due from reinsurers for the six months ended June 30, 2020: (In thousands) Allowance for expected credit losses at January 1, 2020 $ 690 Cumulative effect adjustment resulting from changes in accounting principles 5,927 Provision for expected credit losses 558 Allowance for expected credit losses at June 30, 2020 $ 7,175 The following table presents the rollforward of the allowance for expected credit losses associated with due from reinsurers for the three months ended June 30, 2020: (In thousands) Allowance for expected credit losses at April 1, 2020 $ 6,800 Provision for expected credit losses 375 Allowance for expected credit losses at June 30, 2020 $ 7,175

Restricted Stock Units (Tables)

Restricted Stock Units (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary Of Restricted Stock Units Issued	A summary of RSUs issued in the six months ended June 30, 2020 and 2019 follows: ($ in thousands) Units Fair Value 2020 724 $ 57 2019 5,141 $ 308

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Lease, Cost	Further information relating to operating lease expense and other operating lease information are as follows: For the Three Months Ended For the Six Months Ended (In thousands) 2020 2019 2020 2019 Leases: Lease cost $ 10,878 $ 10,680 $ 22,114 $ 22,235 Cash paid for amounts included in the measurement of lease liabilities reported in operating cash flows $ 11,479 $ 11,132 $ 22,309 $ 22,789 Right-of-use assets obtained in exchange for new lease liabilities $ 2,682 $ 2,918 $ 4,294 $ 7,884
Supplemental Balance Sheet Information	As of June 30, ($ in thousands) 2020 2019 Right-of-use assets $ 180,011 $ 179,984 Lease liabilities $ 219,444 $ 209,107 Weighted-average remaining lease term 6.8 years 6.6 years Weighted-average discount rate 5.94 % 5.97 %
Maturities of Operating Lease Liabilities	Contractual maturities of the Company’s future minimum lease payments are as follows: (In thousands) June 30, 2020 Contractual Maturities: 2020 $ 24,525 2021 45,891 2022 41,509 2023 37,649 2024 31,401 Thereafter 78,745 Total undiscounted future minimum lease payments 259,720 Less: Discount impact (40,276) Total lease liability $ 219,444

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Financial Information Of Company Operating Segments	Revenues (In thousands) Earned Investment Other Total (2) Pre-Tax Income (Loss) Net Income (Loss) to Common Stockholders Three months ended June 30, 2020 Insurance $ 1,465,044 $ 44,105 $ 8,018 $ 1,517,167 $ 76,546 $ 48,607 Reinsurance & Monoline Excess 211,871 23,461 — 235,332 12,566 10,689 Corporate, other and eliminations (3) — 17,865 87,777 105,642 (61,548) (47,823) Net investment gains — — 77,885 77,885 77,885 59,787 Total $ 1,676,915 $ 85,431 $ 173,680 $ 1,936,026 $ 105,449 $ 71,260 Three months ended June 30, 2019 Insurance $ 1,475,184 $ 132,403 $ 13,687 $ 1,621,274 $ 225,871 $ 179,241 Reinsurance & Monoline Excess 171,657 44,449 — 216,106 52,635 41,864 Corporate, other and eliminations (3) — 11,481 100,949 112,430 (78,344) (62,519) Net investment gains — — 73,574 73,574 73,574 58,123 Total $ 1,646,841 $ 188,333 $ 188,210 $ 2,023,384 $ 273,736 $ 216,709 Six months ended June 30, 2020 Insurance $ 2,949,999 $ 167,564 $ 16,490 $ 3,134,053 $ 252,493 $ 185,467 Reinsurance & Monoline Excess 418,334 61,171 — 479,505 49,080 39,877 Corporate, other and eliminations (3) — 31,459 200,907 232,366 (103,302) (81,689) Net investment losses — — (99,289) (99,289) (99,289) (76,813) Total $ 3,368,333 $ 260,194 $ 118,108 $ 3,746,635 $ 98,982 $ 66,842 Six Months Ended June 30, 2019 Insurance $ 2,902,218 $ 232,444 $ 26,931 $ 3,161,593 $ 410,387 $ 325,234 Reinsurance & Monoline Excess 337,479 84,023 — 421,502 97,490 77,389 Corporate, other and eliminations (3) — 30,120 204,965 235,085 (146,928) (117,551) Net investment gains — — 142,226 142,226 142,226 112,359 Total $ 3,239,697 $ 346,587 $ 374,122 $ 3,960,406 $ 503,175 $ 397,431 _________________ (1) Certain amounts included in earned premiums of each segment are related to inter-segment transactions. (2) Revenues for Insurance from foreign countries for the three months ended June 30, 2020 and 2019 were $149 million and $179 million, respectively, and for the six months ended June 30, 2020 and 2019 were $317 million and $349 million, respectively. Revenues for Reinsurance & Monoline Excess from foreign countries for the three months ended June 30, 2020 and 2019 were $65 million and $62 million, respectively, and for the six months ended June 30, 2020 and 2019 were $134 million and $121 million, respectively.
Identifiable Assets By Segment	(In thousands) June 30, December 31, Insurance $ 20,422,642 $ 20,005,802 Reinsurance & Monoline Excess 4,559,313 4,710,819 Corporate, other and eliminations 2,341,337 1,913,409 Consolidated $ 27,323,292 $ 26,630,030
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 Six Months (In thousands) 2020 2019 2020 2019 Insurance: Other liability $ 544,465 $ 505,621 $ 1,091,594 $ 996,282 Short-tail lines (1) 295,968 305,852 591,446 594,943 Workers' compensation 278,699 330,510 580,299 657,186 Commercial automobile 190,335 188,278 379,978 369,203 Professional liability 155,577 144,923 306,682 284,604 Total Insurance 1,465,044 1,475,184 2,949,999 2,902,218 Reinsurance & Monoline Excess: Casualty reinsurance 130,459 95,109 253,190 185,939 Monoline excess (2) 41,062 39,400 83,224 78,381 Property reinsurance 40,350 37,148 81,920 73,159 Total Reinsurance & Monoline Excess 211,871 171,657 418,334 337,479 Total $ 1,676,915 $ 1,646,841 $ 3,368,333 $ 3,239,697 ______________ (1) Short-tail lines include commercial multi-peril (non-liability), inland marine, accident and health, fidelity and surety, boiler and machinery and other lines.

General (Details)

General (Details)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Federal Income Tax Rate	21.00%

Per Share Data (Narrative) (Det

Per Share Data (Narrative) (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Weighted average number of shares held in grantor trust	7,575,168	7,389,781

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) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Basic (shares)	185,979	190,512	188,133	190,456
Diluted (shares)	187,862	193,059	190,078	192,804

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements and Accounting Policies (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles	$ 5,845,391			$ 6,118,342
Fixed maturity securities, allowance for credit loss	46,441
Cumulative effect adjustment resulting from changes in accounting principles | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Premium receivable and reinsurance recoverable, allowance for credit loss			$ 5,700
Fixed maturity securities, allowance for credit loss			24,800
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles	7,927,280	$ 7,877,371		7,932,372	$ 7,826,015	$ 7,721,039	$ 7,558,619
Retained earnings | Cumulative effect adjustment resulting from changes in accounting principles
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles		0		(30,514)		0	0
Retained earnings | Cumulative effect adjustment resulting from changes in accounting principles | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles			(5,700)
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles	$ 209,210	(109,514)		124,514	$ 152,915	34,236	(91,491)
Accumulated Other Comprehensive Income (Loss) | Cumulative effect adjustment resulting from changes in accounting principles
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles		$ 0		$ 24,952		$ 0	$ 0
Investments | Cumulative effect adjustment resulting from changes in accounting principles | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles			200
Investments | Retained earnings | Cumulative effect adjustment resulting from changes in accounting principles | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles			(24,800)
Investments | Accumulated Other Comprehensive Income (Loss) | Cumulative effect adjustment resulting from changes in accounting principles | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment resulting from changes in accounting principles			$ 25,000

Statements of Cash Flows (Detai

Statements of Cash Flows (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Interest payments	$ 73,056,000	$ 77,672,000
Income taxes paid	$ 0	$ 82,800,000

Investments in Fixed Maturity_3

Investments in Fixed Maturity Securities (Investments in fixed maturity securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Total held to maturity, Amortized Cost	$ 79,025		$ 78,683
Held-to-maturity, Allowance for Credit Loss	(948)	$ 107	0
Held to maturity, Gross Unrealized Gains	15,313		13,994
Held to maturity, Gross Unrealized Losses	0		0
Total held to maturity, Fair Value	93,390		92,677
Total held to maturity, Carrying Value	78,077		78,683
Total available for sale, Amortized Cost	12,940,353		13,897,964
Available-for-sale, Allowance for Credit Loss	(45,493)	(67,356)	0
Total available for sale, Gross Unrealized Gains	471,214		340,700
Total available for sale, Gross Unrealized Losses	(163,066)		(136,386)
Total available for sale, Fair Value	13,203,008		14,102,278
Total available for sale, Carrying Value	13,203,008		14,102,278
Total investments in fixed maturity securities, Amortized Value	13,019,378		13,976,647
Fixed maturity securities, allowance for credit loss	(46,441)
Total investments in fixed maturity securities, Gross Unrealized Gains	486,527		354,694
Total investments in fixed maturity securities, Gross Unrealized Losses	(163,066)		(136,386)
Total investments in fixed maturity securities, Fair Value	13,296,398		14,194,955
Total investments in fixed maturity securities, Carrying Value	13,281,085		14,180,961
State and municipal
Debt Securities, Available-for-sale [Line Items]
Total held to maturity, Amortized Cost	71,640		70,312
Held-to-maturity, Allowance for Credit Loss	(948)
Held to maturity, Gross Unrealized Gains	14,137		13,000
Held to maturity, Gross Unrealized Losses	0		0
Total held to maturity, Fair Value	84,829		83,312
Total held to maturity, Carrying Value	70,692		70,312
Total available for sale, Amortized Cost	3,422,224		3,754,641
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	185,713		146,918
Total available for sale, Gross Unrealized Losses	(3,242)		(5,927)
Total available for sale, Fair Value	3,604,695		3,895,632
Total available for sale, Carrying Value	3,604,695		3,895,632
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Total held to maturity, Amortized Cost	7,385		8,371
Held-to-maturity, Allowance for Credit Loss	0
Held to maturity, Gross Unrealized Gains	1,176		994
Held to maturity, Gross Unrealized Losses	0		0
Total held to maturity, Fair Value	8,561		9,365
Total held to maturity, Carrying Value	7,385		8,371
Total available for sale, Amortized Cost	913,065		1,298,145
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	32,241		23,230
Total available for sale, Gross Unrealized Losses	(1,019)		(5,155)
Total available for sale, Fair Value	944,287		1,316,220
Total available for sale, Carrying Value	944,287		1,316,220
U.S. government and government agency
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	670,032		775,157
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	23,784		13,249
Total available for sale, Gross Unrealized Losses	(49)		(1,475)
Total available for sale, Fair Value	693,767		786,931
Total available for sale, Carrying Value	693,767		786,931
Special revenue
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	2,153,909		2,343,209
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	82,603		64,586
Total available for sale, Gross Unrealized Losses	(1,551)		(4,152)
Total available for sale, Fair Value	2,234,961		2,403,643
Total available for sale, Carrying Value	2,234,961		2,403,643
State general obligation
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	350,228		359,298
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	31,192		22,074
Total available for sale, Gross Unrealized Losses	(810)		(97)
Total available for sale, Fair Value	380,610		381,275
Total available for sale, Carrying Value	380,610		381,275
Pre-refunded
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	299,333		364,571
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	20,944		20,342
Total available for sale, Gross Unrealized Losses	(130)		(128)
Total available for sale, Fair Value	320,147		384,785
Total available for sale, Carrying Value	320,147		384,785
Corporate backed
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	224,649		255,230
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	8,581		7,232
Total available for sale, Gross Unrealized Losses	(500)		(903)
Total available for sale, Fair Value	232,730		261,559
Total available for sale, Carrying Value	232,730		261,559
Local general obligation
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	394,105		432,333
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	42,393		32,684
Total available for sale, Gross Unrealized Losses	(251)		(647)
Total available for sale, Fair Value	436,247		464,370
Total available for sale, Carrying Value	436,247		464,370
Commercial
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	211,987		304,506
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	6,370		5,214
Total available for sale, Gross Unrealized Losses	(799)		(346)
Total available for sale, Fair Value	217,558		309,374
Total available for sale, Carrying Value	217,558		309,374
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	1,125,052		1,602,651
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	38,611		28,444
Total available for sale, Gross Unrealized Losses	(1,818)		(5,501)
Total available for sale, Fair Value	1,161,845		1,625,594
Total available for sale, Carrying Value	1,161,845		1,625,594
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	3,170,931		2,802,588
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	10,539		9,532
Total available for sale, Gross Unrealized Losses	(83,272)		(21,490)
Total available for sale, Fair Value	3,098,198		2,790,630
Total available for sale, Carrying Value	3,098,198		2,790,630
Industrial
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	1,922,336		2,260,073
Available-for-sale, Allowance for Credit Loss	(724)
Total available for sale, Gross Unrealized Gains	101,976		72,900
Total available for sale, Gross Unrealized Losses	(24,466)		(3,800)
Total available for sale, Fair Value	1,999,122		2,329,173
Total available for sale, Carrying Value	1,999,122		2,329,173
Financial
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	1,399,238		1,447,589
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	49,596		37,681
Total available for sale, Gross Unrealized Losses	(17,130)		(4,118)
Total available for sale, Fair Value	1,431,704		1,481,152
Total available for sale, Carrying Value	1,431,704		1,481,152
Utilities
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	293,279		325,762
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	29,582		15,281
Total available for sale, Gross Unrealized Losses	(146)		(402)
Total available for sale, Fair Value	322,715		340,641
Total available for sale, Carrying Value	322,715		340,641
Other
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	18,655		5,219
Available-for-sale, Allowance for Credit Loss	0
Total available for sale, Gross Unrealized Gains	385		230
Total available for sale, Gross Unrealized Losses	0		0
Total available for sale, Fair Value	19,040		5,449
Total available for sale, Carrying Value	19,040		5,449
Corporate
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	3,633,508		4,038,643
Available-for-sale, Allowance for Credit Loss	(724)	(6,436)	0
Total available for sale, Gross Unrealized Gains	181,539		126,092
Total available for sale, Gross Unrealized Losses	(41,742)		(8,320)
Total available for sale, Fair Value	3,772,581		4,156,415
Total available for sale, Carrying Value	3,772,581		4,156,415
Foreign government
Debt Securities, Available-for-sale [Line Items]
Total available for sale, Amortized Cost	918,606		924,284
Available-for-sale, Allowance for Credit Loss	(44,769)	$ (60,920)	0
Total available for sale, Gross Unrealized Gains	31,028		16,465
Total available for sale, Gross Unrealized Losses	(32,943)		(93,673)
Total available for sale, Fair Value	871,922		847,076
Total available for sale, Carrying Value	$ 871,922		$ 847,076

Investments in Fixed Maturity_4

Investments in Fixed Maturity Securities (HTM Allowance for Credit Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	$ (107)	$ 0
Cumulative effect adjustment resulting from changes in accounting principles	(107)	0
Provision for expected credit losses	841	879
Allowance for expected credit losses at June 30, 2020	$ 948	948
Cumulative effect adjustment resulting from changes in accounting principles
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		69
Cumulative effect adjustment resulting from changes in accounting principles		$ 69

Investments in Fixed Maturity_5

Investments in Fixed Maturity Securities (AFS Allowance for Credit Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	$ 67,356	$ 0
Cumulative effect adjustment resulting from changes in accounting principles	67,356	0
Expected credit losses on securities for which credit losses were not previously recorded	361	19,291
Expected credit losses on securities for which credit losses were previously recorded	(19,580)	(3,211)
Reduction due to disposals	(2,644)	(6,232)
Allowance for expected credit losses at June 30, 2020	45,493	45,493
Cumulative effect adjustment resulting from changes in accounting principles
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		35,645
Cumulative effect adjustment resulting from changes in accounting principles		35,645
Foreign government
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	60,920	0
Cumulative effect adjustment resulting from changes in accounting principles	60,920	0
Expected credit losses on securities for which credit losses were not previously recorded	0	12,494
Expected credit losses on securities for which credit losses were previously recorded	(15,822)	547
Reduction due to disposals	(329)	(3,917)
Allowance for expected credit losses at June 30, 2020	44,769	44,769
Foreign government | Cumulative effect adjustment resulting from changes in accounting principles
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		35,645
Cumulative effect adjustment resulting from changes in accounting principles		35,645
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	6,436	0
Cumulative effect adjustment resulting from changes in accounting principles	6,436	724
Expected credit losses on securities for which credit losses were not previously recorded	361	6,797
Expected credit losses on securities for which credit losses were previously recorded	(3,758)	(3,758)
Reduction due to disposals	(2,315)	(2,315)
Allowance for expected credit losses at June 30, 2020	$ 724	724
Corporate | Cumulative effect adjustment resulting from changes in accounting principles
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		0
Cumulative effect adjustment resulting from changes in accounting principles		$ 0

Investments in Fixed Maturity_6

Investments in Fixed Maturity Securities (Amortized cost and fair value of fixed maturity securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Due in one year or less	$ 852,249
Amortized Cost, Due after one year through five years	5,021,482
Amortized Cost, Due after five years through ten years	3,148,884
Amortized Cost, Due after ten years	2,863,378
Amortized Cost, Mortgaged-backed securities	1,132,437
Total investments in fixed maturity securities, Amortized Value	13,018,430
Fair Value, Due in one year or less	832,105
Fair Value, Due after one year through five years	5,151,442
Fair Value, Due after five years through ten years	3,297,837
Fair Value, Due after ten years	2,844,608
Fair Value, Mortgage-backed securities	1,170,406
Total investments in fixed maturity securities, Fair Value	13,296,398		$ 14,194,955
Cumulative effect adjustment resulting from changes in accounting principles	$ 948	$ (107)	$ 0

Investments in Equity Securit_3

Investments in Equity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 362,265	$ 480,620
Fair Value
Debt Securities, Available-for-sale [Line Items]
Cost	319,295	345,099
Gross Unrealized, Gains	85,179	165,210
Gross Unrealized, Losses	(42,209)	(29,689)
Equity securities	362,265	480,620
Fair Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Cost	144,674	175,928
Gross Unrealized, Gains	5,739	16,967
Gross Unrealized, Losses	(33,445)	(26,090)
Equity securities	116,968	166,805
Fair Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Cost	174,621	169,171
Gross Unrealized, Gains	79,440	148,243
Gross Unrealized, Losses	(8,764)	(3,599)
Equity securities	245,297	313,815
Carrying Value
Debt Securities, Available-for-sale [Line Items]
Equity securities	362,265	480,620
Carrying Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Equity securities	116,968	166,805
Carrying Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 245,297	$ 313,815

Arbitrage Trading Account (Deta

Arbitrage Trading Account (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Arbitrage trading account	$ 580,950,000	$ 400,809,000
Long | Options held
Derivative [Line Items]
Fair value of derivative	202,000
Notional amount of derivative	5,200,000
Short | Options held
Derivative [Line Items]
Fair value of derivative	88,000
Notional amount of derivative	$ 3,900,000

Investment Funds (Details)

Investment Funds (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Unfunded commitments	$ 145,000
Investment funds	1,159,237		$ 1,213,535
Income (Loss) from Investment Funds	(16,975)	$ 58,251
Real estate
Schedule of Equity Method Investments [Line Items]
Investment funds	313,781		412,275
Income (Loss) from Investment Funds	4,021	13,078
Financial services
Schedule of Equity Method Investments [Line Items]
Investment funds	345,175		280,705
Income (Loss) from Investment Funds	(6,881)	23,297
Energy
Schedule of Equity Method Investments [Line Items]
Investment funds	129,031		156,869
Income (Loss) from Investment Funds	(20,968)	(6,422)
Transportation
Schedule of Equity Method Investments [Line Items]
Investment funds	142,840		147,034
Income (Loss) from Investment Funds	(4,627)	9,536
Other funds
Schedule of Equity Method Investments [Line Items]
Investment funds	228,410		$ 216,652
Income (Loss) from Investment Funds	$ 11,480	$ 18,762

Real Estate (Details)

Real Estate (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Real Estate [Abstract]
Properties in operation	$ 1,623,579	$ 1,351,249
Properties under development	449,193	754,701
Total	$ 2,072,772	$ 2,105,950

Real Estate (Narrative) (Detail

Real Estate (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Accumulated depreciation and amortization on properties	$ 72,036,000		$ 59,832,000
Real estate depreciation expense	13,776,000	$ 8,931,000
Lease future minimum payments 2020	39,127,419
Lease future minimum payments 2021	81,060,656
Lease future minimum payments 2022	81,637,432
Lease future minimum payments 2023	75,278,181
Lease future minimum payments 2024	73,040,940
Lease future minimum payments 2025	69,300,988
Lease future minimum payments there after	660,961,934
Secured Debt
Debt Instrument [Line Items]
Fae value of debt	$ 101,750,000
Interest rate, percent	4.21%

Loans Receivable (Details)

Loans Receivable (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	$ 82,134	$ 91,799
Loans receivable	86,452	94,613
Loans in nonaccrual status	200	200
Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	49,770	58,541
Loans receivable	54,088	59,853
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	32,364	33,258
Loans receivable	$ 32,364	$ 34,760
Loans receivable maturity term	10 years

Loans Receivable - Allowance Fo

Loans Receivable - Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020	$ 3,928	$ 2,146
Cumulative effect adjustment resulting from changes in accounting principles	8,719	8,719
Provision for expected credit losses	4,791	6,930
Allowance for expected credit losses at June 30, 2020	8,719	8,719
Real estate loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020	1,435	1,502
Cumulative effect adjustment resulting from changes in accounting principles	4,318	4,318
Provision for expected credit losses	2,883	3,721
Allowance for expected credit losses at June 30, 2020	4,318	4,318
Commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020	2,493	644
Cumulative effect adjustment resulting from changes in accounting principles	4,401	4,401
Provision for expected credit losses	1,908	3,209
Allowance for expected credit losses at June 30, 2020	$ 4,401	4,401
Cumulative effect adjustment resulting from changes in accounting principles
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020		(357)
Cumulative effect adjustment resulting from changes in accounting principles		(357)
Cumulative effect adjustment resulting from changes in accounting principles | Real estate loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020		(905)
Cumulative effect adjustment resulting from changes in accounting principles		(905)
Cumulative effect adjustment resulting from changes in accounting principles | Commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses at January 1, 2020		548
Cumulative effect adjustment resulting from changes in accounting principles		$ 548

Net Investment Gains (Losses)_2

Net Investment Gains (Losses) (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains	$ 14,844	$ 3,157	$ 19,775	$ 8,403
Fixed maturity securities, losses	(9,234)	(3,377)	(14,081)	(6,895)
Net realized gains (losses) on investment sales	5,727	(6)	5,727	23,339
Change in unrealized gains (losses)	61,914	69,418	(92,552)	111,496
Investment funds	913	41	31,096	58
Real estate (2)	(7,137)	3,021	(7,824)	5,767
Loans receivable	0	0	0	(970)
Other	(5,374)	1,320	(23,773)	1,028
Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses	61,653	73,574	(81,632)	142,226
Fixed maturity securities	21,023	0	(10,727)	0
Loans receivable	(4,791)	0	(6,930)	0
Change in allowance for expected credit losses on investments	16,232	0	(17,657)	0
Net investment gains (losses)	77,885	73,574	(99,289)	142,226
Income tax (expense) benefit	(18,098)	(15,451)	22,476	(29,867)
After-tax net investment gains (losses)	59,787	$ 58,123	(76,813)	$ 112,359
Real estate investment, allowance	$ 8,000		$ 8,000

Net Investment Gains (Losses)_3

Net Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	$ 395,624	$ 147,071	$ 62,777	$ 316,331
Income tax expense	(76,899)	(28,422)	(3,034)	(71,907)
Noncontrolling interests	(1)	30	1	(18)
Total change in unrealized gains	318,724	118,679	59,744	244,406
Debt securities
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	369,615	146,629	43,199	321,123
Fixed maturity securities with allowance for expected credit losses
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	23,450	81	24,991	12
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	4,212	5,762	(3,434)	7,552
Other
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	$ (1,653)	$ (5,401)	$ (1,979)	$ (12,356)

Fixed Maturity Securities In _4

Fixed Maturity Securities In An Unrealized Loss Position (Non-Investment Grade Fixed Maturity Securities) (Details) $ in Thousands	Jun. 30, 2020USD ($)position	Dec. 31, 2019USD ($)
Corporate
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	$ 581,539	$ 428,837
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	112,551	481,506
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	$ 1,943,892	$ 1,529,767
Noninvestment Grade Investments at Loss Position
Debt Securities, Available-for-sale [Line Items]
Number of Securities | position	46
Aggregate Fair Value	$ 106,157
Gross Unrealized Loss	$ 42,095
Noninvestment Grade Investments at Loss Position | Foreign government
Debt Securities, Available-for-sale [Line Items]
Number of Securities | position	14
Aggregate Fair Value	$ 52,126
Gross Unrealized Loss	$ 32,429
Noninvestment Grade Investments at Loss Position | Corporate
Debt Securities, Available-for-sale [Line Items]
Number of Securities | position	18
Aggregate Fair Value	$ 47,404
Gross Unrealized Loss	$ 9,320
Noninvestment Grade Investments at Loss Position | Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Number of Securities | position	12
Aggregate Fair Value	$ 6,348
Gross Unrealized Loss	$ 340
Noninvestment Grade Investments at Loss Position | Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Number of Securities | position	2
Aggregate Fair Value	$ 279
Gross Unrealized Loss	$ 6

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured At Fair Value, On a Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets:
Total fixed maturity securities available for sale	$ 13,203,008	$ 14,102,278
Equity securities	362,265	480,620
Arbitrage trading account	580,950	400,809
Fair Value, Measurements, Recurring
Assets:
Total fixed maturity securities available for sale	13,203,008	14,102,278
Equity securities	362,265	480,620
Arbitrage trading account	580,950	400,809
Assets, fair value disclosure	14,146,223	14,983,707
Liabilities:
Securities sold but not yet purchased	20,814	36,143
Fair Value, Measurements, Recurring | U.S. government and government agency
Assets:
Total fixed maturity securities available for sale	693,767	786,931
Fair Value, Measurements, Recurring | State and municipal
Assets:
Total fixed maturity securities available for sale	3,604,695	3,895,632
Fair Value, Measurements, Recurring | Mortgage-backed securities
Assets:
Total fixed maturity securities available for sale	1,161,845	1,625,594
Fair Value, Measurements, Recurring | Asset-backed
Assets:
Total fixed maturity securities available for sale	3,098,198	2,790,630
Fair Value, Measurements, Recurring | Corporate
Assets:
Total fixed maturity securities available for sale	3,772,581	4,156,415
Fair Value, Measurements, Recurring | Foreign government
Assets:
Total fixed maturity securities available for sale	871,922	847,076
Fair Value, Measurements, Recurring | Common stocks
Assets:
Equity securities	116,968	166,805
Fair Value, Measurements, Recurring | Preferred stocks
Assets:
Equity securities	245,297	313,815
Level 1 | Fair Value, Measurements, Recurring
Assets:
Total fixed maturity securities available for sale	0	0
Equity securities	110,072	157,752
Arbitrage trading account	393,067	381,061
Assets, fair value disclosure	503,139	538,813
Liabilities:
Securities sold but not yet purchased	20,814	36,143
Level 1 | Fair Value, Measurements, Recurring | U.S. government and government agency
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | State and municipal
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | Mortgage-backed securities
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | Asset-backed
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | Corporate
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | Foreign government
Assets:
Total fixed maturity securities available for sale	0	0
Level 1 | Fair Value, Measurements, Recurring | Common stocks
Assets:
Equity securities	110,072	157,752
Level 1 | Fair Value, Measurements, Recurring | Preferred stocks
Assets:
Equity securities	0	0
Level 2 | Fair Value, Measurements, Recurring
Assets:
Total fixed maturity securities available for sale	13,203,008	14,102,278
Equity securities	238,792	307,310
Arbitrage trading account	187,883	19,748
Assets, fair value disclosure	13,629,683	14,429,336
Liabilities:
Securities sold but not yet purchased	0	0
Level 2 | Fair Value, Measurements, Recurring | U.S. government and government agency
Assets:
Total fixed maturity securities available for sale	693,767	786,931
Level 2 | Fair Value, Measurements, Recurring | State and municipal
Assets:
Total fixed maturity securities available for sale	3,604,695	3,895,632
Level 2 | Fair Value, Measurements, Recurring | Mortgage-backed securities
Assets:
Total fixed maturity securities available for sale	1,161,845	1,625,594
Level 2 | Fair Value, Measurements, Recurring | Asset-backed
Assets:
Total fixed maturity securities available for sale	3,098,198	2,790,630
Level 2 | Fair Value, Measurements, Recurring | Corporate
Assets:
Total fixed maturity securities available for sale	3,772,581	4,156,415
Level 2 | Fair Value, Measurements, Recurring | Foreign government
Assets:
Total fixed maturity securities available for sale	871,922	847,076
Level 2 | Fair Value, Measurements, Recurring | Common stocks
Assets:
Equity securities	0	0
Level 2 | Fair Value, Measurements, Recurring | Preferred stocks
Assets:
Equity securities	238,792	307,310
Level 3 | Fair Value, Measurements, Recurring
Assets:
Total fixed maturity securities available for sale	0	0
Equity securities	13,401	15,558
Arbitrage trading account	0	0
Assets, fair value disclosure	13,401	15,558
Liabilities:
Securities sold but not yet purchased	0	0
Level 3 | Fair Value, Measurements, Recurring | U.S. government and government agency
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | State and municipal
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | Mortgage-backed securities
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | Asset-backed
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | Corporate
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | Foreign government
Assets:
Total fixed maturity securities available for sale	0	0
Level 3 | Fair Value, Measurements, Recurring | Common stocks
Assets:
Equity securities	6,896	9,053
Level 3 | Fair Value, Measurements, Recurring | Preferred stocks
Assets:
Equity securities	$ 6,505	$ 6,505

Fair Value Measurements (Summar

Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, impairments		$ 0
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	$ 15,558	29,948
Assets, earnings		(6,794)
Assets, other comprehensive income		61
Assets, purchases		17,369
Assets, (sales)		(39,915)
Assets. transfers out		14,889
Assets, ending balance		15,558
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Liabilities, beginning balance	0	793
Liabilities, earnings		133
Liabilities, other comprehensive income		0
Liabilities, impairments		0
Liabilities, purchases		7,609
Liabilities, (sales)		(8,535)
Liabilities, maturities		0
Liabilities, transfers out		0
Liabilities, ending balance		0
Level 3 | Debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	0	99
Assets, earnings		(26)
Assets, other comprehensive income		61
Assets, impairments		0
Assets, purchases		0
Assets, (sales)		(134)
Assets. transfers out		0
Assets, ending balance		0
Level 3 | Asset-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	0	99
Assets, earnings		(26)
Assets, other comprehensive income		61
Assets, impairments		0
Assets, purchases		0
Assets, (sales)		(134)
Assets, maturities		0
Assets. transfers out		0
Assets, ending balance		0
Level 3 | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	15,558	12,541
Assets, earnings	(1,091)	1,963
Assets, other comprehensive income	0	0
Assets, impairments	0	0
Assets, purchases	0	2,602
Assets, (sales)	(1,066)	(1,548)
Assets, maturities		0
Assets. transfers out	0	0
Assets, ending balance	13,401	15,558
Level 3 | Common stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	9,053	8,596
Assets, earnings	(1,091)	2,005
Assets, other comprehensive income	0
Assets, impairments	0	0
Assets, purchases	0	0
Assets, (sales)	(1,066)	(1,548)
Assets. transfers out	0	0
Assets, ending balance	6,896	9,053
Level 3 | Preferred stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	6,505	3,945
Assets, earnings	0	(42)
Assets, other comprehensive income	0	0
Assets, impairments	0	0
Assets, purchases	0	2,602
Assets, (sales)	0	0
Assets. transfers out	0	0
Assets, ending balance	6,505	6,505
Level 3 | Arbitrage trading account
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	$ 0	17,308
Assets, earnings		(8,731)
Assets, other comprehensive income		0
Assets, impairments		0
Assets, purchases		14,767
Assets, (sales)		(38,233)
Assets. transfers out		14,889
Assets, ending balance		$ 0

Reserves for Loss and Loss Ex_3

Reserves for Loss and Loss Expenses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net reserves at beginning of period	$ 10,697,998	$ 10,248,883
Net provision for losses and loss expenses:
Claims occurring during the current year	2,222,671	1,980,138
Decrease in estimates for claims occurring in prior years	2,050	16,764
Loss reserve discount accretion	17,658	20,577
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	2,242,379	2,017,479
Net payments for claims:
Current year	289,154	548,589
Prior years	1,545,471	1,200,906
Total	1,834,625	1,749,495
Foreign currency translation	(45,572)	(2,228)
Net reserves at end of period	10,697,998	10,248,883	$ 11,066,107	$ 10,697,998	$ 10,514,639
Ceded reserves at end of period			2,022,797		1,805,639
Gross reserves at end of period			$ 13,088,904	12,583,249	$ 12,320,278
Cumulative effect adjustment resulting from changes in accounting principles
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net reserves at beginning of period	5,927	0
Net payments for claims:
Net reserves at end of period	5,927	0		5,927
Cumulative Effect, Period Of Adoption, Adjusted Balance
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net reserves at beginning of period	10,703,925	10,248,883
Net payments for claims:
Net reserves at end of period	$ 10,703,925	$ 10,248,883		$ 10,703,925

Reserves for Loss and Loss Ex_4

Reserves for Loss and Loss Expenses (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Net of loss reserve discounts	$ 5	$ 11
Increase (decrease) in estimates for claims	8	(9)
Adjustment expense	7	13.6
Liability recognized for best estimate net of reinsurance	143
Liability recognized for best estimate net of reinsurance, reported losses	37
Liability recognized for best estimate net of reinsurance, incurred but not reported (IBNR)	106
Insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Liability recognized for best estimate net of reinsurance	102
Favorable reserve development net of premium offsets	11.9	17.2
Reinsurance & Monoline Excess
Liability for Claims and Claims Adjustment Expense [Line Items]
Liability recognized for best estimate net of reinsurance	41
Unfavorable reserve development net of premium offsets	$ 4.9	$ 3.6

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets:
Arbitrage trading account	$ 580,950	$ 400,809
Loans receivable	86,452	94,613
Carrying Value
Assets:
Fixed maturity securities	13,281,085	14,180,961
Equity securities	362,265	480,620
Arbitrage trading account	580,950	400,809
Loans receivable	82,134	91,799
Cash and cash equivalents	2,430,826	1,023,710
Trading account receivables from brokers and clearing organizations	254,230	423,543
Due from broker	993	0
Liabilities:
Due to broker	0	27,116
Trading account securities sold but not yet purchased	20,814	36,143
Subordinated debentures	1,199,198	1,198,704
Senior notes and other debt	1,725,449	1,427,575
Fair Value
Assets:
Fixed maturity securities	13,296,398	14,194,955
Equity securities	362,265	480,620
Arbitrage trading account	580,950	400,809
Loans receivable	86,452	94,613
Cash and cash equivalents	2,430,826	1,023,710
Trading account receivables from brokers and clearing organizations	254,230	423,543
Due from broker	993	0
Liabilities:
Due to broker	0	27,116
Trading account securities sold but not yet purchased	20,814	36,143
Subordinated debentures	1,219,704	1,274,088
Senior notes and other debt	$ 1,935,507	$ 1,582,290

Premiums and Reinsurance Rela_3

Premiums and Reinsurance Related Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019
Written premiums:
Written premiums, direct	$ 1,892,359	$ 1,883,032	$ 3,856,848	$ 3,712,847
Written premiums, assumed	239,887	206,828	506,769	423,243
Written premiums, ceded	(392,428)	(346,396)	(777,953)	(683,025)
Total net premiums written	1,739,818	1,743,464	3,585,664	3,453,065
Earned premiums:
Earned premiums, direct	1,804,844	1,773,437	3,634,558	3,497,047
Earned premiums, assumed	232,996	198,661	461,210	386,852
Earned premiums, ceded	(360,925)	(325,257)	(727,435)	(644,202)
Net premiums earned	1,676,915	1,646,841	3,368,333	3,239,697
Ceded losses and loss expenses incurred	232,873	239,267	468,055	412,314
Ceded commissions earned	85,593	$ 73,092	166,638	$ 144,109
Cumulative effect adjustment resulting from changes in accounting principles	$ 7,175		$ 7,175		$ 6,800	$ 690

Premiums and Reinsurance Rela_4

Premiums and Reinsurance Related Information - Premiums and Reinsurance, Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	$ 21,524	$ 19,823
Cumulative effect adjustment resulting from changes in accounting principles	21,524	19,823
Provision for expected credit losses	582	1,013
Allowance for expected credit losses at June 30, 2020	22,106	22,106
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	6,800	690
Cumulative effect adjustment resulting from changes in accounting principles	7,175	7,175
Reinsurance Recoverable, Credit Loss Expense (Reversal)	375	558
Allowance for expected credit losses at June 30, 2020	$ 7,175	7,175
Cumulative effect adjustment resulting from changes in accounting principles
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		1,270
Cumulative effect adjustment resulting from changes in accounting principles		1,270
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020		5,927
Cumulative effect adjustment resulting from changes in accounting principles		$ 5,927

Restricted Stock Units (Summary

Restricted Stock Units (Summary of Restricted Stock Units Issued) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Share based compensation expense	$ 23,000	$ 25,000
Restricted stock
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Restricted stock units (in units)	724	5,141
Fair Value	$ 57	$ 308
Minimum | Restricted stock
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Award vesting period	3 years
Maximum | Restricted stock
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Award vesting period	5 years

Leases (Lease Cost) (Details)

Leases (Lease Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Lease cost	$ 10,878	$ 10,680	$ 22,114	$ 22,235
Cash paid for amounts included in the measurement of lease liabilities reported in operating cash flows	11,479	11,132	22,309	22,789
Right-of-use assets obtained in exchange for new lease liabilities	$ 2,682	$ 2,918	$ 4,294	$ 7,884

Leases (Supplemental Balance Sh

Leases (Supplemental Balance Sheet Information) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease, right-of-use asset	$ 180,011	$ 179,984
Operating lease, liability	$ 219,444	$ 209,107
Weighted-average remaining lease term	6 years 9 months 18 days	6 years 7 months 6 days
Weighted-average discount rate	5.94%	5.97%

Leases (Maturities of Operating

Leases (Maturities of Operating Lease Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Remainder of 2019	$ 24,525
2021	45,891
2022	41,509
2023	37,649
2024	31,401
Thereafter	78,745
Total undiscounted future minimum lease payments	259,720
Less: Discount impact	(40,276)
Total lease liability	$ 219,444	$ 209,107

Business Segments (Financial In

Business Segments (Financial Information of Company Operating Segments) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)segment	Jun. 30, 2019USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Segment Reporting Information [Line Items]
Earned Premiums (1)	$ 1,676,915	$ 1,646,841	$ 3,368,333	$ 3,239,697
Investment Income	85,431	188,333	260,194	346,587
Other	173,680	188,210	118,108	374,122
Total revenues	1,936,026	2,023,384	3,746,635	3,960,406
Pre-Tax Income (Loss)	105,449	273,736	98,982	503,175
Net Income (Loss) to Common Stockholders	71,260	216,709	66,842	397,431
Net investment gains	77,885	73,574	(99,289)	142,226
Net investment gains, net of tax	59,787	58,123	(76,813)	112,359
Corporate, other and eliminations
Segment Reporting Information [Line Items]
Earned Premiums (1)	0	0	0	0
Investment Income	17,865	11,481	31,459	30,120
Other	87,777	100,949	200,907	204,965
Total revenues	105,642	112,430	232,366	235,085
Pre-Tax Income (Loss)	(61,548)	(78,344)	(103,302)	(146,928)
Net Income (Loss) to Common Stockholders	(47,823)	(62,519)	(81,689)	(117,551)
Insurance
Segment Reporting Information [Line Items]
Earned Premiums (1)		1,475,184		2,902,218
Insurance | Operating Segments
Segment Reporting Information [Line Items]
Earned Premiums (1)	1,465,044	1,475,184	2,949,999	2,902,218
Investment Income	44,105	132,403	167,564	232,444
Other	8,018	13,687	16,490	26,931
Total revenues	1,517,167	1,621,274	3,134,053	3,161,593
Pre-Tax Income (Loss)	76,546	225,871	252,493	410,387
Net Income (Loss) to Common Stockholders	48,607	179,241	185,467	325,234
Reinsurance & Monoline Excess
Segment Reporting Information [Line Items]
Earned Premiums (1)		171,657		337,479
Reinsurance & Monoline Excess | Operating Segments
Segment Reporting Information [Line Items]
Earned Premiums (1)	211,871	171,657	418,334	337,479
Investment Income	23,461	44,449	61,171	84,023
Other	0	0	0	0
Total revenues	235,332	216,106	479,505	421,502
Pre-Tax Income (Loss)	12,566	52,635	49,080	97,490
Net Income (Loss) to Common Stockholders	10,689	41,864	39,877	77,389
Re-insurance - International | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	65,000	62,000	134,000	121,000
Net investment gains
Segment Reporting Information [Line Items]
Earned Premiums (1)	0	0	0	0
Investment Income	0	0	0	0
Insurance-International Segment | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	$ 149,000	$ 179,000	$ 317,000	$ 349,000

Business Segments (Identifiable

Business Segments (Identifiable Assets by Segment) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	$ 27,323,292	$ 26,630,030
Operating Segments | Insurance
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	20,422,642	20,005,802
Operating Segments | Reinsurance & Monoline Excess
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	4,559,313	4,710,819
Corporate, other and eliminations
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	$ 2,341,337	$ 1,913,409

Business Segments (Net Premiums

Business Segments (Net Premiums Earned By Major Line of Business) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Net premiums earned	$ 1,676,915	$ 1,646,841	$ 3,368,333	$ 3,239,697
Insurance
Revenue from External Customer [Line Items]
Net premiums earned		1,475,184		2,902,218
Insurance | Operating Segments
Revenue from External Customer [Line Items]
Net premiums earned	1,465,044	1,475,184	2,949,999	2,902,218
Insurance | Other liability
Revenue from External Customer [Line Items]
Net premiums earned	544,465	505,621	1,091,594	996,282
Insurance | Short-tail lines
Revenue from External Customer [Line Items]
Net premiums earned	295,968	305,852	591,446	594,943
Insurance | Workers' compensation
Revenue from External Customer [Line Items]
Net premiums earned	278,699	330,510	580,299	657,186
Insurance | Commercial automobile
Revenue from External Customer [Line Items]
Net premiums earned	190,335	188,278	379,978	369,203
Insurance | Professional liability
Revenue from External Customer [Line Items]
Net premiums earned	155,577	144,923	306,682	284,604
Reinsurance & Monoline Excess
Revenue from External Customer [Line Items]
Net premiums earned		171,657		337,479
Reinsurance & Monoline Excess | Operating Segments
Revenue from External Customer [Line Items]
Net premiums earned	211,871	171,657	418,334	337,479
Reinsurance & Monoline Excess | Casualty reinsurance
Revenue from External Customer [Line Items]
Net premiums earned	130,459	95,109	253,190	185,939
Reinsurance & Monoline Excess | Monoline excess
Revenue from External Customer [Line Items]
Net premiums earned	41,062	39,400	83,224	78,381
Reinsurance & Monoline Excess | Property reinsurance
Revenue from External Customer [Line Items]
Net premiums earned	$ 40,350	$ 37,148	$ 81,920	$ 73,159