Arch Capital (ACGL) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 01, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2019
Current Fiscal Year End Date	--12-31
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	ARCH CAPITAL GROUP LTD.
Entity Central Index Key	0000947484
Entity Incorporation, State or Country Code	D0
Entity Tax Identification Number	98-0374481
Entity Address, Address Line One	Waterloo House, Ground Floor
Entity Address, Address Line Two	100 Pitts Bay Road,
Entity Address, City or Town	Pembroke
Entity Address, Postal Zip Code	HM 08,
Entity Address, Country	BM
City Area Code	(441)
Local Phone Number	278-9250
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 File Number	001-16209
Amendment Flag	false
Entity Listings [Line Items]
Entity Common Stock, Shares Outstanding		404,987,803
Common shares
Entity Listings [Line Items]
Title of 12(b) Security	Common shares, $0.0011 par value per share
Trading Symbol	ACGL
Security Exchange Name	NASDAQ
Depositary Series E Preferred Stock
Entity Listings [Line Items]
Title of 12(b) Security	Depositary shares, each representing a 1/100th interest in a 5.25% Series E preferred share
Trading Symbol	ACGLP
Security Exchange Name	NASDAQ
Depositary Series F Preferred Stock
Entity Listings [Line Items]
Title of 12(b) Security	Depositary shares, each representing a 1/100th interest in a 5.45% Series F preferred share
Trading Symbol	ACGLO
Security Exchange Name	NASDAQ

Unaudited Consolidated Balance

Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments:
Fixed maturities available for sale, at fair value (amortized cost: $15,584,662 and $14,829,902)	$ 15,881,732	$ 14,699,010
Short-term investments available for sale, at fair value (amortized cost: $822,157 and $956,238)	821,961	955,880
Collateral received under securities lending, at fair value (amortized cost: $450,312 and $274,125)	450,320	274,133
Equity securities, at fair value	670,943	338,899
Investments accounted for using the fair value option	3,721,035	3,983,571
Investments accounted for using the equity method	1,581,972	1,493,791
Total investments	23,127,963	21,745,284
Cash	605,316	646,556
Accrued investment income	119,252	114,641
Securities pledged under securities lending, at fair value (amortized cost: $436,699 and $266,786)	440,510	268,395
Premiums receivable	1,606,040	1,299,150
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	3,171,257	2,919,372
Contractholder receivables	2,102,544	2,079,111
Ceded unearned premiums	1,136,728	975,469
Deferred acquisition costs	600,740	569,574
Receivable for securities sold	164,592	36,246
Goodwill and intangible assets	641,010	634,920
Other assets	1,135,718	929,611
Total assets	34,851,670	32,218,329
Liabilities
Reserve for losses and loss adjustment expenses	12,230,316	11,853,297
Unearned premiums	4,056,860	3,753,636
Reinsurance balances payable	531,990	393,107
Contractholder payables	2,102,544	2,079,111
Collateral held for insured obligations	237,056	236,630
Senior notes	1,733,865	1,733,528
Revolving credit agreement borrowings	491,006	455,682
Securities lending payable	450,312	274,125
Payable for securities purchased	294,109	90,034
Other liabilities	904,438	911,500
Total liabilities	23,032,496	21,780,650
Commitments and Contingencies
Redeemable noncontrolling interests	206,475	206,292
Shareholders' Equity
Non-cumulative preferred shares	780,000	780,000
Common shares ($0.0011 par, shares issued: 573,761,683 and 570,737,283)	638	634
Additional paid-in capital	1,847,949	1,793,781
Retained earnings	10,322,975	9,426,299
Accumulated other comprehensive income (loss), net of deferred income tax	206,827	(178,720)
Common shares held in treasury, at cost (shares: 168,874,149 and 168,282,449)	(2,401,037)	(2,382,167)
Total shareholders' equity available to Arch	10,757,352	9,439,827
Non-redeemable noncontrolling interests	855,347	791,560
Total shareholders' equity	11,612,699	10,231,387
Total liabilities, noncontrolling interests and shareholders' equity	$ 34,851,670	$ 32,218,329

Unaudited Consolidated Balanc_2

Unaudited Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fixed maturities available for sale, at amortized cost	$ 15,584,662	$ 14,829,902
Short-term investments available for sale, at amortized cost	822,157	956,238
Collateral received under securities lending, at amortized cost	450,312	274,125
Securities pledged under securities lending, at amortized cost	$ 436,699	$ 266,786
Common shares, par value per share	$ 0.0011	$ 0.0011
Common shares issued (shares)	573,761,683	570,737,283
Common shares held in treasury (shares)	168,874,149	168,282,449

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Net premiums written	$ 1,444,898	$ 1,298,896	$ 2,970,157	$ 2,711,440
Change in unearned premiums	18,829	37,867	(137,564)	(139,778)
Net premiums earned	1,463,727	1,336,763	2,832,593	2,571,662
Net investment income	155,038	135,668	311,987	262,392
Net realized gains (losses)	120,806	(76,611)	262,371	(187,609)
Other-than-temporary impairment losses	(49)	(470)	(1,358)	(632)
Less investment impairments recognized in other comprehensive income, before taxes	0	0	0	0
Net impairment losses recognized in earnings	(49)	(470)	(1,358)	(632)
Other underwriting income	5,953	3,874	14,778	9,223
Equity in net income of investment funds accounted for using the equity method	32,536	8,472	79,403	36,541
Other income	1,129	3,113	2,212	3,187
Total revenues	1,779,140	1,410,809	3,501,986	2,694,764
Expenses
Losses and loss adjustment expenses	767,543	726,153	1,486,075	1,363,013
Acquisition expenses	210,089	202,838	407,937	394,214
Other operating expenses	198,914	176,181	400,077	351,196
Corporate expenses	18,251	22,512	36,213	37,824
Amortization of intangible assets	19,794	26,472	40,211	53,208
Interest expense	29,280	30,344	58,345	60,980
Net foreign exchange (gains) losses	4,952	(53,706)	1,427	(33,985)
Total expenses	1,248,823	1,130,794	2,430,285	2,226,450
Income before income taxes	530,317	280,015	1,071,701	468,314
Income tax expense	(44,472)	(23,668)	(90,358)	(45,583)
Net income	485,845	256,347	981,343	422,731
Net (income) loss attributable to noncontrolling interests	(16,891)	(12,701)	(63,861)	(28,662)
Net income available to Arch	468,954	243,646	917,482	394,069
Preferred dividends	(10,403)	(10,403)	(20,806)	(20,840)
Loss on redemption of preferred shares	0	0	0	(2,710)
Net income available to Arch common shareholders	$ 458,551	$ 233,243	$ 896,676	$ 370,519
Net income per common share and common share equivalent
Basic (per share)	$ 1.14	$ 0.58	$ 2.24	$ 0.91
Diluted (per share)	$ 1.12	$ 0.56	$ 2.19	$ 0.89
Weighted average common shares and common share equivalents outstanding
Basic (shares)	401,482,784	404,800,421	400,837,181	406,162,508
Diluted (shares)	410,899,483	413,111,205	409,755,250	415,460,756

Unaudited Consolidated Statem_2

Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Comprehensive Income
Net income	$ 485,845	$ 256,347	$ 981,343	$ 422,731
Unrealized appreciation (decline) in value of available-for-sale investments:
Unrealized holding gains (losses) arising during period	222,473	(85,271)	448,360	(251,948)
Reclassification of net realized (gains) losses, net of income taxes, included in net income (loss)	(55,345)	36,643	(65,566)	99,104
Foreign currency translation adjustments	4,267	(12,595)	9,783	(11,313)
Comprehensive income	657,240	195,124	1,373,920	258,574
Net (income) loss attributable to noncontrolling interests	(16,891)	(12,701)	(63,861)	(28,662)
Other comprehensive (income) loss attributable to noncontrolling interests	(2,891)	1,077	(7,030)	1,750
Comprehensive income available to Arch	$ 637,458	$ 183,500	$ 1,303,029	$ 231,662

Unaudited Consolidated Statem_3

Unaudited Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Non-cumulative preferred shares	Common shares	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss), net of deferred income tax	Unrealized appreciation (decline) in value of available-for-sale securities, net of deferred income tax	Foreign currency translation adjustments	Common shares held in treasury, at cost	Convertible non-voting common equivalent preferred shares
Balance at beginning of period, as adjusted					$ 8,712,683		$ 7,606
Balance at beginning of period at Dec. 31, 2017		$ 872,555	$ 611	$ 1,230,617	8,562,889	$ 118,044	157,400	$ (39,356)	$ (2,077,741)	$ 489,627
Cumulative effect of an accounting change at Dec. 31, 2017					149,794		(149,794)
Preferred shares redeemed		(92,555)
Preferred shares converted to common shares				489,608						(489,627)
Common shares issued, net			22
Other changes				40,381
Net income	$ 422,731				422,731
Net (income) loss attributable to noncontrolling interests	(28,662)				(28,662)
Preferred share dividends	(20,840)				(20,840)
Loss on redemption of preferred shares	(2,710)				(2,710)
Unrealized holding gains (losses) during period, net of reclassification adjustment							(152,844)
Unrealized holding gains (losses) during period attributable to noncontrolling interests							1,885
Foreign currency translation adjustments	(11,313)							(11,313)
Foreign currency translation adjustments attributable to noncontrolling interests								(135)
Shares repurchased for treasury	(173,600)								(188,788)
Balance at end of period at Jun. 30, 2018	9,163,755	780,000	633	1,760,606	9,083,202	(194,157)	(143,353)	(50,804)	(2,266,529)	0
Non-redeemable noncontrolling interests, end of period at Jun. 30, 2018	861,153
Total shareholders’ equity at Jun. 30, 2018	10,024,908
Balance at beginning of period, as adjusted					8,849,959		(96,238)
Balance at beginning of period at Mar. 31, 2018		780,000	630	1,737,978	8,849,959	(134,009)	(96,238)	(37,771)	(2,084,186)	0
Cumulative effect of an accounting change at Mar. 31, 2018					0		0
Preferred shares redeemed		0
Preferred shares converted to common shares				0						0
Common shares issued, net			3
Other changes				22,628
Net income	256,347				256,347
Net (income) loss attributable to noncontrolling interests	(12,701)				(12,701)
Preferred share dividends	(10,403)				(10,403)
Loss on redemption of preferred shares	0				0
Unrealized holding gains (losses) during period, net of reclassification adjustment							(48,628)
Unrealized holding gains (losses) during period attributable to noncontrolling interests							1,513
Foreign currency translation adjustments	(12,595)							(12,595)
Foreign currency translation adjustments attributable to noncontrolling interests								(438)
Shares repurchased for treasury									(182,343)
Balance at end of period at Jun. 30, 2018	9,163,755	780,000	633	1,760,606	9,083,202	(194,157)	(143,353)	(50,804)	(2,266,529)	0
Non-redeemable noncontrolling interests, end of period at Jun. 30, 2018	861,153
Total shareholders’ equity at Jun. 30, 2018	10,024,908
Balance at beginning of period, as adjusted					9,426,299		(114,178)
Balance at beginning of period at Dec. 31, 2018	9,439,827	780,000	634	1,793,781	9,426,299	(178,720)	(114,178)	(64,542)	(2,382,167)	0
Cumulative effect of an accounting change at Dec. 31, 2018					0		0
Preferred shares redeemed		0
Preferred shares converted to common shares				0						0
Common shares issued, net			4
Other changes				54,168
Net income	981,343				981,343
Net (income) loss attributable to noncontrolling interests	(63,861)				(63,861)
Preferred share dividends	(20,806)				(20,806)
Loss on redemption of preferred shares	0				0
Unrealized holding gains (losses) during period, net of reclassification adjustment							382,794
Unrealized holding gains (losses) during period attributable to noncontrolling interests							(6,989)
Foreign currency translation adjustments	9,783							9,783
Foreign currency translation adjustments attributable to noncontrolling interests								(41)
Shares repurchased for treasury	(2,900)								(18,870)
Balance at end of period at Jun. 30, 2019	10,757,352	780,000	638	1,847,949	10,322,975	206,827	261,627	(54,800)	(2,401,037)	0
Non-redeemable noncontrolling interests, end of period at Jun. 30, 2019	855,347
Total shareholders’ equity at Jun. 30, 2019	11,612,699
Balance at beginning of period, as adjusted					9,864,424		97,202
Balance at beginning of period at Mar. 31, 2019		780,000	636	1,819,605	9,864,424	38,323	97,202	(58,879)	(2,388,392)	0
Cumulative effect of an accounting change at Mar. 31, 2019					0		0
Preferred shares redeemed		0
Preferred shares converted to common shares				0						0
Common shares issued, net			2
Other changes				28,344
Net income	485,845				485,845
Net (income) loss attributable to noncontrolling interests	(16,891)				(16,891)
Preferred share dividends	(10,403)				(10,403)
Loss on redemption of preferred shares	0				0
Unrealized holding gains (losses) during period, net of reclassification adjustment							167,128
Unrealized holding gains (losses) during period attributable to noncontrolling interests							(2,703)
Foreign currency translation adjustments	4,267							4,267
Foreign currency translation adjustments attributable to noncontrolling interests								(188)
Shares repurchased for treasury									(12,645)
Balance at end of period at Jun. 30, 2019	10,757,352	$ 780,000	$ 638	$ 1,847,949	$ 10,322,975	$ 206,827	$ 261,627	$ (54,800)	$ (2,401,037)	$ 0
Non-redeemable noncontrolling interests, end of period at Jun. 30, 2019	855,347
Total shareholders’ equity at Jun. 30, 2019	$ 11,612,699

Unaudited Consolidated Statem_4

Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating Activities
Net income	$ 981,343	$ 422,731
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized (gains) losses	(264,293)	177,442
Net impairment losses recognized in earnings	1,358	632
Equity in net income or loss of investment funds accounted for using the equity method and other income or loss	(45,720)	(13,543)
Amortization of intangible assets	40,211	53,208
Share-based compensation	41,537	35,419
Changes in:
Reserve for losses and loss adjustment expenses, net of unpaid losses and loss adjustment expenses recoverable	154,396	(77,891)
Unearned premiums, net of ceded unearned premiums	137,564	139,778
Premiums receivable	(302,050)	(236,950)
Deferred acquisition costs	(24,790)	(35,111)
Reinsurance balances payable	139,415	88,961
Other items, net	(146,447)	(57,790)
Net cash provided by (used for) operating activities	712,524	496,886
Investing Activities
Purchases of fixed maturity investments	(16,332,646)	(16,867,570)
Purchases of equity securities	(431,939)	(679,663)
Purchases of other investments	(677,063)	(1,017,147)
Proceeds from sales of fixed maturity investments	15,632,482	16,090,543
Proceeds from sales of equity securities	176,701	622,068
Proceeds from sales, redemptions and maturities of other investments	534,698	773,298
Proceeds from redemptions and maturities of fixed maturity investments	244,949	511,448
Net settlements of derivative instruments	87,701	4,498
Net sales of short-term investments	201,520	451,901
Change in cash collateral related to securities lending	7,590	176,304
Purchases of fixed assets	(16,359)	(13,242)
Other	(174,578)	49,961
Net cash provided by (used for) investing activities	(746,944)	102,399
Financing Activities
Redemption of preferred shares	0	(92,555)
Purchases of common shares under share repurchase program	(2,871)	(173,575)
Proceeds from common shares issued, net	(557)	(13,851)
Proceeds from borrowings	62,800	130,579
Repayments of borrowings	(27,538)	(373,000)
Change in cash collateral related to securities lending	(7,590)	(176,304)
Dividends paid to redeemable noncontrolling interests	(8,994)	(8,994)
Other	(3,529)	(4,489)
Preferred dividends paid	(20,806)	(20,840)
Net cash provided by (used for) financing activities	(9,085)	(733,029)
Effects of exchange rate changes on foreign currency cash and restricted cash	1,937	(10,431)
Increase (decrease) in cash and restricted cash	(41,568)	(144,175)
Cash and restricted cash, beginning of year	724,643	727,284
Cash and restricted cash, end of period	$ 683,075	$ 583,109

Basis of Presentation and Recen

Basis of Presentation and Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Recent Accounting Pronouncements	Basis of Presentation and Recent Accounting Pronouncements General Arch Capital Group Ltd. (“Arch Capital”) is a Bermuda public limited liability company which provides insurance, reinsurance and mortgage insurance on a worldwide basis through its wholly-owned subsidiaries. As used herein, the “Company” means Arch Capital and its subsidiaries. The Company’s consolidated financial statements include the results of Watford Holdings Ltd. and its wholly owned subsidiaries. See note 11 . On January 1, 2019, the Company’s U.K. insurance operations entered into a transaction with The Ardonagh Group to acquire renewal rights for a U.K. commercial lines book of business, consisting of commercial property, casualty, motor, professional liability, personal accident and travel business. Basis of Presentation The interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany transactions and balances have been eliminated in consolidation. 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 disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. In the opinion of management, the accompanying unaudited interim consolidated financial statements reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of results on an interim basis. The results of any interim period are not necessarily indicative of the results for a full year or any future periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted; however, management believes that the disclosures are adequate to make the information presented not misleading. This report should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 (“2018 Form 10-K”), including the Company’s audited consolidated financial statements and related notes. The Company has reclassified the presentation of certain prior year information to conform to the current presentation. Such reclassifications had no effect on the Company’s net income, comprehensive income, shareholders’ equity or cash flows. Tabular amounts are in U.S. Dollars in thousands, except share amounts, unless otherwise noted. Recent Accounting Pronouncements Recently Issued Accounting Standards Adopted The Company adopted ASU 2016-02, “Leases (Topic 842)”, which provides a new comprehensive model for lease accounting. Topic 842 requires a lessee to recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The Company adopted the modified retrospective approach of this standard, that resulted in the recognition of a right-of-use asset of $147.9 million as part of other assets and a lease liability of $163.6 million as part of other liabilities in the consolidated balance sheet as of January 1, 2019. The Company de-recognized the liability for deferred rent that was required under the previous guidance. In addition, the Company adopted ASU 2018-11, “Leases: Targeted Improvements (Topic 842),” which provides an additional (optional) transition method to adopt the new lease standard. The Company adopted the alternative transition method and elected to utilize a cumulative-effect adjustment to the opening balance of the retained earnings for the year of adoption. As such, the Company’s reporting for the comparative periods prior to the adoption continue to be presented in the financial statements in accordance with previous lease accounting guidance. The Company also adopted the practical expedients as a package which allows the Company to not reassess (1) whether any expired or existing contracts are or contain leases (2) the lease classification for any expired or existing leases (3) initial direct costs for any existing leases and (4) to account for the lease and non lease components as a single lease component. In addition to electing the practical expedients as a package, the Company elected to include hindsight to determine the lease term of existing leases, and made an accounting policy election to not apply the recognition requirements to short-term leases (lease term of less than twelve months). The cumulative effect adjustment to the opening balance of retained earnings was zero . The adoption of the updated guidance did not have a material effect on the Company’s results of operations or liquidity. The Company adopted ASU 2018-07 “Improvements to Nonemployee Share-Based Payment Accounting,” which was issued in June 2018 to simplify the accounting for share-based payments granted to nonemployees for goods and services. Under this ASU, most of the guidance on such payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. The ASU is effective for reporting periods beginning after December 15, 2018. This guidance and the adoption of this provision did not have a material effect on the Company's financial position, results of operations or cash flows. The Company adopted ASU 2018-02 “Income Statement-Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which was issued in February 2018 to allow the reclassification of the stranded tax effects in accumulated other comprehensive income (“AOCI”) resulting from the Tax Cuts and Jobs Act of 2017 (“Tax Cuts Act”). Current guidance requires the effect of a change in tax laws or rates on deferred tax balances to be reported in income from continuing operations in the accounting period that includes the period of enactment, even if the related income tax effects were originally charged or credited directly to AOCI. The amount of the reclassification would include the effect of the change in the U.S. federal corporate income tax rate on the gross deferred tax amounts and related valuation allowances, if any, at the date of the enactment of the Tax Cuts Act related to items in AOCI. The updated guidance is effective for reporting periods beginning after December 15, 2018 and is to be applied retrospectively to each period in which the effect of the Tax Cuts Act related to items remaining in AOCI are recognized or at the beginning of the period of adoption. The adoption of this ASU did not have a material effect on the Company’s results of operations, financial position or liquidity. The Company adopted ASU 2017-08 “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities,” which was issued in March, 2017. This ASU shortens the amortization period for certain callable debt securities held at a premium and requires the premium to be amortized to the earliest call date. However, the new guidance does not require an accounting change for securities held at a discount whose discount continues to be amortized to maturity. The standard is effective for financial statements issued for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The adoption of the guidance requires a modified retrospective approach with a cumulative-effect adjustment to retained earnings. The adoption of this ASU did not have a material effect on the Company’s consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted For information regarding additional accounting standards that the Company has not yet adopted, see note 3(q), “Significant Accounting Policies—Recent Accounting Pronouncements,” of the notes to consolidated financial statements in the Company’s 2018 Form 10-K.

Share Transactions

Share Transactions	6 Months Ended
	Jun. 30, 2019
Stockholders' Equity Note [Abstract]
Share Transactions	Share Transactions Share Repurchases The board of directors of Arch Capital has authorized the investment in Arch Capital’s common shares through a share repurchase program. Since the inception of the share repurchase program, Arch Capital has repurchased 386.3 million common shares for an aggregate purchase price of $3.97 billion . For the six months ended June 30, 2019 , Arch Capital repurchased 0.1 million shares under the share repurchase program with an aggregate purchase price of $2.9 million . Arch Capital repurchased 6.5 million shares under the share repurchase program with an aggregate purchase price of $173.6 million during the six months ended June 30, 2018 . At June 30, 2019 , $160.9 million of share repurchases were available under the program, which may be effected from time to time in open market or privately negotiated transactions through December 31, 2019. The timing and amount of the repurchase transactions under this program will depend on a variety of factors, including market conditions and corporate and regulatory considerations. Conversion of Convertible Non-Voting Common Equivalent Preferred Shares In March 2018, Arch Capital completed an underwritten public secondary offering of 17.0 million common shares (split adjusted) by American International Group, Inc. (“AIG”) following transfer of 0.6 million Series D convertible non-voting common equivalent preferred shares (“Series D Preferred Shares”). Proceeds from the sale of common shares pursuant to the public offering were received by AIG. At June 30, 2019 , no Series D Preferred Shares were outstanding. Series C Preferred Shares On January 2, 2018, Arch Capital redeemed all outstanding 6.75% Series C non-cumulative preferred shares. The preferred shares were redeemed at a redemption price equal to $25 per share, plus all declared and unpaid dividends to (but excluding) the redemption date. In accordance with GAAP, following the redemption, original issuance costs related to such shares were removed from additional paid-in capital and recorded as a “loss on redemption of preferred shares.” Such adjustment had no impact on total shareholders’ equity or cash flows.

Earnings Per Common Share

Earnings Per Common Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share The following table sets forth the computation of basic and diluted earnings per common share: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Numerator: Net income $ 485,845 $ 256,347 $ 981,343 $ 422,731 Amounts attributable to noncontrolling interests (16,891 ) (12,701 ) (63,861 ) (28,662 ) Net income available to Arch 468,954 243,646 917,482 394,069 Preferred dividends (10,403 ) (10,403 ) (20,806 ) (20,840 ) Loss on redemption of preferred shares — — — (2,710 ) Net income available to Arch common shareholders $ 458,551 $ 233,243 $ 896,676 $ 370,519 Denominator: Weighted average common shares outstanding 401,482,784 404,800,421 400,837,181 399,485,135 Series D preferred shares (1) — — — 6,677,373 Weighted average common shares and common share equivalents outstanding — basic 401,482,784 404,800,421 400,837,181 406,162,508 Effect of dilutive common share equivalents: Nonvested restricted shares 1,937,626 1,575,749 1,720,417 1,837,356 Stock options (2) 7,479,073 6,735,035 7,197,652 7,460,892 Weighted average common shares and common share equivalents outstanding — diluted 410,899,483 413,111,205 409,755,250 415,460,756 Earnings per common share: Basic $ 1.14 $ 0.58 $ 2.24 $ 0.91 Diluted $ 1.12 $ 0.56 $ 2.19 $ 0.89 (1) Such shares are convertible non-voting common equivalent preferred shares issued in connection with the UGC acquisition. See note 2 . (2) Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2019 second quarter and 2018 second quarter , the number of stock options excluded were 2,016,830 and 5,350,733 , respectively. For the six months ended June 30, 2019 and 2018 period, the number of stock options excluded were 2,560,755 and 5,372,789 , respectively.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The Company classifies its businesses into three underwriting segments — insurance, reinsurance and mortgage — and two other operating segments — ‘other’ and corporate (non-underwriting). The Company determined its reportable segments using the management approach described in accounting guidance regarding disclosures about segments of an enterprise and related information. The accounting policies of the segments are the same as those used for the preparation of the Company’s consolidated financial statements. Intersegment business is allocated to the segment accountable for the underwriting results. The Company’s insurance, reinsurance and mortgage segments each have managers who are responsible for the overall profitability of their respective segments and who are directly accountable to the Company’s chief operating decision makers, the President and Chief Executive Officer of Arch Capital, and the Chief Financial Officer of Arch Capital. The chief operating decision makers do not assess performance, measure return on equity or make resource allocation decisions on a line of business basis. Management measures segment performance for its three underwriting segments based on underwriting income or loss. The Company does not manage its assets by underwriting segment, with the exception of goodwill and intangible assets, and, accordingly, investment income is not allocated to each underwriting segment. The insurance segment consists of the Company’s insurance underwriting units which offer specialty product lines on a worldwide basis. Product lines include: construction and national accounts; excess and surplus casualty; lenders products; professional lines; programs; property, energy, marine and aviation; travel, accident and health; and other (consisting of alternative markets, excess workers' compensation and surety business). The reinsurance segment consists of the Company’s reinsurance underwriting units which offer specialty product lines on a worldwide basis. Product lines include: casualty; marine and aviation; other specialty; property catastrophe; property excluding property catastrophe (losses on a single risk, both excess of loss and pro rata); and other (consisting of life reinsurance, casualty clash and other). The mortgage segment includes the Company’s U.S. and international mortgage insurance and reinsurance operations as well as government sponsored enterprise (“GSE”) credit-risk sharing transactions. Arch Mortgage Insurance Company and United Guaranty Residential Insurance Company (combined “Arch MI U.S.”) are approved as eligible mortgage insurers by Federal National Mortgage Association (“Fannie Mae”) and Federal Home Loan Mortgage Corporation (“Freddie Mac”), each a GSE. The corporate (non-underwriting) segment results include net investment income, other income (loss), corporate expenses, transaction costs and other, interest expense, items related to the Company’s non-cumulative preferred shares, net realized gains or losses, net impairment losses included in earnings, equity in net income or loss of investment funds accounted for using the equity method, net foreign exchange gains or losses and income taxes. Such amounts exclude the results of the ‘other’ segment. The ‘other’ segment includes the results of Watford Holdings Ltd. Watford Holdings Ltd. is the parent of Watford Re Ltd., a multi-line Bermuda reinsurance company (together with Watford Holdings Ltd., “Watford Re”) (see note 11 ). Watford Re has its own management and board of directors that is responsible for the overall profitability of the ‘other’ segment. For the ‘other’ segment, performance is measured based on net income or loss. The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders: Three Months Ended June 30, 2019 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 919,925 $ 545,547 $ 364,465 $ 1,829,829 $ 161,978 $ 1,937,809 Premiums ceded (292,095 ) (169,457 ) (42,857 ) (504,301 ) (42,608 ) (492,911 ) Net premiums written 627,830 376,090 321,608 1,325,528 119,370 1,444,898 Change in unearned premiums (35,388 ) (8,906 ) 31,175 (13,119 ) 31,948 18,829 Net premiums earned 592,442 367,184 352,783 1,312,409 151,318 1,463,727 Other underwriting income (loss) — 1,224 4,056 5,280 673 5,953 Losses and loss adjustment expenses (389,172 ) (240,958 ) (25,997 ) (656,127 ) (111,416 ) (767,543 ) Acquisition expenses (91,094 ) (56,785 ) (32,654 ) (180,533 ) (29,556 ) (210,089 ) Other operating expenses (109,523 ) (33,960 ) (39,819 ) (183,302 ) (15,612 ) (198,914 ) Underwriting income (loss) $ 2,653 $ 36,705 $ 258,369 297,727 (4,593 ) 293,134 Net investment income 123,038 32,000 155,038 Net realized gains (losses) 125,112 (4,306 ) 120,806 Net impairment losses recognized in earnings (49 ) — (49 ) Equity in net income (loss) of investment funds accounted for using the equity method 32,536 — 32,536 Other income (loss) 1,129 — 1,129 Corporate expenses (2) (16,073 ) — (16,073 ) Transaction costs and other (2) (2,178 ) — (2,178 ) Amortization of intangible assets (19,794 ) — (19,794 ) Interest expense (23,375 ) (5,905 ) (29,280 ) Net foreign exchange gains (losses) (6,190 ) 1,238 (4,952 ) Income before income taxes 511,883 18,434 530,317 Income tax expense (44,452 ) (20 ) (44,472 ) Net income 467,431 18,414 485,845 Dividends attributable to redeemable noncontrolling interests — (4,590 ) (4,590 ) Amounts attributable to nonredeemable noncontrolling interests — (12,301 ) (12,301 ) Net income available to Arch 467,431 1,523 468,954 Preferred dividends (10,403 ) — (10,403 ) Net income available to Arch common shareholders $ 457,028 $ 1,523 $ 458,551 Underwriting Ratios Loss ratio 65.7 % 65.6 % 7.4 % 50.0 % 73.6 % 52.4 % Acquisition expense ratio 15.4 % 15.5 % 9.3 % 13.8 % 19.5 % 14.4 % Other operating expense ratio 18.5 % 9.2 % 11.3 % 14.0 % 10.3 % 13.6 % Combined ratio 99.6 % 90.3 % 28.0 % 77.8 % 103.4 % 80.4 % Goodwill and intangible assets $ 157,440 $ — $ 475,920 $ 633,360 $ 7,650 $ 641,010 (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ Three Months Ended June 30, 2018 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 769,372 $ 490,327 $ 330,990 $ 1,591,202 $ 175,175 $ 1,696,544 Premiums ceded (245,265 ) (136,247 ) (50,867 ) (432,892 ) (34,589 ) (397,648 ) Net premiums written 524,107 354,080 280,123 1,158,310 140,586 1,298,896 Change in unearned premiums 22,342 (13,762 ) 10,355 18,935 18,932 37,867 Net premiums earned 546,449 340,318 290,478 1,177,245 159,518 1,336,763 Other underwriting income (loss) — (129 ) 3,315 3,186 688 3,874 Losses and loss adjustment expenses (357,465 ) (229,956 ) (21,591 ) (609,012 ) (117,141 ) (726,153 ) Acquisition expenses (90,670 ) (50,142 ) (27,737 ) (168,549 ) (34,289 ) (202,838 ) Other operating expenses (92,680 ) (35,678 ) (38,729 ) (167,087 ) (9,094 ) (176,181 ) Underwriting income (loss) $ 5,634 $ 24,413 $ 205,736 235,783 (318 ) 235,465 Net investment income 107,761 27,907 135,668 Net realized gains (losses) (59,545 ) (17,066 ) (76,611 ) Net impairment losses recognized in earnings (470 ) — (470 ) Equity in net income (loss) of investment funds accounted for using the equity method 8,472 — 8,472 Other income (loss) 3,113 — 3,113 Corporate expenses (2) (15,604 ) — (15,604 ) Transaction costs and other (2) (6,908 ) — (6,908 ) Amortization of intangible assets (26,472 ) — (26,472 ) Interest expense (26,058 ) (4,286 ) (30,344 ) Net foreign exchange gains (losses) 46,211 7,495 53,706 Income before income taxes 266,283 13,732 280,015 Income tax expense (23,644 ) (24 ) (23,668 ) Net income 242,639 13,708 256,347 Dividends attributable to redeemable noncontrolling interests — (4,585 ) (4,585 ) Amounts attributable to nonredeemable noncontrolling interests — (8,116 ) (8,116 ) Net income available to Arch 242,639 1,007 243,646 Preferred dividends (10,403 ) — (10,403 ) Net income available to Arch common shareholders $ 232,236 $ 1,007 $ 233,243 Underwriting Ratios Loss ratio 65.4 % 67.6 % 7.4 % 51.7 % 73.4 % 54.3 % Acquisition expense ratio 16.6 % 14.7 % 9.5 % 14.3 % 21.5 % 15.2 % Other operating expense ratio 17.0 % 10.5 % 13.3 % 14.2 % 5.7 % 13.2 % Combined ratio 99.0 % 92.8 % 30.2 % 80.2 % 100.6 % 82.7 % Goodwill and intangible assets $ 20,724 $ — $ 564,634 $ 585,358 $ 7,650 $ 593,008 (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders: Six Months Ended June 30, 2019 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 1,861,879 $ 1,228,402 $ 720,515 $ 3,810,282 $ 348,667 $ 4,015,688 Premiums ceded (612,717 ) (401,024 ) (91,655 ) (1,104,882 ) (83,910 ) (1,045,531 ) Net premiums written 1,249,162 827,378 628,860 2,705,400 264,757 2,970,157 Change in unearned premiums (103,215 ) (113,829 ) 46,825 (170,219 ) 32,655 (137,564 ) Net premiums earned 1,145,947 713,549 675,685 2,535,181 297,412 2,832,593 Other underwriting income (loss) — 5,601 7,912 13,513 1,265 14,778 Losses and loss adjustment expenses (745,895 ) (480,768 ) (37,146 ) (1,263,809 ) (222,266 ) (1,486,075 ) Acquisition expenses (173,918 ) (111,111 ) (64,326 ) (349,355 ) (58,582 ) (407,937 ) Other operating expenses (222,919 ) (69,664 ) (79,694 ) (372,277 ) (27,800 ) (400,077 ) Underwriting income (loss) $ 3,215 $ 57,607 $ 502,431 563,253 (9,971 ) 553,282 Net investment income 244,287 67,700 311,987 Net realized gains (losses) 237,545 24,826 262,371 Net impairment losses recognized in earnings (1,358 ) — (1,358 ) Equity in net income (loss) of investment funds accounted for using the equity method 79,403 — 79,403 Other income (loss) 2,212 — 2,212 Corporate expenses (2) (32,845 ) — (32,845 ) Transaction costs and other (2) (3,368 ) — (3,368 ) Amortization of intangible assets (40,211 ) — (40,211 ) Interest expense (46,857 ) (11,488 ) (58,345 ) Net foreign exchange gains (losses) (1,015 ) (412 ) (1,427 ) Income before income taxes 1,001,046 70,655 1,071,701 Income tax expense (90,338 ) (20 ) (90,358 ) Net income 910,708 70,635 981,343 Dividends attributable to redeemable noncontrolling interests — (9,178 ) (9,178 ) Amounts attributable to nonredeemable noncontrolling interests — (54,683 ) (54,683 ) Net income available to Arch 910,708 6,774 917,482 Preferred dividends (20,806 ) — (20,806 ) Net income available to Arch common shareholders $ 889,902 $ 6,774 $ 896,676 Underwriting Ratios Loss ratio 65.1 % 67.4 % 5.5 % 49.9 % 74.7 % 52.5 % Acquisition expense ratio 15.2 % 15.6 % 9.5 % 13.8 % 19.7 % 14.4 % Other operating expense ratio 19.5 % 9.8 % 11.8 % 14.7 % 9.3 % 14.1 % Combined ratio 99.8 % 92.8 % 26.8 % 78.4 % 103.7 % 81.0 % (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ Six Months Ended June 30, 2018 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 1,592,750 $ 1,067,810 $ 652,168 $ 3,312,807 $ 389,045 $ 3,534,758 Premiums ceded (492,445 ) (331,977 ) (97,004 ) (921,505 ) (68,907 ) (823,318 ) Net premiums written 1,100,305 735,833 555,164 2,391,302 320,138 2,711,440 Change in unearned premiums (15,119 ) (116,343 ) 15,556 (115,906 ) (23,872 ) (139,778 ) Net premiums earned 1,085,186 619,490 570,720 2,275,396 296,266 2,571,662 Other underwriting income (loss) — 1,103 6,731 7,834 1,389 9,223 Losses and loss adjustment expenses (711,195 ) (371,631 ) (65,057 ) (1,147,883 ) (215,130 ) (1,363,013 ) Acquisition expenses (175,839 ) (98,461 ) (54,304 ) (328,604 ) (65,610 ) (394,214 ) Other operating expenses (184,654 ) (71,249 ) (77,500 ) (333,403 ) (17,793 ) (351,196 ) Underwriting income (loss) $ 13,498 $ 79,252 $ 380,590 473,340 (878 ) 472,462 Net investment income 208,004 54,388 262,392 Net realized gains (losses) (171,404 ) (16,205 ) (187,609 ) Net impairment losses recognized in earnings (632 ) — (632 ) Equity in net income (loss) of investment funds accounted for using the equity method 36,541 — 36,541 Other income (loss) 3,187 — 3,187 Corporate expenses (2) (30,086 ) — (30,086 ) Transaction costs and other (2) (7,738 ) — (7,738 ) Amortization of intangible assets (53,208 ) — (53,208 ) Interest expense (51,965 ) (9,015 ) (60,980 ) Net foreign exchange gains (losses) 31,172 2,813 33,985 Income before income taxes 437,211 31,103 468,314 Income tax expense (45,556 ) (27 ) (45,583 ) Net income 391,655 31,076 422,731 Dividends attributable to redeemable noncontrolling interests — (9,170 ) (9,170 ) Amounts attributable to nonredeemable noncontrolling interests — (19,492 ) (19,492 ) Net income available to Arch 391,655 2,414 394,069 Preferred dividends (20,840 ) — (20,840 ) Loss on redemption of preferred shares (2,710 ) — (2,710 ) Net income available to Arch common shareholders $ 368,105 $ 2,414 $ 370,519 Underwriting Ratios Loss ratio 65.5 % 60.0 % 11.4 % 50.4 % 72.6 % 53.0 % Acquisition expense ratio 16.2 % 15.9 % 9.5 % 14.4 % 22.1 % 15.3 % Other operating expense ratio 17.0 % 11.5 % 13.6 % 14.7 % 6.0 % 13.7 % Combined ratio 98.7 % 87.4 % 34.5 % 79.5 % 100.7 % 82.0 % (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2)

Reserve for Losses and Loss Adj

Reserve for Losses and Loss Adjustment Expenses	6 Months Ended
	Jun. 30, 2019
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Reserve for losses and loss adjustment expenses	Reserve for Losses and Loss Adjustment Expenses The following table represents an analysis of losses and loss adjustment expenses and a reconciliation of the beginning and ending reserve for losses and loss adjustment expenses: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Reserve for losses and loss adjustment expenses at beginning of period $ 12,010,041 $ 11,496,205 $ 11,853,297 $ 11,383,792 Unpaid losses and loss adjustment expenses recoverable 2,970,159 2,446,990 2,814,291 2,464,910 Net reserve for losses and loss adjustment expenses at beginning of period 9,039,882 9,049,215 9,039,006 8,918,882 Net incurred losses and loss adjustment expenses relating to losses occurring in: Current year 805,728 790,742 1,563,692 1,478,627 Prior years (38,185 ) (64,589 ) (77,617 ) (115,614 ) Total net incurred losses and loss adjustment expenses 767,543 726,153 1,486,075 1,363,013 Retroactive reinsurance transactions (1) — (420,404 ) (225,500 ) (420,404 ) Net foreign exchange (gains) losses (1,277 ) (120,292 ) (1,781 ) (76,278 ) Net paid losses and loss adjustment expenses relating to losses occurring in: Current year (61,148 ) (59,022 ) (125,488 ) (95,022 ) Prior years (539,481 ) (403,062 ) (966,793 ) (917,603 ) Total net paid losses and loss adjustment expenses (600,629 ) (462,084 ) (1,092,281 ) (1,012,625 ) Net reserve for losses and loss adjustment expenses at end of period 9,205,519 8,772,588 9,205,519 8,772,588 Unpaid losses and loss adjustment expenses recoverable 3,024,797 2,651,749 3,024,797 2,651,749 Reserve for losses and loss adjustment expenses at end of period $ 12,230,316 $ 11,424,337 $ 12,230,316 $ 11,424,337 (1) During the 2019 first quarter and 2018 second quarter, a subsidiary of the Company entered into two separate retroactive reinsurance transactions with third party reinsurers to reinsure run-off liabilities associated with certain U.S. exposures. Development on Prior Year Loss Reserves 2019 Second Quarter During the 2019 second quarter , the Company recorded net favorable development on prior year loss reserves of $38.2 million , which consisted of $2.6 million of favorable development from the insurance segment, $12.7 million from the reinsurance segment, $22.8 million from the mortgage segment and $0.1 million from the ‘other’ segment. The insurance segment’s net favorable development of $2.6 million , or 0.4 loss ratio points, for the 2019 second quarter consisted of $8.0 million of net favorable development in short-tailed lines, $10.4 million of net adverse development in medium-tailed lines and $4.9 million of net favorable development in long-tailed lines. Net favorable development in short-tailed lines primarily resulted from property (including special risk other than marine) reserves across all accident years ( i.e. , the year in which a loss occurred). Net adverse development in medium-tailed lines primarily resulted from $15.5 million of adverse development on program business. Such amounts were partially offset by $5.1 million of net favorable development in other medium-tailed lines, including surety business and professional liability, across most accident years. Net favorable development in long-tailed lines primarily resulted from reductions in executive assurance reserves of $5.1 million , primarily from the 2008 to 2014 accident years. The reinsurance segment’s net favorable development of $12.7 million , or 3.5 loss ratio points, for the 2019 second quarter consisted of $1.8 million of net favorable development from short-tailed lines and $10.9 million of net favorable development from long-tailed and medium-tailed lines. Net favorable development in short-tailed lines primarily resulted from other specialty lines across most underwriting years ( i.e. , all premiums and losses attributable to contracts having an inception or renewal date within the given twelve-month period) and in property other than property catastrophe reserves from earlier underwriting years, partially offset by a small amount of adverse development from property catastrophe and property other than property catastrophe reserves in the 2015 and 2018 underwriting years. Favorable development in long-tailed and medium-tailed lines reflected reductions in casualty and marine reserves from most underwriting years. The mortgage segment’s net favorable development was $22.8 million , or 6.5 loss ratio points, for the 2019 second quarter . The 2019 second quarter development was primarily driven by continued favorable claim rates on first lien business and subrogation recoveries on second lien business. 2018 Second Quarter During the 2018 second quarter , the Company recorded net favorable development on prior year loss reserves of $64.6 million , which consisted of $6.1 million from the insurance segment, $33.0 million from the reinsurance segment, $23.3 million from the mortgage segment and adverse development of $2.2 million from the ‘other’ segment. The insurance segment’s net favorable development of $6.1 million , or 1.1 loss ratio points, for the 2018 second quarter consisted of $13.9 million of net favorable development in short-tailed lines and $14.3 million of net favorable development in long-tailed lines, partially offset by $22.1 million of net adverse development in medium-tailed lines. Net favorable development in short-tailed lines primarily resulted from property (including special risk other than marine) reserves from the 2010 to 2017 accident years while net favorable development in long-tailed lines primarily resulted from reductions in executive assurance reserves of $6.9 million , primarily from the 2007 to 2011 accident years, and in healthcare reserves of $4.9 million , primarily from the 2003 accident year. Net adverse development in medium-tailed lines reflected $11.6 million of adverse development in program business, primarily driven by a few inactive programs that were non-renewed in 2015 and early in 2016 and $18.0 million of adverse development on contract binding business, primarily from the 2014 to 2016 accident years. Such amounts were partially offset by $7.6 million of net favorable development in other medium-tailed lines, including professional liability and surety business, across most accident years. The reinsurance segment’s net favorable development of $33.0 million , or 9.7 loss ratio points, for the 2018 second quarter consisted of $22.2 million from short-tailed lines and $10.8 million from long-tailed and medium-tailed lines. Favorable development in short-tailed lines included $19.3 million from property catastrophe and property other than property catastrophe reserves, across most underwriting years, reflecting lower levels of reported and paid claims activity than previously anticipated which led to decreases in certain loss ratio selections during the period. Favorable development in long-tailed and medium-tailed lines reflected reductions in marine reserves of $3.8 million , across most accident years, and in casualty reserves of $6.9 million based on varying levels of reported and paid claims activity, primarily from the 2003 to 2010 underwriting years. The mortgage segment’s net favorable development was $23.3 million , or 8.0 loss ratio points, for the 2018 second quarter . The 2018 second quarter development was primarily driven by continued lower than expected claim rates on first lien business and subrogation recoveries on second lien business. Six Months Ended June 30, 2019 During the six months ended June 30, 2019 , the Company recorded net favorable development on prior year loss reserves of $77.6 million , which consisted of $7.0 million from the insurance segment, $11.0 million from the reinsurance segment, $59.4 million from the mortgage segment and $0.1 million from the ‘other’ segment. The insurance segment’s net favorable development of $7.0 million , or 0.6 loss ratio points, for the 2019 period consisted of $17.7 million of net favorable development in short-tailed lines and $6.6 million of net favorable development in long-tailed lines, partially offset by $17.3 million of net adverse development in medium-tailed lines. Net favorable development in short-tailed lines primarily resulted from property (including special risk other than marine) reserves from the 2010 to 2018 accident years. Net favorable development in long-tailed lines reflected net reductions in executive assurance reserves of $5.7 million , primarily from the 2013 and 2015 accident years. Net adverse development in medium-tailed lines reflected $23.2 million of adverse development in program business, primarily from the 2018 accident year, and $9.7 million of adverse development on contract binding business, across most accident years. Such amounts were partially offset by $15.6 million of net favorable development in other medium-tailed lines, including professional liability, marine and surety business, across most accident years. The reinsurance segment’s net favorable development of $11.0 million , or 1.5 loss ratio points, for the 2019 period consisted of $4.3 million of net adverse development from short-tailed lines, offset by $15.3 million of net favorable development from long-tailed and medium-tailed lines. Net adverse development in short-tailed lines reflected $17.9 million from property catastrophe and property other than property catastrophe reserves, reflecting an increase in reserves on Typhoon Jebi in the 2019 first quarter of $16.0 million following receipt of updated information from cedents and additional updated industry data. Such amounts were partially offset by $10.2 million of favorable development on other specialty lines, primarily from the 2016 to 2018 underwriting years. Favorable development in long-tailed and medium-tailed lines reflected reductions in casualty reserves of $9.1 million based on varying levels of reported and paid claims activity, primarily from the 2002 to 2007 underwriting years, and favorable development in marine reserves of $6.2 million , primarily from the 2015 to 2018 underwriting years. The mortgage segment’s net favorable development was $59.4 million , or 8.8 loss ratio points, for the 2019 period. The 2019 development was primarily driven by continued lower than expected claim rates on first lien business and subrogation recoveries on second lien business. Six Months Ended June 30, 2018 During the six months ended June 30, 2018 , the Company recorded net favorable development on prior year loss reserves of $115.6 million , which consisted of $8.2 million from the insurance segment, $69.6 million from the reinsurance segment, $36.3 million from the mortgage segment and $1.6 million from the ‘other’ segment. The insurance segment’s net favorable development of $8.2 million , or 0.8 loss ratio points, for the 2018 period consisted of $22.7 million of net favorable development in short-tailed lines and $17.2 million of net favorable development in long-tailed lines, partially offset by $31.7 million of net adverse development in medium-tailed lines. Net favorable development in short-tailed lines primarily resulted from property (including special risk other than marine) reserves from the 2010 and 2017 accident years. Net favorable development in long-tailed lines reflected net reductions in executive assurance reserves of $7.5 million , primarily from the 2008 to 2015 accident years, and in healthcare reserves of $7.0 million , primarily from the 2003 accident year. Net adverse development in medium-tailed lines reflected $21.9 million of adverse development in program business, primarily driven by a few inactive programs that were non-renewed in 2015 and early in 2016 and $25.6 million of adverse development on contract binding business, primarily from the 2014 to 2016 accident years. Such amounts were partially offset by $15.8 million of net favorable development in other medium-tailed lines, including professional liability and surety business, across most accident years. The reinsurance segment’s net favorable development of $69.6 million , or 11.2 loss ratio points, for the 2018 period consisted of $51.1 million from short-tailed lines and $18.5 million from long-tailed and medium-tailed lines. Favorable development in short-tailed lines included $40.4 million from property catastrophe and property other than property catastrophe reserves, across most underwriting years, reflecting lower levels of reported and paid claims activity than previously anticipated which led to decreases in certain loss ratio selections during the period. Favorable development in long-tailed and medium-tailed lines reflected reductions in casualty reserves of $8.1 million based on varying levels of reported and paid claims activity, primarily from the 2002 to 2010 underwriting years, and favorable development in marine reserves of $10.0 million across most underwriting years. The mortgage segment’s net favorable development was $36.3 million , or 6.4 loss ratio points, for the 2018 period. The 2018 development was primarily driven by continued lower than expected claim rates on first lien business and subrogation recoveries on second lien business.

Investment Information

Investment Information	6 Months Ended
	Jun. 30, 2019
Disclosure Investment Information [Abstract]
Investment Information	Investment Information At June 30, 2019 , total investable assets of $23.55 billion included $20.78 billion held by the Company and $2.77 billion attributable to Watford Re. Available For Sale Investments The following table summarizes the fair value and cost or amortized cost of the Company’s securities classified as available for sale: Estimated Fair Value Gross Unrealized Gains Gross Unrealized Losses Cost or Amortized Cost OTTI Unrealized Losses (2) June 30, 2019 Fixed maturities (1): Corporate bonds $ 6,044,081 $ 166,372 $ (19,805 ) $ 5,897,514 $ — Mortgage backed securities 523,019 11,385 (187 ) 511,821 (6 ) Municipal bonds 582,497 21,755 (58 ) 560,800 — Commercial mortgage backed securities 686,707 21,272 (228 ) 665,663 — U.S. government and government agencies 4,906,996 68,017 (2,051 ) 4,841,030 — Non-U.S. government securities 1,928,752 45,881 (36,125 ) 1,918,996 — Asset backed securities 1,636,897 28,133 (3,480 ) 1,612,244 — Total 16,308,949 362,815 (61,934 ) 16,008,068 (6 ) Short-term investments 821,961 284 (480 ) 822,157 — Total $ 17,130,910 $ 363,099 $ (62,414 ) $ 16,830,225 $ (6 ) December 31, 2018 Fixed maturities (1): Corporate bonds $ 5,537,548 $ 14,476 $ (105,428 ) $ 5,628,500 $ (69 ) Mortgage backed securities 541,193 3,991 (3,216 ) 540,418 (6 ) Municipal bonds 1,013,395 5,380 (11,891 ) 1,019,906 — Commercial mortgage backed securities 729,442 2,650 (10,751 ) 737,543 — U.S. government and government agencies 3,758,698 27,189 (8,474 ) 3,739,983 — Non-U.S. government securities 1,771,338 14,477 (50,948 ) 1,807,809 — Asset backed securities 1,600,896 8,060 (14,798 ) 1,607,634 — Total 14,952,510 76,223 (205,506 ) 15,081,793 (75 ) Short-term investments 955,880 36 (394 ) 956,238 — Total $ 15,908,390 $ 76,259 $ (205,900 ) $ 16,038,031 $ (75 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.” (2) Represents the total other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income (“AOCI”). It does not include the change in fair value subsequent to the impairment measurement date. At June 30, 2019 the net unrealized loss related to securities for which a non-credit OTTI was recognized in AOCI was $0.01 million , compared to net unrealized loss of $0.04 million at December 31, 2018 . The following table summarizes, for all available for sale securities in an unrealized loss position, the fair value and gross unrealized loss by length of time the security has been in a continual unrealized loss position: Less than 12 Months 12 Months or More Total Estimated Gross Unrealized Losses Estimated Gross Unrealized Losses Estimated Gross Unrealized Losses June 30, 2019 Fixed maturities (1): Corporate bonds $ 259,361 $ (10,678 ) $ 375,478 $ (9,127 ) $ 634,839 $ (19,805 ) Mortgage backed securities 19,612 (169 ) 261 (18 ) 19,873 (187 ) Municipal bonds — — 12,489 (58 ) 12,489 (58 ) Commercial mortgage backed securities 18,917 (106 ) 23,198 (122 ) 42,115 (228 ) U.S. government and government agencies 906,497 (1,711 ) 104,692 (340 ) 1,011,189 (2,051 ) Non-U.S. government securities 1,092,560 (33,985 ) 124,466 (2,140 ) 1,217,026 (36,125 ) Asset backed securities 312,033 (1,901 ) 130,002 (1,579 ) 442,035 (3,480 ) Total 2,608,980 (48,550 ) 770,586 (13,384 ) 3,379,566 (61,934 ) Short-term investments 53,431 (480 ) — — 53,431 (480 ) Total $ 2,662,411 $ (49,030 ) $ 770,586 $ (13,384 ) $ 3,432,997 $ (62,414 ) December 31, 2018 Fixed maturities (1): Corporate bonds $ 2,983,195 $ (68,910 ) $ 1,234,865 $ (36,518 ) $ 4,218,060 $ (105,428 ) Mortgage backed securities 84,296 (695 ) 109,009 (2,521 ) 193,305 (3,216 ) Municipal bonds 233,081 (2,074 ) 408,155 (9,817 ) 641,236 (11,891 ) Commercial mortgage backed securities 223,341 (2,831 ) 193,956 (7,920 ) 417,297 (10,751 ) U.S. government and government agencies 635,049 (1,354 ) 391,102 (7,120 ) 1,026,151 (8,474 ) Non-U.S. government securities 1,028,340 (35,524 ) 389,671 (15,424 ) 1,418,011 (50,948 ) Asset backed securities 533,592 (8,832 ) 368,095 (5,966 ) 901,687 (14,798 ) Total 5,720,894 (120,220 ) 3,094,853 (85,286 ) 8,815,747 (205,506 ) Short-term investments 122,878 (394 ) — — 122,878 (394 ) Total $ 5,843,772 $ (120,614 ) $ 3,094,853 $ (85,286 ) $ 8,938,625 $ (205,900 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.” At June 30, 2019 , on a lot level basis, approximately 1,690 security lots out of a total of approximately 8,730 security lots were in an unrealized loss position and the largest single unrealized loss from a single lot in the Company’s fixed maturity portfolio was $3.1 million . At December 31, 2018 , on a lot level basis, approximately 5,870 security lots out of a total of approximately 8,450 security lots were in an unrealized loss position and the largest single unrealized loss from a single lot in the Company’s fixed maturity portfolio was $2.6 million . The contractual maturities of the Company’s fixed maturities are shown in the following table. Expected maturities, which are management’s best estimates, will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2019 December 31, 2018 Maturity Estimated Fair Value Amortized Cost Estimated Amortized Cost Due in one year or less $ 414,736 $ 413,481 $ 276,682 $ 279,135 Due after one year through five years 9,833,517 9,702,349 8,666,297 8,738,944 Due after five years through 10 years 3,028,435 2,923,881 2,919,232 2,951,582 Due after 10 years 185,638 178,629 218,768 226,537 13,462,326 13,218,340 12,080,979 12,196,198 Mortgage backed securities 523,019 511,821 541,193 540,418 Commercial mortgage backed securities 686,707 665,663 729,442 737,543 Asset backed securities 1,636,897 1,612,244 1,600,896 1,607,634 Total (1) $ 16,308,949 $ 16,008,068 $ 14,952,510 $ 15,081,793 (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.” Securities Lending Agreements The Company enters into securities lending agreements with financial institutions to enhance investment income whereby it loans certain of its securities to third parties, primarily major brokerage firms, for short periods of time through a lending agent. The Company maintains legal control over the securities it lends, retains the earnings and cash flows associated with the loaned securities and receives a fee from the borrower for the temporary use of the securities. An indemnification agreement with the lending agent protects the Company in the event a borrower becomes insolvent or fails to return any of the securities on loan from the Company. The Company receives collateral in the form of cash or securities. Cash collateral primarily consists of short term investments. At June 30, 2019 , the fair value of the cash collateral received on securities lending was $11.4 million and the fair value of security collateral received was $438.9 million . At December 31, 2018 , the fair value of the cash collateral received on securities lending was $19.0 million , and the fair value of security collateral received was $255.1 million . The Company’s securities lending transactions were accounted for as secured borrowings with significant investment categories as follows: Remaining Contractual Maturity of the Agreements Overnight and Continuous Less than 30 Days 30-90 Days 90 Days or More Total June 30, 2019 U.S. government and government agencies $ 216,856 $ — $ 217,722 $ — $ 434,578 Corporate bonds 2,356 — — — 2,356 Equity securities 13,378 — — — 13,378 Total $ 232,590 $ — $ 217,722 $ — $ 450,312 Gross amount of recognized liabilities for securities lending in offsetting disclosure in note 8 $ — Amounts related to securities lending not included in offsetting disclosure in note 8 $ 450,312 December 31, 2018 U.S. government and government agencies $ 219,276 $ — $ 32,583 $ — $ 251,859 Corporate bonds 7,129 — — — 7,129 Equity securities 15,137 — — — 15,137 Total $ 241,542 $ — $ 32,583 $ — $ 274,125 Gross amount of recognized liabilities for securities lending in offsetting disclosure in note 8 $ — Amounts related to securities lending not included in offsetting disclosure in note 8 $ 274,125 Equity Securities, at Fair Value At June 30, 2019 , the Company held $670.9 million of equity securities, at fair value, compared to $338.9 million at December 31, 2018 . Such holdings include publicly traded common stocks in the natural resources, energy, consumer staples and other sectors and exchange-traded funds. Other Investments The following table summarizes the Company’s other investments which are included in investments accounted for using the fair value option, by strategy: June 30, December 31, Term loan investments (par value: $1,427,330 and $1,369,216) $ 1,341,445 $ 1,282,287 Lending 585,954 524,112 Credit related funds 166,673 202,123 Energy 123,547 117,509 Investment grade fixed income 86,808 101,902 Infrastructure 49,260 45,371 Private equity 23,925 24,383 Real estate 16,906 14,252 Total $ 2,394,518 $ 2,311,939 Investments Accounted For Using the Equity Method The following table summarizes the Company’s investments accounted for using the equity method, by strategy: June 30, December 31, Credit related funds $ 436,118 $ 429,402 Equities 324,525 375,273 Real estate 251,891 232,647 Lending 193,397 125,041 Private equity 131,863 114,019 Infrastructure 141,744 113,748 Energy 102,434 103,661 Total $ 1,581,972 $ 1,493,791 Certain of the Company’s other investments are in investment funds for which the Company has the option to redeem at agreed upon values as described in each investment fund’s subscription agreement. Depending on the terms of the various subscription agreements, investments in investment funds may be redeemed daily, monthly, quarterly or on other terms. Two common redemption restrictions which may impact the Company’s ability to redeem these investment funds are gates and lockups. A gate is a suspension of redemptions which may be implemented by the general partner or investment manager of the fund in order to defer, in whole or in part, the redemption request in the event the aggregate amount of redemption requests exceeds a predetermined percentage of the investment fund’s net assets which may otherwise hinder the general partner or investment manager’s ability to liquidate holdings in an orderly fashion in order to generate the cash necessary to fund extraordinarily large redemption payouts. A lockup period is the initial amount of time an investor is contractually required to hold the security before having the ability to redeem. If the investment funds are eligible to be redeemed, the time to redeem such fund can take weeks or months following the notification. Fair Value Option The following table summarizes the Company’s assets which are accounted for using the fair value option: June 30, December 31, Fixed maturities $ 965,161 $ 1,245,562 Other investments 2,394,518 2,311,939 Short-term investments 257,465 322,177 Equity securities 103,891 103,893 Investments accounted for using the fair value option $ 3,721,035 $ 3,983,571 Limited Partnership Interests In the normal course of its activities, the Company invests in limited partnerships as part of its overall investment strategy. Such amounts are included in ‘investments accounted for using the equity method’ and ‘investments accounted for using the fair value option.’ The Company has determined that it is not required to consolidate these investments because it is not the primary beneficiary of the funds. The Company’s maximum exposure to loss with respect to these investments is limited to the investment carrying amounts reported in the Company’s consolidated balance sheet and any unfunded commitment. The following table summarizes investments in limited partnership interests where the Company has a variable interest by balance sheet line item: June 30, December 31, Investments accounted for using the equity method (1) 1,581,972 1,493,791 Investments accounted for using the fair value option (2) 178,977 162,398 Total $ 1,760,949 $ 1,656,189 (1) Aggregate unfunded commitments were $1.41 billion at June 30, 2019 , compared to $1.22 billion at December 31, 2018 . (2) Aggregate unfunded commitments were $63.6 million at June 30, 2019 , compared to $117.5 million at December 31, 2018 . Net Investment Income The components of net investment income were derived from the following sources: June 30, 2019 2018 Three Months Ended Fixed maturities $ 125,018 $ 115,110 Term loans 24,730 20,763 Equity securities 4,368 4,777 Short-term investments 3,859 4,392 Other (1) 18,523 17,405 Gross investment income 176,498 162,447 Investment expenses (21,460 ) (26,779 ) Net investment income $ 155,038 $ 135,668 Six Months Ended Fixed maturities $ 254,817 $ 222,997 Term loans 49,346 40,527 Equity securities 7,356 7,345 Short-term investments 8,038 9,252 Other (1) 39,719 35,015 Gross investment income 359,276 315,136 Investment expenses (47,289 ) (52,744 ) Net investment income $ 311,987 $ 262,392 (1) Includes income distributions from investment funds and other items. Net Realized Gains (Losses) Net realized gains (losses) were as follows, excluding net impairment losses recognized in earnings: June 30, 2019 2018 Three Months Ended Available for sale securities: Gross gains on investment sales $ 75,090 $ 18,777 Gross losses on investment sales (15,281 ) (57,711 ) Change in fair value of assets and liabilities accounted for using the fair value option: Fixed maturities 11,429 (22,927 ) Other investments (33,780 ) (254 ) Equity securities 6,414 1,230 Short-term investments (1,392 ) (136 ) Equity securities, at fair value: Net realized gains (losses) on sales during the period (6,644 ) (5,918 ) Net unrealized gains (losses) on equity securities still held at reporting date 22,632 (7,278 ) Derivative instruments (1) 63,966 (2,146 ) Other (2) (1,628 ) (248 ) Net realized gains (losses) $ 120,806 $ (76,611 ) Six Months Ended Available for sale securities: Gross gains on investment sales $ 118,455 $ 33,742 Gross losses on investment sales (46,937 ) (140,262 ) Change in fair value of assets and liabilities accounted for using the fair value option: Fixed maturities 42,577 (40,478 ) Other investments (15,585 ) (6,628 ) Equity securities 10,680 7,898 Short-term investments (672 ) (287 ) Equity securities, at fair value: Net realized gains (losses) on sales during the period 4,286 (11,286 ) Net unrealized gains (losses) on equity securities still held at reporting date 59,768 (14,861 ) Derivative instruments (1) 99,837 (6,109 ) Other (2) (10,038 ) (9,338 ) Net realized gains (losses) $ 262,371 $ (187,609 ) (1) See note 8 for information on the Company’s derivative instruments. (2) Includes the re-measurement of contingent consideration liability amounts. Equity in Net Income (Loss) of Investment Funds Accounted for Using the Equity Method The Company recorded $32.5 million of equity in net income related to investment funds accounted for using the equity method in the 2019 second quarter , compared to $8.5 million for the 2018 second quarter , and $79.4 million for the six months ended June 30, 2019 , compared to $36.5 million for the 2018 period. In applying the equity method, investments are initially recorded at cost and are subsequently adjusted based on the Company’s proportionate share of the net income or loss of the funds (which include changes in the market value of the underlying securities in the funds). Such investments are generally recorded on a one to three month lag based on the availability of reports from the investment funds. Net Impairment Losses Recognized in Earnings The Company performs quarterly reviews of its available for sale investments in order to determine whether declines in fair value below the amortized cost basis were considered other-than-temporary in accordance with applicable guidance. The following table details the net impairment losses recognized in earnings by asset class: June 30, 2019 2018 Three Months Ended Fixed maturities: Mortgage backed securities $ (24 ) $ (81 ) Corporate bonds (25 ) (241 ) Asset backed securities — (148 ) Total (49 ) (470 ) Net impairment losses recognized in earnings $ (49 ) $ (470 ) Six Months Ended Fixed maturities: Mortgage backed securities $ (555 ) $ (123 ) Corporate bonds (590 ) (361 ) Asset backed securities (213 ) (148 ) Total (1,358 ) (632 ) Net impairment losses recognized in earnings $ (1,358 ) $ (632 ) Net impairment losses recognized in earnings in the 2019 periods were primarily related to foreign currency fluctuations and other impairments on corporate bonds and other securities. The Company believes that the minimal amount of OTTI included in accumulated other comprehensive income at June 30, 2019 on the securities which were considered by the Company to be impaired was due to market and sector-related factors ( i.e. , not credit losses). At June 30, 2019 , the Company did not intend to sell these securities, or any other securities which were in an unrealized loss position, and determined that it is more likely than not that the Company will not be required to sell such securities before recovery of their cost basis. The following table provides a roll forward of the amount related to credit losses recognized in earnings for which a portion of an OTTI was recognized in accumulated other comprehensive income: June 30, 2019 2018 Three Months Ended Balance at start of period $ 346 $ 767 Credit loss impairments recognized on securities not previously impaired — — Credit loss impairments recognized on securities previously impaired — — Reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security — — Reductions for securities sold during the period — (69 ) Balance at end of period $ 346 $ 698 Six Months Ended Balance at start of year $ 637 $ 767 Credit loss impairments recognized on securities not previously impaired — — Credit loss impairments recognized on securities previously impaired — — Reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security — — Reductions for securities sold during the period (291 ) (69 ) Balance at end of period $ 346 $ 698 Restricted Assets The Company is required to maintain assets on deposit, which primarily consist of fixed maturities, with various regulatory authorities to support its underwriting operations. The Company’s subsidiaries maintain assets in trust accounts as collateral for transactions with affiliated companies and also have investments in segregated portfolios primarily to provide collateral or guarantees for letters of credit to third parties. See note 16, “Commitments and Contingencies,” of the notes to consolidated financial statements in the Company’s 2018 Form 10-K. The following table details the value of the Company’s restricted assets: June 30, December 31, Assets used for collateral or guarantees: Affiliated transactions $ 4,758,653 $ 4,623,483 Third party agreements 2,612,380 2,181,682 Deposits with U.S. regulatory authorities 788,750 689,114 Deposits with non-U.S. regulatory authorities 62,449 59,624 Total restricted assets $ 8,222,232 $ 7,553,903 In addition, Watford Re maintains a secured credit facility to provide borrowing capacity for investment purposes and a total return swap agreement and maintains assets pledged as collateral for such purposes. The Company does not guarantee or provide credit support for Watford Re, and the Company’s financial exposure to Watford Re is limited to its investment in Watford Re’s senior notes, common and preferred shares and counterparty credit risk (mitigated by collateral) arising from reinsurance transactions. As of June 30, 2019 and December 31, 2018 Watford Re held $1.1 billion and $1.3 billion , respectively, in pledged assets to collateralize Watford Re’s credit facility mentioned above. Reconciliation of Cash and Restricted Cash The following table details reconciliation of cash and restricted cash within the Consolidated Balance Sheets: June 30, December 31, Cash $ 605,316 $ 646,556 Restricted cash (included in ‘other assets’) $ 77,759 $ 78,087 Cash and restricted cash $ 683,075 $ 724,643

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Accounting guidance regarding fair value measurements addresses how companies should measure fair value when they are required to use a fair value measure for recognition or disclosure purposes under GAAP and provides a common definition of fair value to be used throughout GAAP. It defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly fashion between market participants at the measurement date. In addition, it establishes a three-level valuation hierarchy for the disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The level in the hierarchy within which a given fair value measurement falls is determined based on the lowest level input that is significant to the measurement (Level 1 being the highest priority and Level 3 being the lowest priority). The levels in the hierarchy are defined as follows: Level 1: Inputs to the valuation methodology are observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets Level 2: Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument Level 3: Inputs to the valuation methodology are unobservable and significant to the fair value measurement Following is a description of the valuation methodologies used for securities measured at fair value, as well as the general classification of such securities pursuant to the valuation hierarchy. The Company reviews its securities measured at fair value and discusses the proper classification of such investments with investment advisers and others. The Company determines the existence of an active market based on its judgment as to whether transactions for the financial instrument occur in such market with sufficient frequency and volume to provide reliable pricing information. The independent pricing sources obtain market quotations and actual transaction prices for securities that have quoted prices in active markets. The Company uses quoted values and other data provided by nationally recognized independent pricing sources as inputs into its process for determining fair values of its fixed maturity investments. To validate the techniques or models used by pricing sources, the Company's review process includes, but is not limited to: (i) quantitative analysis ( e.g., comparing the quarterly return for each managed portfolio to its target benchmark, with significant differences identified and investigated); (ii) a review of the average number of prices obtained in the pricing process and the range of resulting fair values; (iii) initial and ongoing evaluation of methodologies used by outside parties to calculate fair value; (iv) a comparison of the fair value estimates to the Company’s knowledge of the current market; (v) a comparison of the pricing services' fair values to other pricing services' fair values for the same investments; and (vi) periodic back-testing, which includes randomly selecting purchased or sold securities and comparing the executed prices to the fair value estimates from the pricing service. A price source hierarchy was maintained in order to determine which price source would be used (i.e. , a price obtained from a pricing service with more seniority in the hierarchy will be used over a less senior one in all cases). The hierarchy prioritizes pricing services based on availability and reliability and assigns the highest priority to index providers. Based on the above review, the Company will challenge any prices for a security or portfolio which are considered not to be representative of fair value. The Company did not adjust any of the prices obtained from the independent pricing sources at June 30, 2019 . In certain circumstances, when fair values are unavailable from these independent pricing sources, quotes are obtained directly from broker-dealers who are active in the corresponding markets. Such quotes are subject to the validation procedures noted above. Of the $21.66 billion of financial assets and liabilities measured at fair value at June 30, 2019 , approximately $183.8 million , or 0.9% , were priced using non-binding broker-dealer quotes. Of the $20.41 billion of financial assets and liabilities measured at fair value at December 31, 2018 , approximately $217.9 million , or 1.1% , were priced using non-binding broker-dealer quotes. Fixed maturities The Company uses the market approach valuation technique to estimate the fair value of its fixed maturity securities, when possible. The market approach includes obtaining prices from independent pricing services, such as index providers and pricing vendors, as well as to a lesser extent quotes from broker-dealers. The independent pricing sources obtain market quotations and actual transaction prices for securities that have quoted prices in active markets. Each source has its own proprietary method for determining the fair value of securities that are not actively traded. In general, these methods involve the use of “matrix pricing” in which the independent pricing source uses observable market inputs including, but not limited to, investment yields, credit risks and spreads, benchmarking of like securities, broker-dealer quotes, reported trades and sector groupings to determine a reasonable fair value. The following describes the significant inputs generally used to determine the fair value of the Company’s fixed maturity securities by asset class: • U.S. government and government agencies — valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The Company determined that all U.S. Treasuries would be classified as Level 1 securities due to observed levels of trading activity, the high number of strongly correlated pricing quotes received on U.S. Treasuries and other factors. The fair values of U.S. government agency securities are generally determined using the spread above the risk-free yield curve. As the yields for the risk-free yield curve and the spreads for these securities are observable market inputs, the fair values of U.S. government agency securities are classified within Level 2. • Corporate bonds — valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined using the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. As the significant inputs used in the pricing process for corporate bonds are observable market inputs, the fair value of these securities are classified within Level 2. A small number of securities are included in Level 3 due to a low level of transparency on the inputs used in the pricing process. During the 2019 second quarter, the Company transferred $23.9 million of corporate bonds from Level 2 to Level 3 based on a review of the pricing of such securities, as described above. • Mortgage-backed securities — valuations provided by independent pricing services, substantially all through pricing vendors and index providers with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models (including Option Adjusted Spread) which use spreads to determine the expected average life of the securities. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for mortgage-backed securities are observable market inputs, the fair value of these securities are classified within Level 2. A small number of securities are included in Level 3 due to a low level of transparency on the inputs used in the pricing process. • Municipal bonds — valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The fair values of these securities are generally determined using spreads obtained from broker-dealers who trade in the relevant security market, trade prices and the new issue market. As the significant inputs used in the pricing process for municipal bonds are observable market inputs, the fair value of these securities are classified within Level 2. • Commercial mortgage-backed securities — valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models which use spreads to determine the appropriate average life of the securities. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for commercial mortgage-backed securities are observable market inputs, the fair value of these securities are classified within Level 2. • Non-U.S. government securities — valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The fair values of these securities are generally based on international indices or valuation models which include daily observed yield curves, cross-currency basis index spreads and country credit spreads. As the significant inputs used in the pricing process for non-U.S. government securities are observable market inputs, the fair value of these securities are classified within Level 2. • Asset-backed securities — valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models (including Option Adjusted Spread) which use spreads to determine the appropriate average life of the securities. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for asset-backed securities are observable market inputs, the fair value of these securities are classified within Level 2. Equity securities The Company determined that exchange-traded equity securities would be included in Level 1 as their fair values are based on quoted market prices in active markets. Other equity securities are included in Level 2 of the valuation hierarchy. A small number of securities are included in Level 3 due to the lack of an available independent price source for such securities. As the significant inputs used to price these securities are unobservable, the fair value of such securities are classified as Level 3. During the 2019 second quarter, the Company transferred $107.4 million of equity securities from Level 2 to Level 3 based on a review of the pricing of such securities, as described above. Other investments The Company determined that exchange-traded investments in mutual funds would be included in Level 1 as their fair values are based on quoted market prices in active markets. Other investments also include term loan investments for which fair values are estimated by using quoted prices of term loan investments with similar characteristics, pricing models or matrix pricing. Such investments are generally classified within Level 2. The fair values for certain of the Company’s other investments are determined using net asset values as advised by external fund managers. The net asset value is based on the fund manager’s valuation of the underlying holdings in accordance with the fund’s governing documents. In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. A small number of securities are included in Level 3 due to the lack of an available independent price source for such securities. During the 2019 second quarter, the Company transferred $44.6 million of other investments from Level 2 to Level 3 based on a review of the pricing of such securities, as described above. Derivative instruments The Company’s futures contracts, foreign currency forward contracts, interest rate swaps and other derivatives trade in the over-the-counter derivative market. The Company uses the market approach valuation technique to estimate the fair value for these derivatives based on significant observable market inputs from third party pricing vendors, non-binding broker-dealer quotes and/or recent trading activity. As the significant inputs used in the pricing process for these derivative instruments are observable market inputs, the fair value of these securities are classified within Level 2. Short-term investments The Company determined that certain of its short-term investments held in highly liquid money market-type funds, Treasury bills and commercial paper would be included in Level 1 as their fair values are based on quoted market prices in active markets. The fair values of other short-term investments are generally determined using the spread above the risk-free yield curve and are classified within Level 2. Contingent consideration liabilities Contingent consideration liabilities (included in ‘other liabilities’ in the consolidated balance sheets) include amounts related to the acquisition of CMG Mortgage Insurance Company and its affiliated mortgage insurance companies and other acquisitions. Such amounts are remeasured at fair value at each balance sheet date with changes in fair value recognized in ‘net realized gains (losses).’ To determine the fair value of contingent consideration liabilities, the Company estimates future payments using an income approach based on modeled inputs which include a weighted average cost of capital. The Company determined that contingent consideration liabilities would be included within Level 3. The following table presents the Company’s financial assets and liabilities measured at fair value by level at June 30, 2019 : Estimated Fair Value Measurements Using: Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured at fair value (1): Available for sale securities: Fixed maturities: Corporate bonds $ 6,044,081 $ — $ 6,036,439 $ 7,642 Mortgage backed securities 523,019 — 522,729 290 Municipal bonds 582,497 — 582,497 — Commercial mortgage backed securities 686,707 — 686,707 — U.S. government and government agencies 4,906,996 4,746,260 160,736 — Non-U.S. government securities 1,928,752 — 1,928,752 — Asset backed securities 1,636,897 — 1,636,897 — Total 16,308,949 4,746,260 11,554,757 7,932 Short-term investments 821,961 803,337 18,624 — Equity securities, at fair value 684,236 620,508 12,516 51,212 Derivative instruments (4) 30,653 — 30,653 — Fair value option: Corporate bonds 673,431 — 647,328 26,103 Non-U.S. government bonds 56,416 — 56,416 — Mortgage backed securities 16,076 — 16,076 — Municipal bonds 6,731 — 6,731 — Commercial mortgage backed securities — — — — Asset backed securities 208,019 — 208,019 — U.S. government and government agencies 4,488 4,378 110 — Short-term investments 257,465 247,216 10,249 — Equity securities 103,891 47,157 589 56,145 Other investments 1,394,344 41,176 1,257,895 95,273 Other investments measured at net asset value (2) 1,000,174 Total 3,721,035 339,927 2,203,413 177,521 Total assets measured at fair value $ 21,566,834 $ 6,510,032 $ 13,819,963 $ 236,665 Liabilities measured at fair value: Contingent consideration liabilities $ (7,825 ) $ — $ — $ (7,825 ) Securities sold but not yet purchased (3) (48,823 ) — (48,823 ) — Derivative instruments (4) (38,363 ) — (38,363 ) — Total liabilities measured at fair value $ (95,011 ) $ — $ (87,186 ) $ (7,825 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See note 6 , “—Securities Lending Agreements.” (2) In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (3) Represents the Company’s obligations to deliver securities that it did not own at the time of sale. Such amounts are included in “other liabilities” on the Company’s consolidated balance sheets. (4) See note 8 . The following table presents the Company’s financial assets and liabilities measured at fair value by level at December 31, 2018 : Estimated Fair Value Measurements Using: Estimated Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured at fair value (1): Available for sale securities: Fixed maturities: Corporate bonds $ 5,537,548 $ — $ 5,529,407 $ 8,141 Mortgage backed securities 541,193 — 540,884 309 Municipal bonds 1,013,395 — 1,013,395 — Commercial mortgage backed securities 729,442 — 729,438 4 U.S. government and government agencies 3,758,698 3,657,181 101,517 — Non-U.S. government securities 1,771,338 — 1,771,338 — Asset backed securities 1,600,896 — 1,600,896 — Total 14,952,510 3,657,181 11,286,875 8,454 Equity securities 353,794 321,927 31,867 — Short-term investments 955,880 875,881 79,999 — Derivative instruments (4) 73,893 — 73,893 — Fair value option: Corporate bonds 852,585 — 846,827 5,758 Non-U.S. government bonds 79,066 — 79,066 — Mortgage backed securities 16,731 — 16,731 — Municipal bonds 7,144 — 7,144 — Commercial mortgage backed securities — — — — Asset backed securities 178,790 — 178,790 — U.S. government and government agencies 111,246 111,138 108 — Short-term investments 322,177 278,579 43,598 — Equity securities 103,893 48,827 55,066 — Other investments 1,254,220 39,107 1,152,408 62,705 Other investments measured at net asset value (2) 1,057,719 Total 3,983,571 477,651 2,379,738 68,463 Total assets measured at fair value $ 20,319,648 $ 5,332,640 $ 13,852,372 $ 76,917 Liabilities measured at fair value: Contingent consideration liabilities $ (66,665 ) $ — $ — $ (66,665 ) Securities sold but not yet purchased (3) (7,790 ) — (7,790 ) — Derivative instruments (4) (20,664 ) — (20,664 ) — Total liabilities measured at fair value $ (95,119 ) $ — $ (28,454 ) $ (66,665 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See note 6 , “—Securities Lending Agreements.” (2) In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (3) Represents the Company’s obligations to deliver securities that it did not own at the time of sale. Such amounts are included in “other liabilities” on the Company’s consolidated balance sheets. (4) See note 8 . The following table presents a reconciliation of the beginning and ending balances for all financial assets and liabilities measured at fair value on a recurring basis using Level 3 inputs: Assets Liabilities s Available For Sale Fair Value Option Fair Value Structured Securities (1) Corporate Corporate Other Investments Equity Securities Equity Securities Contingent Consideration Liabilities Three Months Ended June 30, 2019 Balance at beginning of period $ 302 $ 7,567 $ 2,233 $ 62,329 $ — $ — $ (68,121 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) — — (49 ) (11,614 ) — — (423 ) Included in other comprehensive income 1 102 — — — — — Purchases, issuances, sales and settlements Purchases — 429 — — — — — Issuances — — — — — — — Sales — — — (74 ) — — — Settlements (13 ) (456 ) — — — — 60,719 Transfers in and/or out of Level 3 — — 23,919 44,632 56,145 51,212 — Balance at end of period $ 290 $ 7,642 $ 26,103 $ 95,273 $ 56,145 $ 51,212 $ (7,825 ) Three Months Ended June 30, 2018 Balance at beginning of period $ 5,413 $ 9,152 $ 11,872 $ 58,452 $ — $ — $ (62,449 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 3 — (537 ) 336 — — (1,481 ) Included in other comprehensive income (4 ) (316 ) — — — — — Purchases, issuances, sales and settlements Purchases — 393 — — — — — Issuances — — — — — — — Sales (5,003 ) — — (74 ) — — — Settlements (33 ) (456 ) — (500 ) — — — Transfers in and/or out of Level 3 — — — — — — — Balance at end of period $ 376 $ 8,773 $ 11,335 $ 58,214 $ — $ — $ (63,930 ) Six Months Ended June 30, 2019 Balance at beginning of year $ 313 $ 8,141 $ 5,758 $ 62,705 $ — $ — $ (66,665 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 1,757 — (339 ) (11,316 ) — — (1,331 ) Included in other comprehensive income 5 (16 ) — — — — — Purchases, issuances, sales and settlements Purchases — 429 — — — — — Issuances — — — — — — (548 ) Sales (1,757 ) — (3,235 ) (148 ) — — — Settlements (28 ) (912 ) — (600 ) — — 60,719 Transfers in and/or out of Level 3 — — 23,919 44,632 56,145 51,212 — Balance at end of period $ 290 $ 7,642 $ 26,103 $ 95,273 $ 56,145 $ 51,212 $ (7,825 ) Six Months Ended June 30, 2018 Balance at beginning of year $ 5,927 $ 9,460 $ 12,217 $ 59,167 $ — $ — $ (60,996 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 4 — (612 ) (379 ) — — (2,934 ) Included in other comprehensive income (8 ) (168 ) — — — — — Purchases, issuances, sales and settlements Purchases — 393 — — — — — Issuances — — — — — — — Sales (5,003 ) — — (74 ) — — — Settlements (544 ) (912 ) (270 ) (500 ) — — — Transfers in and/or out of Level 3 — — — — — — — Balance at end of period $ 376 $ 8,773 $ 11,335 $ 58,214 $ — $ — $ (63,930 ) (1) Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities. (2) Gains or losses were included in net realized gains (losses). Financial Instruments Disclosed, But Not Carried, At Fair Value The Company uses various financial instruments in the normal course of its business. The carrying values of cash, accrued investment income, receivable for securities sold, certain other assets, payable for securities purchased and certain other liabilities approximated their fair values at June 30, 2019 , due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 2. At June 30, 2019 , the Company’s senior notes were carried at their cost, net of debt issuance costs, of $1.73 billion and had a fair value of $2.09 billion . At December 31, 2018 , Company’s senior notes were carried at their cost, net of debt issuance costs, of $1.73 billion and had a fair value of $1.88 billion . The fair values of the senior notes were obtained from a third party pricing service and are based on observable market inputs. As such, the fair values of the senior notes are classified within Level 2.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company’s investment strategy allows for the use of derivative instruments. The Company’s derivative instruments are recorded on its consolidated balance sheets at fair value. The Company utilizes exchange traded U.S. Treasury note, Eurodollar and other futures contracts and commodity futures to manage portfolio duration or replicate investment positions in its portfolios and the Company routinely utilizes foreign currency forward contracts, currency options, index futures contracts and other derivatives as part of its total return objective. In addition, certain of the Company’s investments are managed in portfolios which incorporate the use of foreign currency forward contracts which are intended to provide an economic hedge against foreign currency movements. In addition, the Company purchases to-be-announced mortgage backed securities (“TBAs”) as part of its investment strategy. TBAs represent commitments to purchase a future issuance of agency mortgage backed securities. For the period between purchase of a TBA and issuance of the underlying security, the Company’s position is accounted for as a derivative. The Company purchases TBAs in both long and short positions to enhance investment performance and as part of its overall investment strategy. The following table summarizes information on the fair values and notional values of the Company’s derivative instruments: Estimated Fair Value Asset Derivatives Liability Derivatives Notional Value (1) June 30, 2019 Futures contracts (2) $ 5,438 $ (1,586 ) $ 4,354,852 Foreign currency forward contracts (2) 3,190 (10,352 ) 939,940 TBAs (3) 15,509 — 14,846 Other (2) 22,025 (26,425 ) 3,493,526 Total $ 46,162 $ (38,363 ) December 31, 2018 Futures contracts (2) $ 51,800 $ (2,115 ) $ 3,153,518 Foreign currency forward contracts (2) 8,147 (7,796 ) 1,008,907 TBAs (3) 8,292 — 8,132 Other (2) 13,946 (10,753 ) 2,213,981 Total $ 82,185 $ (20,664 ) (1) Represents the absolute notional value of all outstanding contracts, consisting of long and short positions. (2) The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’ (3) The fair value of TBAs are included in ‘fixed maturities available for sale, at fair value.’ The Company did not hold any derivatives which were designated as hedging instruments at June 30, 2019 or December 31, 2018 . The Company’s derivative instruments can be traded under master netting agreements, which establish terms that apply to all derivative transactions with a counterparty. In the event of a bankruptcy or other stipulated event of default, such agreements provide that the non-defaulting party may elect to terminate all outstanding derivative transactions, in which case all individual derivative positions (loss or gain) with a counterparty are closed out and netted and replaced with a single amount, usually referred to as the termination amount, which is expressed in a single currency. The resulting single net amount, where positive, is payable to the party “in-the-money” regardless of whether or not it is the defaulting party, unless the parties have agreed that only the non-defaulting party is entitled to receive a termination payment where the net amount is positive and is in its favor. Contractual close-out netting reduces derivatives credit exposure from gross to net exposure. The remaining derivatives included in the table above were not subject to a master netting agreement. At June 30, 2019 , asset derivatives and liability derivatives of $46.2 million and $38.4 million , respectively, were subject to a master netting agreement, compared to $80.4 million and $18.9 million , respectively, at December 31, 2018 . The remaining derivatives included in the preceding table were not subject to a master netting agreement. Realized and unrealized contract gains and losses on the Company’s derivative instruments are reflected in ‘net realized gains (losses)’ in the consolidated statements of income, as summarized in the following table: Derivatives not designated as June 30, hedging instruments: 2019 2018 Three Months Ended Net realized gains (losses): Futures contracts $ 66,973 $ (240 ) Foreign currency forward contracts (5,365 ) (1,692 ) TBAs 48 — Other 2,310 (214 ) Total $ 63,966 $ (2,146 ) Six Months Ended Net realized gains (losses): Futures contracts $ 94,309 $ 4,790 Foreign currency forward contracts (19,074 ) (7,616 ) TBAs 238 (97 ) Other 24,364 (3,186 ) Total $ 99,837 $ (6,109 )

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Investment Commitments The Company’s investment commitments, which are primarily related to agreements entered into by the Company to invest in funds and separately managed accounts when called upon, were approximately $1.92 billion at June 30, 2019 , compared to $1.77 billion at December 31, 2018 . Interest Paid Interest paid on the Company’s senior notes and other borrowings were $60.9 million for the six months ended June 30, 2019 , consistent with $60.9 million for the 2018

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	Leases In the ordinary course of business, the Company renews and enters into new leases for office property and equipment. At the lease inception date, the Company determines whether a contract contains a lease and its classification as a finance or operating lease. Primarily all of the Company’s leases are classified as operating leases. The Company’s operating leases have remaining lease terms of up to 12 years , some of which include options to extend the lease term. The Company considers these options when determining the lease term and measuring its lease liability and right-of-use asset. In addition, the Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants. Short-term operating leases with an initial term of twelve months or less were excluded on the Company's consolidated balance sheet and represent an inconsequential amount of operating lease expense. As most leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Additional information regarding the Company’s operating leases is as follows: June 30, 2019 Three Months Ended Operating lease costs $ 7,244 Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 7,685 Right-of-use assets obtained in exchange for new lease liabilities $ 4,420 Right-of-use assets (1) $ 134,061 Operating lease liability (1) $ 150,341 Weighted average discount rate 3.9 % Weighted average remaining lease term 6.5 years Six Months Ended Operating lease costs $ 14,860 Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 14,585 Right-of-use assets obtained in exchange for new lease liabilities $ 4,420 Right-of-use assets (1) $ 134,061 Operating lease liability (1) $ 150,341 Weighted average discount rate 3.9 % Weighted average remaining lease term 6.5 years (1) The right-of-use assets are included in ‘other assets’ while the operating lease liability is included in ‘other liabilities.’ The following table presents the contractual maturities of the Company's operating lease liabilities at June 30, 2019 : Years Ending December 31, 2019 (remainder) $ 9,985 2020 32,036 2021 30,673 2022 27,365 2023 22,667 2024 and thereafter 55,610 Total undiscounted lease liability $ 178,336 Less: present value adjustment (27,995 ) Operating lease liability $ 150,341 At December 31, 2018 , the future minimum rental commitments, exclusive of escalation clauses and maintenance costs and net of rental income, for all of the Company’s operating leases was as follows: 2019 $ 31,088 2020 30,491 2021 29,351 2022 26,068 2023 21,408 2024 and thereafter 54,745 Total $ 193,151

Variable Interest Entities and

Variable Interest Entities and Noncontrolling Interests	6 Months Ended
	Jun. 30, 2019
Noncontrolling Interest [Abstract]
Variable Interest Entity and Noncontrolling Interests	Variable Interest Entities and Noncontrolling Interests Watford Holdings Ltd. In March 2014, the Company invested $100.0 million and acquired 2,500,000 common shares, approximately 11% of Watford Holdings Ltd.’s outstanding common equity, and a warrant to purchase up to 975,503 additional common shares. The warrants expire on March 31, 2020. The exercise price of the warrants is determined on the date of exercise based on certain targeted returns for existing common shareholders. Watford Holdings Ltd.’s common shares are listed on the Nasdaq Select Global Market under the ticker symbol “WTRE”. Watford Re is considered a VIE and the Company concluded that it is the primary beneficiary of Watford Re. As such, the results of Watford Re are included in the Company’s consolidated financial statements. The Company does not guarantee or provide credit support for Watford Re, and the Company’s financial exposure to Watford Re is limited to its investment in Watford Re’s senior notes, common and preferred shares and counterparty credit risk (mitigated by collateral) arising from reinsurance transactions. The following table provides the carrying amount and balance sheet caption in which the assets and liabilities of Watford Re are reported: June 30, December 31, 2019 2018 Assets Investments accounted for using the fair value option $ 1,972,947 $ 2,312,003 Fixed maturities available for sale, at fair value 732,454 393,351 Equity securities, at fair value 64,703 32,206 Cash 68,977 63,529 Accrued investment income 16,916 19,461 Premiums receivable 228,588 227,301 Reinsurance recoverable on unpaid and paid losses and LAE 123,961 86,445 Ceded unearned premiums 79,513 61,587 Deferred acquisition costs 71,557 80,858 Receivable for securities sold 29,425 24,507 Goodwill and intangible assets 7,650 7,650 Other assets 71,837 63,959 Total assets of consolidated VIE $ 3,468,528 $ 3,372,857 Liabilities Reserve for losses and loss adjustment expenses $ 1,126,080 $ 1,032,760 Unearned premiums 375,323 390,114 Reinsurance balances payable 23,312 21,034 Revolving credit agreement borrowings 491,006 455,682 Payable for securities purchased 51,216 60,142 Other liabilities (1) 219,120 302,524 Total liabilities of consolidated VIE $ 2,286,057 $ 2,262,256 Redeemable noncontrolling interests $ 221,175 $ 220,992 (1) Includes certain borrowings related to investing activities. For the six months ended June 30, 2019 , Watford Re generated $115.9 million of cash provided by operating activities, $135.7 million of cash used for investing activities and $25.6 million of cash provided by financing activities, compared to $92.4 million of cash provided by operating activities, $168.0 million of cash used for investing activities and $2.1 million of cash used for financing activities for the six months ended June 30, 2018 . Non-redeemable noncontrolling interests The Company accounts for the portion of Watford Re’s common equity attributable to third party investors in the shareholders’ equity section of its consolidated balance sheets. The noncontrolling ownership in Watford Re’s common shares was approximately 89% at June 30, 2019 . The portion of Watford Re’s income or loss attributable to third party investors is recorded in the consolidated statements of income in ‘net (income) loss attributable to noncontrolling interests.’ The following table sets forth activity in the non-redeemable noncontrolling interests: June 30, 2019 2018 Three Months Ended Balance, beginning of period $ 838,081 $ 854,112 Additional paid in capital attributable to noncontrolling interests 2,074 — Amounts attributable to noncontrolling interests 12,301 8,116 Other comprehensive income (loss) attributable to noncontrolling interests 2,891 (1,075 ) Balance, end of period $ 855,347 $ 861,153 Six Months Ended Balance, beginning of year $ 791,560 $ 843,411 Additional paid in capital attributable to noncontrolling interests 2,074 — Amounts attributable to noncontrolling interests 54,683 19,492 Other comprehensive income (loss) attributable to noncontrolling interests 7,030 (1,750 ) Balance, end of period $ 855,347 $ 861,153 Redeemable noncontrolling interests The Company accounts for redeemable noncontrolling interests in the mezzanine section of its consolidated balance sheets in accordance with applicable accounting guidance. Such redeemable noncontrolling interests relate to the 9,065,200 cumulative redeemable preference shares (“Watford Preference Shares”) issued in late March 2014 with a par value of $0.01 per share and a liquidation preference of $25.00 per share. The Watford Preference Shares were issued at a discounted amount of $24.50 per share. Preferred dividends, including the accretion of the discount and issuance costs, are included in ‘net (income) loss attributable to noncontrolling interests’ in the Company’s consolidated statements of income. The following table sets forth activity in the redeemable non-controlling interests: June 30, 2019 2018 Three Months Ended Balance, beginning of period $ 206,383 $ 206,013 Accretion of preference share issuance costs 92 92 Balance, end of period $ 206,475 $ 206,105 Six Months Ended Balance, beginning of year $ 206,292 $ 205,922 Accretion of preference share issuance costs 183 183 Balance, end of period $ 206,475 $ 206,105 The portion of Watford Re’s income or loss attributable to third party investors, recorded in the Company’s consolidated statements of income in ‘net (income) loss attributable to noncontrolling interests,’ are summarized in the table below: June 30, 2019 2018 Three Months Ended Amounts attributable to non-redeemable noncontrolling interests $ (12,301 ) $ (8,116 ) Dividends attributable to redeemable noncontrolling interests (4,590 ) (4,585 ) Net (income) loss attributable to noncontrolling interests $ (16,891 ) $ (12,701 ) Six Months Ended Amounts attributable to non-redeemable noncontrolling interests $ (54,683 ) $ (19,492 ) Dividends attributable to redeemable noncontrolling interests (9,178 ) (9,170 ) Net (income) loss attributable to noncontrolling interests $ (63,861 ) $ (28,662 ) Bellemeade Re The Company has entered into various aggregate excess of loss mortgage reinsurance agreements with various special purpose reinsurance companies domiciled in Bermuda (the “Bellemeade Agreements”). At the time the Bellemeade Agreements were entered into, the applicability of the accounting guidance that addresses VIEs was evaluated. As a result of the evaluation of the Bellemeade Agreements, the Company concluded that these entities are VIEs. However, given that the ceding insurers do not have the unilateral power to direct those activities that are significant to their economic performance, the Company does not consolidate such entities in its consolidated financial statements. The following table presents the total assets of the Bellemeade entities, as well as the Company’s maximum exposure to loss associated with these VIEs, calculated as the maximum historical observable spread between the one month LIBOR, the basis for the contractual payments to bond holders, and short term invested trust asset yields. Maximum Exposure to Loss Bellemeade Entities (Issue Date) Total VIE Assets On-Balance Sheet (Asset) Liability Off-Balance Sheet Total Jun 30, 2019 Bellemeade 2015-1 Ltd. (Jul-15) $ 19,103 $ (4 ) $ 17 $ 13 Bellemeade 2017-1 Ltd. (Oct-17) 277,554 (657 ) 4,892 4,235 Bellemeade 2018-1 Ltd. (Apr-18) 374,460 (1,965 ) 7,799 5,834 Bellemeade 2018-2 Ltd. (Aug-18) 571,129 (1,957 ) 5,265 3,308 Bellemeade 2018-3 Ltd. (Oct-18) 506,110 (2,213 ) 7,251 5,038 Bellemeade 2019-1 Ltd. (Mar-19) 329,085 (237 ) 4,842 4,605 Bellemeade 2019-2 Ltd. (Apr-19) 621,022 (408 ) 11,206 10,798 Total $ 2,698,463 $ (7,441 ) $ 41,272 $ 33,831 Dec 31, 2018 Bellemeade 2015-1 Ltd. (Jul-15) $ 43,246 $ 112 $ 498 $ 610 Bellemeade 2017-1 Ltd. (Oct-17) 304,373 165 1,312 1,477 Bellemeade 2018-1 Ltd. (Apr-18) 374,460 132 3,539 3,671 Bellemeade 2018-2 Ltd. (Aug-18) 653,278 874 4,005 4,879 Bellemeade 2018-3 Ltd. (Oct-18) 506,110 469 1,836 2,305 Total $ 1,881,467 $ 1,752 $ 11,190 $ 12,942 See note 16 .

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2019
Comprehensive Income Note Disclosure [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The following tables present details about amounts reclassified from accumulated other comprehensive income and the tax effects allocated to each component of other comprehensive income (loss): Amounts Reclassified from AOCI Consolidated Statement of Income Three Months Ended Six Months Ended Details About Line Item That Includes June 30, June 30, AOCI Components Reclassification 2019 2018 2019 2018 Unrealized appreciation on available-for-sale investments Net realized gains (losses) $ 59,809 $ (38,935 ) $ 71,518 $ (106,521 ) Other-than-temporary impairment losses (49 ) (470 ) (1,358 ) (632 ) Total before tax 59,760 (39,405 ) 70,160 (107,153 ) Income tax (expense) benefit (4,415 ) 2,762 (4,594 ) 8,049 Net of tax $ 55,345 $ (36,643 ) $ 65,566 $ (99,104 ) Before Tax Amount Tax Expense (Benefit) Net of Tax Amount Three Months Ended June 30, 2019 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ 248,074 $ 25,601 $ 222,473 Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income 59,760 4,415 55,345 Foreign currency translation adjustments 4,409 142 4,267 Other comprehensive income (loss) $ 192,723 $ 21,328 $ 171,395 Three Months Ended June 30, 2018 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ (88,034 ) $ (2,763 ) $ (85,271 ) Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income (39,405 ) (2,762 ) (36,643 ) Foreign currency translation adjustments (12,701 ) (106 ) (12,595 ) Other comprehensive income (loss) $ (61,330 ) $ (107 ) $ (61,223 ) Six Months Ended June 30, 2019 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ 503,064 $ 54,704 $ 448,360 Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income 70,160 4,594 65,566 Foreign currency translation adjustments 10,053 270 9,783 Other comprehensive income (loss) $ 442,957 $ 50,380 $ 392,577 Six Months Ended June 30, 2018 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ (277,977 ) $ (26,029 ) $ (251,948 ) Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income (107,153 ) (8,049 ) (99,104 ) Foreign currency translation adjustments (11,269 ) 44 (11,313 ) Other comprehensive income (loss) $ (182,093 ) $ (17,936 ) $ (164,157 )

Guarantor Financial Information

Guarantor Financial Information	6 Months Ended
	Jun. 30, 2019
Condensed Financial Information Disclosure [Abstract]
Guarantor Financial Information	Guarantor Financial Information The following tables present condensed financial information for Arch Capital, Arch Capital Group (U.S.) Inc. (“Arch-U.S.”), a 100% owned subsidiary of Arch Capital, and Arch Capital’s other subsidiaries. The senior notes of Arch-U.S. due November 1, 2043 are fully and unconditionally guaranteed by Arch Capital. June 30, 2019 Condensed Consolidating Balance Sheet Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Assets Total investments $ 40 $ 483,904 $ 22,693,719 $ (49,700 ) $ 23,127,963 Cash 10,750 47,875 546,691 — 605,316 Investments in subsidiaries 11,045,465 4,493,198 — (15,538,663 ) — Due from subsidiaries and affiliates 332 2 1,881,929 (1,882,263 ) — Premiums receivable — — 2,291,360 (685,320 ) 1,606,040 Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses — — 8,618,279 (5,447,022 ) 3,171,257 Contractholder receivables — — 2,102,544 — 2,102,544 Ceded unearned premiums — — 1,984,219 (847,491 ) 1,136,728 Deferred acquisition costs — — 658,992 (58,252 ) 600,740 Goodwill and intangible assets — — 641,010 — 641,010 Other assets 22,950 40,345 1,953,732 (156,955 ) 1,860,072 Total assets $ 11,079,537 $ 5,065,324 $ 43,372,475 $ (24,665,666 ) $ 34,851,670 Liabilities Reserve for losses and loss adjustment expenses $ — $ — $ 17,430,847 $ (5,200,531 ) $ 12,230,316 Unearned premiums — — 4,904,351 (847,491 ) 4,056,860 Reinsurance balances payable — — 1,217,310 (685,320 ) 531,990 Contractholder payables — — 2,102,544 — 2,102,544 Collateral held for insured obligations — — 237,056 237,056 Senior notes 297,201 494,776 941,888 — 1,733,865 Revolving credit agreement borrowings — — 491,006 — 491,006 Due to subsidiaries and affiliates 9 536,747 1,345,507 (1,882,263 ) — Other liabilities 24,975 64,956 2,055,626 (496,698 ) 1,648,859 Total liabilities 322,185 1,096,479 30,726,135 (9,112,303 ) 23,032,496 Redeemable noncontrolling interests — — 221,175 (14,700 ) 206,475 Shareholders’ Equity Total shareholders’ equity available to Arch 10,757,352 3,968,845 11,569,818 (15,538,663 ) 10,757,352 Non-redeemable noncontrolling interests — — 855,347 — 855,347 Total shareholders’ equity 10,757,352 3,968,845 12,425,165 (15,538,663 ) 11,612,699 Total liabilities, noncontrolling interests and shareholders’ equity $ 11,079,537 $ 5,065,324 $ 43,372,475 $ (24,665,666 ) $ 34,851,670 December 31, 2018 Condensed Consolidating Balance Sheet Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Assets Total investments $ 104 $ 452,674 $ 21,307,206 $ (14,700 ) $ 21,745,284 Cash 6,125 5,940 634,491 — 646,556 Investments in subsidiaries 9,735,256 3,999,243 — (13,734,499 ) — Due from subsidiaries and affiliates 9 2 1,802,686 (1,802,697 ) — Premiums receivable — — 1,834,389 (535,239 ) 1,299,150 Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses — — 8,618,660 (5,699,288 ) 2,919,372 Contractholder receivables — — 2,079,111 — 2,079,111 Ceded unearned premiums — — 1,730,262 (754,793 ) 975,469 Deferred acquisition costs — — 618,535 (48,961 ) 569,574 Goodwill and intangible assets — — 634,920 — 634,920 Other assets 12,588 80,949 1,466,438 (211,082 ) 1,348,893 Total assets $ 9,754,082 $ 4,538,808 $ 40,726,698 $ (22,801,259 ) $ 32,218,329 Liabilities Reserve for losses and loss adjustment expenses $ — $ — $ 17,345,142 $ (5,491,845 ) $ 11,853,297 Unearned premiums — — 4,508,429 (754,793 ) 3,753,636 Reinsurance balances payable — — 928,346 (535,239 ) 393,107 Contractholder payables — — 2,079,111 — 2,079,111 Collateral held for insured obligations — — 236,630 — 236,630 Senior notes 297,150 494,723 941,655 — 1,733,528 Revolving credit agreement borrowings — — 455,682 — 455,682 Due to subsidiaries and affiliates — 536,805 1,265,892 (1,802,697 ) — Other liabilities 17,105 26,270 1,699,768 (467,484 ) 1,275,659 Total liabilities 314,255 1,057,798 29,460,655 (9,052,058 ) 21,780,650 Redeemable noncontrolling interests — — 220,992 (14,700 ) 206,292 Shareholders’ Equity Total shareholders’ equity available to Arch 9,439,827 3,481,010 10,253,491 (13,734,501 ) 9,439,827 Non-redeemable noncontrolling interests — — 791,560 — 791,560 Total shareholders’ equity 9,439,827 3,481,010 11,045,051 (13,734,501 ) 10,231,387 Total liabilities, noncontrolling interests and shareholders’ equity $ 9,754,082 $ 4,538,808 $ 40,726,698 $ (22,801,259 ) $ 32,218,329 Three Months Ended June 30, 2019 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 1,463,727 $ — $ 1,463,727 Net investment income 38 2,847 174,738 (22,585 ) 155,038 Net realized gains (losses) — 5,825 115,620 (639 ) 120,806 Net impairment losses recognized in earnings — — (49 ) — (49 ) Other underwriting income — — 5,953 — 5,953 Equity in net income (loss) of investment funds accounted for using the equity method — (64 ) 32,600 — 32,536 Other income (loss) (242 ) — 1,371 — 1,129 Total revenues (204 ) 8,608 1,793,960 (23,224 ) 1,779,140 Expenses Losses and loss adjustment expenses — — 767,543 — 767,543 Acquisition expenses — — 210,089 — 210,089 Other operating expenses — — 198,914 — 198,914 Corporate expenses 15,293 2,115 843 — 18,251 Amortization of intangible assets — — 19,794 — 19,794 Interest expense 5,538 11,996 34,012 (22,266 ) 29,280 Net foreign exchange (gains) losses — — (1,187 ) 6,139 4,952 Total expenses 20,831 14,111 1,230,008 (16,127 ) 1,248,823 Income (loss) before income taxes (21,035 ) (5,503 ) 563,952 (7,097 ) 530,317 Income tax (expense) benefit — 1,301 (45,773 ) — (44,472 ) Income (loss) before equity in net income of subsidiaries (21,035 ) (4,202 ) 518,179 (7,097 ) 485,845 Equity in net income of subsidiaries 489,989 148,747 — (638,736 ) — Net income 468,954 144,545 518,179 (645,833 ) 485,845 Net (income) loss attributable to noncontrolling interests — — (17,210 ) 319 (16,891 ) Net income available to Arch 468,954 144,545 500,969 (645,514 ) 468,954 Preferred dividends (10,403 ) — — — (10,403 ) Net income available to Arch common shareholders $ 458,551 $ 144,545 $ 500,969 $ (645,514 ) $ 458,551 Comprehensive income available to Arch $ 637,458 $ 231,120 $ 663,685 $ (894,805 ) $ 637,458 Three Months Ended June 30, 2018 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 1,336,763 $ — $ 1,336,763 Net investment income 15 560 157,532 (22,439 ) 135,668 Net realized gains (losses) — — (76,611 ) — (76,611 ) Net impairment losses recognized in earnings — — (470 ) — (470 ) Other underwriting income — — 3,874 — 3,874 Equity in net income (loss) of investment funds accounted for using the equity method — — 8,472 — 8,472 Other income (loss) 2,339 — 774 — 3,113 Total revenues 2,354 560 1,430,334 (22,439 ) 1,410,809 Expenses Losses and loss adjustment expenses — — 726,153 — 726,153 Acquisition expenses — — 202,838 — 202,838 Other operating expenses — — 176,181 — 176,181 Corporate expenses 16,642 470 5,400 — 22,512 Amortization of intangible assets — — 26,472 — 26,472 Interest expense 5,537 12,013 34,911 (22,117 ) 30,344 Net foreign exchange (gains) losses — — (43,357 ) (10,349 ) (53,706 ) Total expenses 22,179 12,483 1,128,598 (32,466 ) 1,130,794 Income (loss) before income taxes (19,825 ) (11,923 ) 301,736 10,027 280,015 Income tax (expense) benefit — 2,477 (26,145 ) — (23,668 ) Income (loss) before equity in net income of subsidiaries (19,825 ) (9,446 ) 275,591 10,027 256,347 Equity in net income of subsidiaries 263,471 86,727 — (350,198 ) — Net income (loss) 243,646 77,281 275,591 (340,171 ) 256,347 Net (income) loss attributable to noncontrolling interests — — (13,023 ) 322 (12,701 ) Net income (loss) available to Arch 243,646 77,281 262,568 (339,849 ) 243,646 Preferred dividends (10,403 ) — — — (10,403 ) Net income (loss) available to Arch common shareholders $ 233,243 $ 77,281 $ 262,568 $ (339,849 ) $ 233,243 Comprehensive income available to Arch $ 183,500 $ 70,066 $ 212,802 $ (282,868 ) $ 183,500 Six Months Ended June 30, 2019 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 2,832,593 $ — $ 2,832,593 Net investment income 84 6,526 350,410 (45,033 ) 311,987 Net realized gains (losses) — 14,343 253,673 (5,645 ) 262,371 Net impairment losses recognized in earnings — — (1,358 ) — (1,358 ) Other underwriting income — — 14,778 — 14,778 Equity in net income (loss) of investment funds accounted for using the equity method — (64 ) 79,467 — 79,403 Other income (loss) (481 ) — 2,693 — 2,212 Total revenues (397 ) 20,805 3,532,256 (50,678 ) 3,501,986 Expenses Losses and loss adjustment expenses — — 1,486,075 — 1,486,075 Acquisition expenses — — 407,937 — 407,937 Other operating expenses — — 400,077 — 400,077 Corporate expenses 31,600 4,281 332 — 36,213 Amortization of intangible assets — — 40,211 — 40,211 Interest expense 11,076 23,947 67,718 (44,396 ) 58,345 Net foreign exchange (gains) losses 2 — (1,310 ) 2,735 1,427 Total expenses 42,678 28,228 2,401,040 (41,661 ) 2,430,285 Income (loss) before income taxes (43,075 ) (7,423 ) 1,131,216 (9,017 ) 1,071,701 Income tax (expense) benefit — 1,844 (92,202 ) — (90,358 ) Income (loss) before equity in net income of subsidiaries (43,075 ) (5,579 ) 1,039,014 (9,017 ) 981,343 Equity in net income of subsidiaries 960,557 285,301 — (1,245,858 ) — Net income 917,482 279,722 1,039,014 (1,254,875 ) 981,343 Net (income) loss attributable to noncontrolling interests — — (64,499 ) 638 (63,861 ) Net income available to Arch 917,482 279,722 974,515 (1,254,237 ) 917,482 Preferred dividends (20,806 ) — — — (20,806 ) Net income available to Arch common shareholders $ 896,676 $ 279,722 $ 974,515 $ (1,254,237 ) $ 896,676 Comprehensive income available to Arch $ 1,303,029 $ 469,276 $ 1,352,225 $ (1,821,501 ) $ 1,303,029 Six Months Ended June 30, 2018 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 2,571,662 $ — $ 2,571,662 Net investment income 35 818 306,299 (44,760 ) 262,392 Net realized gains (losses) 29 (7 ) (187,631 ) — (187,609 ) Net impairment losses recognized in earnings — — (632 ) — (632 ) Other underwriting income — — 9,223 — 9,223 Equity in net income (loss) of investment funds accounted for using the equity method — — 36,541 — 36,541 Other income (loss) 2,261 — 926 — 3,187 Total revenues 2,325 811 2,736,388 (44,760 ) 2,694,764 Expenses Losses and loss adjustment expenses — — 1,363,013 — 1,363,013 Acquisition expenses — — 394,214 — 394,214 Other operating expenses — — 351,196 — 351,196 Corporate expenses 32,811 759 4,254 — 37,824 Amortization of intangible assets — — 53,208 — 53,208 Interest expense 11,073 23,939 70,083 (44,115 ) 60,980 Net foreign exchange (gains) losses 29 — (26,921 ) (7,093 ) (33,985 ) Total expenses 43,913 24,698 2,209,047 (51,208 ) 2,226,450 Income (loss) before income taxes (41,588 ) (23,887 ) 527,341 6,448 468,314 Income tax (expense) benefit — 5,428 (51,011 ) — (45,583 ) Income (loss) before equity in net income of subsidiaries (41,588 ) (18,459 ) 476,330 6,448 422,731 Equity in net income of subsidiaries 435,657 173,147 — (608,804 ) — Net income 394,069 154,688 476,330 (602,356 ) 422,731 Net (income) loss attributable to noncontrolling interests — — (29,307 ) 645 (28,662 ) Net income available to Arch 394,069 154,688 447,023 (601,711 ) 394,069 Preferred dividends (20,840 ) — — — (20,840 ) Loss on redemption of preferred shares (2,710 ) — — — (2,710 ) Net income available to Arch common shareholders $ 370,519 $ 154,688 $ 447,023 $ (601,711 ) $ 370,519 Comprehensive income available to Arch $ 231,662 $ 76,603 $ 291,883 $ (368,486 ) $ 231,662 Six Months Ended June 30, 2019 Condensed Consolidating Statement of Cash Flows Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Operating Activities Net Cash Provided By (Used For) Operating Activities $ 30,946 $ 24,059 $ 749,885 $ (92,366 ) $ 712,524 Investing Activities Purchases of fixed maturity investments — (358,996 ) (15,973,650 ) — (16,332,646 ) Purchases of equity securities — (56,441 ) (447,742 ) 72,244 (431,939 ) Purchases of other investments — (17,891 ) (659,172 ) — (677,063 ) Proceeds from the sales of fixed maturity investments — 452,729 15,179,753 — 15,632,482 Proceeds from the sales of equity securities — — 248,945 (72,244 ) 176,701 Proceeds from the sales, redemptions and maturities of other investments — 391 534,307 — 534,698 Proceeds from redemptions and maturities of fixed maturity investments — 100 244,849 — 244,949 Net settlements of derivative instruments — — 87,701 — 87,701 Net (purchases) sales of short-term investments 64 (2,015 ) 203,471 — 201,520 Change in cash collateral related to securities lending — — 7,590 — 7,590 Contributions to subsidiaries (2,121 ) — (59,527 ) 61,648 — Issuance of intercompany loans — — (53,828 ) 53,828 — Purchases of fixed assets (32 ) — (16,327 ) — (16,359 ) Other — — (174,578 ) — (174,578 ) Net Cash Provided By (Used For) Investing Activities (2,089 ) 17,877 (878,208 ) 115,476 (746,944 ) Financing Activities Purchases of common shares under share repurchase program (2,871 ) — — — (2,871 ) Proceeds from common shares issued, net (557 ) — 61,648 (61,648 ) (557 ) Proceeds from intercompany borrowings — — 53,828 (53,828 ) — Proceeds from borrowings — — 62,800 — 62,800 Repayments of borrowings — — (27,538 ) — (27,538 ) Change in cash collateral related to securities lending — — (7,590 ) — (7,590 ) Dividends paid to redeemable noncontrolling interests — — (9,632 ) 638 (8,994 ) Dividends paid to parent (1) — — (91,728 ) 91,728 — Other — — (3,529 ) — (3,529 ) Preferred dividends paid (20,806 ) — — — (20,806 ) Net Cash Provided By (Used For) Financing Activities (24,234 ) — 38,259 (23,110 ) (9,085 ) Effects of exchange rates changes on foreign currency cash and restricted cash — — 1,937 — 1,937 Increase (decrease) in cash and restricted cash 4,623 41,936 (88,127 ) — (41,568 ) Cash and restricted cash, beginning of year 6,159 5,940 712,544 — 724,643 Cash and restricted cash, end of period $ 10,782 $ 47,876 $ 624,417 $ — $ 683,075 (1) Dividends received by parent are included in net cash provided by (used for) operating activities. Six Months Ended June 30, 2018 Condensed Consolidating Statement of Cash Flows Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Operating Activities Net Cash Provided By (Used For) Operating Activities $ 201,487 $ 149,576 $ 1,010,703 $ (864,880 ) $ 496,886 Investing Activities Purchases of fixed maturity investments — (125,440 ) (17,347,846 ) 605,716 (16,867,570 ) Purchases of equity securities — — (679,663 ) — (679,663 ) Purchases of other investments — — (1,017,147 ) — (1,017,147 ) Proceeds from the sales of fixed maturity investments — 33,793 16,662,466 (605,716 ) 16,090,543 Proceeds from the sales of equity securities — — 622,068 — 622,068 Proceeds from the sales, redemptions and maturities of other investments — — 773,298 — 773,298 Proceeds from redemptions and maturities of fixed maturity investments — — 511,448 — 511,448 Net settlements of derivative instruments — — 4,498 — 4,498 Net (purchases) sales of short-term investments 96,446 (59,798 ) 415,253 — 451,901 Change in cash collateral related to securities lending — — 176,304 — 176,304 Contributions to subsidiaries — (1,000 ) (22,595 ) 23,595 — Purchases of fixed assets (71 ) — (13,171 ) — (13,242 ) Other (4 ) — 49,965 — 49,961 Net Cash Provided By (Used For) Investing Activities 96,371 (152,445 ) 134,878 23,595 102,399 Financing Activities Redemption of preferred shares (92,555 ) — — — (92,555 ) Purchases of common shares under share repurchase program (173,575 ) — — — (173,575 ) Proceeds from common shares issued, net (13,851 ) — 23,595 (23,595 ) (13,851 ) Proceeds from borrowings — — 130,579 — 130,579 Repayments of borrowings — — (373,000 ) — (373,000 ) Change in cash collateral related to securities lending — — (176,304 ) — (176,304 ) Dividends paid to redeemable noncontrolling interests — — (9,632 ) 638 (8,994 ) Dividends paid to parent (1) — — (864,242 ) 864,242 — Other — — (4,489 ) — (4,489 ) Preferred dividends paid (20,840 ) — — — (20,840 ) Net Cash Provided By (Used For) Financing Activities (300,821 ) — (1,273,493 ) 841,285 (733,029 ) Effects of exchange rates changes on foreign currency cash and restricted cash — — (10,431 ) — (10,431 ) Increase (decrease) in cash and restricted cash (2,963 ) (2,869 ) (138,343 ) — (144,175 ) Cash and restricted cash, beginning of year 10,048 30,380 686,856 — 727,284 Cash and restricted cash, end of period $ 7,085 $ 27,511 $ 548,513 $ — $ 583,109 (1) Dividends received by parent are included in net cash provided by (used for) operating activities.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s income tax provision on income before income taxes resulted in an expense of 8.4% for the six months ended June 30, 2019 , compared to an expense of 9.7% for the 2018 period. The Company’s effective tax rate, which is based upon the expected annual effective tax rate, may fluctuate from period to period based on the relative mix of income or loss reported by jurisdiction and the varying tax rates in each jurisdiction. For interim reporting purposes, the Company has calculated its annual effective tax rate for the full year of 2019 by treating excess tax benefits that arise from the accounting for stock based compensation as a discrete item. As such, this amount is not included when projecting the Company’s full year annual effective tax rate but rather is accounted for at the U.S. Federal statutory rate of 21% after applying the projected full year annual effective tax rate to actual six months results before the discrete item. The impact of the discrete item resulted in a benefit of 0.4% for the six months ended June 30, 2019 . The Company had a net deferred tax liability of $49.5 million at June 30, 2019 , compared to a net deferred tax asset of $22.5 million at December 31, 2018 . The change is primarily a result of the appreciation of the Company’s fixed maturities from December 31, 2018 to June 30, 2019. In addition, the Company paid $43.5 million and recovered $46.5 million of income taxes for the six months ended June 30, 2019 and 2018 , respectively.

Legal Proceedings

Legal Proceedings	6 Months Ended
	Jun. 30, 2019
Disclosure Legal Proceedings [Abstract]
Legal Proceedings	Legal Proceedings The Company, in common with the insurance industry in general, is subject to litigation and arbitration in the normal course of its business. As of June 30, 2019 , the Company was not a party to any litigation or arbitration which is expected by management to have a material adverse effect on the Company’s results of operations and financial condition and liquidity.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Bellemeade Re 2019-3 Ltd. In July 2019, the Company’s first-lien U.S. mortgage insurance subsidiaries entered into an aggregate excess of loss reinsurance agreement with Bellemeade Re 2019-3 Ltd. (“Bellemeade 2019-3”), a special purpose reinsurance company domiciled in Bermuda. The Bellemeade 2019-3 agreement provides for up to $700.9 million of aggregate excess of loss reinsurance coverage at inception in excess of $232.1 million of aggregate losses for new delinquencies on a portfolio of in-force policies issued in 2016. The coverage amount decreases over a ten -year period as the underlying covered mortgages amortize. Bellemeade 2019-3 financed the coverage through the issuance of mortgage insurance-linked notes in an aggregate amount of approximately $700.9 million to unrelated investors (the “Notes”). The maturity date of the Notes is July 25, 2029. The Notes will be redeemed prior to maturity upon the occurrence of a mandatory termination event or if the ceding insurers trigger a termination of the reinsurance agreement following the occurrence of an optional termination event. All of the proceeds paid to Bellemeade 2019-3 from the sale of the Notes were deposited into a reinsurance trust as security for Bellemeade 2019-3’s obligations. At all times, funds in the reinsurance trust account are required to be invested in high credit quality money market funds. Watford Re Capital Transactions On July 2, 2019, Watford Holdings Ltd. completed an offering of $175.0 million in aggregate principal amount of its 6.5% senior notes, due July 2, 2029 (“Watford Senior Notes”). Interest on such notes will be paid semi-annually in arrears on each January 2 and July 2, commencing January 2, 2020. The $172.4 million net proceeds from the offering were used to redeem a portion of Watford Holdings Ltd.’s outstanding preference shares. On August 1, 2019, Watford Holdings Ltd. redeemed 6,919,998 of its 9,065,200 total issued and outstanding Watford Preference Shares. The Watford Preference Shares were redeemed at a total redemption price of $25.19748 per share, inclusive of all declared and unpaid dividends, with accumulation of any undeclared dividends on or after June 30, 2019. The Company purchased $35.0 million in aggregate principal amount of the Watford Senior Notes. In addition, the Company received $11.5 million pursuant to the redemption of Watford Preference Shares. Business Acquisition On July 30, 2019, the Company announced that it has entered into an agreement to purchase Barbican Group Holdings Limited from funds managed by Carlson Capital, a U.S. based alternative asset management firm. The acquisition includes Barbican Managing Agency Limited, Lloyd’s Syndicate 1955, Lloyd’s Syndicate 1856, Lloyd’s Special Purpose Arrangement 6132, Castel Underwriting Agencies Limited and other associated entities. The transaction is subject to regulatory approval and is expected to close in the late third or early fourth quarter of 2019.

Basis of Presentation and Rec_2

Basis of Presentation and Recent Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of accounting	The interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany transactions and balances have been eliminated in consolidation.
Use of estimates	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 disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. In the opinion of management, the accompanying unaudited interim consolidated financial statements reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of results on an interim basis. The results of any interim period are not necessarily indicative of the results for a full year or any future periods.
Recent accounting pronouncements	Recently Issued Accounting Standards Adopted The Company adopted ASU 2016-02, “Leases (Topic 842)”, which provides a new comprehensive model for lease accounting. Topic 842 requires a lessee to recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The Company adopted the modified retrospective approach of this standard, that resulted in the recognition of a right-of-use asset of $147.9 million as part of other assets and a lease liability of $163.6 million as part of other liabilities in the consolidated balance sheet as of January 1, 2019. The Company de-recognized the liability for deferred rent that was required under the previous guidance. In addition, the Company adopted ASU 2018-11, “Leases: Targeted Improvements (Topic 842),” which provides an additional (optional) transition method to adopt the new lease standard. The Company adopted the alternative transition method and elected to utilize a cumulative-effect adjustment to the opening balance of the retained earnings for the year of adoption. As such, the Company’s reporting for the comparative periods prior to the adoption continue to be presented in the financial statements in accordance with previous lease accounting guidance. The Company also adopted the practical expedients as a package which allows the Company to not reassess (1) whether any expired or existing contracts are or contain leases (2) the lease classification for any expired or existing leases (3) initial direct costs for any existing leases and (4) to account for the lease and non lease components as a single lease component. In addition to electing the practical expedients as a package, the Company elected to include hindsight to determine the lease term of existing leases, and made an accounting policy election to not apply the recognition requirements to short-term leases (lease term of less than twelve months). The cumulative effect adjustment to the opening balance of retained earnings was zero . The adoption of the updated guidance did not have a material effect on the Company’s results of operations or liquidity. The Company adopted ASU 2018-07 “Improvements to Nonemployee Share-Based Payment Accounting,” which was issued in June 2018 to simplify the accounting for share-based payments granted to nonemployees for goods and services. Under this ASU, most of the guidance on such payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. The ASU is effective for reporting periods beginning after December 15, 2018. This guidance and the adoption of this provision did not have a material effect on the Company's financial position, results of operations or cash flows. The Company adopted ASU 2018-02 “Income Statement-Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which was issued in February 2018 to allow the reclassification of the stranded tax effects in accumulated other comprehensive income (“AOCI”) resulting from the Tax Cuts and Jobs Act of 2017 (“Tax Cuts Act”). Current guidance requires the effect of a change in tax laws or rates on deferred tax balances to be reported in income from continuing operations in the accounting period that includes the period of enactment, even if the related income tax effects were originally charged or credited directly to AOCI. The amount of the reclassification would include the effect of the change in the U.S. federal corporate income tax rate on the gross deferred tax amounts and related valuation allowances, if any, at the date of the enactment of the Tax Cuts Act related to items in AOCI. The updated guidance is effective for reporting periods beginning after December 15, 2018 and is to be applied retrospectively to each period in which the effect of the Tax Cuts Act related to items remaining in AOCI are recognized or at the beginning of the period of adoption. The adoption of this ASU did not have a material effect on the Company’s results of operations, financial position or liquidity. The Company adopted ASU 2017-08 “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities,” which was issued in March, 2017. This ASU shortens the amortization period for certain callable debt securities held at a premium and requires the premium to be amortized to the earliest call date. However, the new guidance does not require an accounting change for securities held at a discount whose discount continues to be amortized to maturity. The standard is effective for financial statements issued for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The adoption of the guidance requires a modified retrospective approach with a cumulative-effect adjustment to retained earnings. The adoption of this ASU did not have a material effect on the Company’s consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted For information regarding additional accounting standards that the Company has not yet adopted, see note 3(q), “Significant Accounting Policies—Recent Accounting Pronouncements,” of the notes to consolidated financial statements in the Company’s 2018 Form 10-K.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings per common share: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Numerator: Net income $ 485,845 $ 256,347 $ 981,343 $ 422,731 Amounts attributable to noncontrolling interests (16,891 ) (12,701 ) (63,861 ) (28,662 ) Net income available to Arch 468,954 243,646 917,482 394,069 Preferred dividends (10,403 ) (10,403 ) (20,806 ) (20,840 ) Loss on redemption of preferred shares — — — (2,710 ) Net income available to Arch common shareholders $ 458,551 $ 233,243 $ 896,676 $ 370,519 Denominator: Weighted average common shares outstanding 401,482,784 404,800,421 400,837,181 399,485,135 Series D preferred shares (1) — — — 6,677,373 Weighted average common shares and common share equivalents outstanding — basic 401,482,784 404,800,421 400,837,181 406,162,508 Effect of dilutive common share equivalents: Nonvested restricted shares 1,937,626 1,575,749 1,720,417 1,837,356 Stock options (2) 7,479,073 6,735,035 7,197,652 7,460,892 Weighted average common shares and common share equivalents outstanding — diluted 410,899,483 413,111,205 409,755,250 415,460,756 Earnings per common share: Basic $ 1.14 $ 0.58 $ 2.24 $ 0.91 Diluted $ 1.12 $ 0.56 $ 2.19 $ 0.89 (1) Such shares are convertible non-voting common equivalent preferred shares issued in connection with the UGC acquisition. See note 2 . (2) Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2019 second quarter and 2018 second quarter , the number of stock options excluded were 2,016,830 and 5,350,733 , respectively. For the six months ended June 30, 2019 and 2018 period, the number of stock options excluded were 2,560,755 and 5,372,789 , respectively.

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Analysis of underwriting income or loss by segment and reconciliation to net income available to common shareholders	The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders: Three Months Ended June 30, 2019 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 919,925 $ 545,547 $ 364,465 $ 1,829,829 $ 161,978 $ 1,937,809 Premiums ceded (292,095 ) (169,457 ) (42,857 ) (504,301 ) (42,608 ) (492,911 ) Net premiums written 627,830 376,090 321,608 1,325,528 119,370 1,444,898 Change in unearned premiums (35,388 ) (8,906 ) 31,175 (13,119 ) 31,948 18,829 Net premiums earned 592,442 367,184 352,783 1,312,409 151,318 1,463,727 Other underwriting income (loss) — 1,224 4,056 5,280 673 5,953 Losses and loss adjustment expenses (389,172 ) (240,958 ) (25,997 ) (656,127 ) (111,416 ) (767,543 ) Acquisition expenses (91,094 ) (56,785 ) (32,654 ) (180,533 ) (29,556 ) (210,089 ) Other operating expenses (109,523 ) (33,960 ) (39,819 ) (183,302 ) (15,612 ) (198,914 ) Underwriting income (loss) $ 2,653 $ 36,705 $ 258,369 297,727 (4,593 ) 293,134 Net investment income 123,038 32,000 155,038 Net realized gains (losses) 125,112 (4,306 ) 120,806 Net impairment losses recognized in earnings (49 ) — (49 ) Equity in net income (loss) of investment funds accounted for using the equity method 32,536 — 32,536 Other income (loss) 1,129 — 1,129 Corporate expenses (2) (16,073 ) — (16,073 ) Transaction costs and other (2) (2,178 ) — (2,178 ) Amortization of intangible assets (19,794 ) — (19,794 ) Interest expense (23,375 ) (5,905 ) (29,280 ) Net foreign exchange gains (losses) (6,190 ) 1,238 (4,952 ) Income before income taxes 511,883 18,434 530,317 Income tax expense (44,452 ) (20 ) (44,472 ) Net income 467,431 18,414 485,845 Dividends attributable to redeemable noncontrolling interests — (4,590 ) (4,590 ) Amounts attributable to nonredeemable noncontrolling interests — (12,301 ) (12,301 ) Net income available to Arch 467,431 1,523 468,954 Preferred dividends (10,403 ) — (10,403 ) Net income available to Arch common shareholders $ 457,028 $ 1,523 $ 458,551 Underwriting Ratios Loss ratio 65.7 % 65.6 % 7.4 % 50.0 % 73.6 % 52.4 % Acquisition expense ratio 15.4 % 15.5 % 9.3 % 13.8 % 19.5 % 14.4 % Other operating expense ratio 18.5 % 9.2 % 11.3 % 14.0 % 10.3 % 13.6 % Combined ratio 99.6 % 90.3 % 28.0 % 77.8 % 103.4 % 80.4 % Goodwill and intangible assets $ 157,440 $ — $ 475,920 $ 633,360 $ 7,650 $ 641,010 (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ Three Months Ended June 30, 2018 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 769,372 $ 490,327 $ 330,990 $ 1,591,202 $ 175,175 $ 1,696,544 Premiums ceded (245,265 ) (136,247 ) (50,867 ) (432,892 ) (34,589 ) (397,648 ) Net premiums written 524,107 354,080 280,123 1,158,310 140,586 1,298,896 Change in unearned premiums 22,342 (13,762 ) 10,355 18,935 18,932 37,867 Net premiums earned 546,449 340,318 290,478 1,177,245 159,518 1,336,763 Other underwriting income (loss) — (129 ) 3,315 3,186 688 3,874 Losses and loss adjustment expenses (357,465 ) (229,956 ) (21,591 ) (609,012 ) (117,141 ) (726,153 ) Acquisition expenses (90,670 ) (50,142 ) (27,737 ) (168,549 ) (34,289 ) (202,838 ) Other operating expenses (92,680 ) (35,678 ) (38,729 ) (167,087 ) (9,094 ) (176,181 ) Underwriting income (loss) $ 5,634 $ 24,413 $ 205,736 235,783 (318 ) 235,465 Net investment income 107,761 27,907 135,668 Net realized gains (losses) (59,545 ) (17,066 ) (76,611 ) Net impairment losses recognized in earnings (470 ) — (470 ) Equity in net income (loss) of investment funds accounted for using the equity method 8,472 — 8,472 Other income (loss) 3,113 — 3,113 Corporate expenses (2) (15,604 ) — (15,604 ) Transaction costs and other (2) (6,908 ) — (6,908 ) Amortization of intangible assets (26,472 ) — (26,472 ) Interest expense (26,058 ) (4,286 ) (30,344 ) Net foreign exchange gains (losses) 46,211 7,495 53,706 Income before income taxes 266,283 13,732 280,015 Income tax expense (23,644 ) (24 ) (23,668 ) Net income 242,639 13,708 256,347 Dividends attributable to redeemable noncontrolling interests — (4,585 ) (4,585 ) Amounts attributable to nonredeemable noncontrolling interests — (8,116 ) (8,116 ) Net income available to Arch 242,639 1,007 243,646 Preferred dividends (10,403 ) — (10,403 ) Net income available to Arch common shareholders $ 232,236 $ 1,007 $ 233,243 Underwriting Ratios Loss ratio 65.4 % 67.6 % 7.4 % 51.7 % 73.4 % 54.3 % Acquisition expense ratio 16.6 % 14.7 % 9.5 % 14.3 % 21.5 % 15.2 % Other operating expense ratio 17.0 % 10.5 % 13.3 % 14.2 % 5.7 % 13.2 % Combined ratio 99.0 % 92.8 % 30.2 % 80.2 % 100.6 % 82.7 % Goodwill and intangible assets $ 20,724 $ — $ 564,634 $ 585,358 $ 7,650 $ 593,008 (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders: Six Months Ended June 30, 2019 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 1,861,879 $ 1,228,402 $ 720,515 $ 3,810,282 $ 348,667 $ 4,015,688 Premiums ceded (612,717 ) (401,024 ) (91,655 ) (1,104,882 ) (83,910 ) (1,045,531 ) Net premiums written 1,249,162 827,378 628,860 2,705,400 264,757 2,970,157 Change in unearned premiums (103,215 ) (113,829 ) 46,825 (170,219 ) 32,655 (137,564 ) Net premiums earned 1,145,947 713,549 675,685 2,535,181 297,412 2,832,593 Other underwriting income (loss) — 5,601 7,912 13,513 1,265 14,778 Losses and loss adjustment expenses (745,895 ) (480,768 ) (37,146 ) (1,263,809 ) (222,266 ) (1,486,075 ) Acquisition expenses (173,918 ) (111,111 ) (64,326 ) (349,355 ) (58,582 ) (407,937 ) Other operating expenses (222,919 ) (69,664 ) (79,694 ) (372,277 ) (27,800 ) (400,077 ) Underwriting income (loss) $ 3,215 $ 57,607 $ 502,431 563,253 (9,971 ) 553,282 Net investment income 244,287 67,700 311,987 Net realized gains (losses) 237,545 24,826 262,371 Net impairment losses recognized in earnings (1,358 ) — (1,358 ) Equity in net income (loss) of investment funds accounted for using the equity method 79,403 — 79,403 Other income (loss) 2,212 — 2,212 Corporate expenses (2) (32,845 ) — (32,845 ) Transaction costs and other (2) (3,368 ) — (3,368 ) Amortization of intangible assets (40,211 ) — (40,211 ) Interest expense (46,857 ) (11,488 ) (58,345 ) Net foreign exchange gains (losses) (1,015 ) (412 ) (1,427 ) Income before income taxes 1,001,046 70,655 1,071,701 Income tax expense (90,338 ) (20 ) (90,358 ) Net income 910,708 70,635 981,343 Dividends attributable to redeemable noncontrolling interests — (9,178 ) (9,178 ) Amounts attributable to nonredeemable noncontrolling interests — (54,683 ) (54,683 ) Net income available to Arch 910,708 6,774 917,482 Preferred dividends (20,806 ) — (20,806 ) Net income available to Arch common shareholders $ 889,902 $ 6,774 $ 896,676 Underwriting Ratios Loss ratio 65.1 % 67.4 % 5.5 % 49.9 % 74.7 % 52.5 % Acquisition expense ratio 15.2 % 15.6 % 9.5 % 13.8 % 19.7 % 14.4 % Other operating expense ratio 19.5 % 9.8 % 11.8 % 14.7 % 9.3 % 14.1 % Combined ratio 99.8 % 92.8 % 26.8 % 78.4 % 103.7 % 81.0 % (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2) Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’ Six Months Ended June 30, 2018 Insurance Reinsurance Mortgage Sub-Total Other Total Gross premiums written (1) $ 1,592,750 $ 1,067,810 $ 652,168 $ 3,312,807 $ 389,045 $ 3,534,758 Premiums ceded (492,445 ) (331,977 ) (97,004 ) (921,505 ) (68,907 ) (823,318 ) Net premiums written 1,100,305 735,833 555,164 2,391,302 320,138 2,711,440 Change in unearned premiums (15,119 ) (116,343 ) 15,556 (115,906 ) (23,872 ) (139,778 ) Net premiums earned 1,085,186 619,490 570,720 2,275,396 296,266 2,571,662 Other underwriting income (loss) — 1,103 6,731 7,834 1,389 9,223 Losses and loss adjustment expenses (711,195 ) (371,631 ) (65,057 ) (1,147,883 ) (215,130 ) (1,363,013 ) Acquisition expenses (175,839 ) (98,461 ) (54,304 ) (328,604 ) (65,610 ) (394,214 ) Other operating expenses (184,654 ) (71,249 ) (77,500 ) (333,403 ) (17,793 ) (351,196 ) Underwriting income (loss) $ 13,498 $ 79,252 $ 380,590 473,340 (878 ) 472,462 Net investment income 208,004 54,388 262,392 Net realized gains (losses) (171,404 ) (16,205 ) (187,609 ) Net impairment losses recognized in earnings (632 ) — (632 ) Equity in net income (loss) of investment funds accounted for using the equity method 36,541 — 36,541 Other income (loss) 3,187 — 3,187 Corporate expenses (2) (30,086 ) — (30,086 ) Transaction costs and other (2) (7,738 ) — (7,738 ) Amortization of intangible assets (53,208 ) — (53,208 ) Interest expense (51,965 ) (9,015 ) (60,980 ) Net foreign exchange gains (losses) 31,172 2,813 33,985 Income before income taxes 437,211 31,103 468,314 Income tax expense (45,556 ) (27 ) (45,583 ) Net income 391,655 31,076 422,731 Dividends attributable to redeemable noncontrolling interests — (9,170 ) (9,170 ) Amounts attributable to nonredeemable noncontrolling interests — (19,492 ) (19,492 ) Net income available to Arch 391,655 2,414 394,069 Preferred dividends (20,840 ) — (20,840 ) Loss on redemption of preferred shares (2,710 ) — (2,710 ) Net income available to Arch common shareholders $ 368,105 $ 2,414 $ 370,519 Underwriting Ratios Loss ratio 65.5 % 60.0 % 11.4 % 50.4 % 72.6 % 53.0 % Acquisition expense ratio 16.2 % 15.9 % 9.5 % 14.4 % 22.1 % 15.3 % Other operating expense ratio 17.0 % 11.5 % 13.6 % 14.7 % 6.0 % 13.7 % Combined ratio 98.7 % 87.4 % 34.5 % 79.5 % 100.7 % 82.0 % (1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total. (2)

Reserve for Losses and Loss A_2

Reserve for Losses and Loss Adjustment Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Analysis of losses and loss adjustment expenses and reconciliation of beginning and ending reserve balances	The following table represents an analysis of losses and loss adjustment expenses and a reconciliation of the beginning and ending reserve for losses and loss adjustment expenses: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Reserve for losses and loss adjustment expenses at beginning of period $ 12,010,041 $ 11,496,205 $ 11,853,297 $ 11,383,792 Unpaid losses and loss adjustment expenses recoverable 2,970,159 2,446,990 2,814,291 2,464,910 Net reserve for losses and loss adjustment expenses at beginning of period 9,039,882 9,049,215 9,039,006 8,918,882 Net incurred losses and loss adjustment expenses relating to losses occurring in: Current year 805,728 790,742 1,563,692 1,478,627 Prior years (38,185 ) (64,589 ) (77,617 ) (115,614 ) Total net incurred losses and loss adjustment expenses 767,543 726,153 1,486,075 1,363,013 Retroactive reinsurance transactions (1) — (420,404 ) (225,500 ) (420,404 ) Net foreign exchange (gains) losses (1,277 ) (120,292 ) (1,781 ) (76,278 ) Net paid losses and loss adjustment expenses relating to losses occurring in: Current year (61,148 ) (59,022 ) (125,488 ) (95,022 ) Prior years (539,481 ) (403,062 ) (966,793 ) (917,603 ) Total net paid losses and loss adjustment expenses (600,629 ) (462,084 ) (1,092,281 ) (1,012,625 ) Net reserve for losses and loss adjustment expenses at end of period 9,205,519 8,772,588 9,205,519 8,772,588 Unpaid losses and loss adjustment expenses recoverable 3,024,797 2,651,749 3,024,797 2,651,749 Reserve for losses and loss adjustment expenses at end of period $ 12,230,316 $ 11,424,337 $ 12,230,316 $ 11,424,337 (1) During the 2019 first quarter and 2018 second quarter, a subsidiary of the Company entered into two separate retroactive reinsurance transactions with third party reinsurers to reinsure run-off liabilities associated with certain U.S. exposures.

Investment Information (Tables)

Investment Information (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure Investment Information [Abstract]
Summary of fair value and cost or amortized cost of available for sale securities	The following table summarizes the fair value and cost or amortized cost of the Company’s securities classified as available for sale: Estimated Fair Value Gross Unrealized Gains Gross Unrealized Losses Cost or Amortized Cost OTTI Unrealized Losses (2) June 30, 2019 Fixed maturities (1): Corporate bonds $ 6,044,081 $ 166,372 $ (19,805 ) $ 5,897,514 $ — Mortgage backed securities 523,019 11,385 (187 ) 511,821 (6 ) Municipal bonds 582,497 21,755 (58 ) 560,800 — Commercial mortgage backed securities 686,707 21,272 (228 ) 665,663 — U.S. government and government agencies 4,906,996 68,017 (2,051 ) 4,841,030 — Non-U.S. government securities 1,928,752 45,881 (36,125 ) 1,918,996 — Asset backed securities 1,636,897 28,133 (3,480 ) 1,612,244 — Total 16,308,949 362,815 (61,934 ) 16,008,068 (6 ) Short-term investments 821,961 284 (480 ) 822,157 — Total $ 17,130,910 $ 363,099 $ (62,414 ) $ 16,830,225 $ (6 ) December 31, 2018 Fixed maturities (1): Corporate bonds $ 5,537,548 $ 14,476 $ (105,428 ) $ 5,628,500 $ (69 ) Mortgage backed securities 541,193 3,991 (3,216 ) 540,418 (6 ) Municipal bonds 1,013,395 5,380 (11,891 ) 1,019,906 — Commercial mortgage backed securities 729,442 2,650 (10,751 ) 737,543 — U.S. government and government agencies 3,758,698 27,189 (8,474 ) 3,739,983 — Non-U.S. government securities 1,771,338 14,477 (50,948 ) 1,807,809 — Asset backed securities 1,600,896 8,060 (14,798 ) 1,607,634 — Total 14,952,510 76,223 (205,506 ) 15,081,793 (75 ) Short-term investments 955,880 36 (394 ) 956,238 — Total $ 15,908,390 $ 76,259 $ (205,900 ) $ 16,038,031 $ (75 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.” (2) Represents the total other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income (“AOCI”). It does not include the change in fair value subsequent to the impairment measurement date. At June 30, 2019 the net unrealized loss related to securities for which a non-credit OTTI was recognized in AOCI was $0.01 million , compared to net unrealized loss of $0.04 million at December 31, 2018
Summary of available for sale securities in a continual unrealized loss position	The following table summarizes, for all available for sale securities in an unrealized loss position, the fair value and gross unrealized loss by length of time the security has been in a continual unrealized loss position: Less than 12 Months 12 Months or More Total Estimated Gross Unrealized Losses Estimated Gross Unrealized Losses Estimated Gross Unrealized Losses June 30, 2019 Fixed maturities (1): Corporate bonds $ 259,361 $ (10,678 ) $ 375,478 $ (9,127 ) $ 634,839 $ (19,805 ) Mortgage backed securities 19,612 (169 ) 261 (18 ) 19,873 (187 ) Municipal bonds — — 12,489 (58 ) 12,489 (58 ) Commercial mortgage backed securities 18,917 (106 ) 23,198 (122 ) 42,115 (228 ) U.S. government and government agencies 906,497 (1,711 ) 104,692 (340 ) 1,011,189 (2,051 ) Non-U.S. government securities 1,092,560 (33,985 ) 124,466 (2,140 ) 1,217,026 (36,125 ) Asset backed securities 312,033 (1,901 ) 130,002 (1,579 ) 442,035 (3,480 ) Total 2,608,980 (48,550 ) 770,586 (13,384 ) 3,379,566 (61,934 ) Short-term investments 53,431 (480 ) — — 53,431 (480 ) Total $ 2,662,411 $ (49,030 ) $ 770,586 $ (13,384 ) $ 3,432,997 $ (62,414 ) December 31, 2018 Fixed maturities (1): Corporate bonds $ 2,983,195 $ (68,910 ) $ 1,234,865 $ (36,518 ) $ 4,218,060 $ (105,428 ) Mortgage backed securities 84,296 (695 ) 109,009 (2,521 ) 193,305 (3,216 ) Municipal bonds 233,081 (2,074 ) 408,155 (9,817 ) 641,236 (11,891 ) Commercial mortgage backed securities 223,341 (2,831 ) 193,956 (7,920 ) 417,297 (10,751 ) U.S. government and government agencies 635,049 (1,354 ) 391,102 (7,120 ) 1,026,151 (8,474 ) Non-U.S. government securities 1,028,340 (35,524 ) 389,671 (15,424 ) 1,418,011 (50,948 ) Asset backed securities 533,592 (8,832 ) 368,095 (5,966 ) 901,687 (14,798 ) Total 5,720,894 (120,220 ) 3,094,853 (85,286 ) 8,815,747 (205,506 ) Short-term investments 122,878 (394 ) — — 122,878 (394 ) Total $ 5,843,772 $ (120,614 ) $ 3,094,853 $ (85,286 ) $ 8,938,625 $ (205,900 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.”
Contractual maturities of the Company's fixed maturities and fixed maturities pledged under securities lending arrangements	The contractual maturities of the Company’s fixed maturities are shown in the following table. Expected maturities, which are management’s best estimates, will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2019 December 31, 2018 Maturity Estimated Fair Value Amortized Cost Estimated Amortized Cost Due in one year or less $ 414,736 $ 413,481 $ 276,682 $ 279,135 Due after one year through five years 9,833,517 9,702,349 8,666,297 8,738,944 Due after five years through 10 years 3,028,435 2,923,881 2,919,232 2,951,582 Due after 10 years 185,638 178,629 218,768 226,537 13,462,326 13,218,340 12,080,979 12,196,198 Mortgage backed securities 523,019 511,821 541,193 540,418 Commercial mortgage backed securities 686,707 665,663 729,442 737,543 Asset backed securities 1,636,897 1,612,244 1,600,896 1,607,634 Total (1) $ 16,308,949 $ 16,008,068 $ 14,952,510 $ 15,081,793 (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.”
Securities lending transactions accounted for as secured borrowings, by significant investment category	The Company’s securities lending transactions were accounted for as secured borrowings with significant investment categories as follows: Remaining Contractual Maturity of the Agreements Overnight and Continuous Less than 30 Days 30-90 Days 90 Days or More Total June 30, 2019 U.S. government and government agencies $ 216,856 $ — $ 217,722 $ — $ 434,578 Corporate bonds 2,356 — — — 2,356 Equity securities 13,378 — — — 13,378 Total $ 232,590 $ — $ 217,722 $ — $ 450,312 Gross amount of recognized liabilities for securities lending in offsetting disclosure in note 8 $ — Amounts related to securities lending not included in offsetting disclosure in note 8 $ 450,312 December 31, 2018 U.S. government and government agencies $ 219,276 $ — $ 32,583 $ — $ 251,859 Corporate bonds 7,129 — — — 7,129 Equity securities 15,137 — — — 15,137 Total $ 241,542 $ — $ 32,583 $ — $ 274,125 Gross amount of recognized liabilities for securities lending in offsetting disclosure in note 8 $ — Amounts related to securities lending not included in offsetting disclosure in note 8 $ 274,125
Summary of other investments	The following table summarizes the Company’s other investments which are included in investments accounted for using the fair value option, by strategy: June 30, December 31, Term loan investments (par value: $1,427,330 and $1,369,216) $ 1,341,445 $ 1,282,287 Lending 585,954 524,112 Credit related funds 166,673 202,123 Energy 123,547 117,509 Investment grade fixed income 86,808 101,902 Infrastructure 49,260 45,371 Private equity 23,925 24,383 Real estate 16,906 14,252 Total $ 2,394,518 $ 2,311,939
Summary of investments accounted for using equity method	The following table summarizes the Company’s investments accounted for using the equity method, by strategy: June 30, December 31, Credit related funds $ 436,118 $ 429,402 Equities 324,525 375,273 Real estate 251,891 232,647 Lending 193,397 125,041 Private equity 131,863 114,019 Infrastructure 141,744 113,748 Energy 102,434 103,661 Total $ 1,581,972 $ 1,493,791
Summary of assets and liabilities accounted for using the fair value option	The following table summarizes the Company’s assets which are accounted for using the fair value option: June 30, December 31, Fixed maturities $ 965,161 $ 1,245,562 Other investments 2,394,518 2,311,939 Short-term investments 257,465 322,177 Equity securities 103,891 103,893 Investments accounted for using the fair value option $ 3,721,035 $ 3,983,571
Summary of investments in limited partnership interests where the Company has a variable interest	The following table summarizes investments in limited partnership interests where the Company has a variable interest by balance sheet line item: June 30, December 31, Investments accounted for using the equity method (1) 1,581,972 1,493,791 Investments accounted for using the fair value option (2) 178,977 162,398 Total $ 1,760,949 $ 1,656,189 (1) Aggregate unfunded commitments were $1.41 billion at June 30, 2019 , compared to $1.22 billion at December 31, 2018 . (2) Aggregate unfunded commitments were $63.6 million at June 30, 2019 , compared to $117.5 million at December 31, 2018 .
Components of net investment income	The components of net investment income were derived from the following sources: June 30, 2019 2018 Three Months Ended Fixed maturities $ 125,018 $ 115,110 Term loans 24,730 20,763 Equity securities 4,368 4,777 Short-term investments 3,859 4,392 Other (1) 18,523 17,405 Gross investment income 176,498 162,447 Investment expenses (21,460 ) (26,779 ) Net investment income $ 155,038 $ 135,668 Six Months Ended Fixed maturities $ 254,817 $ 222,997 Term loans 49,346 40,527 Equity securities 7,356 7,345 Short-term investments 8,038 9,252 Other (1) 39,719 35,015 Gross investment income 359,276 315,136 Investment expenses (47,289 ) (52,744 ) Net investment income $ 311,987 $ 262,392 (1)
Summary of net realized gains (losses), excluding other-than-temporary impairment provisions	Net realized gains (losses) were as follows, excluding net impairment losses recognized in earnings: June 30, 2019 2018 Three Months Ended Available for sale securities: Gross gains on investment sales $ 75,090 $ 18,777 Gross losses on investment sales (15,281 ) (57,711 ) Change in fair value of assets and liabilities accounted for using the fair value option: Fixed maturities 11,429 (22,927 ) Other investments (33,780 ) (254 ) Equity securities 6,414 1,230 Short-term investments (1,392 ) (136 ) Equity securities, at fair value: Net realized gains (losses) on sales during the period (6,644 ) (5,918 ) Net unrealized gains (losses) on equity securities still held at reporting date 22,632 (7,278 ) Derivative instruments (1) 63,966 (2,146 ) Other (2) (1,628 ) (248 ) Net realized gains (losses) $ 120,806 $ (76,611 ) Six Months Ended Available for sale securities: Gross gains on investment sales $ 118,455 $ 33,742 Gross losses on investment sales (46,937 ) (140,262 ) Change in fair value of assets and liabilities accounted for using the fair value option: Fixed maturities 42,577 (40,478 ) Other investments (15,585 ) (6,628 ) Equity securities 10,680 7,898 Short-term investments (672 ) (287 ) Equity securities, at fair value: Net realized gains (losses) on sales during the period 4,286 (11,286 ) Net unrealized gains (losses) on equity securities still held at reporting date 59,768 (14,861 ) Derivative instruments (1) 99,837 (6,109 ) Other (2) (10,038 ) (9,338 ) Net realized gains (losses) $ 262,371 $ (187,609 ) (1) See note 8 for information on the Company’s derivative instruments. (2) Includes the re-measurement of contingent consideration liability amounts.
Summary of OTTI recognized in earnings by asset class	The following table details the net impairment losses recognized in earnings by asset class: June 30, 2019 2018 Three Months Ended Fixed maturities: Mortgage backed securities $ (24 ) $ (81 ) Corporate bonds (25 ) (241 ) Asset backed securities — (148 ) Total (49 ) (470 ) Net impairment losses recognized in earnings $ (49 ) $ (470 ) Six Months Ended Fixed maturities: Mortgage backed securities $ (555 ) $ (123 ) Corporate bonds (590 ) (361 ) Asset backed securities (213 ) (148 ) Total (1,358 ) (632 ) Net impairment losses recognized in earnings $ (1,358 ) $ (632 )
Rollforward of the amount related to credit losses recognized in earnings for which a portion was recognized in AOCI	The following table provides a roll forward of the amount related to credit losses recognized in earnings for which a portion of an OTTI was recognized in accumulated other comprehensive income: June 30, 2019 2018 Three Months Ended Balance at start of period $ 346 $ 767 Credit loss impairments recognized on securities not previously impaired — — Credit loss impairments recognized on securities previously impaired — — Reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security — — Reductions for securities sold during the period — (69 ) Balance at end of period $ 346 $ 698 Six Months Ended Balance at start of year $ 637 $ 767 Credit loss impairments recognized on securities not previously impaired — — Credit loss impairments recognized on securities previously impaired — — Reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security — — Reductions for securities sold during the period (291 ) (69 ) Balance at end of period $ 346 $ 698
Summary of restricted assets	The following table details the value of the Company’s restricted assets: June 30, December 31, Assets used for collateral or guarantees: Affiliated transactions $ 4,758,653 $ 4,623,483 Third party agreements 2,612,380 2,181,682 Deposits with U.S. regulatory authorities 788,750 689,114 Deposits with non-U.S. regulatory authorities 62,449 59,624 Total restricted assets $ 8,222,232 $ 7,553,903
Reconciliation of cash and restricted cash	The following table details reconciliation of cash and restricted cash within the Consolidated Balance Sheets: June 30, December 31, Cash $ 605,316 $ 646,556 Restricted cash (included in ‘other assets’) $ 77,759 $ 78,087 Cash and restricted cash $ 683,075 $ 724,643

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair value hierarchy	The following table presents the Company’s financial assets and liabilities measured at fair value by level at June 30, 2019 : Estimated Fair Value Measurements Using: Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured at fair value (1): Available for sale securities: Fixed maturities: Corporate bonds $ 6,044,081 $ — $ 6,036,439 $ 7,642 Mortgage backed securities 523,019 — 522,729 290 Municipal bonds 582,497 — 582,497 — Commercial mortgage backed securities 686,707 — 686,707 — U.S. government and government agencies 4,906,996 4,746,260 160,736 — Non-U.S. government securities 1,928,752 — 1,928,752 — Asset backed securities 1,636,897 — 1,636,897 — Total 16,308,949 4,746,260 11,554,757 7,932 Short-term investments 821,961 803,337 18,624 — Equity securities, at fair value 684,236 620,508 12,516 51,212 Derivative instruments (4) 30,653 — 30,653 — Fair value option: Corporate bonds 673,431 — 647,328 26,103 Non-U.S. government bonds 56,416 — 56,416 — Mortgage backed securities 16,076 — 16,076 — Municipal bonds 6,731 — 6,731 — Commercial mortgage backed securities — — — — Asset backed securities 208,019 — 208,019 — U.S. government and government agencies 4,488 4,378 110 — Short-term investments 257,465 247,216 10,249 — Equity securities 103,891 47,157 589 56,145 Other investments 1,394,344 41,176 1,257,895 95,273 Other investments measured at net asset value (2) 1,000,174 Total 3,721,035 339,927 2,203,413 177,521 Total assets measured at fair value $ 21,566,834 $ 6,510,032 $ 13,819,963 $ 236,665 Liabilities measured at fair value: Contingent consideration liabilities $ (7,825 ) $ — $ — $ (7,825 ) Securities sold but not yet purchased (3) (48,823 ) — (48,823 ) — Derivative instruments (4) (38,363 ) — (38,363 ) — Total liabilities measured at fair value $ (95,011 ) $ — $ (87,186 ) $ (7,825 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See note 6 , “—Securities Lending Agreements.” (2) In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (3) Represents the Company’s obligations to deliver securities that it did not own at the time of sale. Such amounts are included in “other liabilities” on the Company’s consolidated balance sheets. (4) See note 8 . The following table presents the Company’s financial assets and liabilities measured at fair value by level at December 31, 2018 : Estimated Fair Value Measurements Using: Estimated Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured at fair value (1): Available for sale securities: Fixed maturities: Corporate bonds $ 5,537,548 $ — $ 5,529,407 $ 8,141 Mortgage backed securities 541,193 — 540,884 309 Municipal bonds 1,013,395 — 1,013,395 — Commercial mortgage backed securities 729,442 — 729,438 4 U.S. government and government agencies 3,758,698 3,657,181 101,517 — Non-U.S. government securities 1,771,338 — 1,771,338 — Asset backed securities 1,600,896 — 1,600,896 — Total 14,952,510 3,657,181 11,286,875 8,454 Equity securities 353,794 321,927 31,867 — Short-term investments 955,880 875,881 79,999 — Derivative instruments (4) 73,893 — 73,893 — Fair value option: Corporate bonds 852,585 — 846,827 5,758 Non-U.S. government bonds 79,066 — 79,066 — Mortgage backed securities 16,731 — 16,731 — Municipal bonds 7,144 — 7,144 — Commercial mortgage backed securities — — — — Asset backed securities 178,790 — 178,790 — U.S. government and government agencies 111,246 111,138 108 — Short-term investments 322,177 278,579 43,598 — Equity securities 103,893 48,827 55,066 — Other investments 1,254,220 39,107 1,152,408 62,705 Other investments measured at net asset value (2) 1,057,719 Total 3,983,571 477,651 2,379,738 68,463 Total assets measured at fair value $ 20,319,648 $ 5,332,640 $ 13,852,372 $ 76,917 Liabilities measured at fair value: Contingent consideration liabilities $ (66,665 ) $ — $ — $ (66,665 ) Securities sold but not yet purchased (3) (7,790 ) — (7,790 ) — Derivative instruments (4) (20,664 ) — (20,664 ) — Total liabilities measured at fair value $ (95,119 ) $ — $ (28,454 ) $ (66,665 ) (1) In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See note 6 , “—Securities Lending Agreements.” (2) In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (3) Represents the Company’s obligations to deliver securities that it did not own at the time of sale. Such amounts are included in “other liabilities” on the Company’s consolidated balance sheets. (4) See note 8 .
Rollforward of Level 3 investments	The following table presents a reconciliation of the beginning and ending balances for all financial assets and liabilities measured at fair value on a recurring basis using Level 3 inputs: Assets Liabilities s Available For Sale Fair Value Option Fair Value Structured Securities (1) Corporate Corporate Other Investments Equity Securities Equity Securities Contingent Consideration Liabilities Three Months Ended June 30, 2019 Balance at beginning of period $ 302 $ 7,567 $ 2,233 $ 62,329 $ — $ — $ (68,121 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) — — (49 ) (11,614 ) — — (423 ) Included in other comprehensive income 1 102 — — — — — Purchases, issuances, sales and settlements Purchases — 429 — — — — — Issuances — — — — — — — Sales — — — (74 ) — — — Settlements (13 ) (456 ) — — — — 60,719 Transfers in and/or out of Level 3 — — 23,919 44,632 56,145 51,212 — Balance at end of period $ 290 $ 7,642 $ 26,103 $ 95,273 $ 56,145 $ 51,212 $ (7,825 ) Three Months Ended June 30, 2018 Balance at beginning of period $ 5,413 $ 9,152 $ 11,872 $ 58,452 $ — $ — $ (62,449 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 3 — (537 ) 336 — — (1,481 ) Included in other comprehensive income (4 ) (316 ) — — — — — Purchases, issuances, sales and settlements Purchases — 393 — — — — — Issuances — — — — — — — Sales (5,003 ) — — (74 ) — — — Settlements (33 ) (456 ) — (500 ) — — — Transfers in and/or out of Level 3 — — — — — — — Balance at end of period $ 376 $ 8,773 $ 11,335 $ 58,214 $ — $ — $ (63,930 ) Six Months Ended June 30, 2019 Balance at beginning of year $ 313 $ 8,141 $ 5,758 $ 62,705 $ — $ — $ (66,665 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 1,757 — (339 ) (11,316 ) — — (1,331 ) Included in other comprehensive income 5 (16 ) — — — — — Purchases, issuances, sales and settlements Purchases — 429 — — — — — Issuances — — — — — — (548 ) Sales (1,757 ) — (3,235 ) (148 ) — — — Settlements (28 ) (912 ) — (600 ) — — 60,719 Transfers in and/or out of Level 3 — — 23,919 44,632 56,145 51,212 — Balance at end of period $ 290 $ 7,642 $ 26,103 $ 95,273 $ 56,145 $ 51,212 $ (7,825 ) Six Months Ended June 30, 2018 Balance at beginning of year $ 5,927 $ 9,460 $ 12,217 $ 59,167 $ — $ — $ (60,996 ) Total gains or (losses) (realized/unrealized) Included in earnings (2) 4 — (612 ) (379 ) — — (2,934 ) Included in other comprehensive income (8 ) (168 ) — — — — — Purchases, issuances, sales and settlements Purchases — 393 — — — — — Issuances — — — — — — — Sales (5,003 ) — — (74 ) — — — Settlements (544 ) (912 ) (270 ) (500 ) — — — Transfers in and/or out of Level 3 — — — — — — — Balance at end of period $ 376 $ 8,773 $ 11,335 $ 58,214 $ — $ — $ (63,930 ) (1) Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities. (2) Gains or losses were included in net realized gains (losses).

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value and notional amount of derivatives	The following table summarizes information on the fair values and notional values of the Company’s derivative instruments: Estimated Fair Value Asset Derivatives Liability Derivatives Notional Value (1) June 30, 2019 Futures contracts (2) $ 5,438 $ (1,586 ) $ 4,354,852 Foreign currency forward contracts (2) 3,190 (10,352 ) 939,940 TBAs (3) 15,509 — 14,846 Other (2) 22,025 (26,425 ) 3,493,526 Total $ 46,162 $ (38,363 ) December 31, 2018 Futures contracts (2) $ 51,800 $ (2,115 ) $ 3,153,518 Foreign currency forward contracts (2) 8,147 (7,796 ) 1,008,907 TBAs (3) 8,292 — 8,132 Other (2) 13,946 (10,753 ) 2,213,981 Total $ 82,185 $ (20,664 ) (1) Represents the absolute notional value of all outstanding contracts, consisting of long and short positions. (2) The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’ (3) The fair value of TBAs are included in ‘fixed maturities available for sale, at fair value.’
Summary of net realized gains (losses) recorded in the consolidated statements of income	Realized and unrealized contract gains and losses on the Company’s derivative instruments are reflected in ‘net realized gains (losses)’ in the consolidated statements of income, as summarized in the following table: Derivatives not designated as June 30, hedging instruments: 2019 2018 Three Months Ended Net realized gains (losses): Futures contracts $ 66,973 $ (240 ) Foreign currency forward contracts (5,365 ) (1,692 ) TBAs 48 — Other 2,310 (214 ) Total $ 63,966 $ (2,146 ) Six Months Ended Net realized gains (losses): Futures contracts $ 94,309 $ 4,790 Foreign currency forward contracts (19,074 ) (7,616 ) TBAs 238 (97 ) Other 24,364 (3,186 ) Total $ 99,837 $ (6,109 )

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Additional information regarding operating leases	Additional information regarding the Company’s operating leases is as follows: June 30, 2019 Three Months Ended Operating lease costs $ 7,244 Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 7,685 Right-of-use assets obtained in exchange for new lease liabilities $ 4,420 Right-of-use assets (1) $ 134,061 Operating lease liability (1) $ 150,341 Weighted average discount rate 3.9 % Weighted average remaining lease term 6.5 years Six Months Ended Operating lease costs $ 14,860 Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 14,585 Right-of-use assets obtained in exchange for new lease liabilities $ 4,420 Right-of-use assets (1) $ 134,061 Operating lease liability (1) $ 150,341 Weighted average discount rate 3.9 % Weighted average remaining lease term 6.5 years (1) The right-of-use assets are included in ‘other assets’ while the operating lease liability is included in ‘other liabilities.’
Contractual maturities of lease liabilities	The following table presents the contractual maturities of the Company's operating lease liabilities at June 30, 2019 : Years Ending December 31, 2019 (remainder) $ 9,985 2020 32,036 2021 30,673 2022 27,365 2023 22,667 2024 and thereafter 55,610 Total undiscounted lease liability $ 178,336 Less: present value adjustment (27,995 ) Operating lease liability $ 150,341
Future minimum rental commitments	At December 31, 2018 , the future minimum rental commitments, exclusive of escalation clauses and maintenance costs and net of rental income, for all of the Company’s operating leases was as follows: 2019 $ 31,088 2020 30,491 2021 29,351 2022 26,068 2023 21,408 2024 and thereafter 54,745 Total $ 193,151

Variable Interest Entities an_2

Variable Interest Entities and Noncontrolling Interests (Tables)	6 Months Ended
	Jun. 30, 2019
Noncontrolling Interest [Abstract]
Carrying value of assets and liabilities of variable interest entity	The following table provides the carrying amount and balance sheet caption in which the assets and liabilities of Watford Re are reported: June 30, December 31, 2019 2018 Assets Investments accounted for using the fair value option $ 1,972,947 $ 2,312,003 Fixed maturities available for sale, at fair value 732,454 393,351 Equity securities, at fair value 64,703 32,206 Cash 68,977 63,529 Accrued investment income 16,916 19,461 Premiums receivable 228,588 227,301 Reinsurance recoverable on unpaid and paid losses and LAE 123,961 86,445 Ceded unearned premiums 79,513 61,587 Deferred acquisition costs 71,557 80,858 Receivable for securities sold 29,425 24,507 Goodwill and intangible assets 7,650 7,650 Other assets 71,837 63,959 Total assets of consolidated VIE $ 3,468,528 $ 3,372,857 Liabilities Reserve for losses and loss adjustment expenses $ 1,126,080 $ 1,032,760 Unearned premiums 375,323 390,114 Reinsurance balances payable 23,312 21,034 Revolving credit agreement borrowings 491,006 455,682 Payable for securities purchased 51,216 60,142 Other liabilities (1) 219,120 302,524 Total liabilities of consolidated VIE $ 2,286,057 $ 2,262,256 Redeemable noncontrolling interests $ 221,175 $ 220,992 (1) Includes certain borrowings related to investing activities.
Activity in non-redeemable noncontrolling interests	The following table sets forth activity in the non-redeemable noncontrolling interests: June 30, 2019 2018 Three Months Ended Balance, beginning of period $ 838,081 $ 854,112 Additional paid in capital attributable to noncontrolling interests 2,074 — Amounts attributable to noncontrolling interests 12,301 8,116 Other comprehensive income (loss) attributable to noncontrolling interests 2,891 (1,075 ) Balance, end of period $ 855,347 $ 861,153 Six Months Ended Balance, beginning of year $ 791,560 $ 843,411 Additional paid in capital attributable to noncontrolling interests 2,074 — Amounts attributable to noncontrolling interests 54,683 19,492 Other comprehensive income (loss) attributable to noncontrolling interests 7,030 (1,750 ) Balance, end of period $ 855,347 $ 861,153
Activity in redeemable noncontrolling interests	The following table sets forth activity in the redeemable non-controlling interests: June 30, 2019 2018 Three Months Ended Balance, beginning of period $ 206,383 $ 206,013 Accretion of preference share issuance costs 92 92 Balance, end of period $ 206,475 $ 206,105 Six Months Ended Balance, beginning of year $ 206,292 $ 205,922 Accretion of preference share issuance costs 183 183 Balance, end of period $ 206,475 $ 206,105
Portion of income or loss attributable to third party investors	The portion of Watford Re’s income or loss attributable to third party investors, recorded in the Company’s consolidated statements of income in ‘net (income) loss attributable to noncontrolling interests,’ are summarized in the table below: June 30, 2019 2018 Three Months Ended Amounts attributable to non-redeemable noncontrolling interests $ (12,301 ) $ (8,116 ) Dividends attributable to redeemable noncontrolling interests (4,590 ) (4,585 ) Net (income) loss attributable to noncontrolling interests $ (16,891 ) $ (12,701 ) Six Months Ended Amounts attributable to non-redeemable noncontrolling interests $ (54,683 ) $ (19,492 ) Dividends attributable to redeemable noncontrolling interests (9,178 ) (9,170 ) Net (income) loss attributable to noncontrolling interests $ (63,861 ) $ (28,662 )
Total assets and maximum exposure to loss associated with VIEs	The following table presents the total assets of the Bellemeade entities, as well as the Company’s maximum exposure to loss associated with these VIEs, calculated as the maximum historical observable spread between the one month LIBOR, the basis for the contractual payments to bond holders, and short term invested trust asset yields. Maximum Exposure to Loss Bellemeade Entities (Issue Date) Total VIE Assets On-Balance Sheet (Asset) Liability Off-Balance Sheet Total Jun 30, 2019 Bellemeade 2015-1 Ltd. (Jul-15) $ 19,103 $ (4 ) $ 17 $ 13 Bellemeade 2017-1 Ltd. (Oct-17) 277,554 (657 ) 4,892 4,235 Bellemeade 2018-1 Ltd. (Apr-18) 374,460 (1,965 ) 7,799 5,834 Bellemeade 2018-2 Ltd. (Aug-18) 571,129 (1,957 ) 5,265 3,308 Bellemeade 2018-3 Ltd. (Oct-18) 506,110 (2,213 ) 7,251 5,038 Bellemeade 2019-1 Ltd. (Mar-19) 329,085 (237 ) 4,842 4,605 Bellemeade 2019-2 Ltd. (Apr-19) 621,022 (408 ) 11,206 10,798 Total $ 2,698,463 $ (7,441 ) $ 41,272 $ 33,831 Dec 31, 2018 Bellemeade 2015-1 Ltd. (Jul-15) $ 43,246 $ 112 $ 498 $ 610 Bellemeade 2017-1 Ltd. (Oct-17) 304,373 165 1,312 1,477 Bellemeade 2018-1 Ltd. (Apr-18) 374,460 132 3,539 3,671 Bellemeade 2018-2 Ltd. (Aug-18) 653,278 874 4,005 4,879 Bellemeade 2018-3 Ltd. (Oct-18) 506,110 469 1,836 2,305 Total $ 1,881,467 $ 1,752 $ 11,190 $ 12,942

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2019
Comprehensive Income Note Disclosure [Abstract]
Details about amounts reclassified from AOCI	The following tables present details about amounts reclassified from accumulated other comprehensive income and the tax effects allocated to each component of other comprehensive income (loss): Amounts Reclassified from AOCI Consolidated Statement of Income Three Months Ended Six Months Ended Details About Line Item That Includes June 30, June 30, AOCI Components Reclassification 2019 2018 2019 2018 Unrealized appreciation on available-for-sale investments Net realized gains (losses) $ 59,809 $ (38,935 ) $ 71,518 $ (106,521 ) Other-than-temporary impairment losses (49 ) (470 ) (1,358 ) (632 ) Total before tax 59,760 (39,405 ) 70,160 (107,153 ) Income tax (expense) benefit (4,415 ) 2,762 (4,594 ) 8,049 Net of tax $ 55,345 $ (36,643 ) $ 65,566 $ (99,104 )
Schedule of comprehensive income (loss)	Before Tax Amount Tax Expense (Benefit) Net of Tax Amount Three Months Ended June 30, 2019 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ 248,074 $ 25,601 $ 222,473 Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income 59,760 4,415 55,345 Foreign currency translation adjustments 4,409 142 4,267 Other comprehensive income (loss) $ 192,723 $ 21,328 $ 171,395 Three Months Ended June 30, 2018 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ (88,034 ) $ (2,763 ) $ (85,271 ) Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income (39,405 ) (2,762 ) (36,643 ) Foreign currency translation adjustments (12,701 ) (106 ) (12,595 ) Other comprehensive income (loss) $ (61,330 ) $ (107 ) $ (61,223 ) Six Months Ended June 30, 2019 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ 503,064 $ 54,704 $ 448,360 Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income 70,160 4,594 65,566 Foreign currency translation adjustments 10,053 270 9,783 Other comprehensive income (loss) $ 442,957 $ 50,380 $ 392,577 Six Months Ended June 30, 2018 Unrealized appreciation (decline) in value of investments: Unrealized holding gains (losses) arising during period $ (277,977 ) $ (26,029 ) $ (251,948 ) Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss) — — — Less reclassification of net realized gains (losses) included in net income (107,153 ) (8,049 ) (99,104 ) Foreign currency translation adjustments (11,269 ) 44 (11,313 ) Other comprehensive income (loss) $ (182,093 ) $ (17,936 ) $ (164,157 )

Guarantor Financial Informati_2

Guarantor Financial Information (Tables)	6 Months Ended
	Jun. 30, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed consolidating balance sheet	June 30, 2019 Condensed Consolidating Balance Sheet Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Assets Total investments $ 40 $ 483,904 $ 22,693,719 $ (49,700 ) $ 23,127,963 Cash 10,750 47,875 546,691 — 605,316 Investments in subsidiaries 11,045,465 4,493,198 — (15,538,663 ) — Due from subsidiaries and affiliates 332 2 1,881,929 (1,882,263 ) — Premiums receivable — — 2,291,360 (685,320 ) 1,606,040 Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses — — 8,618,279 (5,447,022 ) 3,171,257 Contractholder receivables — — 2,102,544 — 2,102,544 Ceded unearned premiums — — 1,984,219 (847,491 ) 1,136,728 Deferred acquisition costs — — 658,992 (58,252 ) 600,740 Goodwill and intangible assets — — 641,010 — 641,010 Other assets 22,950 40,345 1,953,732 (156,955 ) 1,860,072 Total assets $ 11,079,537 $ 5,065,324 $ 43,372,475 $ (24,665,666 ) $ 34,851,670 Liabilities Reserve for losses and loss adjustment expenses $ — $ — $ 17,430,847 $ (5,200,531 ) $ 12,230,316 Unearned premiums — — 4,904,351 (847,491 ) 4,056,860 Reinsurance balances payable — — 1,217,310 (685,320 ) 531,990 Contractholder payables — — 2,102,544 — 2,102,544 Collateral held for insured obligations — — 237,056 237,056 Senior notes 297,201 494,776 941,888 — 1,733,865 Revolving credit agreement borrowings — — 491,006 — 491,006 Due to subsidiaries and affiliates 9 536,747 1,345,507 (1,882,263 ) — Other liabilities 24,975 64,956 2,055,626 (496,698 ) 1,648,859 Total liabilities 322,185 1,096,479 30,726,135 (9,112,303 ) 23,032,496 Redeemable noncontrolling interests — — 221,175 (14,700 ) 206,475 Shareholders’ Equity Total shareholders’ equity available to Arch 10,757,352 3,968,845 11,569,818 (15,538,663 ) 10,757,352 Non-redeemable noncontrolling interests — — 855,347 — 855,347 Total shareholders’ equity 10,757,352 3,968,845 12,425,165 (15,538,663 ) 11,612,699 Total liabilities, noncontrolling interests and shareholders’ equity $ 11,079,537 $ 5,065,324 $ 43,372,475 $ (24,665,666 ) $ 34,851,670 December 31, 2018 Condensed Consolidating Balance Sheet Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Assets Total investments $ 104 $ 452,674 $ 21,307,206 $ (14,700 ) $ 21,745,284 Cash 6,125 5,940 634,491 — 646,556 Investments in subsidiaries 9,735,256 3,999,243 — (13,734,499 ) — Due from subsidiaries and affiliates 9 2 1,802,686 (1,802,697 ) — Premiums receivable — — 1,834,389 (535,239 ) 1,299,150 Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses — — 8,618,660 (5,699,288 ) 2,919,372 Contractholder receivables — — 2,079,111 — 2,079,111 Ceded unearned premiums — — 1,730,262 (754,793 ) 975,469 Deferred acquisition costs — — 618,535 (48,961 ) 569,574 Goodwill and intangible assets — — 634,920 — 634,920 Other assets 12,588 80,949 1,466,438 (211,082 ) 1,348,893 Total assets $ 9,754,082 $ 4,538,808 $ 40,726,698 $ (22,801,259 ) $ 32,218,329 Liabilities Reserve for losses and loss adjustment expenses $ — $ — $ 17,345,142 $ (5,491,845 ) $ 11,853,297 Unearned premiums — — 4,508,429 (754,793 ) 3,753,636 Reinsurance balances payable — — 928,346 (535,239 ) 393,107 Contractholder payables — — 2,079,111 — 2,079,111 Collateral held for insured obligations — — 236,630 — 236,630 Senior notes 297,150 494,723 941,655 — 1,733,528 Revolving credit agreement borrowings — — 455,682 — 455,682 Due to subsidiaries and affiliates — 536,805 1,265,892 (1,802,697 ) — Other liabilities 17,105 26,270 1,699,768 (467,484 ) 1,275,659 Total liabilities 314,255 1,057,798 29,460,655 (9,052,058 ) 21,780,650 Redeemable noncontrolling interests — — 220,992 (14,700 ) 206,292 Shareholders’ Equity Total shareholders’ equity available to Arch 9,439,827 3,481,010 10,253,491 (13,734,501 ) 9,439,827 Non-redeemable noncontrolling interests — — 791,560 — 791,560 Total shareholders’ equity 9,439,827 3,481,010 11,045,051 (13,734,501 ) 10,231,387 Total liabilities, noncontrolling interests and shareholders’ equity $ 9,754,082 $ 4,538,808 $ 40,726,698 $ (22,801,259 ) $ 32,218,329
Condensed consolidating statement of income and comprehensive income	Three Months Ended June 30, 2019 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 1,463,727 $ — $ 1,463,727 Net investment income 38 2,847 174,738 (22,585 ) 155,038 Net realized gains (losses) — 5,825 115,620 (639 ) 120,806 Net impairment losses recognized in earnings — — (49 ) — (49 ) Other underwriting income — — 5,953 — 5,953 Equity in net income (loss) of investment funds accounted for using the equity method — (64 ) 32,600 — 32,536 Other income (loss) (242 ) — 1,371 — 1,129 Total revenues (204 ) 8,608 1,793,960 (23,224 ) 1,779,140 Expenses Losses and loss adjustment expenses — — 767,543 — 767,543 Acquisition expenses — — 210,089 — 210,089 Other operating expenses — — 198,914 — 198,914 Corporate expenses 15,293 2,115 843 — 18,251 Amortization of intangible assets — — 19,794 — 19,794 Interest expense 5,538 11,996 34,012 (22,266 ) 29,280 Net foreign exchange (gains) losses — — (1,187 ) 6,139 4,952 Total expenses 20,831 14,111 1,230,008 (16,127 ) 1,248,823 Income (loss) before income taxes (21,035 ) (5,503 ) 563,952 (7,097 ) 530,317 Income tax (expense) benefit — 1,301 (45,773 ) — (44,472 ) Income (loss) before equity in net income of subsidiaries (21,035 ) (4,202 ) 518,179 (7,097 ) 485,845 Equity in net income of subsidiaries 489,989 148,747 — (638,736 ) — Net income 468,954 144,545 518,179 (645,833 ) 485,845 Net (income) loss attributable to noncontrolling interests — — (17,210 ) 319 (16,891 ) Net income available to Arch 468,954 144,545 500,969 (645,514 ) 468,954 Preferred dividends (10,403 ) — — — (10,403 ) Net income available to Arch common shareholders $ 458,551 $ 144,545 $ 500,969 $ (645,514 ) $ 458,551 Comprehensive income available to Arch $ 637,458 $ 231,120 $ 663,685 $ (894,805 ) $ 637,458 Three Months Ended June 30, 2018 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 1,336,763 $ — $ 1,336,763 Net investment income 15 560 157,532 (22,439 ) 135,668 Net realized gains (losses) — — (76,611 ) — (76,611 ) Net impairment losses recognized in earnings — — (470 ) — (470 ) Other underwriting income — — 3,874 — 3,874 Equity in net income (loss) of investment funds accounted for using the equity method — — 8,472 — 8,472 Other income (loss) 2,339 — 774 — 3,113 Total revenues 2,354 560 1,430,334 (22,439 ) 1,410,809 Expenses Losses and loss adjustment expenses — — 726,153 — 726,153 Acquisition expenses — — 202,838 — 202,838 Other operating expenses — — 176,181 — 176,181 Corporate expenses 16,642 470 5,400 — 22,512 Amortization of intangible assets — — 26,472 — 26,472 Interest expense 5,537 12,013 34,911 (22,117 ) 30,344 Net foreign exchange (gains) losses — — (43,357 ) (10,349 ) (53,706 ) Total expenses 22,179 12,483 1,128,598 (32,466 ) 1,130,794 Income (loss) before income taxes (19,825 ) (11,923 ) 301,736 10,027 280,015 Income tax (expense) benefit — 2,477 (26,145 ) — (23,668 ) Income (loss) before equity in net income of subsidiaries (19,825 ) (9,446 ) 275,591 10,027 256,347 Equity in net income of subsidiaries 263,471 86,727 — (350,198 ) — Net income (loss) 243,646 77,281 275,591 (340,171 ) 256,347 Net (income) loss attributable to noncontrolling interests — — (13,023 ) 322 (12,701 ) Net income (loss) available to Arch 243,646 77,281 262,568 (339,849 ) 243,646 Preferred dividends (10,403 ) — — — (10,403 ) Net income (loss) available to Arch common shareholders $ 233,243 $ 77,281 $ 262,568 $ (339,849 ) $ 233,243 Comprehensive income available to Arch $ 183,500 $ 70,066 $ 212,802 $ (282,868 ) $ 183,500 Six Months Ended June 30, 2019 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 2,832,593 $ — $ 2,832,593 Net investment income 84 6,526 350,410 (45,033 ) 311,987 Net realized gains (losses) — 14,343 253,673 (5,645 ) 262,371 Net impairment losses recognized in earnings — — (1,358 ) — (1,358 ) Other underwriting income — — 14,778 — 14,778 Equity in net income (loss) of investment funds accounted for using the equity method — (64 ) 79,467 — 79,403 Other income (loss) (481 ) — 2,693 — 2,212 Total revenues (397 ) 20,805 3,532,256 (50,678 ) 3,501,986 Expenses Losses and loss adjustment expenses — — 1,486,075 — 1,486,075 Acquisition expenses — — 407,937 — 407,937 Other operating expenses — — 400,077 — 400,077 Corporate expenses 31,600 4,281 332 — 36,213 Amortization of intangible assets — — 40,211 — 40,211 Interest expense 11,076 23,947 67,718 (44,396 ) 58,345 Net foreign exchange (gains) losses 2 — (1,310 ) 2,735 1,427 Total expenses 42,678 28,228 2,401,040 (41,661 ) 2,430,285 Income (loss) before income taxes (43,075 ) (7,423 ) 1,131,216 (9,017 ) 1,071,701 Income tax (expense) benefit — 1,844 (92,202 ) — (90,358 ) Income (loss) before equity in net income of subsidiaries (43,075 ) (5,579 ) 1,039,014 (9,017 ) 981,343 Equity in net income of subsidiaries 960,557 285,301 — (1,245,858 ) — Net income 917,482 279,722 1,039,014 (1,254,875 ) 981,343 Net (income) loss attributable to noncontrolling interests — — (64,499 ) 638 (63,861 ) Net income available to Arch 917,482 279,722 974,515 (1,254,237 ) 917,482 Preferred dividends (20,806 ) — — — (20,806 ) Net income available to Arch common shareholders $ 896,676 $ 279,722 $ 974,515 $ (1,254,237 ) $ 896,676 Comprehensive income available to Arch $ 1,303,029 $ 469,276 $ 1,352,225 $ (1,821,501 ) $ 1,303,029 Six Months Ended June 30, 2018 Condensed Consolidating Statement of Income and Comprehensive Income Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Revenues Net premiums earned $ — $ — $ 2,571,662 $ — $ 2,571,662 Net investment income 35 818 306,299 (44,760 ) 262,392 Net realized gains (losses) 29 (7 ) (187,631 ) — (187,609 ) Net impairment losses recognized in earnings — — (632 ) — (632 ) Other underwriting income — — 9,223 — 9,223 Equity in net income (loss) of investment funds accounted for using the equity method — — 36,541 — 36,541 Other income (loss) 2,261 — 926 — 3,187 Total revenues 2,325 811 2,736,388 (44,760 ) 2,694,764 Expenses Losses and loss adjustment expenses — — 1,363,013 — 1,363,013 Acquisition expenses — — 394,214 — 394,214 Other operating expenses — — 351,196 — 351,196 Corporate expenses 32,811 759 4,254 — 37,824 Amortization of intangible assets — — 53,208 — 53,208 Interest expense 11,073 23,939 70,083 (44,115 ) 60,980 Net foreign exchange (gains) losses 29 — (26,921 ) (7,093 ) (33,985 ) Total expenses 43,913 24,698 2,209,047 (51,208 ) 2,226,450 Income (loss) before income taxes (41,588 ) (23,887 ) 527,341 6,448 468,314 Income tax (expense) benefit — 5,428 (51,011 ) — (45,583 ) Income (loss) before equity in net income of subsidiaries (41,588 ) (18,459 ) 476,330 6,448 422,731 Equity in net income of subsidiaries 435,657 173,147 — (608,804 ) — Net income 394,069 154,688 476,330 (602,356 ) 422,731 Net (income) loss attributable to noncontrolling interests — — (29,307 ) 645 (28,662 ) Net income available to Arch 394,069 154,688 447,023 (601,711 ) 394,069 Preferred dividends (20,840 ) — — — (20,840 ) Loss on redemption of preferred shares (2,710 ) — — — (2,710 ) Net income available to Arch common shareholders $ 370,519 $ 154,688 $ 447,023 $ (601,711 ) $ 370,519 Comprehensive income available to Arch $ 231,662 $ 76,603 $ 291,883 $ (368,486 ) $ 231,662
Condensed consolidating statement of cash flows	Six Months Ended June 30, 2019 Condensed Consolidating Statement of Cash Flows Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Operating Activities Net Cash Provided By (Used For) Operating Activities $ 30,946 $ 24,059 $ 749,885 $ (92,366 ) $ 712,524 Investing Activities Purchases of fixed maturity investments — (358,996 ) (15,973,650 ) — (16,332,646 ) Purchases of equity securities — (56,441 ) (447,742 ) 72,244 (431,939 ) Purchases of other investments — (17,891 ) (659,172 ) — (677,063 ) Proceeds from the sales of fixed maturity investments — 452,729 15,179,753 — 15,632,482 Proceeds from the sales of equity securities — — 248,945 (72,244 ) 176,701 Proceeds from the sales, redemptions and maturities of other investments — 391 534,307 — 534,698 Proceeds from redemptions and maturities of fixed maturity investments — 100 244,849 — 244,949 Net settlements of derivative instruments — — 87,701 — 87,701 Net (purchases) sales of short-term investments 64 (2,015 ) 203,471 — 201,520 Change in cash collateral related to securities lending — — 7,590 — 7,590 Contributions to subsidiaries (2,121 ) — (59,527 ) 61,648 — Issuance of intercompany loans — — (53,828 ) 53,828 — Purchases of fixed assets (32 ) — (16,327 ) — (16,359 ) Other — — (174,578 ) — (174,578 ) Net Cash Provided By (Used For) Investing Activities (2,089 ) 17,877 (878,208 ) 115,476 (746,944 ) Financing Activities Purchases of common shares under share repurchase program (2,871 ) — — — (2,871 ) Proceeds from common shares issued, net (557 ) — 61,648 (61,648 ) (557 ) Proceeds from intercompany borrowings — — 53,828 (53,828 ) — Proceeds from borrowings — — 62,800 — 62,800 Repayments of borrowings — — (27,538 ) — (27,538 ) Change in cash collateral related to securities lending — — (7,590 ) — (7,590 ) Dividends paid to redeemable noncontrolling interests — — (9,632 ) 638 (8,994 ) Dividends paid to parent (1) — — (91,728 ) 91,728 — Other — — (3,529 ) — (3,529 ) Preferred dividends paid (20,806 ) — — — (20,806 ) Net Cash Provided By (Used For) Financing Activities (24,234 ) — 38,259 (23,110 ) (9,085 ) Effects of exchange rates changes on foreign currency cash and restricted cash — — 1,937 — 1,937 Increase (decrease) in cash and restricted cash 4,623 41,936 (88,127 ) — (41,568 ) Cash and restricted cash, beginning of year 6,159 5,940 712,544 — 724,643 Cash and restricted cash, end of period $ 10,782 $ 47,876 $ 624,417 $ — $ 683,075 (1) Dividends received by parent are included in net cash provided by (used for) operating activities. Six Months Ended June 30, 2018 Condensed Consolidating Statement of Cash Flows Arch Capital (Parent Guarantor) Arch-U.S. (Subsidiary Issuer) Other Arch Capital Subsidiaries Consolidating Adjustments and Eliminations Arch Capital Consolidated Operating Activities Net Cash Provided By (Used For) Operating Activities $ 201,487 $ 149,576 $ 1,010,703 $ (864,880 ) $ 496,886 Investing Activities Purchases of fixed maturity investments — (125,440 ) (17,347,846 ) 605,716 (16,867,570 ) Purchases of equity securities — — (679,663 ) — (679,663 ) Purchases of other investments — — (1,017,147 ) — (1,017,147 ) Proceeds from the sales of fixed maturity investments — 33,793 16,662,466 (605,716 ) 16,090,543 Proceeds from the sales of equity securities — — 622,068 — 622,068 Proceeds from the sales, redemptions and maturities of other investments — — 773,298 — 773,298 Proceeds from redemptions and maturities of fixed maturity investments — — 511,448 — 511,448 Net settlements of derivative instruments — — 4,498 — 4,498 Net (purchases) sales of short-term investments 96,446 (59,798 ) 415,253 — 451,901 Change in cash collateral related to securities lending — — 176,304 — 176,304 Contributions to subsidiaries — (1,000 ) (22,595 ) 23,595 — Purchases of fixed assets (71 ) — (13,171 ) — (13,242 ) Other (4 ) — 49,965 — 49,961 Net Cash Provided By (Used For) Investing Activities 96,371 (152,445 ) 134,878 23,595 102,399 Financing Activities Redemption of preferred shares (92,555 ) — — — (92,555 ) Purchases of common shares under share repurchase program (173,575 ) — — — (173,575 ) Proceeds from common shares issued, net (13,851 ) — 23,595 (23,595 ) (13,851 ) Proceeds from borrowings — — 130,579 — 130,579 Repayments of borrowings — — (373,000 ) — (373,000 ) Change in cash collateral related to securities lending — — (176,304 ) — (176,304 ) Dividends paid to redeemable noncontrolling interests — — (9,632 ) 638 (8,994 ) Dividends paid to parent (1) — — (864,242 ) 864,242 — Other — — (4,489 ) — (4,489 ) Preferred dividends paid (20,840 ) — — — (20,840 ) Net Cash Provided By (Used For) Financing Activities (300,821 ) — (1,273,493 ) 841,285 (733,029 ) Effects of exchange rates changes on foreign currency cash and restricted cash — — (10,431 ) — (10,431 ) Increase (decrease) in cash and restricted cash (2,963 ) (2,869 ) (138,343 ) — (144,175 ) Cash and restricted cash, beginning of year 10,048 30,380 686,856 — 727,284 Cash and restricted cash, end of period $ 7,085 $ 27,511 $ 548,513 $ — $ 583,109 (1) Dividends received by parent are included in net cash provided by (used for) operating activities.

Basis of Presentation and Rec_3

Basis of Presentation and Recent Accounting Pronouncements (Details) - USD ($)	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability	$ 150,341,000
ASU 2018-11
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of an accounting change			$ 0
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of an accounting change		$ 0		$ 0	$ 0	$ 149,794,000
Accumulated other comprehensive income (loss), net of deferred income tax
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of an accounting change		$ 0		$ 0	$ 0	$ (149,794,000)
Other assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	134,061,000
Other assets | ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets			147,900,000
Other liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability	$ 150,341,000
Other liabilities | ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability			$ 163,600,000

Share Transactions - Share repu

Share Transactions - Share repurchases (Details) - USD ($) shares in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Class of Stock [Line Items]
Treasury stock, shares acquired (shares)	0.1	6.5
Shares repurchased for treasury	$ 2.9	$ 173.6
Common shares
Class of Stock [Line Items]
Cumulative number of shares acquired since inception of share repurchase program	386.3
Aggregate purchase price of shares acquired since inception of share repurchase program	$ 3,970
Remaining authorized repurchase amount	$ 160.9

Share Transactions - Conversion

Share Transactions - Conversion of Non-voting common equivalent preferred shares (Details) - shares shares in Millions	1 Months Ended
	Mar. 31, 2018	Jun. 30, 2018
Class of Stock [Line Items]
Number of common shares issued on conversion	17
Number of convertible shares transferred		0.6

Share Transactions - Series C P

Share Transactions - Series C Preferred Shares (Details) - Series C Preferred Shares	Jan. 02, 2018$ / shares
Class of Stock [Line Items]
Preferred shares, dividend rate	6.75%
Preferred shares, redemption price	$ 25

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income		$ 485,845	$ 256,347	$ 981,343	$ 422,731
Amounts attributable to noncontrolling interests		(16,891)	(12,701)	(63,861)	(28,662)
Net income available to Arch		468,954	243,646	917,482	394,069
Preferred dividends		(10,403)	(10,403)	(20,806)	(20,840)
Loss on redemption of preferred shares		0	0	0	(2,710)
Net income available to Arch common shareholders		$ 458,551	$ 233,243	$ 896,676	$ 370,519
Denominator:
Weighted average common shares outstanding		401,482,784	404,800,421	400,837,181	399,485,135
Series D preferred shares	[1]	0	0	0	6,677,373
Weighted average common shares outstanding — basic		401,482,784	404,800,421	400,837,181	406,162,508
Effect of dilutive common share equivalents:
Nonvested restricted shares		1,937,626	1,575,749	1,720,417	1,837,356
Stock options	[2]	7,479,073	6,735,035	7,197,652	7,460,892
Weighted average common shares and common share equivalents outstanding — diluted		410,899,483	413,111,205	409,755,250	415,460,756
Earnings per common share:
Basic (per share)		$ 1.14	$ 0.58	$ 2.24	$ 0.91
Diluted (per share)		$ 1.12	$ 0.56	$ 2.19	$ 0.89
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per common share (shares)		2,016,830	5,350,733	2,560,755	5,372,789
[1]	Such shares are convertible non-voting common equivalent preferred shares issued in connection with the UGC acquisition.
[2]	Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2019 second quarter and 2018 second quarter , the number of stock options excluded were 2,016,830 and 5,350,733 , respectively. For the six months ended June 30, 2019 and 2018 period, the number of stock options excluded were 2,560,755 and 5,372,789 , respectively.

Segment Information - Summary o

Segment Information - Summary of underwriting income or loss by segment (Details) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2019USD ($)		Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)segment		Jun. 30, 2018USD ($)		Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Gross premiums written		$ 1,937,809		$ 1,696,544	$ 4,015,688		$ 3,534,758
Premiums ceded		(492,911)		(397,648)	(1,045,531)		(823,318)
Net premiums written		1,444,898		1,298,896	2,970,157		2,711,440
Change in unearned premiums		18,829		37,867	(137,564)		(139,778)
Net premiums earned		1,463,727		1,336,763	2,832,593		2,571,662
Other underwriting income		5,953		3,874	14,778		9,223
Losses and loss adjustment expenses		(767,543)		(726,153)	(1,486,075)		(1,363,013)
Acquisition expenses, net		(210,089)		(202,838)	(407,937)		(394,214)
Other operating expenses		(198,914)		(176,181)	(400,077)		(351,196)
Underwriting income (loss)		293,134		235,465	553,282		472,462
Net investment income		155,038		135,668	311,987		262,392
Net realized gains (losses)		120,806		(76,611)	262,371		(187,609)
Net impairment losses recognized in earnings		(49)		(470)	(1,358)		(632)
Equity in net income of investment funds accounted for using the equity method		32,536		8,472	79,403		36,541
Other income (loss)		1,129		3,113	2,212		3,187
Corporate expenses		(16,073)	[1]	(15,604)	(32,845)	[1]	(30,086)	[1]
Transaction costs and other		(2,178)	[1]	(6,908)	(3,368)	[1]	(7,738)	[1]
Amortization of intangible assets		(19,794)		(26,472)	(40,211)		(53,208)
Interest expense		(29,280)		(30,344)	(58,345)		(60,980)
Net foreign exchange gains (losses)		(4,952)		53,706	(1,427)		33,985
Income before income taxes		530,317		280,015	1,071,701		468,314
Income tax expense		(44,472)		(23,668)	(90,358)		(45,583)
Net income		485,845		256,347	981,343		422,731
Dividends attributable to redeemable noncontrolling interests		(4,590)		(4,585)	(9,178)		(9,170)
Amounts attributable to non-redeemable noncontrolling interests		(12,301)		(8,116)	(54,683)		(19,492)
Net income available to Arch		468,954		243,646	917,482		394,069
Preferred dividends		(10,403)		(10,403)	(20,806)		(20,840)
Loss on redemption of preferred shares		0		0	0		(2,710)
Net income available to Arch common shareholders		$ 458,551		$ 233,243	$ 896,676		$ 370,519
Underwriting Ratios
Loss ratio		52.40%		54.30%	52.50%		53.00%
Acquisition expense ratio		14.40%		15.20%	14.40%		15.30%
Other operating expense ratio		13.60%		13.20%	14.10%		13.70%
Combined ratio		80.40%		82.70%	81.00%		82.00%
Goodwill and intangible assets		$ 641,010		$ 593,008	$ 641,010		$ 593,008		$ 634,920
Other
Segment Reporting Information [Line Items]
Number of segments | segment					2
Gross premiums written	[2]	161,978		175,175	$ 348,667		389,045
Premiums ceded		(42,608)		(34,589)	(83,910)		(68,907)
Net premiums written		119,370		140,586	264,757		320,138
Change in unearned premiums		31,948		18,932	32,655		(23,872)
Net premiums earned		151,318		159,518	297,412		296,266
Other underwriting income		673		688	1,265		1,389
Losses and loss adjustment expenses		(111,416)		(117,141)	(222,266)		(215,130)
Acquisition expenses, net		(29,556)		(34,289)	(58,582)		(65,610)
Other operating expenses		(15,612)		(9,094)	(27,800)		(17,793)
Underwriting income (loss)		(4,593)		(318)	(9,971)		(878)
Net investment income		32,000		27,907	67,700		54,388
Net realized gains (losses)		(4,306)		(17,066)	24,826		(16,205)
Net impairment losses recognized in earnings		0		0	0		0
Equity in net income of investment funds accounted for using the equity method		0		0	0		0
Other income (loss)		0		0	0		0
Corporate expenses		0	[1]	0	0	[1]	0	[1]
Transaction costs and other		0	[1]	0	0	[1]	0	[1]
Amortization of intangible assets		0		0	0		0
Interest expense		(5,905)		(4,286)	(11,488)		(9,015)
Net foreign exchange gains (losses)		1,238		7,495	(412)		2,813
Income before income taxes		18,434		13,732	70,655		31,103
Income tax expense		(20)		(24)	(20)		(27)
Net income		18,414		13,708	70,635		31,076
Dividends attributable to redeemable noncontrolling interests		(4,590)		(4,585)	(9,178)		(9,170)
Amounts attributable to non-redeemable noncontrolling interests		(12,301)		(8,116)	(54,683)		(19,492)
Net income available to Arch		1,523		1,007	6,774		2,414
Preferred dividends		0		0	0		0
Loss on redemption of preferred shares							0
Net income available to Arch common shareholders		$ 1,523		$ 1,007	$ 6,774		$ 2,414
Underwriting Ratios
Loss ratio		73.60%		73.40%	74.70%		72.60%
Acquisition expense ratio		19.50%		21.50%	19.70%		22.10%
Other operating expense ratio		10.30%		5.70%	9.30%		6.00%
Combined ratio		103.40%		100.60%	103.70%		100.70%
Goodwill and intangible assets		$ 7,650		$ 7,650	$ 7,650		$ 7,650
Sub-Total
Segment Reporting Information [Line Items]
Number of segments | segment					3
Gross premiums written	[2]	1,829,829		1,591,202	$ 3,810,282		3,312,807
Premiums ceded		(504,301)		(432,892)	(1,104,882)		(921,505)
Net premiums written		1,325,528		1,158,310	2,705,400		2,391,302
Change in unearned premiums		(13,119)		18,935	(170,219)		(115,906)
Net premiums earned		1,312,409		1,177,245	2,535,181		2,275,396
Other underwriting income		5,280		3,186	13,513		7,834
Losses and loss adjustment expenses		(656,127)		(609,012)	(1,263,809)		(1,147,883)
Acquisition expenses, net		(180,533)		(168,549)	(349,355)		(328,604)
Other operating expenses		(183,302)		(167,087)	(372,277)		(333,403)
Underwriting income (loss)		297,727		235,783	563,253		473,340
Net investment income		123,038		107,761	244,287		208,004
Net realized gains (losses)		125,112		(59,545)	237,545		(171,404)
Net impairment losses recognized in earnings		(49)		(470)	(1,358)		(632)
Equity in net income of investment funds accounted for using the equity method		32,536		8,472	79,403		36,541
Other income (loss)		1,129		3,113	2,212		3,187
Corporate expenses		(16,073)	[1]	(15,604)	(32,845)	[1]	(30,086)	[1]
Transaction costs and other		(2,178)	[1]	(6,908)	(3,368)	[1]	(7,738)	[1]
Amortization of intangible assets		(19,794)		(26,472)	(40,211)		(53,208)
Interest expense		(23,375)		(26,058)	(46,857)		(51,965)
Net foreign exchange gains (losses)		(6,190)		46,211	(1,015)		31,172
Income before income taxes		511,883		266,283	1,001,046		437,211
Income tax expense		(44,452)		(23,644)	(90,338)		(45,556)
Net income		467,431		242,639	910,708		391,655
Dividends attributable to redeemable noncontrolling interests		0		0	0		0
Amounts attributable to non-redeemable noncontrolling interests		0		0	0		0
Net income available to Arch		467,431		242,639	910,708		391,655
Preferred dividends		(10,403)		(10,403)	(20,806)		(20,840)
Loss on redemption of preferred shares							(2,710)
Net income available to Arch common shareholders		$ 457,028		$ 232,236	$ 889,902		$ 368,105
Underwriting Ratios
Loss ratio		50.00%		51.70%	49.90%		50.40%
Acquisition expense ratio		13.80%		14.30%	13.80%		14.40%
Other operating expense ratio		14.00%		14.20%	14.70%		14.70%
Combined ratio		77.80%		80.20%	78.40%		79.50%
Goodwill and intangible assets		$ 633,360		$ 585,358	$ 633,360		$ 585,358
Sub-Total | Insurance
Segment Reporting Information [Line Items]
Gross premiums written	[2]	919,925		769,372	1,861,879		1,592,750
Premiums ceded		(292,095)		(245,265)	(612,717)		(492,445)
Net premiums written		627,830		524,107	1,249,162		1,100,305
Change in unearned premiums		(35,388)		22,342	(103,215)		(15,119)
Net premiums earned		592,442		546,449	1,145,947		1,085,186
Other underwriting income		0		0	0		0
Losses and loss adjustment expenses		(389,172)		(357,465)	(745,895)		(711,195)
Acquisition expenses, net		(91,094)		(90,670)	(173,918)		(175,839)
Other operating expenses		(109,523)		(92,680)	(222,919)		(184,654)
Underwriting income (loss)		$ 2,653		$ 5,634	$ 3,215		$ 13,498
Underwriting Ratios
Loss ratio		65.70%		65.40%	65.10%		65.50%
Acquisition expense ratio		15.40%		16.60%	15.20%		16.20%
Other operating expense ratio		18.50%		17.00%	19.50%		17.00%
Combined ratio		99.60%		99.00%	99.80%		98.70%
Goodwill and intangible assets		$ 157,440		$ 20,724	$ 157,440		$ 20,724
Sub-Total | Reinsurance
Segment Reporting Information [Line Items]
Gross premiums written	[2]	545,547		490,327	1,228,402		1,067,810
Premiums ceded		(169,457)		(136,247)	(401,024)		(331,977)
Net premiums written		376,090		354,080	827,378		735,833
Change in unearned premiums		(8,906)		(13,762)	(113,829)		(116,343)
Net premiums earned		367,184		340,318	713,549		619,490
Other underwriting income		1,224		(129)	5,601		1,103
Losses and loss adjustment expenses		(240,958)		(229,956)	(480,768)		(371,631)
Acquisition expenses, net		(56,785)		(50,142)	(111,111)		(98,461)
Other operating expenses		(33,960)		(35,678)	(69,664)		(71,249)
Underwriting income (loss)		$ 36,705		$ 24,413	$ 57,607		$ 79,252
Underwriting Ratios
Loss ratio		65.60%		67.60%	67.40%		60.00%
Acquisition expense ratio		15.50%		14.70%	15.60%		15.90%
Other operating expense ratio		9.20%		10.50%	9.80%		11.50%
Combined ratio		90.30%		92.80%	92.80%		87.40%
Goodwill and intangible assets		$ 0		$ 0	$ 0		$ 0
Sub-Total | Mortgage
Segment Reporting Information [Line Items]
Gross premiums written	[2]	364,465		330,990	720,515		652,168
Premiums ceded		(42,857)		(50,867)	(91,655)		(97,004)
Net premiums written		321,608		280,123	628,860		555,164
Change in unearned premiums		31,175		10,355	46,825		15,556
Net premiums earned		352,783		290,478	675,685		570,720
Other underwriting income		4,056		3,315	7,912		6,731
Losses and loss adjustment expenses		(25,997)		(21,591)	(37,146)		(65,057)
Acquisition expenses, net		(32,654)		(27,737)	(64,326)		(54,304)
Other operating expenses		(39,819)		(38,729)	(79,694)		(77,500)
Underwriting income (loss)		$ 258,369		$ 205,736	$ 502,431		$ 380,590
Underwriting Ratios
Loss ratio		7.40%		7.40%	5.50%		11.40%
Acquisition expense ratio		9.30%		9.50%	9.50%		9.50%
Other operating expense ratio		11.30%		13.30%	11.80%		13.60%
Combined ratio		28.00%		30.20%	26.80%		34.50%
Goodwill and intangible assets		$ 475,920		$ 564,634	$ 475,920		$ 564,634
[1]	Certain expenses have been excluded from ‘corporate expenses’ and reflected in ‘transaction costs and other.’
[2]	Certain amounts included in the gross premiums written of each segment are related to intersegment transactions. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total.

Reserve for Losses and Loss A_3

Reserve for Losses and Loss Adjustment Expenses - Reconciliation of beginning and ending balances of losses and loss adjustment reserves (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019	Jun. 30, 2018
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Reserve for losses and loss adjustment expenses at beginning of period	$ 12,010,041		$ 11,496,205		$ 11,853,297	$ 11,383,792
Unpaid losses and loss adjustment expenses recoverable	2,970,159		2,446,990		2,814,291	2,464,910
Net reserve for losses and loss adjustment expenses at beginning of period	9,039,882		9,049,215		9,039,006	8,918,882
Net incurred losses and loss adjustment expenses relating to losses occurring in:
Current year	805,728		790,742		1,563,692	1,478,627
Prior years	(38,185)		(64,589)		(77,617)	(115,614)
Total net incurred losses and loss adjustment expenses	767,543		726,153		1,486,075	1,363,013
Retroactive reinsurance transaction	0	[1]	(420,404)	[1]	(225,500)	(420,404)
Net foreign exchange (gains) losses	(1,277)		(120,292)		(1,781)	(76,278)
Net paid losses and loss adjustment expenses relating to losses occurring in:
Current year	(61,148)		(59,022)		(125,488)	(95,022)
Prior years	(539,481)		(403,062)		(966,793)	(917,603)
Total net paid losses and loss adjustment expenses	(600,629)		(462,084)		(1,092,281)	(1,012,625)
Net reserve for losses and loss adjustment expenses at end of period	9,205,519		8,772,588		9,205,519	8,772,588
Unpaid losses and loss adjustment expenses recoverable	3,024,797		2,651,749		3,024,797	2,651,749
Reserve for losses and loss adjustment expenses at end of period	$ 12,230,316		$ 11,424,337		$ 12,230,316	$ 11,424,337
[1]	During the 2019 first quarter

Reserve for Losses and Loss A_4

Reserve for Losses and Loss Adjustment Expenses - Prior year development (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (38,185)	$ (64,589)	$ (77,617)	$ (115,614)
Underwriting segments | Insurance
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (2,600)	$ (6,100)	$ (7,000)	$ (8,200)
Percentage of prior year development	0.40%	1.10%	0.60%	0.80%
Underwriting segments | Insurance | Short Tailed Lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (8,000)	$ (13,900)	$ (17,700)	$ (22,700)
Underwriting segments | Insurance | Medium Tailed Lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	10,400	22,100	17,300	31,700
Underwriting segments | Insurance | Medium Tailed Lines | Programs
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	15,500	11,600	23,200	21,900
Underwriting segments | Insurance | Medium Tailed Lines | Contract binding
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development		18,000	9,700	25,600
Underwriting segments | Insurance | Medium Tailed Lines | Other product lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	(5,100)	(7,600)	(15,600)	(15,800)
Underwriting segments | Insurance | Long Tailed Lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	(4,900)	(14,300)	(6,600)	(17,200)
Underwriting segments | Insurance | Long Tailed Lines | Executive assurance
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	(5,100)	(6,900)	(5,700)	(7,500)
Underwriting segments | Insurance | Long Tailed Lines | Healthcare
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development		(4,900)		(7,000)
Underwriting segments | Reinsurance
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (12,700)	$ (33,000)	$ (11,000)	$ (69,600)
Percentage of prior year development	3.50%	9.70%	1.50%	11.20%
Underwriting segments | Reinsurance | Short Tailed Lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (1,800)	$ (22,200)	$ 4,300	$ (51,100)
Underwriting segments | Reinsurance | Short Tailed Lines | Property catastrophe and property other than property catastrophe
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development		(19,300)	17,900	(40,400)
Underwriting segments | Reinsurance | Short Tailed Lines | Property catastrophe and property other than property catastrophe | Typhoon Jebi
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development			16,000
Underwriting segments | Reinsurance | Short Tailed Lines | Other specialty lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development			(10,200)
Underwriting segments | Reinsurance | Medium Tailed And Long Tailed Lines
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	(10,900)	(10,800)	(15,300)	(18,500)
Underwriting segments | Reinsurance | Medium Tailed And Long Tailed Lines | Casualty
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development		(6,900)	(9,100)	(8,100)
Underwriting segments | Reinsurance | Medium Tailed And Long Tailed Lines | Marine
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development		(3,800)	(6,200)	(10,000)
Underwriting segments | Mortgage
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (22,800)	$ (23,300)	$ (59,400)	$ (36,300)
Percentage of prior year development	6.50%	8.00%	8.80%	6.40%
Underwriting segments | Other
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (100)	$ (2,200)	$ (100)	$ (1,600)

Investment Information - Summar

Investment Information - Summary of available for sale securities (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2019	Dec. 31, 2018
Available for sale securities:
Estimated Fair Value		$ 17,130,910	$ 15,908,390
Gross Unrealized Gains		363,099	76,259
Gross Unrealized Losses		(62,414)	(205,900)
Cost or Amortized Cost		16,830,225	16,038,031
OTTI Unrealized Losses		(6)	(75)
Fixed maturities
Available for sale securities:
Estimated Fair Value		16,308,949	14,952,510
Gross Unrealized Gains	[1]	362,815	76,223
Gross Unrealized Losses	[1]	(61,934)	(205,506)
Cost or Amortized Cost	[1]	16,008,068	15,081,793
OTTI Unrealized Losses	[1],[2]	(6)	(75)
Fixed maturities | Corporate bonds
Available for sale securities:
Estimated Fair Value		6,044,081	5,537,548
Gross Unrealized Gains	[1]	166,372	14,476
Gross Unrealized Losses	[1]	(19,805)	(105,428)
Cost or Amortized Cost	[1]	5,897,514	5,628,500
OTTI Unrealized Losses	[1],[2]	0	(69)
Fixed maturities | Mortgage backed securities
Available for sale securities:
Estimated Fair Value		523,019	541,193
Gross Unrealized Gains	[1]	11,385	3,991
Gross Unrealized Losses	[1]	(187)	(3,216)
Cost or Amortized Cost	[1]	511,821	540,418
OTTI Unrealized Losses	[1],[2]	(6)	(6)
Fixed maturities | Municipal bonds
Available for sale securities:
Estimated Fair Value		582,497	1,013,395
Gross Unrealized Gains	[1]	21,755	5,380
Gross Unrealized Losses	[1]	(58)	(11,891)
Cost or Amortized Cost	[1]	560,800	1,019,906
OTTI Unrealized Losses	[1],[2]	0	0
Fixed maturities | Commercial mortgage backed securities
Available for sale securities:
Estimated Fair Value		686,707	729,442
Gross Unrealized Gains	[1]	21,272	2,650
Gross Unrealized Losses	[1]	(228)	(10,751)
Cost or Amortized Cost	[1]	665,663	737,543
OTTI Unrealized Losses	[1],[2]	0	0
Fixed maturities | US government and government agencies
Available for sale securities:
Estimated Fair Value		4,906,996	3,758,698
Gross Unrealized Gains	[1]	68,017	27,189
Gross Unrealized Losses	[1]	(2,051)	(8,474)
Cost or Amortized Cost	[1]	4,841,030	3,739,983
OTTI Unrealized Losses	[1],[2]	0	0
Fixed maturities | Non-US government securities
Available for sale securities:
Estimated Fair Value		1,928,752	1,771,338
Gross Unrealized Gains	[1]	45,881	14,477
Gross Unrealized Losses	[1]	(36,125)	(50,948)
Cost or Amortized Cost	[1]	1,918,996	1,807,809
OTTI Unrealized Losses	[1],[2]	0	0
Fixed maturities | Asset backed securities
Available for sale securities:
Estimated Fair Value		1,636,897	1,600,896
Gross Unrealized Gains	[1]	28,133	8,060
Gross Unrealized Losses	[1]	(3,480)	(14,798)
Cost or Amortized Cost	[1]	1,612,244	1,607,634
OTTI Unrealized Losses	[1],[2]	0	0
Short-term investments
Available for sale securities:
Estimated Fair Value		821,961	955,880
Gross Unrealized Gains		284	36
Gross Unrealized Losses		(480)	(394)
Cost or Amortized Cost		822,157	956,238
OTTI Unrealized Losses	[2]	$ 0	$ 0
[1]	In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.”
[2]	Represents the total other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income (“AOCI”). It does not include the change in fair value subsequent to the impairment measurement date. At June 30, 2019 the net unrealized loss related to securities for which a non-credit OTTI was recognized in AOCI was $0.01 million , compared to net unrealized loss of $0.04 million at December 31, 2018

Investment Information - Aging

Investment Information - Aging of available for sale securities in an unrealized loss position (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Available for sale securities:
Estimated Fair Value - Less than 12 Months		$ 2,662,411	$ 5,843,772
Gross Unrealized Losses - Less than 12 Months		(49,030)	(120,614)
Estimated Fair Value - 12 Months or More		770,586	3,094,853
Gross Unrealized Losses - 12 Months or More		(13,384)	(85,286)
Estimated Fair Value - Total		3,432,997	8,938,625
Gross Unrealized Losses - Total		(62,414)	(205,900)
Fixed maturities
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	2,608,980	5,720,894
Gross Unrealized Losses - Less than 12 Months	[1]	(48,550)	(120,220)
Estimated Fair Value - 12 Months or More	[1]	770,586	3,094,853
Gross Unrealized Losses - 12 Months or More	[1]	(13,384)	(85,286)
Estimated Fair Value - Total	[1]	3,379,566	8,815,747
Gross Unrealized Losses - Total	[1]	(61,934)	(205,506)
Fixed maturities | Corporate bonds
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	259,361	2,983,195
Gross Unrealized Losses - Less than 12 Months	[1]	(10,678)	(68,910)
Estimated Fair Value - 12 Months or More	[1]	375,478	1,234,865
Gross Unrealized Losses - 12 Months or More	[1]	(9,127)	(36,518)
Estimated Fair Value - Total	[1]	634,839	4,218,060
Gross Unrealized Losses - Total	[1]	(19,805)	(105,428)
Fixed maturities | Mortgage backed securities
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	19,612	84,296
Gross Unrealized Losses - Less than 12 Months	[1]	(169)	(695)
Estimated Fair Value - 12 Months or More	[1]	261	109,009
Gross Unrealized Losses - 12 Months or More	[1]	(18)	(2,521)
Estimated Fair Value - Total	[1]	19,873	193,305
Gross Unrealized Losses - Total	[1]	(187)	(3,216)
Fixed maturities | Municipal bonds
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	0	233,081
Gross Unrealized Losses - Less than 12 Months	[1]	0	(2,074)
Estimated Fair Value - 12 Months or More	[1]	12,489	408,155
Gross Unrealized Losses - 12 Months or More	[1]	(58)	(9,817)
Estimated Fair Value - Total	[1]	12,489	641,236
Gross Unrealized Losses - Total	[1]	(58)	(11,891)
Fixed maturities | Commercial mortgage backed securities
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	18,917	223,341
Gross Unrealized Losses - Less than 12 Months	[1]	(106)	(2,831)
Estimated Fair Value - 12 Months or More	[1]	23,198	193,956
Gross Unrealized Losses - 12 Months or More	[1]	(122)	(7,920)
Estimated Fair Value - Total	[1]	42,115	417,297
Gross Unrealized Losses - Total	[1]	(228)	(10,751)
Fixed maturities | US government and government agencies
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	906,497	635,049
Gross Unrealized Losses - Less than 12 Months	[1]	(1,711)	(1,354)
Estimated Fair Value - 12 Months or More	[1]	104,692	391,102
Gross Unrealized Losses - 12 Months or More	[1]	(340)	(7,120)
Estimated Fair Value - Total	[1]	1,011,189	1,026,151
Gross Unrealized Losses - Total	[1]	(2,051)	(8,474)
Fixed maturities | Non-US government securities
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	1,092,560	1,028,340
Gross Unrealized Losses - Less than 12 Months	[1]	(33,985)	(35,524)
Estimated Fair Value - 12 Months or More	[1]	124,466	389,671
Gross Unrealized Losses - 12 Months or More	[1]	(2,140)	(15,424)
Estimated Fair Value - Total	[1]	1,217,026	1,418,011
Gross Unrealized Losses - Total	[1]	(36,125)	(50,948)
Fixed maturities | Asset backed securities
Available for sale securities:
Estimated Fair Value - Less than 12 Months	[1]	312,033	533,592
Gross Unrealized Losses - Less than 12 Months	[1]	(1,901)	(8,832)
Estimated Fair Value - 12 Months or More	[1]	130,002	368,095
Gross Unrealized Losses - 12 Months or More	[1]	(1,579)	(5,966)
Estimated Fair Value - Total	[1]	442,035	901,687
Gross Unrealized Losses - Total	[1]	(3,480)	(14,798)
Short-term investments
Available for sale securities:
Estimated Fair Value - Less than 12 Months		53,431	122,878
Gross Unrealized Losses - Less than 12 Months		(480)	(394)
Estimated Fair Value - 12 Months or More		0	0
Gross Unrealized Losses - 12 Months or More		0	0
Estimated Fair Value - Total		53,431	122,878
Gross Unrealized Losses - Total		$ (480)	$ (394)
[1]	In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.”

Investment Information - Maturi

Investment Information - Maturity profile of available for sale securities) (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Estimated Fair Value:
Estimated fair value		$ 15,881,732	$ 14,699,010
Amortized Cost:
Amortized cost		15,584,662	14,829,902
Fixed maturities
Estimated Fair Value:
Due in one year or less		414,736	276,682
Due after one year through five years		9,833,517	8,666,297
Due after five years through 10 years		3,028,435	2,919,232
Due after 10 years		185,638	218,768
Single maturity date		13,462,326	12,080,979
Estimated fair value	[1]	16,308,949	14,952,510
Amortized Cost:
Due in one year or less		413,481	279,135
Due after one year through five years		9,702,349	8,738,944
Due after five years through 10 years		2,923,881	2,951,582
Due after 10 years		178,629	226,537
Single maturity date		13,218,340	12,196,198
Amortized cost	[1]	16,008,068	15,081,793
Fixed maturities | Mortgage backed securities
Estimated Fair Value:
Securities without single maturity date		523,019	541,193
Amortized Cost:
Securities without single maturity date		511,821	540,418
Fixed maturities | Commercial mortgage backed securities
Estimated Fair Value:
Securities without single maturity date		686,707	729,442
Amortized Cost:
Securities without single maturity date		665,663	737,543
Fixed maturities | Asset backed securities
Estimated Fair Value:
Securities without single maturity date		1,636,897	1,600,896
Amortized Cost:
Securities without single maturity date		$ 1,612,244	$ 1,607,634
[1]	In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See “—Securities Lending Agreements.”

Investment Information - Securi

Investment Information - Securities lending agreements (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Disclosure Investment Information [Abstract]
Fair value of cash collateral received on securities lending	$ 11,400	$ 19,000
Fair value of non-cash collateral received on securities lending	438,900	255,100
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	450,312	274,125
Gross amount of recognized liabilities for securities lending in offsetting disclosure in note 8	0	0
Amounts related to securities lending not included in offsetting disclosure in note 8	450,312	274,125
US government and government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	434,578	251,859
Corporate bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	2,356	7,129
Equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	13,378	15,137
Overnight and continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	232,590	241,542
Overnight and continuous | US government and government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	216,856	219,276
Overnight and continuous | Corporate bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	2,356	7,129
Overnight and continuous | Equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	13,378	15,137
Less than 30 days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
Less than 30 days | US government and government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
Less than 30 days | Corporate bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
Less than 30 days | Equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
30 - 90 days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	217,722	32,583
30 - 90 days | US government and government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	217,722	32,583
30 - 90 days | Corporate bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
30 - 90 days | Equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
90 days or more
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
90 days or more | US government and government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
90 days or more | Corporate bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	0	0
90 days or more | Equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending payable	$ 0	$ 0

Investment Information - Other

Investment Information - Other investments (Details) - Fair value option - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule Of Other Investments [Line Items]
Other investments	$ 2,394,518	$ 2,311,939
Term loan investments
Schedule Of Other Investments [Line Items]
Other investments	1,341,445	1,282,287
Other investments par	1,427,330	1,369,216
Lending
Schedule Of Other Investments [Line Items]
Other investments	585,954	524,112
Credit related funds
Schedule Of Other Investments [Line Items]
Other investments	166,673	202,123
Energy
Schedule Of Other Investments [Line Items]
Other investments	123,547	117,509
Investment grade fixed income
Schedule Of Other Investments [Line Items]
Other investments	86,808	101,902
Infrastructure
Schedule Of Other Investments [Line Items]
Other investments	49,260	45,371
Private equity
Schedule Of Other Investments [Line Items]
Other investments	23,925	24,383
Real estate
Schedule Of Other Investments [Line Items]
Other investments	$ 16,906	$ 14,252

Investment Information - Equity

Investment Information - Equity method investments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	$ 1,581,972	$ 1,493,791
Credit related funds
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	436,118	429,402
Equity securities
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	324,525	375,273
Real estate
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	251,891	232,647
Lending
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	193,397	125,041
Private equity
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	131,863	114,019
Infrastructure
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	141,744	113,748
Energy
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	$ 102,434	$ 103,661

Investment Information - Fair v

Investment Information - Fair value option (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Option, Quantitative Disclosures [Line Items]
Investments accounted for using the fair value option	$ 3,721,035	$ 3,983,571
Fixed maturities
Fair Value, Option, Quantitative Disclosures [Line Items]
Investments accounted for using the fair value option	965,161	1,245,562
Other investments
Fair Value, Option, Quantitative Disclosures [Line Items]
Investments accounted for using the fair value option	2,394,518	2,311,939
Short-term investments
Fair Value, Option, Quantitative Disclosures [Line Items]
Investments accounted for using the fair value option	257,465	322,177
Equity securities
Fair Value, Option, Quantitative Disclosures [Line Items]
Investments accounted for using the fair value option	$ 103,891	$ 103,893

Investment Information - Limite

Investment Information - Limited partnership interests (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss		$ 1,760,949	$ 1,656,189
Aggregate unfunded commitments		1,920,000	1,770,000
Equity method investments
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[1]	1,581,972	1,493,791
Aggregate unfunded commitments		1,410,000	1,220,000
Fair value option
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[2]	178,977	162,398
Aggregate unfunded commitments		$ 63,600	$ 117,500
[1]	Aggregate unfunded commitments were $1.41 billion at June 30, 2019 , compared to $1.22 billion at December 31, 2018 .
[2]	Aggregate unfunded commitments were $63.6 million at June 30, 2019 , compared to $117.5 million at December 31, 2018 .

Investment Information - Net in

Investment Information - Net investment income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net investment income:
Gross investment income		$ 176,498	$ 162,447	$ 359,276	$ 315,136
Investment expenses		(21,460)	(26,779)	(47,289)	(52,744)
Net investment income		155,038	135,668	311,987	262,392
Fixed maturities
Net investment income:
Gross investment income		125,018	115,110	254,817	222,997
Term loans
Net investment income:
Gross investment income		24,730	20,763	49,346	40,527
Equity securities
Net investment income:
Gross investment income		4,368	4,777	7,356	7,345
Short-term investments
Net investment income:
Gross investment income		3,859	4,392	8,038	9,252
Other
Net investment income:
Gross investment income	[1]	$ 18,523	$ 17,405	$ 39,719	$ 35,015
[1]	Includes income distributions from investment funds and other items.

Investment Information - Net re

Investment Information - Net realized gains and losses (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net realized gains and losses:
Available for sale securities, gross gains on investment sales		$ 75,090	$ 18,777	$ 118,455	$ 33,742
Available for sale securities, gross losses on investment sales		(15,281)	(57,711)	(46,937)	(140,262)
Net realized gains (losses) on sales during the period		(6,644)	(5,918)	4,286	(11,286)
Net unrealized gains (losses) on equity securities still held at reporting date		22,632	(7,278)	59,768	(14,861)
Derivative instruments	[1]	63,966	(2,146)	99,837	(6,109)
Other	[2]	(1,628)	(248)	(10,038)	(9,338)
Net realized gains (losses)		120,806	(76,611)	262,371	(187,609)
Fixed maturities
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option		11,429	(22,927)	42,577	(40,478)
Other investments
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option		(33,780)	(254)	(15,585)	(6,628)
Equity securities
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option		6,414	1,230	10,680	7,898
Short-term investments
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option		$ (1,392)	$ (136)	$ (672)	$ (287)
[1]	See note 8 for information on the Company’s derivative instruments.
[2]	Includes the re-measurement of contingent consideration liability amounts.

Investment Information - Net im

Investment Information - Net impairment losses recognized in earnings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net impairment losses recognized in earnings	$ (49)	$ (470)	$ (1,358)	$ (632)
Fixed maturities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net impairment losses recognized in earnings	(49)	(470)	(1,358)	(632)
Fixed maturities | Mortgage backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net impairment losses recognized in earnings	(24)	(81)	(555)	(123)
Fixed maturities | Corporate bonds
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net impairment losses recognized in earnings	(25)	(241)	(590)	(361)
Fixed maturities | Asset backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net impairment losses recognized in earnings	$ 0	$ (148)	$ (213)	$ (148)

Investment Information - Othe_2

Investment Information - Other than temporary impairments rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Rollforward:
Balance at start of period	$ 346	$ 767	$ 637	$ 767
Credit loss impairments recognized on securities not previously impaired	0	0	0	0
Credit loss impairments recognized on securities previously impaired	0	0	0	0
Reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security	0	0	0	0
Reductions for securities sold during the period	0	(69)	(291)	(69)
Balance at end of period	$ 346	$ 698	$ 346	$ 698

Investment Information - Restri

Investment Information - Restricted assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Restricted Assets [Line Items]
Restricted assets	$ 8,222,232	$ 7,553,903
Collateral or guarantees - affiliated transactions
Restricted Assets [Line Items]
Restricted assets	4,758,653	4,623,483
Collateral or guarantees - third party agreements
Restricted Assets [Line Items]
Restricted assets	2,612,380	2,181,682
Deposits with US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	788,750	689,114
Deposits with non-US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	62,449	59,624
Watford Re
Restricted Assets [Line Items]
Assets pledged as collateral	$ 1,100,000	$ 1,300,000

Investment Information - Cash a

Investment Information - Cash and restricted cash (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Disclosure Investment Information [Abstract]
Cash	$ 605,316	$ 646,556
Restricted cash (included in ‘other assets’)	77,759	78,087
Cash and restricted cash	$ 683,075	$ 724,643	$ 583,109	$ 727,284

Investment Information - Narrat

Investment Information - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019USD ($)lots	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)lots	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)lots
Narrative items:
Investable assets	$ 23,550,000		$ 23,550,000
Equity in net income of investment funds accounted for using the equity method	32,536	$ 8,472	79,403	$ 36,541
OTTI unrealized (losses) gains at current fair value	$ (10)		$ (10)		$ (40)
Continuous unrealized loss, qualitative disclosures:
Number of positions in an unrealized loss position (lots) | lots	1,690		1,690		5,870
Total number of positions (lots) | lots	8,730		8,730		8,450
Largest single loss	$ 3,100		$ 3,100		$ 2,600
Equity securities, at fair value	670,943		670,943		338,899
OTTI unrealized losses (gains)			$ 6		$ 75
Minimum
Narrative items:
Time lag for reporting			1 month
Maximum
Narrative items:
Time lag for reporting			3 months
Underwriting segments
Narrative items:
Investable assets	20,780,000		$ 20,780,000
Equity in net income of investment funds accounted for using the equity method	32,536	8,472	79,403	36,541
Other
Narrative items:
Investable assets	2,770,000		2,770,000
Equity in net income of investment funds accounted for using the equity method	$ 0	$ 0	$ 0	$ 0

Fair Value - Fair Value Hierarc

Fair Value - Fair Value Hierarchy (Details) - Recurring - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		$ 6,510,032	$ 5,332,640
Liabilities measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Contingent consideration liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Securities sold but not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[1]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	4,746,260	3,657,181
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	4,746,260	3,657,181
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		620,508	321,927
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		803,337	875,881
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		339,927	477,651
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		4,378	111,138
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		247,216	278,579
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		47,157	48,827
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Other investments fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		41,176	39,107
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		13,819,963	13,852,372
Liabilities measured at fair value		(87,186)	(28,454)
Significant Other Observable Inputs (Level 2) | Contingent consideration liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		0	0
Significant Other Observable Inputs (Level 2) | Securities sold but not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[1]	(48,823)	(7,790)
Significant Other Observable Inputs (Level 2) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		(38,363)	(20,664)
Significant Other Observable Inputs (Level 2) | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	11,554,757	11,286,875
Significant Other Observable Inputs (Level 2) | Fixed maturities | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	6,036,439	5,529,407
Significant Other Observable Inputs (Level 2) | Fixed maturities | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	522,729	540,884
Significant Other Observable Inputs (Level 2) | Fixed maturities | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	582,497	1,013,395
Significant Other Observable Inputs (Level 2) | Fixed maturities | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	686,707	729,438
Significant Other Observable Inputs (Level 2) | Fixed maturities | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	160,736	101,517
Significant Other Observable Inputs (Level 2) | Fixed maturities | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	1,928,752	1,771,338
Significant Other Observable Inputs (Level 2) | Fixed maturities | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	1,636,897	1,600,896
Significant Other Observable Inputs (Level 2) | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		12,516	31,867
Significant Other Observable Inputs (Level 2) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		18,624	79,999
Significant Other Observable Inputs (Level 2) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		30,653	73,893
Significant Other Observable Inputs (Level 2) | Fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		2,203,413	2,379,738
Significant Other Observable Inputs (Level 2) | Fair value option | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		647,328	846,827
Significant Other Observable Inputs (Level 2) | Fair value option | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		16,076	16,731
Significant Other Observable Inputs (Level 2) | Fair value option | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		6,731	7,144
Significant Other Observable Inputs (Level 2) | Fair value option | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Other Observable Inputs (Level 2) | Fair value option | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		110	108
Significant Other Observable Inputs (Level 2) | Fair value option | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		56,416	79,066
Significant Other Observable Inputs (Level 2) | Fair value option | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		208,019	178,790
Significant Other Observable Inputs (Level 2) | Fair value option | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		10,249	43,598
Significant Other Observable Inputs (Level 2) | Fair value option | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		589	55,066
Significant Other Observable Inputs (Level 2) | Fair value option | Other investments fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		1,257,895	1,152,408
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		236,665	76,917
Liabilities measured at fair value		(7,825)	(66,665)
Significant Unobservable Inputs (Level 3) | Contingent consideration liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		(7,825)	(66,665)
Significant Unobservable Inputs (Level 3) | Securities sold but not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[1]	0	0
Significant Unobservable Inputs (Level 3) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	7,932	8,454
Significant Unobservable Inputs (Level 3) | Fixed maturities | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	7,642	8,141
Significant Unobservable Inputs (Level 3) | Fixed maturities | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	290	309
Significant Unobservable Inputs (Level 3) | Fixed maturities | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	4
Significant Unobservable Inputs (Level 3) | Fixed maturities | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Significant Unobservable Inputs (Level 3) | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		51,212	0
Significant Unobservable Inputs (Level 3) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		177,521	68,463
Significant Unobservable Inputs (Level 3) | Fair value option | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		26,103	5,758
Significant Unobservable Inputs (Level 3) | Fair value option | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Significant Unobservable Inputs (Level 3) | Fair value option | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		56,145	0
Significant Unobservable Inputs (Level 3) | Fair value option | Other investments fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		95,273	62,705
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		21,566,834	20,319,648
Liabilities measured at fair value		(95,011)	(95,119)
Estimated Fair Value | Contingent consideration liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		(7,825)	(66,665)
Estimated Fair Value | Securities sold but not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[1]	(48,823)	(7,790)
Estimated Fair Value | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value		(38,363)	(20,664)
Estimated Fair Value | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		16,308,949	14,952,510
Estimated Fair Value | Fixed maturities | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		6,044,081	5,537,548
Estimated Fair Value | Fixed maturities | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		523,019	541,193
Estimated Fair Value | Fixed maturities | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		582,497	1,013,395
Estimated Fair Value | Fixed maturities | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		686,707	729,442
Estimated Fair Value | Fixed maturities | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		4,906,996	3,758,698
Estimated Fair Value | Fixed maturities | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		1,928,752	1,771,338
Estimated Fair Value | Fixed maturities | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		1,636,897	1,600,896
Estimated Fair Value | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		684,236	353,794
Estimated Fair Value | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		821,961	955,880
Estimated Fair Value | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		30,653	73,893
Estimated Fair Value | Fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		3,721,035	3,983,571
Estimated Fair Value | Fair value option | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		673,431	852,585
Estimated Fair Value | Fair value option | Mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		16,076	16,731
Estimated Fair Value | Fair value option | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		6,731	7,144
Estimated Fair Value | Fair value option | Commercial mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Estimated Fair Value | Fair value option | US government and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		4,488	111,246
Estimated Fair Value | Fair value option | Non-US government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		56,416	79,066
Estimated Fair Value | Fair value option | Asset backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		208,019	178,790
Estimated Fair Value | Fair value option | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		257,465	322,177
Estimated Fair Value | Fair value option | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		103,891	103,893
Estimated Fair Value | Fair value option | Other investments fair value option
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		1,394,344	1,254,220
Estimated Fair Value | Fair value option | Other investments measured at net asset value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[3]	$ 1,000,174	$ 1,057,719
[1]	Represents the Company’s obligations to deliver securities that it did not own at the time of sale. Such amounts are included in “other liabilities” on the Company’s consolidated balance sheets.
[2]	In securities lending transactions, the Company receives collateral in excess of the fair value of the securities pledged. For purposes of this table, the Company has excluded the collateral received under securities lending, at fair value and included the securities pledged under securities lending, at fair value. See note 6 , “—Securities Lending Agreements.”
[3]	In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.

Fair Value - Rollforward of Lev

Fair Value - Rollforward of Level 3 assets and liabilities (Details) - Recurring - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Contingent consideration liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		$ (68,121)	$ (62,449)	$ (66,665)	$ (60,996)
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	(423)	(1,481)	(1,331)	(2,934)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0	0	0
Purchases, issuances, sales and settlements
Purchases		0	0	0	0
Issuances		0	0	(548)	0
Sales		0	0	0	0
Settlements		60,719	0	(60,719)	0
Transfers in and/or out of Level 3		0	0	0	0
Balance at end of period		(7,825)	(63,930)	(7,825)	(63,930)
Available for sale | Structured securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	[2]	302	5,413	313	5,927
Total gains or (losses) (realized/unrealized) - included in earnings	[1],[2]	0	3	1,757	4
Total gains or (losses) (realized/unrealized) - included in other comprehensive income	[2]	1	(4)	5	(8)
Purchases, issuances, sales and settlements
Purchases	[2]	0	0	0	0
Issuances	[2]	0	0	0	0
Sales	[2]	0	(5,003)	(1,757)	(5,003)
Settlements	[2]	(13)	(33)	(28)	(544)
Transfers in and/or out of Level 3	[2]	0	0	0	0
Balance at end of period	[2]	290	376	290	376
Available for sale | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		7,567	9,152	8,141	9,460
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	0	0	0	0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		102	(316)	(16)	(168)
Purchases, issuances, sales and settlements
Purchases		429	393	429	393
Issuances		0	0	0	0
Sales		0	0	0	0
Settlements		(456)	(456)	(912)	(912)
Transfers in and/or out of Level 3		0	0	0	0
Balance at end of period		7,642	8,773	7,642	8,773
Fair value option | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		2,233	11,872	5,758	12,217
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	(49)	(537)	(339)	(612)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0	0	0
Purchases, issuances, sales and settlements
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		0	0	(3,235)	0
Settlements		0	0	0	(270)
Transfers in and/or out of Level 3		23,919	0	23,919	0
Balance at end of period		26,103	11,335	26,103	11,335
Fair value option | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		62,329	58,452	62,705	59,167
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	(11,614)	336	(11,316)	(379)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0	0	0
Purchases, issuances, sales and settlements
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		(74)	(74)	(148)	(74)
Settlements		0	(500)	(600)	(500)
Transfers in and/or out of Level 3		44,632	0	44,632	0
Balance at end of period		95,273	58,214	95,273	58,214
Fair value option | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		0	0	0	0
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	0	0	0	0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0	0	0
Purchases, issuances, sales and settlements
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	0
Transfers in and/or out of Level 3		56,145	0	56,145	0
Balance at end of period		56,145	0	56,145	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		0	0	0	0
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	0	0	0	0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0	0	0
Purchases, issuances, sales and settlements
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	0
Transfers in and/or out of Level 3		51,212	0	51,212	0
Balance at end of period		$ 51,212	$ 0	$ 51,212	$ 0
[1]	Gains or losses were included in net realized gains (losses).
[2]	Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.

Fair Value - Narrative (Details

Fair Value - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Total assets and liabilities measured at fair value	$ 21,660,000	$ 20,410,000
Total assets and liabilities measured at fair value priced using non-binding broker quotes	$ 183,800	$ 217,900
Total assets and liabilities measured at fair value priced using non-binding broker quotes (percentage)	0.90%	1.10%
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Senior notes	$ 1,733,865	$ 1,733,528
Estimated fair value of senior notes	2,090,000	$ 1,880,000
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers from Level 2 to Level 3	107,400
Fair value option | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers from Level 2 to Level 3	23,900
Fair value option | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers from Level 2 to Level 3	$ 44,600

Derivative Instruments (Details

Derivative Instruments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Derivative offsetting [Abstract]
Derivative assets subject to master netting agreements		$ 46,200		$ 46,200		$ 80,400
Derivative liabilities subject to master netting agreements		38,400		38,400		18,900
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments	[1]	63,966	$ (2,146)	99,837	$ (6,109)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives - fair value		46,162		46,162		82,185
Liability derivatives - fair value		(38,363)		(38,363)		(20,664)
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments		63,966	(2,146)	99,837	(6,109)
Not Designated as Hedging Instrument [Member] | Futures contracts
Derivative [Line Items]
Net derivatives - notional value	[2],[3]	4,354,852		4,354,852		3,153,518
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments		66,973	(240)	94,309	4,790
Not Designated as Hedging Instrument [Member] | Futures contracts | Other assets
Derivative [Line Items]
Asset derivatives - fair value	[3]	5,438		5,438		51,800
Not Designated as Hedging Instrument [Member] | Futures contracts | Other liabilities
Derivative [Line Items]
Liability derivatives - fair value	[3]	(1,586)		(1,586)		(2,115)
Not Designated as Hedging Instrument [Member] | Foreign currency forward contracts
Derivative [Line Items]
Net derivatives - notional value	[2],[3]	939,940		939,940		1,008,907
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments		(5,365)	(1,692)	(19,074)	(7,616)
Not Designated as Hedging Instrument [Member] | Foreign currency forward contracts | Other assets
Derivative [Line Items]
Asset derivatives - fair value	[3]	3,190		3,190		8,147
Not Designated as Hedging Instrument [Member] | Foreign currency forward contracts | Other liabilities
Derivative [Line Items]
Liability derivatives - fair value	[3]	(10,352)		(10,352)		(7,796)
Not Designated as Hedging Instrument [Member] | TBAs
Derivative [Line Items]
Net derivatives - notional value	[2],[4]	14,846		14,846		8,132
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments		48	0	238	(97)
Not Designated as Hedging Instrument [Member] | TBAs | Fixed maturities available for sale
Derivative [Line Items]
Asset derivatives - fair value	[4]	15,509		15,509		8,292
Liability derivatives - fair value	[4]	0		0		0
Not Designated as Hedging Instrument [Member] | Other
Derivative [Line Items]
Net derivatives - notional value	[2],[3]	3,493,526		3,493,526		2,213,981
Net realized gains (losses) on derivative instruments
Net realized gains (losses) on derivative instruments		2,310	$ (214)	24,364	$ (3,186)
Not Designated as Hedging Instrument [Member] | Other | Other assets
Derivative [Line Items]
Asset derivatives - fair value	[3]	22,025		22,025		13,946
Not Designated as Hedging Instrument [Member] | Other | Other liabilities
Derivative [Line Items]
Liability derivatives - fair value	[3]	$ (26,425)		$ (26,425)		$ (10,753)
[1]	See note 8 for information on the Company’s derivative instruments.
[2]	Represents the absolute notional value of all outstanding contracts, consisting of long and short positions.
[3]	The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’
[4]	The fair value of TBAs are included in ‘fixed maturities available for sale, at fair value.’

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Investment commitments	$ 1,920		$ 1,770
Interest expense on senior notes and other borrowings	$ 60.9	$ 60.9

Leases - Additional information

Leases - Additional information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 7,244	$ 14,860
Cash payments included in the measurement of lease liabilities reported in operating cash flows	7,685	14,585
Right-of-use assets obtained in exchange for new lease liabilities	4,420	4,420
Lease liability	$ 150,341	$ 150,341
Weighted average discount rate	3.90%	3.90%
Weighted average remaining lease term in years	6 years 6 months	6 years 6 months
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term	12 years	12 years
Other assets
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 134,061	$ 134,061
Other liabilities
Lessee, Lease, Description [Line Items]
Lease liability	$ 150,341	$ 150,341

Leases - Contractual maturities

Leases - Contractual maturities and future minimum rental payments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Contractual maturities of operating lease liabilities
2019 (remainder)	$ 9,985
2020	32,036
2021	30,673
2022	27,365
2023	22,667
2024 and thereafter	55,610
Total undiscounted lease liability	178,336
Less: present value adjustment	(27,995)
Operating lease liability	$ 150,341
Future minimum rental commitments:
2019		$ 31,088
2020		30,491
2021		29,351
2022		26,068
2023		21,408
2024 and thereafter		54,745
Total future minimum payments		$ 193,151

Variable Interest Entities an_3

Variable Interest Entities and Noncontrolling Interests - Variable interest entity (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Mar. 31, 2014	Jun. 30, 2019	Jun. 30, 2018
Variable Interest Entity [Line Items]
Net cash provided by operating activities		$ 712,524	$ 496,886
Net cash used for investing activities		(746,944)	102,399
Net cash used for financing activities		(9,085)	(733,029)
Variable Interest Entity, Primary Beneficiary | Watford Holdings Ltd
Variable Interest Entity [Line Items]
Initial investment contribution amount	$ 100,000
Number of shares acquired	2,500,000
Ownership percentage	11.00%
Number of shares called by warrants	975,503
Variable Interest Entity, Primary Beneficiary | Watford Re
Variable Interest Entity [Line Items]
Net cash provided by operating activities		115,900	92,400
Net cash used for investing activities		(135,700)	(168,000)
Net cash used for financing activities		$ 25,600	$ (2,100)

Variable Interest Entities an_4

Variable Interest Entities and Noncontrolling Interests - Carrying amount of assets and liabilities of variable interest entity (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments accounted for using the fair value option		$ 3,721,035		$ 3,983,571
Fixed maturities available for sale, at fair value		15,881,732		14,699,010
Equity securities, at fair value		670,943		338,899
Cash		605,316		646,556
Accrued investment income		119,252		114,641
Premiums receivable		1,606,040		1,299,150
Reinsurance recoverable on unpaid and paid losses and LAE		3,171,257		2,919,372
Ceded unearned premiums		1,136,728		975,469
Deferred acquisition costs		600,740		569,574
Receivable for securities sold		164,592		36,246
Goodwill and intangible assets		641,010		634,920	$ 593,008
Other assets		1,135,718		929,611
Total assets		34,851,670		32,218,329
Reserve for losses and loss adjustment expenses		12,230,316	$ 12,010,041	11,853,297	11,424,337	$ 11,496,205	$ 11,383,792
Unearned premiums		4,056,860		3,753,636
Reinsurance balances payable		531,990		393,107
Revolving credit agreement borrowings		491,006		455,682
Payable for securities purchased		294,109		90,034
Other liabilities		904,438		911,500
Total liabilities of consolidated VIE		23,032,496		21,780,650
Redeemable noncontrolling interests		206,475		206,292
Watford Re
Variable Interest Entity [Line Items]
Redeemable noncontrolling interests		206,475	$ 206,383	206,292	$ 206,105	$ 206,013	$ 205,922
Variable Interest Entity, Primary Beneficiary | Watford Re
Variable Interest Entity [Line Items]
Investments accounted for using the fair value option		1,972,947		2,312,003
Fixed maturities available for sale, at fair value		732,454		393,351
Equity securities, at fair value		64,703		32,206
Cash		68,977		63,529
Accrued investment income		16,916		19,461
Premiums receivable		228,588		227,301
Reinsurance recoverable on unpaid and paid losses and LAE		123,961		86,445
Ceded unearned premiums		79,513		61,587
Deferred acquisition costs		71,557		80,858
Receivable for securities sold		29,425		24,507
Goodwill and intangible assets		7,650		7,650
Other assets		71,837		63,959
Total assets		3,468,528		3,372,857
Reserve for losses and loss adjustment expenses		1,126,080		1,032,760
Unearned premiums		375,323		390,114
Reinsurance balances payable		23,312		21,034
Revolving credit agreement borrowings		491,006		455,682
Payable for securities purchased		51,216		60,142
Other liabilities	[1]	219,120		302,524
Total liabilities of consolidated VIE		2,286,057		2,262,256
Redeemable noncontrolling interests		$ 221,175		$ 220,992
[1]	Includes certain borrowings related to investing activities.

Variable Interest Entities an_5

Variable Interest Entities and Noncontrolling Interests - Non-redeemable noncontrolling interests (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interests, beginning of period			$ 791,560
Amounts attributable to noncontrolling interests	$ 12,301	$ 8,116	54,683	$ 19,492
Other comprehensive (income) loss attributable to noncontrolling interests	2,891	(1,077)	7,030	(1,750)
Non-redeemable noncontrolling interests, end of period	855,347	861,153	855,347	861,153
Watford Re
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interests, beginning of period	838,081	854,112	791,560	843,411
Additional paid in capital attributable to noncontrolling interests	2,074	0	2,074	0
Amounts attributable to noncontrolling interests	12,301	8,116	54,683	19,492
Other comprehensive (income) loss attributable to noncontrolling interests	2,891	(1,075)	7,030	(1,750)
Non-redeemable noncontrolling interests, end of period	$ 855,347	$ 861,153	$ 855,347	$ 861,153
Common shares | Watford Re
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	89.00%		89.00%

Variable Interest Entities an_6

Variable Interest Entities and Noncontrolling Interests - Redeemable noncontrolling interests (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests, beginning of period			$ 206,292
Redeemable noncontrolling interests, end of period	$ 206,475		206,475
Watford Re
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests, beginning of period	206,383	$ 206,013	206,292	$ 205,922
Accretion of preference share issuance costs	92	92	183	183
Redeemable noncontrolling interests, end of period	$ 206,475	$ 206,105	$ 206,475	$ 206,105
Cumulative redeemable preference shares | Watford Re
Redeemable Noncontrolling Interest [Line Items]
Preference shares, number of shares issued	9,065,200		9,065,200
Par value per share	$ 0.01		$ 0.01
Liquidation preference per share	25		25
Issue price per share	$ 24.50		$ 24.50

Variable Interest Entities an_7

Variable Interest Entities and Noncontrolling Interests - Income or loss attributable to third party investors (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Noncontrolling Interest [Abstract]
Amounts attributable to non-redeemable noncontrolling interests	$ (12,301)	$ (8,116)	$ (54,683)	$ (19,492)
Dividends attributable to redeemable noncontrolling interests	(4,590)	(4,585)	(9,178)	(9,170)
Net (income) loss attributable to noncontrolling interests	$ (16,891)	$ (12,701)	$ (63,861)	$ (28,662)

Variable Interest Entities an_8

Variable Interest Entities and Noncontrolling Interests - Other variable interest entity disclosures (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	$ 1,760,949	$ 1,656,189
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total VIE Assets	2,698,463	1,881,467
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(7,441)	1,752
Maximum Exposure to Loss - Off-Balance Sheet	41,272	11,190
Maximum Exposure to Loss	33,831	12,942
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2015-1 Ltd. (Jul-15)
Variable Interest Entity [Line Items]
Total VIE Assets	19,103	43,246
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(4)	112
Maximum Exposure to Loss - Off-Balance Sheet	17	498
Maximum Exposure to Loss	13	610
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2017-1 Ltd. (Oct-17)
Variable Interest Entity [Line Items]
Total VIE Assets	277,554	304,373
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(657)	165
Maximum Exposure to Loss - Off-Balance Sheet	4,892	1,312
Maximum Exposure to Loss	4,235	1,477
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2018-1 Ltd. (Apr-18)
Variable Interest Entity [Line Items]
Total VIE Assets	374,460	374,460
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(1,965)	132
Maximum Exposure to Loss - Off-Balance Sheet	7,799	3,539
Maximum Exposure to Loss	5,834	3,671
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2018-2 Ltd. (Aug-18)
Variable Interest Entity [Line Items]
Total VIE Assets	571,129	653,278
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(1,957)	874
Maximum Exposure to Loss - Off-Balance Sheet	5,265	4,005
Maximum Exposure to Loss	3,308	4,879
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2018-3 Ltd. (Oct-18)
Variable Interest Entity [Line Items]
Total VIE Assets	506,110	506,110
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(2,213)	469
Maximum Exposure to Loss - Off-Balance Sheet	7,251	1,836
Maximum Exposure to Loss	5,038	$ 2,305
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2019-1 Ltd. (Mar-19)
Variable Interest Entity [Line Items]
Total VIE Assets	329,085
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(237)
Maximum Exposure to Loss - Off-Balance Sheet	4,842
Maximum Exposure to Loss	4,605
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2019-2 Ltd. (Apr-19)
Variable Interest Entity [Line Items]
Total VIE Assets	621,022
Maximum Exposure to Loss - On-Balance Sheet (Asset) Liability	(408)
Maximum Exposure to Loss - Off-Balance Sheet	11,206
Maximum Exposure to Loss	$ 10,798

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) - Amounts reclassified from accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-than-temporary impairment losses	$ (49)	$ (470)	$ (1,358)	$ (632)
Income before income taxes	530,317	280,015	1,071,701	468,314
Income tax expense	(44,472)	(23,668)	(90,358)	(45,583)
Net of tax	468,954	243,646	917,482	394,069
Reclassification out of accumulated other comprehensive income | Unrealized appreciation on available-for-sale investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses)	59,809	(38,935)	71,518	(106,521)
Other-than-temporary impairment losses	(49)	(470)	(1,358)	(632)
Income before income taxes	59,760	(39,405)	70,160	(107,153)
Income tax expense	(4,415)	2,762	(4,594)	8,049
Net of tax	$ 55,345	$ (36,643)	$ 65,566	$ (99,104)

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) - Components of other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Before tax amount:
Unrealized holding gains (losses) arising during period, before tax	$ 248,074	$ (88,034)	$ 503,064	$ (277,977)
Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss), before tax	0	0	0	0
Less reclassification of net realized gains included in net income, before tax	59,760	(39,405)	70,160	(107,153)
Foreign currency translation adjustments, before tax	4,409	(12,701)	10,053	(11,269)
Other comprehensive income (loss), before tax	192,723	(61,330)	442,957	(182,093)
Tax expense (benefit):
Unrealized holding gains (losses) arising during period, tax	25,601	(2,763)	54,704	(26,029)
Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss), tax	0	0	0	0
Less reclassification of net realized gains included in net income, tax	4,415	(2,762)	4,594	(8,049)
Foreign currency translation adjustments, tax	142	(106)	270	44
Other comprehensive income (loss), tax	21,328	(107)	50,380	(17,936)
Net of tax amount:
Unrealized holding gains (losses) arising during period, net of tax	222,473	(85,271)	448,360	(251,948)
Portion of other-than-temporary impairment losses recognized in other comprehensive income (loss), net of tax	0	0	0	0
Less reclassification of net realized gains included in net income, net of tax	55,345	(36,643)	65,566	(99,104)
Foreign currency translation adjustments, net of tax	4,267	(12,595)	9,783	(11,313)
Net current period other comprehensive income (loss)	$ 171,395	$ (61,223)	$ 392,577	$ (164,157)

Guarantor Financial Informati_3

Guarantor Financial Information - Condensed consolidating balance sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Assets
Total investments	$ 23,127,963		$ 21,745,284
Cash	605,316		646,556
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates	0		0
Premiums receivable	1,606,040		1,299,150
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	3,171,257		2,919,372
Contractholder receivables	2,102,544		2,079,111
Ceded unearned premiums	1,136,728		975,469
Deferred acquisition costs	600,740		569,574
Goodwill and intangible assets	641,010		634,920	$ 593,008
Other assets	1,860,072		1,348,893
Total assets	34,851,670		32,218,329
Liabilities
Reserve for losses and loss adjustment expenses	12,230,316	$ 12,010,041	11,853,297	11,424,337	$ 11,496,205	$ 11,383,792
Unearned premiums	4,056,860		3,753,636
Reinsurance balances payable	531,990		393,107
Contractholder payables	2,102,544		2,079,111
Collateral held for insured obligations	237,056		236,630
Senior notes	1,733,865		1,733,528
Revolving credit agreement borrowings	491,006		455,682
Due to subsidiaries and affiliates	0		0
Other liabilities	1,648,859		1,275,659
Total liabilities	23,032,496		21,780,650
Redeemable noncontrolling interests	206,475		206,292
Shareholders' Equity
Total shareholders’ equity available to Arch	10,757,352		9,439,827	9,163,755
Non-redeemable noncontrolling interests	855,347		791,560	861,153
Total shareholders’ equity	11,612,699		10,231,387	$ 10,024,908
Total liabilities, noncontrolling interests and shareholders’ equity	34,851,670		32,218,329
Reportable Legal Entities | Arch Capital (Parent Guarantor)
Assets
Total investments	40		104
Cash	10,750		6,125
Investments in subsidiaries	11,045,465		9,735,256
Due from subsidiaries and affiliates	332		9
Premiums receivable	0		0
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	0		0
Contractholder receivables	0		0
Ceded unearned premiums	0		0
Deferred acquisition costs	0		0
Goodwill and intangible assets	0		0
Other assets	22,950		12,588
Total assets	11,079,537		9,754,082
Liabilities
Reserve for losses and loss adjustment expenses	0		0
Unearned premiums	0		0
Reinsurance balances payable	0		0
Contractholder payables	0		0
Collateral held for insured obligations	0		0
Senior notes	297,201		297,150
Revolving credit agreement borrowings	0		0
Due to subsidiaries and affiliates	9		0
Other liabilities	24,975		17,105
Total liabilities	322,185		314,255
Redeemable noncontrolling interests	0		0
Shareholders' Equity
Total shareholders’ equity available to Arch	10,757,352		9,439,827
Non-redeemable noncontrolling interests	0		0
Total shareholders’ equity	10,757,352		9,439,827
Total liabilities, noncontrolling interests and shareholders’ equity	11,079,537		9,754,082
Reportable Legal Entities | Arch-U.S. (Subsidiary Issuer)
Assets
Total investments	483,904		452,674
Cash	47,875		5,940
Investments in subsidiaries	4,493,198		3,999,243
Due from subsidiaries and affiliates	2		2
Premiums receivable	0		0
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	0		0
Contractholder receivables	0		0
Ceded unearned premiums	0		0
Deferred acquisition costs	0		0
Goodwill and intangible assets	0		0
Other assets	40,345		80,949
Total assets	5,065,324		4,538,808
Liabilities
Reserve for losses and loss adjustment expenses	0		0
Unearned premiums	0		0
Reinsurance balances payable	0		0
Contractholder payables	0		0
Collateral held for insured obligations	0		0
Senior notes	494,776		494,723
Revolving credit agreement borrowings	0		0
Due to subsidiaries and affiliates	536,747		536,805
Other liabilities	64,956		26,270
Total liabilities	1,096,479		1,057,798
Redeemable noncontrolling interests	0		0
Shareholders' Equity
Total shareholders’ equity available to Arch	3,968,845		3,481,010
Non-redeemable noncontrolling interests	0		0
Total shareholders’ equity	3,968,845		3,481,010
Total liabilities, noncontrolling interests and shareholders’ equity	$ 5,065,324		4,538,808
Percentage Ownership of Subsidiary	100.00%
Reportable Legal Entities | Other Arch Capital Subsidiaries
Assets
Total investments	$ 22,693,719		21,307,206
Cash	546,691		634,491
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates	1,881,929		1,802,686
Premiums receivable	2,291,360		1,834,389
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	8,618,279		8,618,660
Contractholder receivables	2,102,544		2,079,111
Ceded unearned premiums	1,984,219		1,730,262
Deferred acquisition costs	658,992		618,535
Goodwill and intangible assets	641,010		634,920
Other assets	1,953,732		1,466,438
Total assets	43,372,475		40,726,698
Liabilities
Reserve for losses and loss adjustment expenses	17,430,847		17,345,142
Unearned premiums	4,904,351		4,508,429
Reinsurance balances payable	1,217,310		928,346
Contractholder payables	2,102,544		2,079,111
Collateral held for insured obligations	237,056		236,630
Senior notes	941,888		941,655
Revolving credit agreement borrowings	491,006		455,682
Due to subsidiaries and affiliates	1,345,507		1,265,892
Other liabilities	2,055,626		1,699,768
Total liabilities	30,726,135		29,460,655
Redeemable noncontrolling interests	221,175		220,992
Shareholders' Equity
Total shareholders’ equity available to Arch	11,569,818		10,253,491
Non-redeemable noncontrolling interests	855,347		791,560
Total shareholders’ equity	12,425,165		11,045,051
Total liabilities, noncontrolling interests and shareholders’ equity	43,372,475		40,726,698
Consolidating Adjustments and Eliminations
Assets
Total investments	(49,700)		(14,700)
Cash	0		0
Investments in subsidiaries	(15,538,663)		(13,734,499)
Due from subsidiaries and affiliates	(1,882,263)		(1,802,697)
Premiums receivable	(685,320)		(535,239)
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	(5,447,022)		(5,699,288)
Contractholder receivables	0		0
Ceded unearned premiums	(847,491)		(754,793)
Deferred acquisition costs	(58,252)		(48,961)
Goodwill and intangible assets	0		0
Other assets	(156,955)		(211,082)
Total assets	(24,665,666)		(22,801,259)
Liabilities
Reserve for losses and loss adjustment expenses	(5,200,531)		(5,491,845)
Unearned premiums	(847,491)		(754,793)
Reinsurance balances payable	(685,320)		(535,239)
Contractholder payables	0		0
Collateral held for insured obligations			0
Senior notes	0		0
Revolving credit agreement borrowings	0		0
Due to subsidiaries and affiliates	(1,882,263)		(1,802,697)
Other liabilities	(496,698)		(467,484)
Total liabilities	(9,112,303)		(9,052,058)
Redeemable noncontrolling interests	(14,700)		(14,700)
Shareholders' Equity
Total shareholders’ equity available to Arch	(15,538,663)		(13,734,501)
Non-redeemable noncontrolling interests	0		0
Total shareholders’ equity	(15,538,663)		(13,734,501)
Total liabilities, noncontrolling interests and shareholders’ equity	$ (24,665,666)		$ (22,801,259)

Guarantor Financial Informati_4

Guarantor Financial Information - Condensed consolidating statement of income and comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Net premiums earned	$ 1,463,727	$ 1,336,763	$ 2,832,593	$ 2,571,662
Net investment income	155,038	135,668	311,987	262,392
Net realized gains (losses)	120,806	(76,611)	262,371	(187,609)
Net impairment losses recognized in earnings	(49)	(470)	(1,358)	(632)
Other underwriting income	5,953	3,874	14,778	9,223
Equity in net income of investment funds accounted for using the equity method	32,536	8,472	79,403	36,541
Other income (loss)	1,129	3,113	2,212	3,187
Total revenues	1,779,140	1,410,809	3,501,986	2,694,764
Expenses
Losses and loss adjustment expenses	767,543	726,153	1,486,075	1,363,013
Acquisition expenses	210,089	202,838	407,937	394,214
Other operating expenses	198,914	176,181	400,077	351,196
Corporate expenses	18,251	22,512	36,213	37,824
Amortization of intangible assets	19,794	26,472	40,211	53,208
Interest expense	29,280	30,344	58,345	60,980
Net foreign exchange (gains) losses	4,952	(53,706)	1,427	(33,985)
Total expenses	1,248,823	1,130,794	2,430,285	2,226,450
Income (loss) before income taxes	530,317	280,015	1,071,701	468,314
Income tax (expense) benefit	(44,472)	(23,668)	(90,358)	(45,583)
Income (loss) before equity in net income of subsidiaries	485,845	256,347	981,343	422,731
Equity in net income of subsidiaries	0	0	0	0
Net income	485,845	256,347	981,343	422,731
Net (income) loss attributable to noncontrolling interests	(16,891)	(12,701)	(63,861)	(28,662)
Net income available to Arch	468,954	243,646	917,482	394,069
Preferred dividends	(10,403)	(10,403)	(20,806)	(20,840)
Loss on redemption of preferred shares	0	0	0	(2,710)
Net income available to Arch common shareholders	458,551	233,243	896,676	370,519
Comprehensive income available to Arch	637,458	183,500	1,303,029	231,662
Reportable Legal Entities | Arch Capital (Parent Guarantor)
Revenues
Net premiums earned	0	0	0	0
Net investment income	38	15	84	35
Net realized gains (losses)	0	0	0	29
Net impairment losses recognized in earnings	0	0	0	0
Other underwriting income	0	0	0	0
Equity in net income of investment funds accounted for using the equity method	0	0	0	0
Other income (loss)	(242)	2,339	(481)	2,261
Total revenues	(204)	2,354	(397)	2,325
Expenses
Losses and loss adjustment expenses	0	0	0	0
Acquisition expenses	0	0	0	0
Other operating expenses	0	0	0	0
Corporate expenses	15,293	16,642	31,600	32,811
Amortization of intangible assets	0	0	0	0
Interest expense	5,538	5,537	11,076	11,073
Net foreign exchange (gains) losses	0	0	2	29
Total expenses	20,831	22,179	42,678	43,913
Income (loss) before income taxes	(21,035)	(19,825)	(43,075)	(41,588)
Income tax (expense) benefit	0	0	0	0
Income (loss) before equity in net income of subsidiaries	(21,035)	(19,825)	(43,075)	(41,588)
Equity in net income of subsidiaries	489,989	263,471	960,557	435,657
Net income	468,954	243,646	917,482	394,069
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net income available to Arch	468,954	243,646	917,482	394,069
Preferred dividends	(10,403)	(10,403)	(20,806)	(20,840)
Loss on redemption of preferred shares				(2,710)
Net income available to Arch common shareholders	458,551	233,243	896,676	370,519
Comprehensive income available to Arch	637,458	183,500	1,303,029	231,662
Reportable Legal Entities | Arch-U.S. (Subsidiary Issuer)
Revenues
Net premiums earned	0	0	0	0
Net investment income	2,847	560	6,526	818
Net realized gains (losses)	5,825	0	14,343	(7)
Net impairment losses recognized in earnings	0	0	0	0
Other underwriting income	0	0	0	0
Equity in net income of investment funds accounted for using the equity method	(64)	0	(64)	0
Other income (loss)	0	0	0	0
Total revenues	8,608	560	20,805	811
Expenses
Losses and loss adjustment expenses	0	0	0	0
Acquisition expenses	0	0	0	0
Other operating expenses	0	0	0	0
Corporate expenses	2,115	470	4,281	759
Amortization of intangible assets	0	0	0	0
Interest expense	11,996	12,013	23,947	23,939
Net foreign exchange (gains) losses	0	0	0	0
Total expenses	14,111	12,483	28,228	24,698
Income (loss) before income taxes	(5,503)	(11,923)	(7,423)	(23,887)
Income tax (expense) benefit	1,301	2,477	1,844	5,428
Income (loss) before equity in net income of subsidiaries	(4,202)	(9,446)	(5,579)	(18,459)
Equity in net income of subsidiaries	148,747	86,727	285,301	173,147
Net income	144,545	77,281	279,722	154,688
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net income available to Arch	144,545	77,281	279,722	154,688
Preferred dividends	0	0	0	0
Loss on redemption of preferred shares				0
Net income available to Arch common shareholders	144,545	77,281	279,722	154,688
Comprehensive income available to Arch	231,120	70,066	469,276	76,603
Reportable Legal Entities | Other Arch Capital Subsidiaries
Revenues
Net premiums earned	1,463,727	1,336,763	2,832,593	2,571,662
Net investment income	174,738	157,532	350,410	306,299
Net realized gains (losses)	115,620	(76,611)	253,673	(187,631)
Net impairment losses recognized in earnings	(49)	(470)	(1,358)	(632)
Other underwriting income	5,953	3,874	14,778	9,223
Equity in net income of investment funds accounted for using the equity method	32,600	8,472	79,467	36,541
Other income (loss)	1,371	774	2,693	926
Total revenues	1,793,960	1,430,334	3,532,256	2,736,388
Expenses
Losses and loss adjustment expenses	767,543	726,153	1,486,075	1,363,013
Acquisition expenses	210,089	202,838	407,937	394,214
Other operating expenses	198,914	176,181	400,077	351,196
Corporate expenses	843	5,400	332	4,254
Amortization of intangible assets	19,794	26,472	40,211	53,208
Interest expense	34,012	34,911	67,718	70,083
Net foreign exchange (gains) losses	(1,187)	(43,357)	(1,310)	(26,921)
Total expenses	1,230,008	1,128,598	2,401,040	2,209,047
Income (loss) before income taxes	563,952	301,736	1,131,216	527,341
Income tax (expense) benefit	(45,773)	(26,145)	(92,202)	(51,011)
Income (loss) before equity in net income of subsidiaries	518,179	275,591	1,039,014	476,330
Equity in net income of subsidiaries	0	0	0	0
Net income	518,179	275,591	1,039,014	476,330
Net (income) loss attributable to noncontrolling interests	(17,210)	(13,023)	(64,499)	(29,307)
Net income available to Arch	500,969	262,568	974,515	447,023
Preferred dividends	0	0	0	0
Loss on redemption of preferred shares				0
Net income available to Arch common shareholders	500,969	262,568	974,515	447,023
Comprehensive income available to Arch	663,685	212,802	1,352,225	291,883
Consolidating Adjustments and Eliminations
Revenues
Net premiums earned	0	0	0	0
Net investment income	(22,585)	(22,439)	(45,033)	(44,760)
Net realized gains (losses)	(639)	0	(5,645)	0
Net impairment losses recognized in earnings	0	0	0	0
Other underwriting income	0	0	0	0
Equity in net income of investment funds accounted for using the equity method	0	0	0	0
Other income (loss)	0	0	0	0
Total revenues	(23,224)	(22,439)	(50,678)	(44,760)
Expenses
Losses and loss adjustment expenses	0	0	0	0
Acquisition expenses	0	0	0	0
Other operating expenses	0	0	0	0
Corporate expenses	0	0	0	0
Amortization of intangible assets	0	0	0	0
Interest expense	(22,266)	(22,117)	(44,396)	(44,115)
Net foreign exchange (gains) losses	6,139	(10,349)	2,735	(7,093)
Total expenses	(16,127)	(32,466)	(41,661)	(51,208)
Income (loss) before income taxes	(7,097)	10,027	(9,017)	6,448
Income tax (expense) benefit	0	0	0	0
Income (loss) before equity in net income of subsidiaries	(7,097)	10,027	(9,017)	6,448
Equity in net income of subsidiaries	(638,736)	(350,198)	(1,245,858)	(608,804)
Net income	(645,833)	(340,171)	(1,254,875)	(602,356)
Net (income) loss attributable to noncontrolling interests	319	322	638	645
Net income available to Arch	(645,514)	(339,849)	(1,254,237)	(601,711)
Preferred dividends	0	0	0	0
Loss on redemption of preferred shares				0
Net income available to Arch common shareholders	(645,514)	(339,849)	(1,254,237)	(601,711)
Comprehensive income available to Arch	$ (894,805)	$ (282,868)	$ (1,821,501)	$ (368,486)

Guarantor Financial Informati_5

Guarantor Financial Information - Condensed consolidating statement of cash flows (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Operating Activities
Net Cash Provided by (Used in) Operating Activities		$ 712,524	$ 496,886
Investing Activities
Purchases of fixed maturity investments		(16,332,646)	(16,867,570)
Purchases of equity securities		(431,939)	(679,663)
Purchases of other investments		(677,063)	(1,017,147)
Proceeds from sales of fixed maturity investments		15,632,482	16,090,543
Proceeds from sales of equity securities		176,701	622,068
Proceeds from sales, redemptions and maturities of other investments		534,698	773,298
Proceeds from redemptions and maturities of fixed maturity investments		244,949	511,448
Net settlements of derivative instruments		87,701	4,498
Net (purchases) sales of short-term investments		201,520	451,901
Change in cash collateral related to securities lending		7,590	176,304
Contributions to subsidiaries		0	0
Issuance of intercompany loans		0
Purchases of fixed assets		(16,359)	(13,242)
Other		(174,578)	49,961
Net Cash Provided By (Used For) Investing Activities		(746,944)	102,399
Financing Activities
Redemption of preferred shares		0	(92,555)
Purchases of common shares under share repurchase program		(2,871)	(173,575)
Proceeds from common shares issued, net		(557)	(13,851)
Proceeds from intercompany borrowings		0
Proceeds from borrowings		62,800	130,579
Repayments of borrowings		(27,538)	(373,000)
Change in cash collateral related to securities lending		(7,590)	(176,304)
Dividends paid to redeemable noncontrolling interests		(8,994)	(8,994)
Dividends paid to parent	[1]	0	0
Other		(3,529)	(4,489)
Preferred dividends paid		(20,806)	(20,840)
Net Cash Provided By (Used For) Financing Activities		(9,085)	(733,029)
Effects of exchange rate changes on foreign currency cash and restricted cash		1,937	(10,431)
Increase (decrease) in cash and restricted cash		(41,568)	(144,175)
Cash and restricted cash, beginning of year		724,643	727,284
Cash and restricted cash, end of period		683,075	583,109
Reportable Legal Entities | Arch Capital (Parent Guarantor)
Operating Activities
Net Cash Provided by (Used in) Operating Activities		30,946	201,487
Investing Activities
Purchases of fixed maturity investments		0	0
Purchases of equity securities		0	0
Purchases of other investments		0	0
Proceeds from sales of fixed maturity investments		0	0
Proceeds from sales of equity securities		0	0
Proceeds from sales, redemptions and maturities of other investments		0	0
Proceeds from redemptions and maturities of fixed maturity investments		0	0
Net settlements of derivative instruments		0	0
Net (purchases) sales of short-term investments		64	96,446
Change in cash collateral related to securities lending		0	0
Contributions to subsidiaries		(2,121)	0
Issuance of intercompany loans		0
Purchases of fixed assets		(32)	(71)
Other		0	(4)
Net Cash Provided By (Used For) Investing Activities		(2,089)	96,371
Financing Activities
Redemption of preferred shares			(92,555)
Purchases of common shares under share repurchase program		(2,871)	(173,575)
Proceeds from common shares issued, net		(557)	(13,851)
Proceeds from intercompany borrowings		0
Proceeds from borrowings		0	0
Repayments of borrowings		0	0
Change in cash collateral related to securities lending		0	0
Dividends paid to redeemable noncontrolling interests		0	0
Dividends paid to parent	[1]	0	0
Other		0	0
Preferred dividends paid		(20,806)	(20,840)
Net Cash Provided By (Used For) Financing Activities		(24,234)	(300,821)
Effects of exchange rate changes on foreign currency cash and restricted cash		0	0
Increase (decrease) in cash and restricted cash		4,623	(2,963)
Cash and restricted cash, beginning of year		6,159	10,048
Cash and restricted cash, end of period		10,782	7,085
Reportable Legal Entities | Arch-U.S. (Subsidiary Issuer)
Operating Activities
Net Cash Provided by (Used in) Operating Activities		24,059	149,576
Investing Activities
Purchases of fixed maturity investments		(358,996)	(125,440)
Purchases of equity securities		(56,441)	0
Purchases of other investments		(17,891)	0
Proceeds from sales of fixed maturity investments		452,729	33,793
Proceeds from sales of equity securities		0	0
Proceeds from sales, redemptions and maturities of other investments		391	0
Proceeds from redemptions and maturities of fixed maturity investments		100	0
Net settlements of derivative instruments		0	0
Net (purchases) sales of short-term investments		(2,015)	(59,798)
Change in cash collateral related to securities lending		0	0
Contributions to subsidiaries		0	(1,000)
Issuance of intercompany loans		0
Purchases of fixed assets		0	0
Other		0	0
Net Cash Provided By (Used For) Investing Activities		17,877	(152,445)
Financing Activities
Redemption of preferred shares			0
Purchases of common shares under share repurchase program		0	0
Proceeds from common shares issued, net		0	0
Proceeds from intercompany borrowings		0
Proceeds from borrowings		0	0
Repayments of borrowings		0	0
Change in cash collateral related to securities lending		0	0
Dividends paid to redeemable noncontrolling interests		0	0
Dividends paid to parent	[1]	0	0
Other		0	0
Preferred dividends paid		0	0
Net Cash Provided By (Used For) Financing Activities		0	0
Effects of exchange rate changes on foreign currency cash and restricted cash		0	0
Increase (decrease) in cash and restricted cash		41,936	(2,869)
Cash and restricted cash, beginning of year		5,940	30,380
Cash and restricted cash, end of period		47,876	27,511
Reportable Legal Entities | Other Arch Capital Subsidiaries
Operating Activities
Net Cash Provided by (Used in) Operating Activities		749,885	1,010,703
Investing Activities
Purchases of fixed maturity investments		(15,973,650)	(17,347,846)
Purchases of equity securities		(447,742)	(679,663)
Purchases of other investments		(659,172)	(1,017,147)
Proceeds from sales of fixed maturity investments		15,179,753	16,662,466
Proceeds from sales of equity securities		248,945	622,068
Proceeds from sales, redemptions and maturities of other investments		534,307	773,298
Proceeds from redemptions and maturities of fixed maturity investments		244,849	511,448
Net settlements of derivative instruments		87,701	4,498
Net (purchases) sales of short-term investments		203,471	415,253
Change in cash collateral related to securities lending		7,590	176,304
Contributions to subsidiaries		(59,527)	(22,595)
Issuance of intercompany loans		(53,828)
Purchases of fixed assets		(16,327)	(13,171)
Other		(174,578)	49,965
Net Cash Provided By (Used For) Investing Activities		(878,208)	134,878
Financing Activities
Redemption of preferred shares			0
Purchases of common shares under share repurchase program		0	0
Proceeds from common shares issued, net		61,648	23,595
Proceeds from intercompany borrowings		53,828
Proceeds from borrowings		62,800	130,579
Repayments of borrowings		(27,538)	(373,000)
Change in cash collateral related to securities lending		(7,590)	(176,304)
Dividends paid to redeemable noncontrolling interests		(9,632)	(9,632)
Dividends paid to parent	[1]	(91,728)	(864,242)
Other		(3,529)	(4,489)
Preferred dividends paid		0	0
Net Cash Provided By (Used For) Financing Activities		38,259	(1,273,493)
Effects of exchange rate changes on foreign currency cash and restricted cash		1,937	(10,431)
Increase (decrease) in cash and restricted cash		(88,127)	(138,343)
Cash and restricted cash, beginning of year		712,544	686,856
Cash and restricted cash, end of period		624,417	548,513
Consolidating Adjustments and Eliminations
Operating Activities
Net Cash Provided by (Used in) Operating Activities		(92,366)	(864,880)
Investing Activities
Purchases of fixed maturity investments		0	605,716
Purchases of equity securities		72,244	0
Purchases of other investments		0	0
Proceeds from sales of fixed maturity investments		0	(605,716)
Proceeds from sales of equity securities		(72,244)	0
Proceeds from sales, redemptions and maturities of other investments		0	0
Proceeds from redemptions and maturities of fixed maturity investments		0	0
Net settlements of derivative instruments		0	0
Net (purchases) sales of short-term investments		0	0
Change in cash collateral related to securities lending		0	0
Contributions to subsidiaries		61,648	23,595
Issuance of intercompany loans		53,828
Purchases of fixed assets		0	0
Other		0	0
Net Cash Provided By (Used For) Investing Activities		115,476	23,595
Financing Activities
Redemption of preferred shares			0
Purchases of common shares under share repurchase program		0	0
Proceeds from common shares issued, net		(61,648)	(23,595)
Proceeds from intercompany borrowings		(53,828)
Proceeds from borrowings		0	0
Repayments of borrowings		0	0
Change in cash collateral related to securities lending		0	0
Dividends paid to redeemable noncontrolling interests		638	638
Dividends paid to parent	[1]	91,728	864,242
Other		0	0
Preferred dividends paid		0	0
Net Cash Provided By (Used For) Financing Activities		(23,110)	841,285
Effects of exchange rate changes on foreign currency cash and restricted cash		0	0
Increase (decrease) in cash and restricted cash		0	0
Cash and restricted cash, beginning of year		0	0
Cash and restricted cash, end of period		$ 0	$ 0
[1]	Dividends received by parent are included in net cash provided by (used for) operating activities

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective tax rate on income before income taxes (percentage)	8.40%	9.70%
Statutory federal tax rate	21.00%
Tax benefit on share-based compensation	0.40%
Net deferred tax liabilities	$ 49.5
Net deferred tax assets			$ 22.5
Income taxes paid (recovered)	$ 43.5	$ (46.5)

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - USD ($) $ / shares in Units, $ in Millions	Aug. 01, 2019	Jul. 02, 2019	Jul. 31, 2019
Variable Interest Entity, Not Primary Beneficiary | Bellemeade 2019-3 Ltd.
Bellemeade 2019-3 Ltd.
Aggregate excess of loss reinsurance agreement			$ 700.9
Aggregate losses			$ 232.1
Agreement period			10 years
SPV issuance of insurance-linked notes			$ 700.9
Variable Interest Entity, Primary Beneficiary | Watford Holdings Ltd | Senior notes
Watford Holdings Ltd.
Aggregate principal amount of senior notes		$ 175
Stated interest rate (percent)		6.50%
Net proceeds on issuance		$ 172.4
Variable Interest Entity, Primary Beneficiary | Watford Holdings Ltd | Preference shares
Watford Holdings Ltd.
Preference shares, number of shares redeemed	6,919,998
Preference shares, number of shares issued			9,065,200
Preference shares, number of shares outstanding			9,065,200
Preferred shares, redemption price	$ 25.19748
Investment in senior notes		$ 35
Proceeds from redemption of preference shares	$ 11.5