Validus 10-Q 2 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 31, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	VALIDUS HOLDINGS LTD
Entity Central Index Key	1,348,259
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		79,465,860

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Fixed maturity investments trading, at fair value (amortized cost: 2017—$5,424,562; 2016—$5,584,599)	$ 5,418,643	$ 5,543,030
Short-term investments trading, at fair value (amortized cost: 2017—$2,871,126; 2016—$2,796,358)	2,871,353	2,796,170
Other investments, at fair value (cost: 2017—$416,996; 2016—$380,130)	448,618	405,712
Investments in investment affiliates, equity method (cost: 2017—$72,532; 2016—$84,840)	103,377	100,431
Cash and cash equivalents	800,405	419,976
Restricted cash	195,039	70,956
Total investments and cash	9,837,435	9,336,275
Premiums receivable	1,940,637	725,390
Deferred acquisition costs	302,857	209,227
Prepaid reinsurance premiums	335,837	77,996
Securities lending collateral	2,514	9,779
Loss reserves recoverable	600,207	430,421
Paid losses recoverable	35,675	35,247
Income taxes recoverable	4,763	4,870
Deferred tax asset	52,655	43,529
Receivable for investments sold	20,519	3,901
Intangible assets	175,518	115,592
Goodwill	227,701	196,758
Accrued investment income	26,968	26,488
Other assets	387,860	134,282
Total assets	13,951,146	11,349,755
Liabilities
Reserve for losses and loss expenses	3,305,191	2,995,195
Unearned premiums	1,970,896	1,076,049
Reinsurance balances payable	461,261	54,781
Securities lending payable	2,980	10,245
Deferred tax liability	4,012	3,331
Payable for investments purchased	92,077	29,447
Accounts payable and accrued expenses	385,958	587,648
Notes payable to AlphaCat investors	1,066,159	278,202
Senior notes payable	245,463	245,362
Debentures payable	538,400	537,226
Total liabilities	8,072,397	5,817,486
Commitments and contingent liabilities
Redeemable noncontrolling interests	1,251,660	1,528,001
Shareholders' equity
Preferred shares (Issued and Outstanding: 2017—16,000; 2016—6,000)	400,000	150,000
Common shares (Issued: 2017—161,934,355; 2016—161,279,976; Outstanding: 2017—79,518,581; 2016—79,132,252)	28,339	28,224
Treasury shares (2017—82,415,774; 2016—82,147,724)	(14,423)	(14,376)
Additional paid-in capital	807,321	821,023
Accumulated other comprehensive loss	(19,924)	(23,216)
Retained earnings	3,010,118	2,876,636
Total shareholders' equity available to Validus	4,211,431	3,838,291
Noncontrolling interests	415,658	165,977
Total shareholders' equity	4,627,089	4,004,268
Total liabilities, noncontrolling interests and shareholders’ equity	$ 13,951,146	$ 11,349,755

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Fixed maturities, at amortized cost or cost	$ 5,424,562	$ 5,584,599
Short-term investments, at amortized cost or cost	2,871,126	2,796,358
Other investments, at amortized cost or cost	416,996	380,130
Investments in and advance to affiliates, subsidiaries, associates, and joint ventures, at cost	$ 72,532	$ 84,840
Preferred shares - Shareholders' Equity
Preferred shares, shares issued	16,000	6,000
Preferred shares, shares outstanding	16,000	6,000
Common Shares - Shareholders' Equity
Common shares, shares issued	161,934,355	161,279,976
Common shares, shares outstanding	79,518,581	79,132,252
Treasury stock, common shares	82,415,774	82,147,724

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Gross premiums written	$ 792,902	$ 764,042	$ 1,983,759	$ 1,936,833
Reinsurance premiums ceded	(56,222)	(36,229)	(256,328)	(204,064)
Net premiums written	736,680	727,813	1,727,431	1,732,769
Change in unearned premiums	(105,653)	(154,090)	(521,028)	(587,778)
Net premiums earned	631,027	573,723	1,206,403	1,144,991
Net investment income	44,241	39,257	84,455	68,718
Net realized gains on investments	2,274	2,724	1,110	2,140
Change in net unrealized gains on investments	16,321	31,428	29,669	78,872
Income (loss) from investment affiliates	9,466	(589)	14,654	(4,702)
Other insurance related income and other income	1,339	824	2,669	2,237
Foreign exchange (losses) gains	(7,329)	6,286	(5,760)	12,531
Total revenues	697,339	653,653	1,333,200	1,304,787
Expenses
Losses and loss expenses	296,149	307,130	565,734	531,577
Policy acquisition costs	117,268	107,966	228,896	215,159
General and administrative expenses	96,349	89,688	184,273	175,896
Share compensation expenses	11,146	10,727	20,637	21,964
Finance expenses	14,209	14,166	28,152	29,369
Transaction expenses	4,427	0	4,427	0
Total expenses	539,548	529,677	1,032,119	973,965
Income before taxes, loss from operating affiliate and (income) attributable to AlphaCat investors	157,791	123,976	301,081	330,822
Tax benefit (expense)	987	(1,706)	4,536	412
Loss from operating affiliate	0	0	0	(23)
(Income) attributable to AlphaCat investors	(11,830)	(6,114)	(19,333)	(10,714)
Net income	146,948	116,156	286,284	320,497
Net (income) attributable to noncontrolling interest	(43,650)	(21,193)	(86,222)	(58,724)
Net income available to Validus	103,298	94,963	200,062	261,773
Dividends on preferred shares	(2,203)	0	(4,406)
Net income available to Validus common shareholders	101,095	94,963	195,656	261,773
Comprehensive income
Net income	146,948	116,156	286,284	320,497
Other comprehensive income (loss)
Change in foreign currency translation adjustments	1,489	(3,287)	2,086	(5,315)
Change in minimum pension liability, net of tax	1,184	479	1,252	396
Change in fair value of cash flow hedge	(144)	64	(46)	(694)
Other comprehensive income (loss), net of tax	2,529	(2,744)	3,292	(5,613)
Comprehensive (income) attributable to noncontrolling interests	(43,650)	(21,193)	(86,222)	(58,724)
Comprehensive income available to Validus	$ 105,827	$ 92,219	$ 203,354	$ 256,160
Earnings per common share
Basic earnings per share available to common shareholders	$ 1.28	$ 1.16	$ 2.47	$ 3.18
Earnings per diluted share available to Validus common shareholders	1.25	1.14	2.42	3.12
Cash dividends declared per share	$ 0.38	$ 0.35	$ 0.76	$ 0.70
Weighted average number of common shares and common share equivalents outstanding:
Basic (in shares)	79,270,561	81,950,833	79,202,116	82,386,047
Diluted (in shares)	80,872,451	83,373,003	80,861,998	83,785,659

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred shares	Common shares	Treasury shares	Additional paid-in capital	Accumulated other comprehensive loss	Retained earnings
Balance - Beginning of period at Dec. 31, 2015		$ 0	$ 28,100	$ (13,592)	$ 1,002,980	$ (12,569)	$ 2,634,056
Preferred shares issued		150,000
Offering expenses on preferred shares					(5,148)
Common shares Issued (redeemed), net			119		(7,504)
Repurchase of common shares				(492)	(128,591)
Share compensation expenses					21,964
Other comprehensive (loss) income	$ (5,613)					(5,613)
Net income	320,497						320,497
Net (income) attributable to noncontrolling interest	(58,724)						(58,724)
Dividends on preferred shares							0
Dividends on common shares							(59,227)
Balance - End of period at Jun. 30, 2016	3,866,256	150,000	28,219	(14,084)	883,701	(18,182)	2,836,602
Noncontrolling interests at Jun. 30, 2016	212,154
Total shareholders' equity at Jun. 30, 2016	4,078,410					(18,182)
Other comprehensive (loss) income	(2,744)
Net income	116,156
Net (income) attributable to noncontrolling interest	(21,193)
Balance - End of period at Jun. 30, 2016	3,866,256	150,000	28,219	(14,084)	883,701	(18,182)	2,836,602
Noncontrolling interests at Jun. 30, 2016	212,154
Total shareholders' equity at Jun. 30, 2016	4,078,410					(18,182)
Balance - Beginning of period at Dec. 31, 2016	3,838,291	150,000	28,224	(14,376)	821,023	(23,216)	2,876,636
Preferred shares issued		250,000
Offering expenses on preferred shares					(8,314)
Common shares Issued (redeemed), net			115		(12,076)
Repurchase of common shares				(47)	(13,949)
Share compensation expenses					20,637
Other comprehensive (loss) income	3,292					3,292
Net income	286,284						286,284
Net (income) attributable to noncontrolling interest	(86,222)						(86,222)
Dividends on preferred shares							(4,406)
Dividends on common shares							(62,174)
Balance - End of period at Jun. 30, 2017	4,211,431	400,000	28,339	(14,423)	807,321	(19,924)	3,010,118
Noncontrolling interests at Jun. 30, 2017	415,658
Total shareholders' equity at Jun. 30, 2017	4,627,089					(19,924)
Other comprehensive (loss) income	2,529
Net income	146,948
Net (income) attributable to noncontrolling interest	(43,650)
Balance - End of period at Jun. 30, 2017	4,211,431	$ 400,000	$ 28,339	$ (14,423)	$ 807,321	(19,924)	$ 3,010,118
Noncontrolling interests at Jun. 30, 2017	415,658
Total shareholders' equity at Jun. 30, 2017	$ 4,627,089					$ (19,924)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows provided by (used in) operating activities
Net income	$ 286,284	$ 320,497
Adjustments to reconcile net income to cash provided by (used in) operating activities:
Share compensation expenses	20,637	21,964
Loss on deconsolidation of AlphaCat ILS fund	402	0
Amortization of discount on senior notes	54	54
(Income) loss from investment affiliates	(14,654)	4,702
Net realized and change in net unrealized gains on investments	(30,779)	(81,012)
Amortization of intangible assets	3,995	2,832
Loss from operating affiliate	0	23
Foreign exchange gains included in net income	(9,686)	(6,289)
Amortization of premium on fixed maturities	7,012	8,710
Change in:
Premiums receivable	(648,195)	(719,070)
Deferred acquisition costs	(97,746)	(102,211)
Prepaid reinsurance premiums	(30,684)	(67,575)
Loss reserves recoverable	(113,508)	(95,429)
Paid losses recoverable	17,500	(4,571)
Reserve for losses and loss expenses	199,985	147,305
Unearned premiums	488,198	655,353
Reinsurance balances payable	111,488	18,610
Other operational balance sheet items, net	(137,618)	(34,450)
Net cash provided by operating activities	52,685	69,443
Cash flows provided by (used in) investing activities
Proceeds on sales of fixed maturity investments	1,632,371	1,376,077
Proceeds on maturities of fixed maturity investments	247,394	184,413
Purchases of fixed maturity investments	(1,682,609)	(1,537,606)
Purchases of short-term investments, net	(88,623)	(428,040)
Purchases of other investments, net	(33,870)	(19,796)
Decrease (increase) in securities lending collateral	7,265	(5,361)
Redemption from operating affiliates	0	369
Distributions from (investments in) investment affiliates, net	11,708	(16,307)
Increase in restricted cash	(124,083)	(22,752)
Purchase of subsidiary, net of cash acquired	183,923	0
Net cash used in investing activities	(214,370)	(469,003)
Cash flows provided by (used in) financing activities
Net proceeds on issuance of notes payable to AlphaCat investors	269,645	294,748
Net proceeds on issuance of preferred shares	241,686	144,852
Redemption of common shares, net	(11,961)	(7,385)
Purchases of common shares under share repurchase program	(13,996)	(129,083)
Dividends paid on preferred shares	(4,406)	0
Dividends paid on common shares	(63,286)	(59,961)
(Decrease) increase in securities lending payable	(7,265)	5,361
Third party investment in redeemable noncontrolling interests	210,200	381,250
Third party redemption of redeemable noncontrolling interests	(79,334)	(10,800)
Third party investment in noncontrolling interests	258,300	171,674
Third party distributions of noncontrolling interests	(96,125)	(127,103)
Third party subscriptions deployed in AlphaCat Funds and Sidecars	(171,952)	(411,336)
Net cash provided by financing activities	531,506	252,217
Effect of foreign currency rate changes on cash and cash equivalents	10,608	(6,968)
Net increase (decrease) in cash and cash equivalents	380,429	(154,311)
Cash and cash equivalents - beginning of period	419,976	723,109
Cash and cash equivalents - end of period	800,405	568,798
Supplemental disclosure of cash flow information:
Taxes paid during the period	568	3,837
Interest paid during the period	$ 27,186	$ 27,552

Basis of preparation and consol

Basis of preparation and consolidation	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation and consolidation	Basis of preparation and consolidation These unaudited Consolidated Financial Statements (the “Consolidated Financial Statements”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 in Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In addition, the year-end balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. This Quarterly Report on Form 10-Q should be read in conjunction with the financial statements and related notes included in Validus Holdings, Ltd.’s (the “Company”) Annual Report on Form 10-K for the year ended December 31, 2016 , as filed with the U.S. Securities and Exchange Commission (the “SEC”). The Company consolidates in these Consolidated Financial Statements the results of operations and financial position of all voting interest entities (“VOE”) in which the Company has a controlling financial interest and all variable interest entities (“VIE”) in which the Company is considered to be the primary beneficiary. The consolidation assessment, including the determination as to whether an entity qualifies as a VIE or VOE, depends on the facts and circumstances surrounding each entity. In the opinion of management, these unaudited Consolidated Financial Statements reflect all adjustments (including normal recurring adjustments) considered necessary for a fair statement of the Company’s financial position and results of operations as at the end of and for the periods presented. All significant intercompany accounts and transactions have been eliminated. The results of operations for any interim period are not necessarily indicative of the results for a full year. The preparation of these financial statements in conformity with U.S. 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. While management believes that the amounts included in the Consolidated Financial Statements reflect its best estimates and assumptions, actual results could differ materially from those estimates. The Company’s principal estimates include: • reserve for losses and loss expenses; • premium estimates for business written on a line slip or proportional basis; • the valuation of goodwill and intangible assets; • reinsurance recoverable balances including the provision for uncollectible amounts; and • investment valuation of financial assets. The term “ASC” used in these notes refers to Accounting Standard Codification issued by the United States Financial Accounting Standards Board (the “FASB”).

Recent accounting pronouncement

Recent accounting pronouncements	6 Months Ended
	Jun. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent accounting pronouncements	Recent accounting pronouncements Recently issued accounting standards not yet adopted In May 2017, the FASB issued ASU 2017-09, “Compensation - Stock Compensation (Topic 718).” This ASU is directed at reducing diversity in practice when applying the accounting guidance to a change in the terms or conditions of a share-based payment award. The ASU is effective for fiscal periods beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company has evaluated the impact of this guidance and it will not have a material impact on the Company’s Consolidated Financial Statements. The Company plans to adopt this guidance on January 1, 2018.

Business combination

Business combination	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Business combination	Business combination On May 1, 2017, Western World Insurance Group, Inc. (“Western World”), a wholly owned subsidiary of the Company acquired all of the outstanding capital stock of Crop Risk Services (“CRS”) for an aggregate purchase price of $185,576 in cash. CRS is a primary crop insurance managing general agent (“MGA”) based in Decatur, Illinois with 1,170 agents across 36 states. CRS does not have insurance licenses of its own, but acts solely as an MGA in that it can produce business for any properly licensed entity on a commission basis. Concurrent with closing of the transaction, Stratford Insurance Company (“Stratford”), a wholly–owned subsidiary of Western World, was granted the required license to write crop insurance in the United States and executed several agreements to transfer the related agriculture book of business to Stratford. The CRS acquisition was undertaken to complement the Company’s existing agricultural business and expand the Company’s presence in U.S. primary specialty lines. For segmental reporting purposes, the results of CRS’ operations, including the related agricultural book of business have been included within the Western World segment in the Consolidated Financial Statements from the date of acquisition. On closing, the Company recorded intangible assets totaling $63,921 for Distribution Channels, Brand Name and Technology. Distribution Channels and Brand Name were estimated to have finite useful economic lives of ten years on acquisition and are being amortized on a straight line basis over such period. Technology was estimated to have a finite useful economic life of two years on acquisition and is being amortized on a straight line basis over such a period. The purchase price was allocated to the acquired assets and liabilities of CRS based on estimated fair values on May 1, 2017, the date the transaction closed, as detailed below. The Company recognized goodwill of $30,943 primarily attributable to CRS’s assembled workforce and synergies expected to result upon the integration of CRS and its related book of business into the Company’s operations. The estimates of fair values for tangible assets acquired and liabilities assumed were determined by management based on various market and income analyses. The Company estimated the fair values of intangible assets acquired based on variations of the income and cost approaches. Significant judgment was required to arrive at these estimates of fair value and changes to assumptions used could have led to materially different results. The purchase of CRS was a taxable transaction and as such, goodwill and intangibles recorded at closing will be deductible for income tax purposes. The Company has recognized and recorded a deferred tax asset of $6,443 which results from the excess of tax-deductible goodwill over book goodwill as recognized in the purchase price allocation. The fair value of net assets acquired, including GAAP adjustments, are summarized as follows: Total purchase price $ 185,576 Assets acquired Cash and cash equivalents $ 1,653 Premiums receivable 564,453 Prepaid reinsurance premiums 227,157 Other assets 157,146 Assets acquired 950,409 Liabilities acquired Reinsurance balances payable $ 294,201 Unearned premiums 406,649 Net loss reserves 42,575 Other liabilities 122,715 Liabilities acquired 866,140 Excess purchase price $ 101,307 Goodwill and other intangible assets acquired Intangible asset - Distribution channels $ 52,898 Intangible asset - Brand name 9,568 Intangible asset - Technology 1,455 Total intangible assets 63,921 Goodwill 30,943 Deferred tax arising on Goodwill 6,443 Total goodwill and intangible assets $ 101,307 The Company also incurred transaction expenses related to the CRS acquisition of $4,427 . Transaction expenses included legal, financial advisory and audit related services. The following tables reconcile the carrying amount of goodwill and intangible assets from December 31, 2016 to June 30, 2017 : Goodwill Six Months Ended June 30, 2017 Talbot Western World Total Balance at December 31, 2016 20,393 176,365 196,758 Additions — 30,943 30,943 Balance at June 30, 2017 20,393 207,308 227,701 Intangible assets Six Months Ended June 30, 2017 Talbot Western World Total Balance at December 31, 2016 93,924 21,668 115,592 Additions — 63,921 63,921 Amortization (2,081 ) (1,914 ) (3,995 ) Balance at June 30, 2017 91,843 83,675 175,518 Intangible assets Six Months Ended June 30, 2017 With a Finite Life With an Indefinite Life Total Balance at December 31, 2016 11,424 104,168 115,592 Additions 63,921 — 63,921 Amortization (3,995 ) — (3,995 ) Balance at June 30, 2017 71,350 104,168 175,518 Operating results of CRS have been included in the Consolidated Financial Statements from the May 1, 2017 acquisition date. The following selected unaudited information has been provided to present a summary of the results of CRS that have been included in the Consolidated Financial Statements for the three and six months ended June 30, 2017 . From Acquisition Date to June 30, 2017 Net premiums written 6,988 Net premiums earned 50,044 Total underwriting deductions 44,780 Underwriting income, before general and administrative expenses 5,264

Investments

Investments	6 Months Ended
	Jun. 30, 2017
Investments [Abstract]
Investments	Investments Managed investments represent assets governed by the Company’s investment policy statement (“IPS”) whereas, non-managed investments represent assets held in support of consolidated AlphaCat VIEs which are not governed by the Company’s IPS. Refer to Note 6 , “Variable interest entities,” for further details. The Company classifies its fixed maturity and short-term investments as trading and accounts for its other investments in accordance with ASC Topic 825 “ Financial Instruments. ” As such, all investments are carried at fair value with interest and dividend income and realized and unrealized gains and losses included in net income for the period. The amortized cost (or cost) and fair value of the Company’s investments as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Amortized Amortized Fair Value Managed investments U.S. government and government agency $ 649,214 $ 646,436 $ 809,392 $ 804,126 Non-U.S. government and government agency 293,002 292,504 245,651 240,791 U.S. states, municipalities and political subdivisions 227,047 227,949 271,742 271,830 Agency residential mortgage-backed securities 786,784 783,006 684,490 679,595 Non-agency residential mortgage-backed securities 26,745 26,683 15,858 15,477 U.S. corporate 1,378,884 1,386,484 1,540,036 1,534,508 Non-U.S. corporate 380,317 379,480 418,520 410,227 Bank loans 560,446 552,901 579,121 570,399 Asset-backed securities 500,679 502,056 528,563 526,814 Commercial mortgage-backed securities 317,732 316,190 333,740 330,932 Total fixed maturities 5,120,850 5,113,689 5,427,113 5,384,699 Short-term investments 255,289 255,516 228,574 228,386 Other investments Fund of hedge funds — — 1,457 955 Hedge funds 11,292 18,303 11,292 17,381 Private equity investments 79,871 100,391 66,383 82,627 Fixed income investment funds 266,041 268,110 247,967 249,275 Overseas deposits 57,874 57,874 50,106 50,106 Mutual funds 1,918 3,940 2,925 5,368 Total other investments 416,996 448,618 380,130 405,712 Investments in investment affiliates (a) 72,532 103,377 84,840 100,431 Total managed investments $ 5,865,667 $ 5,921,200 $ 6,120,657 $ 6,119,228 Non-managed investments Catastrophe bonds $ 303,712 $ 304,954 $ 157,486 $ 158,331 Short-term investments 2,615,837 2,615,837 2,567,784 2,567,784 Total non-managed investments 2,919,549 2,920,791 2,725,270 2,726,115 Total investments $ 8,785,216 $ 8,841,991 $ 8,845,927 $ 8,845,343 (a) The Company’s investments in investment affiliates have been treated as equity method investments with the corresponding gains and losses recorded in income as “Income (loss) from investment affiliates.” (a) Fixed maturity investments The following table sets forth certain information regarding the investment ratings of the Company’s fixed maturity investments as at June 30, 2017 and December 31, 2016 . June 30, 2017 December 31, 2016 Fair Value % of Total Fair Value % of Total Managed fixed maturities AAA $ 2,318,254 42.8 % $ 2,405,597 43.4 % AA 463,060 8.5 % 538,289 9.7 % A 1,009,366 18.6 % 1,081,949 19.5 % BBB 703,563 13.0 % 740,861 13.4 % Total investment grade managed fixed maturities 4,494,243 82.9 % 4,766,696 86.0 % BB 229,023 4.2 % 213,568 3.9 % B 176,743 3.3 % 177,737 3.2 % CCC 11,114 0.2 % 13,371 0.2 % NR 202,566 3.8 % 213,327 3.8 % Total non-investment grade fixed maturities 619,446 11.5 % 618,003 11.1 % Total managed fixed maturities $ 5,113,689 94.4 % $ 5,384,699 97.1 % Non-managed fixed maturities BB 28,177 0.4 % 29,731 0.6 % B 2,781 0.1 % 4,524 0.1 % NR 273,996 5.1 % 124,076 2.2 % Total non-managed fixed maturities 304,954 5.6 % 158,331 2.9 % Total fixed maturities $ 5,418,643 100.0 % $ 5,543,030 100.0 % The amortized cost and fair value amounts for the Company’s fixed maturity investments held at June 30, 2017 and December 31, 2016 are shown below by contractual maturity. Actual maturity may differ from contractual maturity because certain borrowers may have the right to call or prepay certain obligations with or without call or prepayment penalties. June 30, 2017 December 31, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Managed fixed maturities Due in one year or less $ 497,473 $ 492,256 $ 350,733 $ 346,161 Due after one year through five years 2,464,093 2,461,870 2,954,856 2,933,146 Due after five years through ten years 456,793 459,311 430,365 426,647 Due after ten years 70,551 72,317 128,508 125,927 3,488,910 3,485,754 3,864,462 3,831,881 Asset-backed and mortgage-backed securities 1,631,940 1,627,935 1,562,651 1,552,818 Total managed fixed maturities $ 5,120,850 $ 5,113,689 $ 5,427,113 $ 5,384,699 Non-managed catastrophe bonds Due in one year or less $ 33,662 $ 32,441 $ 43,664 $ 45,418 Due after one year through five years 263,300 265,735 112,572 111,656 Due after five years through ten years 6,750 6,778 1,250 1,257 Due after ten years — — — — Total non-managed fixed maturities 303,712 304,954 157,486 158,331 Total fixed maturities $ 5,424,562 $ 5,418,643 $ 5,584,599 $ 5,543,030 (b) Other investments The following tables set forth certain information regarding the Company’s other investment portfolio as at June 30, 2017 and December 31, 2016 : June 30, 2017 Fair Value Investments with redemption restrictions Investments without redemption restrictions Redemption frequency (a) Redemption notice period (a) Hedge funds 18,303 18,303 — Private equity investments 100,391 100,391 — Fixed income investment funds 268,110 237,986 30,124 Daily Daily to 2 days Overseas deposits 57,874 57,874 — Mutual funds 3,940 — 3,940 Daily Daily Total other investments $ 448,618 $ 414,554 $ 34,064 December 31, 2016 Fair Value Investments with redemption restrictions Investments without redemption restrictions Redemption frequency (a) Redemption notice period (a) Fund of hedge funds $ 955 $ 955 $ — Hedge funds 17,381 17,381 — Private equity investments 82,627 82,627 — Fixed income investment funds 249,275 218,333 30,942 Daily 2 days Overseas deposits 50,106 50,106 — Mutual funds 5,368 — 5,368 Daily Daily Total other investments $ 405,712 $ 369,402 $ 36,310 (a) The redemption frequency and notice periods only apply to investments without redemption restrictions. Other investments include alternative investments in various funds and pooled investment schemes. These alternative investments employ various investment strategies primarily involving, but not limited to, investments in collateralized obligations, fixed income securities, private equities, distressed debt and equity securities. Certain securities included in other investments are subject to redemption restrictions and are unable to be redeemed from the funds. Distributions from these funds will be received as the underlying investments of the funds are liquidated. Currently, it is not known to the Company when these underlying assets will be sold by their investment managers; however, it is estimated that the majority of the underlying assets of the investments would liquidate over five to ten years from inception of the funds. In addition, one of the investment funds with a fair value of $192,437 ( December 31, 2016 : $184,749 ), has a lock-up period of approximately two years as at June 30, 2017 and may also impose a redemption gate. A lock-up period refers to the initial amount of time an investor is contractually required to remain invested before having the ability to redeem. Typically, the imposition of a gate delays a portion of the requested redemption, with the remaining portion settled in cash shortly after the redemption date. The underlying investments held in the overseas deposit funds are liquid and will generally trade freely in an open market. However, the Company’s ability to withdraw from the overseas deposit funds is restricted by an annual and quarterly funding and release process for Lloyd’s market participants. The Company’s maximum exposure to any of these alternative investments is limited to the amount invested and any remaining capital commitments. Refer to Note 15 , “ Commitments and contingencies ,” for further details. As at June 30, 2017 , the Company does not have any plans to sell any of the other investments listed above. (c) Investments in investment affiliates Included in the Company’s managed investment portfolio as at June 30, 2017 were investments in Aquiline Financial Services Fund II L.P. (“Aquiline II”), Aquiline Financial Services Fund III L.P. (“Aquiline III”) and Aquiline Technology Growth Fund L.P. (“Aquiline Tech”). Aquiline II and III For further information regarding Aquiline II and III please refer to Note 7(c), “Investments in investment affiliates,” included within the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 . As at June 30, 2017 , the Company’s total unfunded investment commitment to Aquiline II and III was $3,229 and $62,031 , respectively ( December 31, 2016 : $2,040 and $62,031 ). Aquiline Tech On March 20, 2017, the Company entered into a Subscription Agreement (the “Subscription Agreement”) with Aquiline Technology Growth GP Ltd, (the “General Partner”) pursuant to which the Company committed and agreed to purchase limited partnership or other comparable limited liability equity interests in Aquiline Tech, a Cayman Islands exempted limited partnership, with a capital commitment in an amount equal to $20,000 . The limited partnership interests are governed by the terms of an amended and restated exempted limited partnership agreement. As at June 30, 2017 , the unfunded investment commitment to Aquiline Tech was $18,786 . The following table presents a reconciliation of the Company’s beginning and ending investments in investment affiliates for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Investments in investment affiliates, beginning of period $ 94,697 $ 84,135 $ 100,431 $ 87,673 Net capital (distributions) contributions (786 ) 15,732 (11,708 ) 16,307 Income (loss) from investment affiliates 9,466 (589 ) 14,654 (4,702 ) Investments in investment affiliates, end of period $ 103,377 $ 99,278 $ 103,377 $ 99,278 The following table presents the Company’s investments in investment affiliates as at June 30, 2017 and December 31, 2016 : June 30, 2017 Investment at cost Voting ownership % Equity ownership % Carrying value Aquiline II $ 33,349 — % 8.1 % $ 52,010 Aquiline III 37,969 — % 9.0 % 50,153 Aquiline Tech 1,214 — % 16.4 % 1,214 Total investments in investment affiliates $ 72,532 $ 103,377 December 31, 2016 Investment at cost Voting ownership % Equity ownership % Carrying value Aquiline II $ 46,871 — % 8.1 % $ 61,999 Aquiline III 37,969 — % 9.0 % 38,432 Total investments in investment affiliates $ 84,840 $ 100,431 (d) Net investment income Net investment income was derived from the following sources: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Managed investments Fixed maturities and short-term investments $ 31,312 $ 30,621 $ 62,983 $ 58,638 Other investments 7,571 8,026 14,441 8,898 Cash and cash equivalents and restricted cash 616 380 1,226 1,245 Securities lending income 7 12 20 17 Total gross investment income 39,506 39,039 78,670 68,798 Investment expenses (1,443 ) (2,190 ) (4,415 ) (4,026 ) Total managed net investment income $ 38,063 $ 36,849 $ 74,255 $ 64,772 Non managed investments Fixed maturities and short-term investments $ 4,500 $ 1,977 $ 7,560 $ 3,272 Restricted cash, cash and cash equivalents 1,678 431 2,640 674 Total non-managed net investment income 6,178 2,408 10,200 3,946 Total net investment income $ 44,241 $ 39,257 $ 84,455 $ 68,718 Net investment income from other investments includes distributed and undistributed net income from hedge funds, overseas deposits and certain fixed income investment funds. (e) Net realized and change in net unrealized gains on investments The following table sets forth an analysis of net realized gains and the change in net unrealized gains on investments: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Managed fixed maturities, short-term and other investments Gross realized gains $ 5,175 $ 3,306 $ 7,865 $ 6,523 Gross realized (losses) (2,906 ) (786 ) (8,488 ) (5,089 ) Net realized gains (losses) on investments 2,269 2,520 (623 ) 1,434 Change in net unrealized gains on investments 15,942 30,052 30,291 77,130 Total net realized and change in net unrealized gains on managed investments $ 18,211 $ 32,572 $ 29,668 $ 78,564 Non-managed fixed maturities, short-term and other investments Gross realized gains $ 5 $ 204 $ 1,733 $ 715 Gross realized (losses) — — — (9 ) Net realized gains on investments 5 204 1,733 706 Change in net unrealized gains (losses) on investments 379 1,376 (622 ) 1,742 Total net realized and change in net unrealized gains on non-managed investments 384 1,580 1,111 2,448 Total net realized and change in net unrealized gains on total investments $ 18,595 $ 34,152 $ 30,779 $ 81,012 (f) Pledged cash and investments As at June 30, 2017 , the Company had $5,221,174 ( December 31, 2016 : $5,173,966 ) of cash and cash equivalents, restricted cash, short-term investments and fixed maturity investments that were pledged during the normal course of business. Of those, $5,156,173 were held in trust ( December 31, 2016 : $5,068,092 ). Pledged assets are generally for the benefit of the Company’s cedants and policyholders, to support AlphaCat’s fully collateralized reinsurance transactions and to facilitate the accreditation of Validus Reinsurance, Ltd., Validus Reinsurance (Switzerland) Ltd. (“Validus Re Swiss”) and Talbot as an alien Insurer/Reinsurer by certain regulators. In addition, the Company has pledged cash and investments as collateral under the Company’s credit facilities in the total amount of $404,516 ( December 31, 2016 : $442,184 ). For further details on the credit facilities, please refer to Note 13 , “ Debt and financing arrangements .”

Fair value measurements

Fair value measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements (a) Classification within the fair value hierarchy Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants. Under U.S. GAAP, a company must determine the appropriate level in the fair value hierarchy for each fair value measurement. The fair value hierarchy prioritizes the inputs, which refer broadly to assumptions market participants would use in pricing an asset or liability, into three levels. It gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The level in the fair value hierarchy within which a fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The three levels of the fair value hierarchy are described below: Level 1 - Fair values are measured based on unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access. Level 2 - Fair values are measured based on quoted prices in active markets for similar assets or liabilities, quoted prices for identical assets or liabilities in inactive markets, or for which significant inputs are observable (e.g., interest rates, yield curves, prepayment speeds, default rates, loss severities, etc.) or can be corroborated by observable market data. Level 3 - Fair values are measured based on inputs that are unobservable and significant to the overall fair value measurement. The unobservable inputs reflect the Company’s own judgments about assumptions where there is little, if any, market activity for that asset or liability that market participants might use. The availability of observable inputs can vary from financial instrument to financial instrument and is affected by a wide variety of factors including, for example, the type of financial instrument, whether the financial instrument is new and not yet established in the marketplace, and other characteristics particular to the instrument. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires significantly more judgment. Accordingly, the degree of judgment exercised by management in determining fair value is greatest for instruments categorized in Level 3. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This may lead the Company to change the selection of our valuation technique (for example, from market to cash flow approach) or to use multiple valuation techniques to estimate the fair value of a financial instrument. These circumstances could cause an instrument to be reclassified between levels within the fair value hierarchy. At June 30, 2017 , the Company’s investments were allocated between Levels 1, 2 and 3 as follows: Level 1 Level 2 Level 3 Fair value based on NAV practical expedient (a) Total Managed investments U.S. government and government agency $ — $ 646,436 $ — $ — $ 646,436 Non-U.S. government and government agency — 292,504 — — 292,504 U.S. states, municipalities and political subdivisions — 227,949 — — 227,949 Agency residential mortgage-backed securities — 783,006 — — 783,006 Non-agency residential mortgage-backed securities — 26,683 — — 26,683 U.S. corporate — 1,386,484 — — 1,386,484 Non-U.S. corporate — 379,480 — — 379,480 Bank loans — 328,729 224,172 — 552,901 Asset-backed securities — 466,135 35,921 — 502,056 Commercial mortgage-backed securities — 316,190 — — 316,190 Total fixed maturities — 4,853,596 260,093 — 5,113,689 Short-term investments 248,439 7,077 — — 255,516 Other investments Hedge funds — — — 18,303 18,303 Private equity investments — — — 100,391 100,391 Fixed income investment funds — 30,137 16,400 221,573 268,110 Overseas deposits — — — 57,874 57,874 Mutual funds — 3,940 — — 3,940 Total other investments — 34,077 16,400 398,141 448,618 Investments in investment affiliates (b) — — — — 103,377 Total managed investments $ 248,439 $ 4,894,750 $ 276,493 $ 398,141 $ 5,921,200 Non-managed investments Catastrophe bonds $ — $ 236,929 $ 68,025 $ — $ 304,954 Short-term investments 2,615,837 — — — 2,615,837 Total non-managed investments 2,615,837 236,929 68,025 — 2,920,791 Total investments $ 2,864,276 $ 5,131,679 $ 344,518 $ 398,141 $ 8,841,991 (a) In accordance with ASC Topic 820 “Fair Value Measurements,” investments measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (b) In accordance with ASC Topic 825 “Financial Instruments,” the Company’s investments in investment affiliates have not been classified in the fair value hierarchy. At December 31, 2016 , the Company’s investments were allocated between Levels 1, 2 and 3 as follows: Level 1 Level 2 Level 3 Fair value based on NAV practical expedient (a) Total Managed investments U.S. government and government agency $ — $ 804,126 $ — $ — $ 804,126 Non-U.S. government and government agency — 240,791 — — 240,791 U.S. states, municipalities and political subdivisions — 271,830 — — 271,830 Agency residential mortgage-backed securities — 679,595 — — 679,595 Non-agency residential mortgage-backed securities — 15,477 — — 15,477 U.S. corporate — 1,534,508 — — 1,534,508 Non-U.S. corporate — 410,227 — — 410,227 Bank loans — 323,903 246,496 — 570,399 Asset-backed securities — 502,883 23,931 — 526,814 Commercial mortgage-backed securities — 330,932 — — 330,932 Total fixed maturities — 5,114,272 270,427 — 5,384,699 Short-term investments 209,651 18,735 — — 228,386 Other investments Fund of hedge funds — — — 955 955 Hedge funds — — — 17,381 17,381 Private equity investments — — — 82,627 82,627 Fixed income investment funds — 30,941 12,168 206,166 249,275 Overseas deposits — — — 50,106 50,106 Mutual funds — 5,368 — — 5,368 Total other investments — 36,309 12,168 357,235 405,712 Investments in investment affiliates (b) — — — — 100,431 Total managed investments $ 209,651 $ 5,169,316 $ 282,595 $ 357,235 $ 6,119,228 Non-managed investments Catastrophe bonds $ — $ 109,956 $ 48,375 $ — $ 158,331 Short-term investments 2,567,784 — — — 2,567,784 Total non-managed investments 2,567,784 109,956 48,375 — 2,726,115 Total investments $ 2,777,435 $ 5,279,272 $ 330,970 $ 357,235 $ 8,845,343 (a) In accordance with ASC Topic 820 “Fair Value Measurements,” investments measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (b) In accordance with ASC Topic 825 “Financial Instruments,” the Company’s investments in investment affiliates have not been classified in the fair value hierarchy. At June 30, 2017 , managed Level 3 investments totaled $276,493 (December 31, 2016 : $282,595 ), representing 4.7% (December 31, 2016 : 4.6% ) of total managed investments. (b) Valuation techniques There have been no material changes in the Company’s valuation techniques during the period, or periods, represented by these Consolidated Financial Statements. The following methods and assumptions were used in estimating the fair value of each class of financial instrument recorded in the Consolidated Balance Sheets. Fixed maturity investments In general, valuation of the Company’s fixed maturity investment portfolio is provided by pricing services, such as index providers and pricing vendors, as well as broker quotations. The pricing vendors provide valuations for a high volume of liquid securities that are actively traded. For securities that do not trade on an exchange, the pricing services generally utilize market data and other observable inputs in matrix pricing models to determine month end prices. Prices are generally verified using third party data. Securities which are priced by an index provider are generally included in the index. In general, broker-dealers value securities through their trading desks based on observable inputs. The methodologies include mapping securities based on trade data, bids or offers, observed spreads, and performance on newly issued securities. Broker-dealers also determine valuations by observing secondary trading of similar securities. Prices obtained from broker quotations are considered non-binding, however they are based on observable inputs and by observing secondary trading of similar securities obtained from active, non-distressed markets. The Company considers these Level 2 inputs as they are corroborated with other market observable inputs. The techniques generally used to determine the fair value of the Company’s fixed maturity investments are detailed below by asset class. U.S. government and government agency U.S. government and government agency securities consist primarily of debt securities issued by the U.S. Treasury and mortgage pass-through agencies such as the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and the Government National Mortgage Association. Fixed maturity investments included in U.S. government and government agency securities are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources and integrate other observations from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The fair value of each security is individually computed using analytical models which incorporate option adjusted spreads and other daily interest rate data. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Non-U.S. government and government agency Non-U.S. government and government agency securities consist of debt securities issued by non-U.S. governments and their agencies along with supranational organizations (also known as sovereign debt securities). Securities held in these sectors are primarily priced by pricing services who employ proprietary discounted cash flow models to value the securities. Key quantitative inputs for these models are daily observed benchmark curves for treasury, swap and high issuance credits. The pricing services then apply a credit spread for each security which is developed by in-depth and real time market analysis. For securities in which trade volume is low, the pricing services utilize data from more frequently traded securities with similar attributes. These models may also be supplemented by daily market and credit research for international markets. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. U.S. states, municipalities and political subdivisions The Company’s U.S. states, municipalities and political subdivisions portfolio contains debt securities issued by U.S. domiciled state and municipal entities. These securities are generally priced by independent pricing services using the techniques described for U.S. government and government agency securities described above. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Agency residential mortgage-backed securities The Company’s agency residential mortgage-backed investments are primarily priced by pricing services using a mortgage pool specific model which utilizes daily inputs from the active to be announced ( “ TBA ” ) market which is very liquid, as well as the U.S. treasury market. The model also utilizes additional information, such as the weighted average maturity, weighted average coupon and other available pool level data which is provided by the sponsoring agency. Valuations are also corroborated with daily active market quotes. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Non-agency residential mortgage-backed securities The Company’s non-agency mortgage-backed investments include non-agency prime residential mortgage-backed fixed maturity investments. The Company has no fixed maturity investments classified as sub-prime held in its fixed maturity investments portfolio. Securities held in these sectors are primarily priced by pricing services using an option adjusted spread model or other relevant models, which principally utilize inputs including benchmark yields, available trade information or broker quotes, and issuer spreads. The pricing services also review collateral prepayment speeds, loss severity and delinquencies among other collateral performance indicators for the securities valuation, when applicable. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. U.S. corporate Corporate debt securities consist primarily of investment-grade debt of a wide variety of U.S. corporate issuers and industries. The Company’s corporate fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk. In certain instances, securities are individually evaluated using a spread which is added to the U.S. treasury curve or a security specific swap curve as appropriate. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Non-U.S. corporate Non-U.S. corporate debt securities consist primarily of investment-grade debt of a wide variety of non-U.S. corporate issuers and industries. The Company’s non-U.S. corporate fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Bank loans The Company’s bank loan investments consist primarily of below-investment-grade debt of a wide variety of corporate issuers and industries. The Company’s bank loans are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Also, included in the bank loan portfolio is a collection of loan participations held through an intermediary. A third party pricing service provides monthly valuation reports for each loan and participation using a combination of quotations from loan pricing services, leveraged loan indices or market price quotes obtained directly from the intermediary. Significant unobservable inputs used to price these securities include credit spreads and default rates; therefore, the fair value of these investments are classified as Level 3. Asset-backed securities Asset backed securities include mostly investment-grade debt securities backed by pools of loans with a variety of underlying collateral, including automobile loan receivables, student loans, credit card receivables, and collateralized loan obligations originated by a variety of financial institutions. Securities held in these sectors are primarily priced by pricing services. The pricing services apply dealer quotes and other available trade information such as bids and offers, prepayment speeds which may be adjusted for the underlying collateral or current price data, the U.S. treasury curve and swap curve as well as cash settlement. The pricing services determine the expected cash flows for each security held in this sector using historical prepayment and default projections for the underlying collateral and current market data. In addition, a spread is applied to the relevant benchmark and used to discount the cash flows noted above to determine the fair value of the securities held in this sector. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. Broker-dealer quotes for which significant observable inputs are unable to be corroborated with market observable information are classified as Level 3. Commercial mortgage-backed securities Commercial mortgage backed securities are investment-grade debt primarily priced by pricing services. The pricing services apply dealer quotes and other available trade information such as bids and offers, prepayment speeds which may be adjusted for the underlying collateral or current price data, the U.S. treasury curve and swap curve as well as cash settlement. The pricing services determine the expected cash flows for each security held in this sector using historical prepayment and default projections for the underlying collateral and current market data. In addition, a spread is applied to the relevant benchmark and used to discount the cash flows noted above to determine the fair value of the securities held in this sector. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. Catastrophe bonds Catastrophe bonds are priced based on broker or underwriter bid indications. As the significant inputs used to price these securities are observable, the fair value of these investments are classified as Level 2. To the extent that these indications are based on significant unobservable inputs, the fair value of the relevant bonds will be classified as a Level 3. Short-term investments Short-term investments consist primarily of highly liquid securities, all with maturities of less than one year from the date of purchase. The fair value of the portfolio is generally determined using amortized cost which approximates fair value. As the highly liquid money market-type funds are actively traded, the fair value of these investments are classified as Level 1. To the extent that the remaining securities are not actively traded due to their approaching maturity, the fair value of these investments are classified as Level 2. Other investments Fund of hedge funds During the three months ended June 30, 2017, the Company’s investment in a fund of hedge funds was liquidated. Prior to liquidation, the fund’s administrator provided a monthly reported NAV with a three month delay in its valuation. The fund manager provided an estimate of the fund NAV at year end based on the estimated performance provided from the underlying funds. To determine the reasonableness of the estimated NAV, the Company compared the fund administrator’s NAV to the fund manager’s estimated NAV that incorporates relevant valuation sources. Prior to liquidation, the fair value of these investments were measured using the NAV practical expedient and therefore were not categorized within the fair value hierarchy. Hedge funds The hedge fund investment was assumed by the Company in the acquisition of Flagstone Reinsurance Holdings, S.A. (“Flagstone”) (the “Flagstone hedge fund”). The Flagstone hedge fund’s administrator provides quarterly NAVs with a three month delay in valuation. The fair value of this investment is measured using the NAV practical expedient and therefore has not been categorized within the fair value hierarchy. Private equity investments The private equity funds provide quarterly or semi-annual partnership capital statements with a three or six month delay which are used as a basis for valuation. These private equity investments vary in investment strategies and are not actively traded in any open markets. The fair value of these investments are measured using the NAV practical expedient and therefore have not been categorized within the fair value hierarchy. Fixed income investment funds The Company’s investment funds classified as Level 2 consist of a pooled investment fund. The pooled investment is invested in fixed income securities with high credit ratings and is only open to Lloyd’s Trust Fund participants. The fair value of units in the investment fund is based on the NAV of the fund and is traded on a daily basis. Included in investment funds is a residual equity tranche of a structured credit fund valued using a dynamic yield that calculates an income accrual based on an underlying valuation model with a typical cash flow waterfall structure. Significant unobservable inputs used to price this fund include default rates and prepayment rates; therefore, the fair value of the investment fund is classified as Level 3. The fair value of the Company’s remaining investment funds is based on the NAV of the fund as reported by the independent fund administrator. The fund’s administrators provide a monthly reported NAV with a one or three month delay in their valuation. The fair value of these investments are measured using the NAV practical expedient and therefore have not been categorized within the fair value hierarchy. Overseas deposits The Company’s share of a portfolio of Lloyd’s overseas deposits are managed centrally by Lloyd’s and invested according to local regulatory requirements. The composition of the portfolio varies and the deposits are made across the market. The fair value of the deposits is based on the portfolio level reporting that is provided by Lloyd’s. The fair value of these investments are measured using the NAV practical expedient and therefore have not been categorized within the fair value hierarchy. Mutual funds Mutual funds consist of an investment fund which invests in various quoted investments. The fair value of units in the mutual fund is based on the NAV of the fund as reported by the fund manager. The mutual fund has daily liquidity which allows us to redeem our holdings at the applicable NAV in the near term. As such, the Company has classified this investment as Level 2. (c) Level 3 investments The following table presents a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, 2017 Bank Loans Catastrophe Bonds Fixed Income Investment Funds Asset Backed Securities Total Level 3 investments, beginning of period $ 236,694 $ 72,676 $ 12,560 $ 23,882 $ 345,812 Purchases 16,757 5,000 3,432 11,053 36,242 Sales — — — (53 ) (53 ) Settlements (28,893 ) (10,216 ) 408 — (38,701 ) Net realized gains — 216 — — 216 Change in net unrealized (losses) gains (386 ) 349 — 49 12 Amortization — — — 990 990 Level 3 investments, end of period $ 224,172 $ 68,025 $ 16,400 $ 35,921 $ 344,518 Three Months Ended June 30, 2016 Bank Loans Catastrophe Bonds Asset Backed Securities Total Level 3 investments, beginning of period $ 255,011 $ 37,105 $ — $ 292,116 Purchases 8,885 — 12,383 21,268 Settlements (17,784 ) — — (17,784 ) Change in net unrealized (losses) gains (2,964 ) 413 — (2,551 ) Level 3 investments, end of period $ 243,148 $ 37,518 $ 12,383 $ 293,049 Six Months Ended June 30, 2017 Bank Loans Catastrophe Bonds Fixed Income Investment Funds Asset Backed Securities Total Level 3 investments—beginning of period $ 246,496 $ 48,375 $ 12,168 $ 23,931 $ 330,970 Purchases 39,933 66,091 3,432 11,053 120,509 Sales — — — (53 ) (53 ) Settlements (62,003 ) (48,996 ) 800 — (110,199 ) Net realized gains — 3,350 — — 3,350 Change in net unrealized (losses) (254 ) (795 ) — — (1,049 ) Amortization — — — 990 990 Level 3 investments—end of period $ 224,172 $ 68,025 $ 16,400 $ 35,921 $ 344,518 Six Months Ended June 30, 2016 Bank Loans Catastrophe Bonds Asset Backed Securities Total Level 3 investments—beginning of period $ 232,337 $ 13,500 $ — $ 245,837 Purchases 50,988 23,272 12,383 86,643 Sales (2,389 ) — — (2,389 ) Settlements (34,033 ) (125 ) — (34,158 ) Change in net unrealized (losses) gains (3,755 ) 871 — (2,884 ) Level 3 investments—end of period $ 243,148 $ 37,518 $ 12,383 $ 293,049 There have not been any transfers into or out of Level 3 during the three and six months ended June 30, 2017 or 2016 . (d) Financial instruments not carried at fair value ASC Topic 825 “Financial Instruments” is also applicable to disclosures of financial instruments not carried at fair value, except for certain financial instruments, including insurance contracts and investments in affiliates. The carrying values of cash and cash equivalents, restricted cash, accrued investment income, other assets, net payable for investments purchased and accounts payable and accrued expenses approximated their fair values at June 30, 2017 , due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 2.

Variable interest entities

Variable interest entities	6 Months Ended
	Jun. 30, 2017
Variable Interest Entities Disclosure [Abstract]
Variable Interest Entity Disclosure [Text Block]	Variable interest entities The Company consolidates all VOEs in which it has a controlling financial interest and all VIEs in which it is considered to be the primary beneficiary. The Company’s VIEs are primarily entities in the AlphaCat segment. (a) Consolidated VIEs AlphaCat sidecars Beginning on May 25, 2011, the Company joined with other investors in capitalizing a series of sidecars for the purpose of investing in collateralized reinsurance and retrocessional contracts. Certain of these sidecars deployed their capital through transactions entered into by AlphaCat Reinsurance Ltd. (“AlphaCat Re”). Each of these entities return capital once the risk period expires and all losses have been paid out. The AlphaCat sidecars are VIEs and are consolidated by the Company as the primary beneficiary. The Company’s maximum exposure to any of the sidecars is the amount of capital invested at any given time. AlphaCat ILS funds The AlphaCat ILS funds received third party subscriptions beginning on December 17, 2012 . The Company and third party investors invest in the AlphaCat ILS funds for the purpose of investing in instruments with returns linked to property catastrophe reinsurance, retrocession and ILS contracts. The AlphaCat ILS funds have varying risk profiles and are categorized by the expected loss of the fund. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit. Lower risk ILS funds are defined as having a maximum permitted portfolio expected loss of less than 7% , whereas higher risk ILS funds have a maximum permitted portfolio expected loss of greater than 7% . The AlphaCat ILS funds primarily deploy their capital through transactions entered into by AlphaCat Re and AlphaCat Master Fund Ltd. (“AlphaCat Master Fund”). All of the AlphaCat ILS funds are VIEs and were consolidated by the Company as the primary beneficiary through May 31, 2017. However, on June 1, 2017, the Company redeemed its investment in one of the lower risk AlphaCat ILS funds. As a result, the Company was no longer deemed to be the primary beneficiary and therefore this fund was deconsolidated effective June 1, 2017. The deconsolidation resulted in a loss of $402 which is included in the Consolidated Statements of Comprehensive Income as other insurance related income for the three and six months ended June 30, 2017 . The Company’s maximum exposure to any of the funds is the amount of capital invested at any given time and any remaining capital commitments. Refer to Note 15 , “Commitments and contingencies,” for further details. AlphaCat Re and AlphaCat Master Fund The Company utilizes AlphaCat Re and AlphaCat Master Fund (collectively the “master funds”), both market facing entities, for the purpose of writing collateralized reinsurance and investing in capital markets products, respectively, on behalf of certain entities within the AlphaCat segment and direct third party investors. AlphaCat Re enters into transactions on behalf of the AlphaCat sidecars and ILS funds (collectively the “feeder funds”) and direct third party investors, whereas AlphaCat Master Fund only enters into transactions on behalf of certain AlphaCat ILS funds. All of the risks and rewards of the underlying transactions are allocated to the feeder funds and direct third party investors using variable funding notes. The master funds are VIEs and are consolidated by the Company as the primary beneficiary. Notes Payable to AlphaCat Investors The master funds issue variable funding notes to the feeder funds, and direct to third party investors, in order to write collateralized reinsurance and invest in capital markets products on their behalf. The Company’s investments in the feeder funds, together with investments made by third parties in the feeder funds and on a direct basis, are provided as consideration for the notes to the master funds. The duration of the underlying collateralized reinsurance contracts and capital market products is typically twelve months ; however, the variable funding notes do not have a stated maturity date or principal amount since repayment is dependent on the settlement and income or loss of the underlying transactions. Therefore, the notes are subsequently redeemed as the underlying transactions are settled. The income or loss generated by the underlying transactions is then transferred to the feeder funds and direct third party investors via the variable funding notes. Any notes issued by the master funds to the consolidated feeder funds are eliminated on consolidation and only variable funding notes issued by AlphaCat Re to direct third party investors and non-consolidated feeder funds remain on the Consolidated Balance Sheets as notes payable to AlphaCat investors with the related income or loss included in the Consolidated Statements of Income and Comprehensive Income as (income) attributable to AlphaCat investors. To the extent that the income has not been returned to the investors, it is included in accounts payable and accrued expenses in the Consolidated Balance Sheets. During 2017 and 2016, one of the AlphaCat ILS funds (the “Fund”) issued both common shares and structured notes to the Company and other third party investors in order to capitalize the fund. The Fund deploys its capital through AlphaCat Re; therefore, the structured notes do not have a stated maturity date or principal amount since repayment is dependent on the settlement and income or loss of the variable funding notes with AlphaCat Re. The structured notes rank senior to the common shares of the Fund and earn an interest rate of 7% (2016: 8% ) per annum, payable on a cumulative basis in arrears. As the Fund is consolidated by the Company, the structured notes issued to the Company are eliminated on consolidation and only the structured notes issued to third party investors remain on the Consolidated Balance Sheets as notes payable to AlphaCat investors with any related interest included in the Consolidated Statements of Income and Comprehensive Income as (income) attributable to AlphaCat investors. To the extent that the accrued interest on the structured notes has not been returned to the investors, it is included in accounts payable and accrued expenses in the Consolidated Balance Sheets. The following tables present a reconciliation of the beginning and ending notes payable to AlphaCat investors for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, 2017 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 343,256 $ 103,320 $ 446,576 Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund 423,269 — 423,269 Issuance of notes payable to AlphaCat investors 267,867 68,880 336,747 Redemption of notes payable to AlphaCat investors (140,150 ) — (140,150 ) Foreign exchange gains (283 ) — (283 ) Notes payable to AlphaCat investors, end of period $ 893,959 $ 172,200 $ 1,066,159 Three Months Ended June 30, 2016 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 261,793 $ 61,717 $ 323,510 Issuance of notes payable to AlphaCat investors 102,817 32,609 135,426 Redemption of notes payable to AlphaCat investors (88,079 ) — (88,079 ) Foreign exchange losses 125 — 125 Notes payable to AlphaCat investors, end of period $ 276,656 $ 94,326 $ 370,982 Six Months Ended June 30, 2017 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 278,202 $ — $ 278,202 Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund 423,269 — 423,269 Issuance of notes payable to AlphaCat investors 541,877 172,200 714,077 Redemption of notes payable to AlphaCat investors (349,106 ) — (349,106 ) Foreign exchange gains (283 ) — (283 ) Notes payable to AlphaCat investors, end of period $ 893,959 $ 172,200 $ 1,066,159 Six Months Ended June 30, 2016 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 75,493 $ — $ 75,493 Issuance of notes payable to AlphaCat investors 298,105 94,326 392,431 Redemption of notes payable to AlphaCat investors (97,684 ) — (97,684 ) Foreign exchange losses 742 — 742 Notes payable to AlphaCat investors, end of period $ 276,656 $ 94,326 $ 370,982 As at December 31, 2016 , $1,000 of the structured notes redeemed during the year were payable to AlphaCat investors and included in accounts payable and accrued expenses. The income attributable to AlphaCat investors for the three and six months ended June 30, 2017 was $11,830 and $19,333 ( 2016 : $6,114 and $10,714 ), with $63,352 included in accounts payable and accrued expenses as at June 30, 2017 (December 31, 2016 : $17,068 ). BetaCat ILS funds The BetaCat ILS funds invest exclusively in catastrophe bonds (principal-at-risk variable rate notes and other event-linked securities, being referred to collectively as “Cat Bonds”) focused on property and casualty risk and issued under Rule 144A of the Securities Act of 1933, as amended, following a passive buy-and-hold investment strategy. Two of the funds are VIEs, one of which is consolidated by the Company as the primary beneficiary. The remaining fund is a VOE and is consolidated by the Company as it owns all of the voting equity interests. The Company’s maximum exposure to any of the funds is the amount of capital invested at any given time. The following table presents the total assets and total liabilities of the Company’s consolidated VIEs, excluding intercompany eliminations, as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Total Assets Total Liabilities Total Assets Total Liabilities AlphaCat sidecars $ 29,330 $ 3,455 $ 40,041 $ 3,206 AlphaCat ILS funds - Lower Risk (a) 951,428 951,428 13,371 1,498,276 42,457 AlphaCat ILS funds - Higher Risk (a) 1,037,568 207,300 972,633 381,332 AlphaCat Re and AlphaCat Master Fund 2,828,096 2,827,926 2,510,415 2,510,245 BetaCat ILS funds 146,098 278 82,471 30,663 (a) Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit. Assets of consolidated VIEs can only be used to settle obligations and liabilities of the consolidated VIEs and do not have recourse to the general credit of the Company. Investments held by these entities are presented separately in Note 4 , “ Investments ,” as non-managed investments. (b) Non-Consolidated VIEs The Company invests in private equity and other investment vehicles as part of the Company’s investment portfolio. The activities of these VIEs are generally limited to holding investments and the Company’s involvement in these entities is passive in nature. The Company’s maximum exposure to the VIEs is the amount of capital invested at any given time, and the Company does not have the power to direct the activities which most significantly impact the VIEs economic performance. The Company is therefore not the primary beneficiary of these VIEs.

Noncontrolling interest

Noncontrolling interest	6 Months Ended
	Jun. 30, 2017
Noncontrolling Interest [Abstract]
Noncontrolling interest	Noncontrolling interests Investors in certain of the AlphaCat and BetaCat ILS funds have rights that enable them, subject to certain limitations, to redeem their shares. The third party equity is therefore recorded in the Company’s Consolidated Balance Sheets as redeemable noncontrolling interests. When and if a redemption notice is received, the fair value of the redemption is reclassified to a liability. The AlphaCat sidecars and one of the AlphaCat ILS funds have no shareholder redemption rights. Therefore, the third party equity is recorded in the Company’s Consolidated Balance Sheets as noncontrolling interests. The following tables present a reconciliation of the beginning and ending balances of redeemable noncontrolling interests and noncontrolling interests for the three and six months ended June 30, 2017 and 2016 : Redeemable noncontrolling interests Noncontrolling interests Total Three Months Ended June 30, Three Months Ended June 30, Three Months Ended June 30, 2017 2016 2017 2016 2017 2016 Balance, beginning of period $ 1,657,630 $ 1,409,037 $ 330,597 $ 157,223 $ 1,988,227 $ 1,566,260 Issuance of shares 106,501 112,500 103,320 59,349 209,821 171,849 Adjustment to noncontrolling interests as a result of deconsolidation (459,021 ) — — — (459,021 ) — Income attributable to noncontrolling interests 28,555 17,230 15,095 3,963 43,650 21,193 Redemption of shares / distributions (82,005 ) (6,484 ) (33,354 ) (8,381 ) (115,359 ) (14,865 ) Balance, end of period $ 1,251,660 $ 1,532,283 $ 415,658 $ 212,154 $ 1,667,318 $ 1,744,437 Redeemable noncontrolling interests Noncontrolling interests Total Six Months Ended June 30, Six Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 2017 2016 Balance, beginning of period $ 1,528,001 $ 1,111,714 $ 165,977 $ 154,662 $ 1,693,978 $ 1,266,376 Issuance of shares 210,200 381,250 258,300 171,674 468,500 552,924 Adjustment to noncontrolling interests as a result of deconsolidation (459,021 ) — — — (459,021 ) — Income attributable to noncontrolling interests 54,485 45,803 31,737 12,921 86,222 58,724 Redemption of shares / distributions (82,005 ) (6,484 ) (40,356 ) (127,103 ) (122,361 ) (133,587 ) Balance, end of period $ 1,251,660 $ 1,532,283 $ 415,658 $ 212,154 $ 1,667,318 $ 1,744,437 As at June 30, 2017 , redemptions of $74,200 and distributions of $nil (December 31, 2016 : $71,530 and $16,144 ) were payable to redeemable noncontrolling interests and noncontrolling interests, respectively. These amounts are classified within accounts payable and accrued expenses on the Company’s Consolidated Balance Sheets.

Derivative instruments

Derivative instruments	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative instruments	Derivative instruments The Company enters into derivative instruments for risk management purposes, specifically to hedge unmatched foreign currency exposures, interest rate exposures and to shorten the duration of the Company’s fixed maturities portfolio. (a) Derivatives not designated as hedging instruments The following table summarizes information on the classification and amount of the fair value of derivatives not designated as hedging instruments for accounting purposes within the Company’s Consolidated Balance Sheets as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Derivatives not designated as hedging instruments Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Foreign currency forward contracts $ 223,018 $ 1,972 $ 6,325 $ 181,375 $ 2,351 $ 3,421 Interest rate swap contracts $ 150,000 $ 330 $ 648 $ — $ — $ — (a) Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses, respectively, within the Company’s consolidated balance sheets. The following table summarizes information on the classification and net impact on earnings, recognized in the Company’s Consolidated Statements of Income and Comprehensive Income relating to the foreign currency forward and interest rate swap contracts that were not designated as hedging instruments for accounting purposes during the three and six months ended June 30, 2017 and 2016 : Derivatives not designated as hedging instruments Classification of (losses) gains recognized in earnings Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Foreign currency forward contracts Foreign exchange (losses) gains $ (6,525 ) $ 896 $ (6,072 ) $ (1,117 ) Foreign currency forward contracts Other (loss) income $ (874 ) $ 84 $ (979 ) $ 120 Interest rate swap contracts Change in unrealized losses on investments $ (319 ) $ — $ (319 ) $ — (b) Derivatives designated as hedging instruments The following table summarizes information on the classification and amount of the fair value of derivatives designated as hedging instruments for accounting purposes on the Consolidated Balance Sheets as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Derivatives designated as hedging instruments Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Interest rate swap contracts $ 552,263 $ 20 $ 1,409 $ 552,263 $ 20 $ 1,479 (a) Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses, respectively, within the Company’s consolidated balance sheets. Derivative instruments designated as a cash flow hedge The Company designates its interest rate derivative instruments as cash flow hedges for accounting purposes and formally and contemporaneously documents all relationships between the hedging instruments and hedged items and links the derivative instruments to specific assets and liabilities. The Company assesses the effectiveness of the hedges, both at inception and on an on-going basis and determines whether the hedges are highly effective in offsetting changes in fair value of the linked hedged items. The Company currently applies the long haul method when assessing the hedge’s effectiveness. The following table provides the total impact on other comprehensive income (loss) and earnings relating to the derivative instruments formally designated as cash flow hedges along with the impact of the related hedged items for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, Interest rate swap contracts 2017 2016 2017 2016 Amount of effective portion recognized in other comprehensive income $ 2,217 $ 2,694 $ 4,376 $ 6,350 Amount of effective portion subsequently reclassified to earnings $ (2,073 ) $ (2,758 ) $ (4,330 ) $ (5,656 ) Amount of ineffective portion excluded from effectiveness testing $ (144 ) $ 64 $ (46 ) $ (694 ) The above balances relate to interest payments and have therefore been classified as finance expenses in the Consolidated Statements of Income and Comprehensive Income. (c) Classification within the fair value hierarchy As described in Note 5 , “ Fair value measurements ,” under U.S. GAAP, a company must determine the appropriate level in the fair value hierarchy for each fair value measurement. The assumptions used within the valuation of the Company’s derivative instruments are observable in the marketplace, can be derived from observable data or are supported by observable levels at which other similar transactions are executed in the marketplace. Accordingly, these derivatives were classified within Level 2 of the fair value hierarchy. (d) Balance sheet offsetting There was no balance sheet offsetting activity as at June 30, 2017 or December 31, 2016 . The Company currently provides cash collateral as security for interest rate swap contracts. The Company does not provide cash collateral or financial instruments as security for foreign currency forward contracts. Our derivative instruments are generally traded under International Swaps and Derivatives Association master netting agreements, which establish terms that apply to all transactions. On a periodic basis, the amounts receivable from or payable to the counterparties are settled in cash. The Company has not elected to settle multiple transactions with an individual counterparty on a net basis.

Reserve for losses and loss exp

Reserve for losses and loss expenses	6 Months Ended
	Jun. 30, 2017
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Reserve for losses and loss expenses	Reserve for losses and loss expenses Reserves for losses and loss expenses are based in part upon the estimation of case reserves from broker, insured and ceding company reported data. The Company also uses statistical and actuarial methods to estimate ultimate expected losses and loss expenses, from which incurred but not reported losses (“IBNR”) can be calculated. The period of time from the occurrence of a loss to the reporting of a loss to the Company and to the settlement of the Company’s liability may be several months or years. During this period, additional facts and trends may be revealed. As these factors become apparent, reserves will be adjusted, sometimes requiring an increase or decrease in the overall reserves of the Company, and at other times requiring a reallocation of incurred but not reported reserves to specific case reserves. These estimates are reviewed and adjusted regularly, and such adjustments, if any, are reflected in earnings in the period in which they become known. While management believes that it has made a reasonable estimate of ultimate losses, there can be no assurances that ultimate losses and loss expenses will not exceed this estimate. The following table summarizes the total reserve for losses and loss expenses as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Case reserves $ 1,236,799 $ 1,237,772 IBNR 2,068,392 1,757,423 Total reserve for losses and loss expenses $ 3,305,191 $ 2,995,195 The following table represents an analysis of paid and unpaid losses and loss expenses incurred and a reconciliation of the beginning and ending unpaid losses and loss expenses for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Reserve for losses and loss expenses, beginning of period $ 3,052,745 $ 2,980,300 $ 2,995,195 $ 2,996,567 Loss reserves recoverable (451,856 ) (370,689 ) (430,421 ) (350,586 ) Net reserves for losses and loss expenses, beginning of period 2,600,889 2,609,611 2,564,774 2,645,981 Net reserves acquired (a) 23,753 — 23,753 — Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in: Current year 339,439 369,911 670,255 648,097 Prior years (43,290 ) (62,781 ) (104,521 ) (116,520 ) Total net incurred losses and loss expenses 296,149 307,130 565,734 531,577 Less net losses and loss expenses paid in respect of losses occurring in: Current year (42,758 ) (45,882 ) (50,456 ) (61,655 ) Prior years (193,265 ) (176,775 ) (431,354 ) (430,079 ) Total net paid losses (236,023 ) (222,657 ) (481,810 ) (491,734 ) Foreign exchange losses (gains) 20,216 (14,354 ) 32,533 (6,094 ) Net reserve for losses and loss expenses, end of period 2,704,984 2,679,730 2,704,984 2,679,730 Loss reserves recoverable 600,207 442,987 600,207 442,987 Reserve for losses and loss expenses, end of period $ 3,305,191 $ 3,122,717 $ 3,305,191 $ 3,122,717 (a) Equals net reserves acquired of $42,575 less net reserves commuted at closing of $18,822 . Incurred losses and loss expenses comprise: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Gross losses and loss expenses $ 415,013 $ 397,863 $ 761,808 $ 667,716 Reinsurance recoverable (118,864 ) (90,733 ) (196,074 ) (136,139 ) Net incurred losses and loss expenses $ 296,149 $ 307,130 $ 565,734 $ 531,577 The net favorable development on prior years by segment and line of business for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended June 30, 2017 Property Marine Specialty Liability Total Validus Re $ (671 ) $ (16,313 ) $ (6,115 ) $ — $ (23,099 ) Talbot (4,894 ) (17,056 ) 6,074 — (15,876 ) Western World (479 ) — — 16 (463 ) AlphaCat (3,097 ) — (755 ) — (3,852 ) Net (favorable) adverse development $ (9,141 ) $ (33,369 ) $ (796 ) $ 16 $ (43,290 ) The net favorable loss reserve development on prior accident years of $43.3 million during the three months ended June 30, 2017 was primarily due to favorable development on attritional losses. Three Months Ended June 30, 2016 Property Marine Specialty Liability Total Validus Re $ (9,468 ) $ (10,018 ) $ (11,391 ) $ — $ (30,877 ) Talbot (10,094 ) (8,928 ) (9,306 ) — (28,328 ) Western World (1,582 ) — — (1,576 ) (3,158 ) AlphaCat (296 ) — (122 ) — (418 ) Net favorable development $ (21,440 ) $ (18,946 ) $ (20,819 ) $ (1,576 ) $ (62,781 ) The net favorable loss reserve development on prior accident years of $62.8 million during the three months ended June 30, 2016 was primarily due to favorable development on attritional losses. Six Months Ended June 30, 2017 Property Marine Specialty Liability Total Validus Re $ (4,242 ) $ (31,742 ) $ (15,895 ) $ — $ (51,879 ) Talbot (11,228 ) (33,052 ) (410 ) — (44,690 ) Western World (3,302 ) — — 2,620 (682 ) AlphaCat (7,492 ) — 222 — (7,270 ) Net (favorable) adverse development $ (26,264 ) $ (64,794 ) $ (16,083 ) $ 2,620 $ (104,521 ) The net favorable loss reserve development on prior accident years of $104.5 million during the six months ended June 30, 2017 was primarily due to favorable development on attritional losses. Six Months Ended June 30, 2016 Property Marine Specialty Liability Total Validus Re $ (32,300 ) $ (6,463 ) $ (17,798 ) $ — $ (56,561 ) Talbot (28,540 ) (5,964 ) (16,544 ) — (51,048 ) Western World (2,023 ) — — (5,561 ) (7,584 ) AlphaCat (477 ) — (850 ) — (1,327 ) Net favorable development $ (63,340 ) $ (12,427 ) $ (35,192 ) $ (5,561 ) $ (116,520 ) The net favorable development of $116.5 million for the six months ended June 30, 2016 was primarily due to favorable development on attritional losses.

Reinsurance

Reinsurance	6 Months Ended
	Jun. 30, 2017
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The Company’s reinsurance balances recoverable at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Loss reserves recoverable on unpaid: Case reserves $ 176,416 $ 165,328 IBNR 423,791 265,093 Total loss reserves recoverable 600,207 430,421 Paid losses recoverable 35,675 35,247 Total reinsurance balances recoverable $ 635,882 $ 465,668 The Company enters into reinsurance and retrocession agreements in order to mitigate its accumulation of loss, reduce its liability on individual risks, enable it to underwrite policies with higher limits and increase its aggregate capacity. The cession of insurance and reinsurance does not legally discharge the Company from its primary liability for the full amount of the policies, and the Company is required to pay the loss and bear collection risk if the reinsurer fails to meet its obligations under the reinsurance or retrocession agreement. Amounts recoverable from reinsurers are estimated in a manner consistent with the underlying liabilities. Credit risk The Company evaluates the financial condition of its reinsurers and monitors concentration of credit risk arising from its exposure to individual reinsurers. The reinsurance program is generally placed with reinsurers whose rating, at the time of placement, was A- or better as rated by Standard & Poor’s or the equivalent with other rating agencies. Exposure to a single reinsurer is also controlled with restrictions dependent on rating. As at June 30, 2017 , $630,821 or 99.2% ( December 31, 2016 : $461,369 or 99.1% ) of the Company’s reinsurance balances recoverable were either fully collateralized or recoverable from reinsurers rated A- or better. Reinsurance balances recoverable by reinsurer as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Reinsurance Recoverable % of Total Reinsurance Recoverable % of Total Top 10 reinsurers $ 521,027 81.9 % $ 395,308 84.9 % Other reinsurers’ balances > $1 million 106,432 16.8 % 66,944 14.4 % Other reinsurers’ balances < $1 million 8,423 1.3 % 3,416 0.7 % Total $ 635,882 100.0 % $ 465,668 100.0 % The following tables show the reinsurance balances recoverable due from, and the ratings associated with, the Company’s top ten reinsurers as at June 30, 2017 and December 31, 2016 : June 30, 2017 Top 10 Reinsurers Rating Reinsurance Recoverable % of Total Munich Re AA- $ 96,997 15.2 % Lloyd's Syndicates A+ 84,742 13.2 % Fully collateralized reinsurers NR 80,558 12.7 % Swiss Re AA- 77,928 12.3 % Everest Re A+ 54,565 8.6 % Hannover Re AA- 48,037 7.6 % Federal Crop Insurance Corporation (a) 29,009 4.6 % Transatlantic Re A+ 23,066 3.6 % XL Catlin A+ 16,062 2.5 % Helvetia Group A 10,063 1.6 % Total $ 521,027 81.9 % (a) The Company participates in a crop reinsurance program sponsored by the U.S. federal government. The Company remains obligated for amounts ceded in the event that its reinsurers or retrocessionaires do not meet their obligations, except for amounts ceded to the U.S. federal government in the agriculture line of business. December 31, 2016 Top 10 Reinsurers Rating Reinsurance Recoverable % of Total Lloyd's Syndicates A+ $ 84,419 18.2 % Swiss Re AA- 84,044 18.1 % Fully collateralized reinsurers NR 83,088 17.8 % Hannover Re AA- 50,603 10.9 % Everest Re A+ 36,912 7.9 % Munich Re AA- 18,214 3.9 % Transatlantic Re A+ 10,593 2.3 % Hamilton Re A- 10,343 2.2 % Toa Re A+ 9,510 2.0 % National Indemnity Company AA+ 7,582 1.6 % Total $ 395,308 84.9 % At June 30, 2017 and December 31, 2016 , the provision for uncollectible reinsurance relating to reinsurance balances recoverable was $6,741 and $5,153 , respectively. To estimate this provision for uncollectible reinsurance, reinsurance balances recoverable are first allocated to applicable reinsurers. This determination is based on a process rather than an estimate, although an element of judgment is applied, especially in relation to ceded IBNR. The Company then uses default factors to determine the portion of a reinsurer’s balance deemed to be uncollectible. Default factors require considerable judgment and are determined in part using the current rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions.

Share capital

Share capital	6 Months Ended
	Jun. 30, 2017
Stockholders' Equity Note [Abstract]
Share capital	Share capital The Company is authorized to issue up to an aggregate of 571,428,571 common and preferred shares with a par value of $0.175 per share. (a) Preferred shares On June 12, 2017, the Company issued 10,000 shares of its 5.800% Non-Cumulative Preferred Shares, Series B (the “Series B Preferred Shares”) (equivalent to 10,000,000 Depositary Shares, each of which represents a 1/1,000th interest in a Series B Preferred Share), $0.175 par value and $25,000 liquidation preference per share (equivalent to $25 per Depositary Share). The Series B Preferred Shares were registered and sold under the Securities Act of 1933, as amended, and were issued at a price to the public of $25,000 per share (equivalent to $25 per Depositary Share). After underwriting discounts and expenses, the Company received net proceeds of $241,686 which was used for general corporate purposes. The Depositary Shares, representing the Series B Preferred Shares, are traded on the New York Stock Exchange (“NYSE”) under the symbol “VRPRB.” The Series B Preferred Shares have no stated maturity date and are redeemable, in whole or in part, at the Company’s option on and after June 21, 2022, at a redemption price of $25,000 per Series B Preferred Share (equivalent to $25 per Depository Share), plus declared and unpaid dividends. The Company may also redeem all, but not less than all, of the Series B Preferred Shares before the redemption date at a redemption price of $26,000 per share (equivalent to $26 per Depository Share), plus declared and unpaid dividends, if the Company is required to submit a proposal to the holders of the Series B Preferred Shares concerning an amalgamation, consolidation, merger or other similar corporate transaction or change in Bermuda law. The Series B Preferred Shares may also be redeemed before the redemption date at a redemption price of $25,000 per Series B Preferred Share (equivalent to $25.00 per Depository Share), plus declared and unpaid dividends, in whole, if there is a certain change in tax law, or in whole or in part, in the case of a capital disqualification event. However, no redemption may occur prior to June 21, 2027 unless the Company has sufficient funds in order to meet the Bermuda Monetary Authority’s (“the BMA”) Enhanced Capital Requirements (“ECR”) and the BMA approves of the redemption, or the Company replaces the capital represented by the Series B Preferred Shares with capital having equal or better capital treatment as the Series B Preferred Shares under the ECR. Dividends on the Series B Preferred Shares, when, as and if declared by the Company’s Board of Directors or a duly authorized committee thereof, will accrue and be payable on the liquidation preference amount from the original issue date, on a non-cumulative basis, quarterly in arrears on each dividend payment date at an annual rate of 5.800% . The Company will be restricted from paying dividends on and repurchasing its common shares, unless certain dividend payments are made on the Series B Preferred Shares. Upon any voluntary or involuntary liquidation, dissolution or winding up of the Company, holders of the Series B Preferred Shares and any parity shares are entitled to receive out of our assets available for distribution to shareholders, before any distribution is made to holders of common shares or other junior shares, a liquidating distribution in the amount of $25,000 per Series B Preferred Share (equivalent to $25 per Depositary Share) plus declared and unpaid dividends. Distributions will be made pro rata in accordance with the respective aggregate liquidation preferences of the Series B Preferred Shares and any parity shares and only to the extent of our assets, if any, that are available after satisfaction of all liabilities to creditors. Holders of the Series B Preferred Shares have no voting rights, except with respect to certain fundamental changes in the terms of the Series B Preferred Shares and in the case of certain dividend non-payments or as otherwise required by Bermuda law or the Company’s bye-laws. On June 13, 2016, the Company issued 6,000 shares of its 5.875% Non-Cumulative Preferred Shares, Series A (the “Series A Preferred Shares”) (equivalent to 6,000,000 Depositary Shares, each of which represents a 1/1,000th interest in a Series A Preferred Share), $0.175 par value and $25,000 liquidation preference per share (equivalent to $25 per Depositary Share). Holders of the Series A Preferred Shares have no voting rights, except with respect to certain fundamental changes in the terms of the Series A Preferred Shares and in the case of certain dividend non-payments or as otherwise required by Bermuda law or the Company’s bye-laws. The following table is a summary of the preferred share activity during the six months ended June 30, 2017 and 2016 : Six Months Ended June 30, 2017 2016 Preferred shares issued and outstanding, beginning of period 6,000 — Preferred shares issued 10,000 6,000 Preferred shares issued and outstanding, end of period 16,000 6,000 The Company had 6,000 Series A Preferred Shares and 10,000 Series B Preferred Shares issued and outstanding as at June 30, 2017 and 6,000 Series A Preferred Shares issued and outstanding as at December 31, 2016. (b) Common Shares The holders of common shares are entitled to receive dividends and are allocated one vote per share , provided that, if the controlled shares of any shareholder or group of related shareholders constitute more than 9.09 percent of the outstanding common shares of the Company, their voting power will be reduced to 9.09 percent. The Company may from time to time repurchase its securities, including common shares, Junior Subordinated Deferrable Debentures and Senior Notes. On February 3, 2015, the Board of Directors of the Company approved an increase in the Company’s common share repurchase authorization to $750,000 . This amount is in addition to the $2,274,401 of common shares repurchased by the Company through February 3, 2015 under its previously authorized share repurchase programs. The Company has repurchased 80,776,802 common shares for an aggregate purchase price of $2,718,402 from the inception of its share repurchase program to June 30, 2017 . The Company had $305,999 remaining under its authorized share repurchase program as of June 30, 2017 . The Company expects the purchases under its share repurchase program to be made from time to time in the open market or in privately negotiated transactions. The timing, form and amount of the share repurchases under the program will depend on a variety of factors, including market conditions, the Company’s capital position relative to internal and rating agency targets, legal requirements and other factors. The repurchase program may be modified, extended or terminated by the Board of Directors at any time. The following table is a summary of the common share activity during the six months ended June 30, 2017 and 2016 : Six Months Ended June 30, 2017 2016 Common shares issued, beginning of period 161,279,976 160,570,772 Restricted share awards vested, net of shares withheld 597,021 601,890 Restricted share units vested, net of shares withheld 14,948 18,486 Options exercised — 13,635 Performance share awards vested, net of shares withheld 42,410 48,088 Common shares issued, end of period 161,934,355 161,252,871 Treasury shares, end of period (82,415,774 ) (80,480,633 ) Common shares outstanding, end of period 79,518,581 80,772,238 (c) Dividends On May 10, 2017 , the Company announced a quarterly cash dividend of $0.38 ( 2016 : $0.35 ) per common share and a quarterly cash dividend of $0.3671875 per depositary share on its outstanding Series A Preferred Shares. The common share dividend was paid on June 30, 2017 to holders of record on June 15, 2017 . The preferred share dividend was paid on June 15, 2017 to holders of record on June 1, 2017. On February 9, 2017, the Company announced a quarterly cash dividend of $0.38 (2016: $0.35 ) per common share and a quarterly cash dividend of $0.3671875 per depositary share on its outstanding Series A Preferred Shares. The common share dividend was paid on March 31, 2017 to holders of record on March 15, 2017. The preferred share dividend was paid on March 15, 2017 to holders of record on March 1, 2017.

Stock plans

Stock plans	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock plans	Stock plans (a) Long Term Incentive Plan The Company’s Amended and Restated 2005 Long Term Incentive Plan (“LTIP”) provides for grants to employees of options, stock appreciation rights (“SARs”), restricted shares, restricted share units, performance shares, dividend equivalents or other share-based awards. The total number of shares reserved for issuance under the LTIP are 2,753,292 shares of which 714,817 shares remain available for issuance at June 30, 2017 . The LTIP is administered by the Compensation Committee of the Board of Directors. No SARs have been granted to date. Grant prices are established at the fair market value of the Company’s common shares at the date of grant. i. Options Options may be exercised for voting common shares upon vesting. Outstanding options have a life of 10 years and vest either pro rata or at the end of the required service period from the date of grant. Fair value of the option awards at the date of grant is determined using the Black-Scholes option-pricing model. Expected volatility is based on stock price volatility of comparable publicly-traded companies. The Company used the simplified method consistent with U.S. GAAP authoritative guidance on stock compensation expenses to estimate expected lives for options granted during the period as historical exercise data was not available and the options met the requirement as set out in the guidance. The Company has not granted any stock option awards since September 4, 2009. These stock option awards were fully amortized during the year ended December 31, 2012. Activity with respect to options for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Options Weighted Average Grant Date Fair Value Weighted Average Grant Date Exercise Price Options Weighted Average Grant Date Fair Value Weighted Average Grant Date Exercise Price Options outstanding, beginning of period 26,136 $ 6.78 $ 23.48 65,401 $ 7.74 $ 20.17 Options exercised — — — (14,044 ) 7.69 17.02 Options outstanding, end of period 26,136 $ 6.78 $ 23.48 51,357 $ 7.75 $ 21.03 ii. Restricted share awards Restricted shares granted under the LTIP vest either pro rata or at the end of the required service period and contain certain restrictions during the vesting period, relating to, among other things, forfeiture in the event of termination of employment and transferability. The Company recognized share compensation expenses during the three and six months ended June 30, 2017 of $9,745 ( 2016 : $9,517 ) and $18,789 ( 2016 : $18,646 ), respectively. The expenses represent the proportionate accrual of the fair value of each grant based on the remaining vesting period. Activity with respect to unvested restricted share awards for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Restricted Share Awards Weighted Average Grant Date Fair Value Restricted Share Awards Weighted Average Grant Date Fair Value Restricted share awards outstanding, beginning of period 2,469,982 $ 40.89 2,739,446 $ 38.25 Restricted share awards granted 481,619 53.42 534,905 48.69 Restricted share awards vested (803,764 ) 41.31 (783,523 ) 37.32 Restricted share awards forfeited (39,617 ) 41.98 (8,317 ) 37.94 Restricted share awards outstanding, end of period 2,108,220 $ 43.58 2,482,511 $ 40.79 At June 30, 2017 , there were $63,931 ( December 31, 2016 : $58,804 ) of total unrecognized share compensation expenses in respect of restricted share awards that are expected to be recognized over a weighted-average period of 2.6 years ( December 31, 2016 : 2.3 years ). iii. Restricted share units Restricted share units under the LTIP vest either ratably or at the end of the required service period and contain certain restrictions during the vesting period, relating to, among other things, forfeiture in the event of termination of employment and transferability. The Company recognized share compensation expenses during the three and six months ended June 30, 2017 of $327 ( 2016 : $377 ) and $642 ( 2016 : $688 ), respectively. The expenses represent the proportionate accrual of the fair value of each grant based on the remaining vesting period. Activity with respect to unvested restricted share units for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Restricted Share Units Weighted Average Grant Date Fair Value Restricted Share Units Weighted Average Grant Date Fair Value Restricted share units outstanding, beginning of period 112,808 $ 40.95 114,337 $ 38.47 Restricted share units granted 12,236 53.40 20,129 48.69 Restricted share units vested (18,241 ) 41.66 (23,982 ) 38.18 Restricted share units issued in lieu of cash dividends 1,468 40.98 1,629 38.47 Restricted share units outstanding, end of period 108,271 $ 42.24 112,113 $ 40.37 At June 30, 2017 , there were $2,558 ( December 31, 2016 : $2,542 ) of total unrecognized share compensation expenses in respect of restricted share units that are expected to be recognized over a weighted-average period of 2.6 years ( December 31, 2016 : 2.6 years ). iv. Performance share awards The performance share awards contain a performance based component. The performance component relates to the compounded growth in the Dividend Adjusted Diluted Book Value per Share (“DBVPS”) over a three -year period relative to the Company’s peer group. For performance share awards granted during the period, the grant date DBVPS is based on the DBVPS at the end of the most recent financial reporting year. The Dividend Adjusted Performance Period End DBVPS will be the DBVPS three years after the grant date DBVPS. The fair value estimate earns over the requisite attribution period and the estimate will be reassessed at the end of each performance period which will reflect any adjustments in the Consolidated Statements of Income and Comprehensive Income in the period in which they are determined. The Company recognized share compensation expenses during the three and six months ended June 30, 2017 of $1,074 ( 2016 : $833 ) and $1,206 ( 2016 : $2,630 ), respectively. Activity with respect to unvested performance share awards for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Performance Share Awards Weighted Average Grant Date Fair Value Performance Share Awards Weighted Average Grant Date Fair Value Performance share awards outstanding, beginning of period 285,820 $ 44.53 172,594 $ 40.70 Performance share awards granted 107,209 53.40 121,844 48.69 Performance share awards vested (52,639 ) 37.33 (57,581 ) 36.11 Performance share awards conversion adjustment (26,322 ) 36.82 45,517 36.82 Performance share awards outstanding, end of period 314,068 $ 49.37 282,374 $ 44.46 At June 30, 2017 , there were $10,250 ( December 31, 2016 : $6,902 ) of total unrecognized share compensation expenses in respect of performance share awards that are expected to be recognized over a weighted-average period of 2.3 years ( December 31, 2016 : 2.1 years ). (b) Total share compensation expenses The breakdown of share compensation expenses by award type for the periods indicated was as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Restricted share awards $ 9,745 $ 9,517 $ 18,789 $ 18,646 Restricted share units 327 377 642 688 Performance share awards 1,074 833 1,206 2,630 Total $ 11,146 $ 10,727 $ 20,637 $ 21,964

Debt and financing arrangements

Debt and financing arrangements	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Debt and financing arrangements	Debt and financing arrangements The Company’s financing structure is comprised of debentures and senior notes payable along with credit and other facilities. The Company’s outstanding debentures and senior notes payable as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Deferrable debentures 2006 Junior Subordinated $ 150,000 $ 150,000 2007 Junior Subordinated 139,800 139,800 Flagstone 2006 Junior Subordinated 134,850 133,676 Flagstone 2007 Junior Subordinated 113,750 113,750 Total debentures payable 538,400 537,226 2010 Senior notes payable 250,000 250,000 Less: Unamortized debt issuance costs (4,537 ) (4,638 ) Total senior notes payable 245,463 245,362 Total debentures and senior notes payable $ 783,863 $ 782,588 The Company’s outstanding credit and other facilities as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Commitment Drawn and outstanding Commitment Drawn and outstanding Credit and other facilities $85,000 syndicated unsecured letter of credit facility $ 85,000 $ — $ 85,000 $ — $300,000 syndicated secured letter of credit facility 300,000 87,718 300,000 90,252 $24,000 secured bi-lateral letter of credit facility 24,000 5,648 24,000 4,553 $20,000 AlphaCat Re secured letter of credit facility (a) — — 20,000 20,000 $25,000 IPC bi-lateral facility 25,000 5,535 25,000 5,842 $236,000 Flagstone bi-lateral facility 236,000 102,190 236,000 144,392 Total credit and other facilities $ 670,000 $ 201,091 $ 690,000 $ 265,039 (a) The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017. (a) Senior notes and junior subordinated deferrable debentures The following table summarizes the key terms of the Company’s senior notes and junior subordinated deferrable debentures: Description Issuance date Issued Maturity date Interest Rate as at Interest payments due Issuance Date June 30, 2017 2006 Junior Subordinated Deferrable Debentures June 15, 2006 $ 150,000 June 15, 2036 9.069 % (a) 5.831 % (e) Quarterly Flagstone 2006 Junior Subordinated Deferrable Debentures August 23, 2006 $ 134,850 September 15, 2036 3.540 % (b) 6.463 % (e) Quarterly 2007 Junior Subordinated Deferrable Debentures June 21, 2007 $ 200,000 June 15, 2037 8.480 % (c) 5.180 % (e) Quarterly Flagstone 2007 Junior Subordinated Deferrable Debentures June 8, 2007 $ 100,000 July 30, 2037 3.000 % (b) 5.900 % (e) Quarterly Flagstone 2007 Junior Subordinated Deferrable Debentures September 20, 2007 $ 25,000 September 15, 2037 3.100 % (b) 5.983 % (e) Quarterly 2010 Senior Notes due 2040 January 26, 2010 $ 250,000 January 26, 2040 8.875 % (d) 8.875 % (d) Semi-annually in arrears (a) Fixed interest rate for 5 years , floating interest rate of three-month LIBOR plus 3.550% thereafter, reset quarterly. (b) Floating interest rate of three-month LIBOR plus amount stated, reset quarterly. (c) Fixed interest rate for 5 years , floating interest rate of three-month LIBOR plus 2.950% thereafter, reset quarterly. (d) Fixed interest rate. (e) Fixed interest rate as a result of interest rate swap contracts entered into by the Company. Future payments of principal of $250,000 and $538,400 on the 2010 Senior Notes and the debentures, respectively, are expected to be made after 2022. (b) Credit facilities The Company has pledged cash and investments as collateral under the Company’s credit facilities in the total amount of $404,516 (December 31, 2016 : $442,184 ) as detailed in the table below: Cash and investments pledged as collateral June 30, 2017 December 31, 2016 $300,000 syndicated secured letter of credit facility $ 147,048 $ 157,597 $24,000 secured bi-lateral letter of credit facility 33,353 48,097 AlphaCat Re secured letter of credit facility (a) — 20,032 $236,000 Flagstone bi-lateral facility 224,115 216,458 Total cash and investments pledged as collateral $ 404,516 $ 442,184 (a) The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017. As of June 30, 2017 and December 31, 2016 , the Company was in compliance with all covenants and restrictions under its credit facilities. (c) Finance expenses Finance expenses consist of interest on the junior subordinated deferrable debentures and senior notes, the amortization of debt offering costs, credit facility fees, bank charges, Talbot Funds at Lloyds (“FAL”) facility, AlphaCat financing fees and other charges as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 2006 Junior Subordinated Deferrable Debentures $ 2,211 $ 2,211 $ 4,398 $ 4,422 2007 Junior Subordinated Deferrable Debentures 1,831 1,830 3,641 3,661 Flagstone 2006 Junior Subordinated Deferrable Debentures 2,248 2,244 4,469 4,489 Flagstone 2007 Junior Subordinated Deferrable Debentures 1,751 1,766 3,474 3,533 2010 Senior Notes due 2040 5,598 5,597 11,195 11,194 Credit facilities 403 235 621 896 Bank and other charges 131 206 282 213 AlphaCat fees (a) 36 77 72 961 Total finance expenses $ 14,209 $ 14,166 $ 28,152 $ 29,369 (a) Includes finance expenses incurred by AlphaCat Managers Ltd. in relation to fund raising for the AlphaCat sidecars, the AlphaCat ILS funds and AlphaCat direct.

Accumulated other comprehensive

Accumulated other comprehensive loss	6 Months Ended
	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive loss	Accumulated other comprehensive loss The changes in accumulated other comprehensive loss, by component for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended June 30, 2017 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (21,677 ) $ (82 ) $ (694 ) $ (22,453 ) Other comprehensive income (loss), net of tax 1,489 1,184 (144 ) 2,529 Balance, net of tax, end of period $ (20,188 ) $ 1,102 $ (838 ) $ (19,924 ) Three Months Ended June 30, 2016 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (13,862 ) $ 251 $ (1,827 ) $ (15,438 ) Other comprehensive (loss) income, net of tax (3,287 ) 479 64 (2,744 ) Balance, net of tax, end of period $ (17,149 ) $ 730 $ (1,763 ) $ (18,182 ) Six Months Ended June 30, 2017 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (22,274 ) $ (150 ) $ (792 ) $ (23,216 ) Other comprehensive income (loss), net of tax 2,086 1,252 (46 ) 3,292 Balance, net of tax, end of period $ (20,188 ) $ 1,102 $ (838 ) $ (19,924 ) Six Months Ended June 30, 2016 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (11,834 ) $ 334 $ (1,069 ) $ (12,569 ) Other comprehensive (loss) income, net of tax (5,315 ) 396 (694 ) (5,613 ) Balance, net of tax, end of period $ (17,149 ) $ 730 $ (1,763 ) $ (18,182 )

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies (a) Funds at Lloyd’s Talbot operates in Lloyd’s through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment and reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd’s (“FAL”), comprises cash and investments. The Company provided FAL in the amount of $583,600 for the 2017 underwriting year ( 2016 underwriting year: $617,000 ). The amounts which are provided as FAL are not available for distribution to the Company for the payment of dividends. Talbot’s corporate member may also be required to maintain funds under the control of Lloyd’s in excess of its capital requirement and such funds also may not be available for distribution to the Company for the payment of dividends. (b) Lloyd’s Central Fund Whenever a member of Lloyd’s is unable to pay its debts to policyholders, such debts may be payable by the Lloyd’s Central Fund. If Lloyd’s determines that the Central Fund needs to be increased, it has the power to assess premium levies on current Lloyd’s members up to 3% of a member’s underwriting capacity in any one year. The Company does not believe that any assessment is likely in the foreseeable future and has not provided any allowance for such an assessment. However, based on the Company’s 2017 underwriting capacity at Lloyd’s of £600,000 , at the June 30, 2017 exchange rate of £1 equals $1.30 and assuming the maximum 3% assessment, the Company would be assessed approximately $23,400 . (c) Marketing Services Agreement (“MSA”) On May 1, 2017, the Company entered into a MSA with Archer Daniels Midland (“ADM”). Under this agreement, ADM agrees to provide marketing services via its own distribution channels for an annual fee of $2,000 for a period of seven years , with an option for the Company to extend for an additional three years . For the three and six months ended June 30, 2017 , the Company had incurred fees of $333 in relation to the MSA. (d) Unfunded investment commitments As at June 30, 2017 and December 31, 2016 , the Company had total unfunded investment commitments related to the following: Unfunded investment commitments June 30, 2017 December 31, 2016 Fixed maturity investments (a) $ 25,238 $ 28,499 Other investments (b) 119,495 156,134 Investments in investment affiliates (c) 84,046 64,071 AlphaCat ILS Fund — 10,000 Total unfunded investment commitments $ 228,779 $ 258,704 (a) The Company has an outstanding commitment to participate in certain secured loan facilities through participation agreements with an established loan originator. (b) The Company’s total capital commitments related to other investments as at June 30, 2017 was $313,000 ( December 31, 2016 : $308,000 ). (c) Refer to Note 4 (c), “Investments in Investment Affiliates.”

Related party transactions

Related party transactions	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
Related party transactions	Related party transactions The transactions listed below are classified as related party transactions as principals and/or directors of each counterparty are members of the Company’s board of directors. (a) Aquiline Capital Partners LLC (“Aquiline Capital”) Group Ark Insurance Subsequent to July 2016, Aquiline Capital ceased to be shareholders of Group Ark Insurance Holdings Ltd. (“Group Ark”). Christopher E. Watson, a director of the Company and senior principal of Aquiline Capital, continues to serve as a director of Group Ark. Pursuant to reinsurance agreements with a subsidiary of Group Ark, the Company recognized gross premiums written during the three and six months ended June 30, 2016 of $65 and $1,971 , respectively. The Company also recognized reinsurance premiums ceded during the three and six months ended June 30, 2016 of $(17) and $nil , respectively. Earned premium adjustments were recorded during the three and six months ended June 30, 2016 of $473 and $999 , respectively. As at December 31, 2016 the Company had recorded premiums receivable and loss reserves recoverable of $292 and $798 , respectively. Wellington Pursuant to reinsurance agreements with a subsidiary of Wellington Insurance Company (“Wellington”), during the three and six months ended June 30, 2017 the Company recognized gross premiums written of $1,144 and $4,118 ( 2016 : $nil and $nil ), respectively, and earned premium adjustments of $1,676 and $2,537 ( 2016 : $nil and $nil ), respectively. As at June 30, 2017 and December 31, 2016 the Company had recorded premiums receivable of $3,531 and $666 , respectively. Aquiline Capital are shareholders of Wellington and Christopher E. Watson, a director of the Company and senior principal of Aquiline Capital, serves as a director of Wellington. Aquiline II, Aquiline III and Aquiline Tech The Company had, as of June 30, 2017 and December 31, 2016 , investments in Aquiline II, III and Tech with a total value of $103,377 and $100,431 and outstanding unfunded commitments of $84,046 and $64,071 , respectively. For the three and six months ended June 30, 2017 , the Company incurred $130 and $486 ( 2016 : $440 and $440 ), respectively, in partnership fees associated with these investments. Additional information related to Aquiline II, III and Tech is disclosed in Note 4 (c), “Investments in Investment Affiliates.” (b) Other Certain shareholders of the Company and their affiliates, as well as employers of entities associated with directors or officers have purchased insurance and/or reinsurance from the Company in the ordinary course of business. The Company believes these transactions were settled for arm’s length consideration.

Earnings per share

Earnings per share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings per share	Earnings per common share The following table sets forth the computation of basic earnings per common share and earnings per diluted common share for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Basic earnings per common share Net income available to Validus common shareholders $ 101,095 $ 94,963 $ 195,656 $ 261,773 Weighted average number of common shares outstanding 79,270,561 81,950,833 79,202,116 82,386,047 Basic earnings per share available to Validus common shareholders $ 1.28 $ 1.16 $ 2.47 $ 3.18 Earnings per diluted common share Net income available to Validus common shareholders $ 101,095 $ 94,963 $ 195,656 $ 261,773 Weighted average number of common shares outstanding 79,270,561 81,950,833 79,202,116 82,386,047 Share equivalents: Stock options 14,739 33,796 15,059 34,837 Unvested restricted shares 1,587,151 1,388,374 1,644,823 1,364,775 Weighted average number of diluted common shares outstanding 80,872,451 83,373,003 80,861,998 83,785,659 Earnings per diluted share available to Validus common shareholders $ 1.25 $ 1.14 $ 2.42 $ 3.12 Share equivalents that would result in the issuance of common shares of 412,603 ( 2016 : 507,262 ) and 207,054 ( 2016 : 253,631 ) were outstanding for the three and six months ended June 30, 2017 , respectively, but were not included in the computation of earnings per diluted common share because the effect would be antidilutive.

Segment information

Segment information	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Segment information	Segment information The Company conducts its operations worldwide through four operating segments, which have been determined under ASC Topic 280 “Segment Reporting” to be Validus Re, Talbot, Western World and AlphaCat. For segmental reporting purposes, the results of CRS have been included in the results of the Western World segment as of May 1, 2017, the date of acquisition. The Company’s operating segments are strategic business units that offer different products and services. They are managed and have capital allocated separately because each segment undertakes different strategies. A description of each of the Company’s operating segments and its Corporate and Investments function is as follows: Validus Re Segment The Validus Re segment is focused primarily on treaty reinsurance. The primary lines in which the segment conducts business are property, marine and specialty which includes agriculture, aerospace and aviation, financial lines of business, nuclear, terrorism, life, accident & health, workers’ compensation, crisis management, contingency, technical lines, composite, trade credit and casualty. Talbot Segment The Talbot segment is focused on a wide range of marine and energy, political lines, commercial property, financial lines, contingency, accident & health and aviation classes of business on an insurance or facultative reinsurance basis and principally property, aerospace and marine classes of business on a treaty reinsurance basis. Western World Segment The Western World segment is focused on providing commercial insurance products on a surplus lines and specialty admitted basis. Western World specializes in underwriting classes of business that are not easily placed in the standard insurance market due to their complexity, high hazard, or unusual nature; including general liability, property and professional liability, homeowners, commercial package and agriculture classes of business. AlphaCat Segment The AlphaCat segment leverages the Company’s underwriting and analytical expertise and earns management and performance fees from the Company and other third party investors primarily through the AlphaCat ILS funds and sidecars. Corporate and Investments The Company has a corporate and investments function (“Corporate and Investments”), which includes the activities of the parent company, and which carries out certain functions for the group, including investment management. Corporate and Investments includes investment income on a managed basis and other non-segment expenses, predominantly general and administrative, stock compensation, finance and transaction expenses. Transaction expenses are primarily comprised of legal, financial advisory and audit related services incurred in connection with the acquisition of CRS. Corporate and Investments also includes the activities of certain key executives such as the Chief Executive Officer and Chief Financial Officer. For reporting purposes, Corporate and Investments is reflected separately; however, it is not considered an operating segment under these circumstances. Other reconciling items include, but are not limited to, the elimination of certain inter segment revenues and expenses and other items that are not allocated to the operating segments. A reconciliation of segmental income to net income available to Validus is included in the tables below. The following tables summarize the results of our operating segments and “Corporate and Investments”: Three Months Ended June 30, Six Months Ended June 30, Validus Re Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 296,997 $ 285,810 $ 917,519 $ 977,478 Reinsurance premiums ceded (11,387 ) (3,196 ) (120,200 ) (95,691 ) Net premiums written 285,610 282,614 797,319 881,787 Change in unearned premiums (45,003 ) (35,492 ) (338,300 ) (390,834 ) Net premiums earned 240,607 247,122 459,019 490,953 Other insurance related income (loss) 58 150 136 (165 ) Total underwriting revenues 240,665 247,272 459,155 490,788 Underwriting deductions Losses and loss expenses 104,685 132,139 190,839 215,007 Policy acquisition costs 47,158 42,564 88,414 84,823 General and administrative expenses 19,274 17,872 36,106 35,051 Share compensation expenses 2,663 2,775 5,140 5,676 Total underwriting deductions 173,780 195,350 320,499 340,557 Underwriting income $ 66,885 $ 51,922 $ 138,656 $ 150,231 Selected ratios Ratio of net to gross premiums written 96.2 % 98.9 % 86.9 % 90.2 % Losses and loss expense ratio 43.5 % 53.5 % 41.6 % 43.8 % Policy acquisition cost ratio 19.6 % 17.2 % 19.3 % 17.3 % General and administrative expense ratio (a) 9.1 % 8.4 % 8.9 % 8.3 % Expense ratio 28.7 % 25.6 % 28.2 % 25.6 % Combined ratio 72.2 % 79.1 % 69.8 % 69.4 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, Talbot Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 262,477 $ 296,067 $ 509,652 $ 562,384 Reinsurance premiums ceded (24,977 ) (27,161 ) (117,801 ) (114,619 ) Net premiums written 237,500 268,906 391,851 447,765 Change in unearned premiums (45,626 ) (67,357 ) (4,912 ) (39,424 ) Net premiums earned 191,874 201,549 386,939 408,341 Other insurance related income 65 279 820 290 Total underwriting revenues 191,939 201,828 387,759 408,631 Underwriting deductions Losses and loss expenses 93,389 109,310 199,801 209,411 Policy acquisition costs 44,305 43,613 87,581 87,956 General and administrative expenses 35,582 39,061 74,025 77,596 Share compensation expenses 3,155 3,270 5,982 6,792 Total underwriting deductions 176,431 195,254 367,389 381,755 Underwriting income $ 15,508 $ 6,574 $ 20,370 $ 26,876 Selected ratios Ratio of net to gross premiums written 90.5 % 90.8 % 76.9 % 79.6 % Losses and loss expense ratio 48.7 % 54.2 % 51.6 % 51.3 % Policy acquisition cost ratio 23.1 % 21.6 % 22.6 % 21.5 % General and administrative expense ratio (a) 20.2 % 21.1 % 20.7 % 20.7 % Expense ratio 43.3 % 42.7 % 43.3 % 42.2 % Combined ratio 92.0 % 96.9 % 94.9 % 93.5 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, Western World Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 131,068 $ 86,971 $ 303,111 $ 150,930 Reinsurance premiums ceded (23,180 ) (5,006 ) (28,798 ) (9,145 ) Net premiums written 107,888 81,965 274,313 141,785 Change in unearned premiums 22,806 (16,309 ) (46,347 ) (14,630 ) Net premiums earned 130,694 65,656 227,966 127,155 Other insurance related income 663 189 904 477 Total underwriting revenues 131,357 65,845 228,870 127,632 Underwriting deductions Losses and loss expenses 97,008 44,229 171,933 83,875 Policy acquisition costs 19,230 15,410 39,466 29,610 General and administrative expenses 18,316 11,458 29,070 23,533 Share compensation expenses 609 542 1,301 1,123 Total underwriting deductions 135,163 71,639 241,770 138,141 Underwriting loss $ (3,806 ) $ (5,794 ) $ (12,900 ) $ (10,509 ) Selected ratios Ratio of net to gross premiums written 82.3 % 94.2 % 90.5 % 93.9 % Losses and loss expense ratio 74.2 % 67.4 % 75.4 % 66.0 % Policy acquisition cost ratio 14.7 % 23.5 % 17.3 % 23.3 % General and administrative expense ratio (a) 14.5 % 18.2 % 13.4 % 19.3 % Expense ratio 29.2 % 41.7 % 30.7 % 42.6 % Combined ratio 103.4 % 109.1 % 106.1 % 108.6 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, AlphaCat Segment Information 2017 2016 2017 2016 Fee revenues Third party $ 5,549 $ 3,091 $ 10,193 $ 7,818 Related party 644 328 1,275 1,219 Total fee revenues 6,193 3,419 11,468 9,037 Expenses General and administrative expenses 3,549 2,751 7,393 4,233 Share compensation expenses 83 133 165 274 Finance expenses 44 75 75 883 Tax expense 135 — 134 — Foreign exchange losses 1 4 — 12 Total expenses 3,812 2,963 7,767 5,402 Income before investments from AlphaCat Funds and Sidecars 2,381 456 3,701 3,635 Investment income (loss) from AlphaCat Funds and Sidecars (a) AlphaCat Sidecars (21 ) 541 (133 ) 665 AlphaCat ILS Funds - Lower Risk (b) 1,301 2,075 3,490 4,582 AlphaCat ILS Funds - Higher Risk (b) 2,600 692 4,967 3,128 BetaCat ILS Funds 263 1,113 631 1,676 PaCRe — — — (23 ) Validus’ share of investment income from AlphaCat Funds and Sidecars 4,143 4,421 8,955 10,028 Validus’ share of AlphaCat segment income $ 6,524 $ 4,877 $ 12,656 $ 13,663 Supplemental information Gross premiums written AlphaCat Sidecars $ — $ (14 ) $ 66 $ (66 ) AlphaCat ILS Funds - Lower Risk (b) 53,632 50,234 106,540 110,192 AlphaCat ILS Funds - Higher Risk (b) 43,672 42,010 137,208 138,330 AlphaCat Direct (c) 8,378 6,675 26,794 17,797 Total gross premiums written $ 105,682 $ 98,905 $ 270,608 $ 266,253 (a) The investment income from the AlphaCat funds and sidecars is based on equity accounting. (b) Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit. (c) AlphaCat Direct includes direct investments from third party investors in AlphaCat Re. Three Months Ended June 30, Six Months Ended June 30, Corporate and Investments 2017 2016 2017 2016 Investment income Managed net investment income (a) $ 38,063 $ 36,849 $ 74,255 $ 64,772 Corporate expenses General and administrative expenses 18,847 17,872 36,024 34,055 Share compensation expenses 4,636 4,007 8,049 8,099 Finance expenses (b) 14,149 13,979 28,013 28,320 Dividends on preferred shares 2,203 — 4,406 — Tax (benefit) expense (1,122 ) 1,706 (4,670 ) (412 ) Total Corporate expenses 38,713 37,564 71,822 70,062 Other items Net realized gains (losses) on managed investments (b) 2,269 2,520 (623 ) 1,434 Change in net unrealized gains on managed investments (b) 15,942 30,052 30,291 77,130 Income (loss) from investment affiliate 9,466 (589 ) 14,654 (4,702 ) Foreign exchange (losses) gains (b) (7,323 ) 6,621 (6,220 ) 12,695 Other income 174 79 268 756 Transaction expenses (4,427 ) — (4,427 ) — Total other items 16,101 38,683 33,943 87,313 Total Corporate and Investments $ 15,451 $ 37,968 $ 36,376 $ 82,023 (a) Managed net investment income excludes the components which are included in the Company’s share of AlphaCat, net realized and change in unrealized gains on managed investments and income (loss) from investment affiliates. (b) These items exclude the components which are included in Validus’ share of AlphaCat and amounts which are consolidated from VIEs. The following tables reconcile the results of our operating segments along with our corporate and investments function to the Consolidated results of the Company for the periods indicated: Three Months Ended June 30, 2017 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 296,997 $ 262,477 $ 131,068 $ 105,682 $ — $ (3,322 ) $ 792,902 Reinsurance premiums ceded (11,387 ) (24,977 ) (23,180 ) — — 3,322 (56,222 ) Net premiums written 285,610 237,500 107,888 105,682 — — 736,680 Change in unearned premiums (45,003 ) (45,626 ) 22,806 (37,830 ) — — (105,653 ) Net premiums earned 240,607 191,874 130,694 67,852 — — 631,027 Other insurance related income 58 65 663 5,874 — (5,495 ) 1,165 Total underwriting revenues 240,665 191,939 131,357 73,726 — (5,495 ) 632,192 Underwriting deductions Losses and loss expenses 104,685 93,389 97,008 1,067 — — 296,149 Policy acquisition costs 47,158 44,305 19,230 7,165 — (590 ) 117,268 General and administrative expenses 19,274 35,582 18,316 9,768 18,847 (5,438 ) 96,349 Share compensation expenses 2,663 3,155 609 83 4,636 — 11,146 Total underwriting deductions 173,780 176,431 135,163 18,083 23,483 (6,028 ) 520,912 Underwriting income (loss) $ 66,885 $ 15,508 $ (3,806 ) $ 55,643 $ (23,483 ) $ 533 $ 111,280 Other items (a) — — — 183 7,501 — 7,684 Dividends on preferred shares — — — — (2,203 ) — (2,203 ) Net investment income — — — 6,178 38,063 — 44,241 Transaction expenses — — — — (4,427 ) — (4,427 ) (Income) attributable to AlphaCat investors — — — (11,830 ) — — (11,830 ) Net (income) attributable to noncontrolling interest — — — (43,650 ) — — (43,650 ) Segmental income (loss) $ 66,885 $ 15,508 $ (3,806 ) $ 6,524 $ 15,451 $ 533 Net income available to Validus common shareholders $ 101,095 (a) Other items includes finance expenses, tax benefit (expense), foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Three Months Ended June 30, 2016 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 285,810 $ 296,067 $ 86,971 $ 98,905 $ — $ (3,711 ) $ 764,042 Reinsurance premiums ceded (3,196 ) (27,161 ) (5,006 ) (4,577 ) — 3,711 (36,229 ) Net premiums written 282,614 268,906 81,965 94,328 — — 727,813 Change in unearned premiums (35,492 ) (67,357 ) (16,309 ) (34,932 ) — — (154,090 ) Net premiums earned 247,122 201,549 65,656 59,396 — — 573,723 Other insurance related income 150 279 189 3,401 — (3,274 ) 745 Total underwriting revenues 247,272 201,828 65,845 62,797 — (3,274 ) 574,468 Underwriting deductions Losses and loss expenses 132,139 109,310 44,229 21,452 — — 307,130 Policy acquisition costs 42,564 43,613 15,410 6,530 — (151 ) 107,966 General and administrative expenses 17,872 39,061 11,458 6,561 17,872 (3,136 ) 89,688 Share compensation expenses 2,775 3,270 542 133 4,007 — 10,727 Total underwriting deductions 195,350 195,254 71,639 34,676 21,879 (3,287 ) 515,511 Underwriting income (loss) $ 51,922 $ 6,574 $ (5,794 ) $ 28,121 $ (21,879 ) $ 13 $ 58,957 Other items (a) — — — 1,058 22,998 — 24,056 Dividends on preferred shares — — — — — — — Net investment income — — — 3,005 36,849 (597 ) 39,257 (Income) attributable to AlphaCat investors — — — (6,114 ) — — (6,114 ) Net (income) attributable to noncontrolling interest — — — (21,193 ) — — (21,193 ) Segmental income (loss) $ 51,922 $ 6,574 $ (5,794 ) $ 4,877 $ 37,968 $ (584 ) Net income available to Validus common shareholders $ 94,963 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Six Months Ended June 30, 2017 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 917,519 $ 509,652 $ 303,111 $ 270,608 $ — $ (17,131 ) $ 1,983,759 Reinsurance premiums ceded (120,200 ) (117,801 ) (28,798 ) (6,660 ) — 17,131 (256,328 ) Net premiums written 797,319 391,851 274,313 263,948 — — 1,727,431 Change in unearned premiums (338,300 ) (4,912 ) (46,347 ) (131,469 ) — — (521,028 ) Net premiums earned 459,019 386,939 227,966 132,479 — — 1,206,403 Other insurance related income 136 820 904 11,035 — (10,494 ) 2,401 Total underwriting revenues 459,155 387,759 228,870 143,514 — (10,494 ) 1,208,804 Underwriting deductions Losses and loss expenses 190,839 199,801 171,933 3,161 — — 565,734 Policy acquisition costs 88,414 87,581 39,466 14,066 — (631 ) 228,896 General and administrative expenses 36,106 74,025 29,070 19,409 36,024 (10,361 ) 184,273 Share compensation expenses 5,140 5,982 1,301 165 8,049 — 20,637 Total underwriting deductions 320,499 367,389 241,770 36,801 44,073 (10,992 ) 999,540 Underwriting income (loss) $ 138,656 $ 20,370 $ (12,900 ) $ 106,713 $ (44,073 ) $ 498 $ 209,264 Other items (a) — — — 1,298 15,027 — 16,325 Dividends on preferred shares — — — — (4,406 ) — (4,406 ) Net investment income — — — 10,200 74,255 — 84,455 Transaction expenses — — — — (4,427 ) — (4,427 ) (Income) attributable to AlphaCat investors — — — (19,333 ) — — (19,333 ) Net (income) attributable to noncontrolling interest — — — (86,222 ) — — (86,222 ) Segmental income (loss) $ 138,656 $ 20,370 $ (12,900 ) $ 12,656 $ 36,376 $ 498 Net income available to Validus common shareholders $ 195,656 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Six Months Ended June 30, 2016 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 977,478 $ 562,384 $ 150,930 $ 266,253 $ — $ (20,212 ) $ 1,936,833 Reinsurance premiums ceded (95,691 ) (114,619 ) (9,145 ) (4,821 ) — 20,212 (204,064 ) Net premiums written 881,787 447,765 141,785 261,432 — — 1,732,769 Change in unearned premiums (390,834 ) (39,424 ) (14,630 ) (142,890 ) — — (587,778 ) Net premiums earned 490,953 408,341 127,155 118,542 — — 1,144,991 Other insurance related (loss) income (165 ) 290 477 9,066 — (8,187 ) 1,481 Total underwriting revenues 490,788 408,631 127,632 127,608 — (8,187 ) 1,146,472 Underwriting deductions Losses and loss expenses 215,007 209,411 83,875 23,284 — — 531,577 Policy acquisition costs 84,823 87,956 29,610 12,687 — 83 215,159 General and administrative expenses 35,051 77,596 23,533 14,017 34,055 (8,356 ) 175,896 Share compensation expenses 5,676 6,792 1,123 274 8,099 — 21,964 Total underwriting deductions 340,557 381,755 138,141 50,262 42,154 (8,273 ) 944,596 Underwriting income (loss) $ 150,231 $ 26,876 $ (10,509 ) $ 77,346 $ (42,154 ) $ 86 $ 201,876 Other items (a) — — — 1,212 59,405 — 60,617 Dividends on preferred shares — — — — — — — Net investment income — — — 4,543 64,772 (597 ) 68,718 (Income) attributable to AlphaCat investors — — — (10,714 ) — — (10,714 ) Net (income) attributable to noncontrolling interest — — — (58,724 ) — — (58,724 ) Segmental income (loss) $ 150,231 $ 26,876 $ (10,509 ) $ 13,663 $ 82,023 $ (511 ) Net income available to Validus common shareholders $ 261,773 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). The Company’s exposures are generally diversified across geographic zones. The following tables set forth the gross premiums written by operating segment allocated to the territory of coverage exposure for the periods indicated: Gross Premiums Written Three Months Ended June 30, 2017 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 100,312 $ 34,470 $ 131,068 $ 70,048 $ (3,443 ) $ 332,455 41.9 % Worldwide excluding United States (a) 4,537 32,627 — 870 114 38,148 4.7 % Australia and New Zealand 3,264 1,848 — 2,003 40 7,155 0.9 % Europe 748 5,857 — (15 ) 275 6,865 0.9 % Latin America and Caribbean 11,874 24,800 — 46 (1,411 ) 35,309 4.5 % Japan 39,305 3,381 — 2,662 (6 ) 45,342 5.7 % Canada 3,155 1,111 — 130 (4 ) 4,392 0.6 % Rest of the world (b) 4,877 23,168 — — 105 28,150 3.6 % Sub-total, non United States 67,760 92,792 — 5,696 (887 ) 165,361 20.9 % Worldwide including United States (a) 53,524 30,735 — 29,937 1,006 115,202 14.5 % Other locations non-specific (c) 75,401 104,480 — 1 2 179,884 22.7 % Total $ 296,997 $ 262,477 $ 131,068 $ 105,682 $ (3,322 ) $ 792,902 100.0 % Gross Premiums Written Three Months Ended June 30, 2016 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 129,087 $ 39,135 $ 86,971 $ 37,338 $ (417 ) $ 292,114 38.2 % Worldwide excluding United States (a) 16,975 30,028 — 6,496 (136 ) 53,363 7.0 % Australia and New Zealand 1,926 2,063 — 867 21 4,877 0.6 % Europe 3,267 6,855 — (145 ) 216 10,193 1.3 % Latin America and Caribbean 5,992 27,597 — — (2,511 ) 31,078 4.1 % Japan 39,053 3,965 — 1,721 (7 ) 44,732 5.9 % Canada 1,821 2,470 — 223 (36 ) 4,478 0.6 % Rest of the world (b) 3,259 29,806 — — (457 ) 32,608 4.3 % Sub-total, non United States 72,293 102,784 — 9,162 (2,910 ) 181,329 23.8 % Worldwide including United States (a) 35,561 34,198 — 52,394 (380 ) 121,773 15.9 % Other locations non-specific (c) 48,869 119,950 — 11 (4 ) 168,826 22.1 % Total $ 285,810 $ 296,067 $ 86,971 $ 98,905 $ (3,711 ) $ 764,042 100.0 % Gross Premiums Written Six Months Ended June 30, 2017 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 314,180 $ 63,555 $ 303,111 $ 98,251 $ (4,323 ) $ 774,774 39.1 % Worldwide excluding United States (a) 38,605 66,958 — 7,905 (539 ) 112,929 5.7 % Australia and New Zealand 4,195 5,030 — 2,003 (110 ) 11,118 0.6 % Europe 30,364 17,572 — 451 (430 ) 47,957 2.3 % Latin America and Caribbean 21,216 48,977 — 46 (4,283 ) 65,956 3.3 % Japan 40,466 5,206 — 3,855 (36 ) 49,491 2.5 % Canada 4,870 2,248 — 130 (49 ) 7,199 0.4 % Rest of the world (b) 18,782 46,440 — — (1,577 ) 63,645 3.2 % Sub-total, non United States 158,498 192,431 — 14,390 (7,024 ) 358,295 18.0 % Worldwide including United States (a) 155,945 58,092 — 153,246 (5,784 ) 361,499 18.2 % Other locations non-specific (c) 288,896 195,574 — 4,721 — 489,191 24.7 % Total $ 917,519 $ 509,652 $ 303,111 $ 270,608 $ (17,131 ) $ 1,983,759 100.0 % Gross Premiums Written Six Months Ended June 30, 2016 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 424,481 $ 65,245 $ 150,930 $ 62,729 $ (1,555 ) $ 701,830 36.2 % Worldwide excluding United States (a) 47,239 65,532 — 22,507 (611 ) 134,667 7.0 % Australia and New Zealand 6,849 4,375 — 4,949 (113 ) 16,060 0.8 % Europe 25,734 20,716 — 3,306 (708 ) 49,048 2.5 % Latin America and Caribbean 19,574 51,404 — — (5,537 ) 65,441 3.4 % Japan 39,925 4,582 — 3,221 (31 ) 47,697 2.5 % Canada 3,497 3,562 — 223 (87 ) 7,195 0.4 % Rest of the world (b) 19,947 57,290 — — (2,342 ) 74,895 3.9 % Sub-total, non United States 162,765 207,461 — 34,206 (9,429 ) 395,003 20.5 % Worldwide including United States (a) 147,338 62,652 — 167,767 (9,214 ) 368,543 19.0 % Other locations non-specific (c) 242,894 227,026 — 1,551 (14 ) 471,457 24.3 % Total $ 977,478 $ 562,384 $ 150,930 $ 266,253 $ (20,212 ) $ 1,936,833 100.0 % (a) Represents risks in two or more geographic zones. (b) Represents risks in one geographic zone. (c) The Other locations non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable since these exposures can span multiple geographic areas and, in some instances, are not fixed locations.

Subsequent events

Subsequent events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent events	Subsequent events Placeholder for credit facilities.

Significant accounting policies

Significant accounting policies (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Basis of preparation	These unaudited Consolidated Financial Statements (the “Consolidated Financial Statements”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 in Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In addition, the year-end balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. This Quarterly Report on Form 10-Q should be read in conjunction with the financial statements and related notes included in Validus Holdings, Ltd.’s (the “Company”) Annual Report on Form 10-K for the year ended December 31, 2016 , as filed with the U.S. Securities and Exchange Commission (the “SEC”). In the opinion of management, these unaudited Consolidated Financial Statements reflect all adjustments (including normal recurring adjustments) considered necessary for a fair statement of the Company’s financial position and results of operations as at the end of and for the periods presented. All significant intercompany accounts and transactions have been eliminated. The results of operations for any interim period are not necessarily indicative of the results for a full year.
Use of estimates	The preparation of these financial statements in conformity with U.S. 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. While management believes that the amounts included in the Consolidated Financial Statements reflect its best estimates and assumptions, actual results could differ materially from those estimates. The Company’s principal estimates include: • reserve for losses and loss expenses; • premium estimates for business written on a line slip or proportional basis; • the valuation of goodwill and intangible assets; • reinsurance recoverable balances including the provision for uncollectible amounts; and • investment valuation of financial assets.
Consolidating voting interest entities and variable interest entities	The Company consolidates in these Consolidated Financial Statements the results of operations and financial position of all voting interest entities (“VOE”) in which the Company has a controlling financial interest and all variable interest entities (“VIE”) in which the Company is considered to be the primary beneficiary. The consolidation assessment, including the determination as to whether an entity qualifies as a VIE or VOE, depends on the facts and circumstances surrounding each entity.

Business combination (Tables)

Business combination (Tables)	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Schedule of fair value of net assets acquired	The fair value of net assets acquired, including GAAP adjustments, are summarized as follows: Total purchase price $ 185,576 Assets acquired Cash and cash equivalents $ 1,653 Premiums receivable 564,453 Prepaid reinsurance premiums 227,157 Other assets 157,146 Assets acquired 950,409 Liabilities acquired Reinsurance balances payable $ 294,201 Unearned premiums 406,649 Net loss reserves 42,575 Other liabilities 122,715 Liabilities acquired 866,140 Excess purchase price $ 101,307 Goodwill and other intangible assets acquired Intangible asset - Distribution channels $ 52,898 Intangible asset - Brand name 9,568 Intangible asset - Technology 1,455 Total intangible assets 63,921 Goodwill 30,943 Deferred tax arising on Goodwill 6,443 Total goodwill and intangible assets $ 101,307
Reconciliation of goodwill and intangible assets	The following tables reconcile the carrying amount of goodwill and intangible assets from December 31, 2016 to June 30, 2017 : Goodwill Six Months Ended June 30, 2017 Talbot Western World Total Balance at December 31, 2016 20,393 176,365 196,758 Additions — 30,943 30,943 Balance at June 30, 2017 20,393 207,308 227,701 Intangible assets Six Months Ended June 30, 2017 Talbot Western World Total Balance at December 31, 2016 93,924 21,668 115,592 Additions — 63,921 63,921 Amortization (2,081 ) (1,914 ) (3,995 ) Balance at June 30, 2017 91,843 83,675 175,518 Intangible assets Six Months Ended June 30, 2017 With a Finite Life With an Indefinite Life Total Balance at December 31, 2016 11,424 104,168 115,592 Additions 63,921 — 63,921 Amortization (3,995 ) — (3,995 ) Balance at June 30, 2017 71,350 104,168 175,518
Supplemental pro forma information	The following selected unaudited information has been provided to present a summary of the results of CRS that have been included in the Consolidated Financial Statements for the three and six months ended June 30, 2017 . From Acquisition Date to June 30, 2017 Net premiums written 6,988 Net premiums earned 50,044 Total underwriting deductions 44,780 Underwriting income, before general and administrative expenses 5,264

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2017
Investments [Abstract]
Amortized cost (or cost), gross unrealized gains and (losses) and fair value of investments	The amortized cost (or cost) and fair value of the Company’s investments as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Amortized Amortized Fair Value Managed investments U.S. government and government agency $ 649,214 $ 646,436 $ 809,392 $ 804,126 Non-U.S. government and government agency 293,002 292,504 245,651 240,791 U.S. states, municipalities and political subdivisions 227,047 227,949 271,742 271,830 Agency residential mortgage-backed securities 786,784 783,006 684,490 679,595 Non-agency residential mortgage-backed securities 26,745 26,683 15,858 15,477 U.S. corporate 1,378,884 1,386,484 1,540,036 1,534,508 Non-U.S. corporate 380,317 379,480 418,520 410,227 Bank loans 560,446 552,901 579,121 570,399 Asset-backed securities 500,679 502,056 528,563 526,814 Commercial mortgage-backed securities 317,732 316,190 333,740 330,932 Total fixed maturities 5,120,850 5,113,689 5,427,113 5,384,699 Short-term investments 255,289 255,516 228,574 228,386 Other investments Fund of hedge funds — — 1,457 955 Hedge funds 11,292 18,303 11,292 17,381 Private equity investments 79,871 100,391 66,383 82,627 Fixed income investment funds 266,041 268,110 247,967 249,275 Overseas deposits 57,874 57,874 50,106 50,106 Mutual funds 1,918 3,940 2,925 5,368 Total other investments 416,996 448,618 380,130 405,712 Investments in investment affiliates (a) 72,532 103,377 84,840 100,431 Total managed investments $ 5,865,667 $ 5,921,200 $ 6,120,657 $ 6,119,228 Non-managed investments Catastrophe bonds $ 303,712 $ 304,954 $ 157,486 $ 158,331 Short-term investments 2,615,837 2,615,837 2,567,784 2,567,784 Total non-managed investments 2,919,549 2,920,791 2,725,270 2,726,115 Total investments $ 8,785,216 $ 8,841,991 $ 8,845,927 $ 8,845,343 (a) The Company’s investments in investment affiliates have been treated as equity method investments with the corresponding gains and losses recorded in income as “Income (loss) from investment affiliates.”
Investment ratings on fixed maturities	The following table sets forth certain information regarding the investment ratings of the Company’s fixed maturity investments as at June 30, 2017 and December 31, 2016 . June 30, 2017 December 31, 2016 Fair Value % of Total Fair Value % of Total Managed fixed maturities AAA $ 2,318,254 42.8 % $ 2,405,597 43.4 % AA 463,060 8.5 % 538,289 9.7 % A 1,009,366 18.6 % 1,081,949 19.5 % BBB 703,563 13.0 % 740,861 13.4 % Total investment grade managed fixed maturities 4,494,243 82.9 % 4,766,696 86.0 % BB 229,023 4.2 % 213,568 3.9 % B 176,743 3.3 % 177,737 3.2 % CCC 11,114 0.2 % 13,371 0.2 % NR 202,566 3.8 % 213,327 3.8 % Total non-investment grade fixed maturities 619,446 11.5 % 618,003 11.1 % Total managed fixed maturities $ 5,113,689 94.4 % $ 5,384,699 97.1 % Non-managed fixed maturities BB 28,177 0.4 % 29,731 0.6 % B 2,781 0.1 % 4,524 0.1 % NR 273,996 5.1 % 124,076 2.2 % Total non-managed fixed maturities 304,954 5.6 % 158,331 2.9 % Total fixed maturities $ 5,418,643 100.0 % $ 5,543,030 100.0 %
Fixed maturities investments by contractual maturity	The amortized cost and fair value amounts for the Company’s fixed maturity investments held at June 30, 2017 and December 31, 2016 are shown below by contractual maturity. Actual maturity may differ from contractual maturity because certain borrowers may have the right to call or prepay certain obligations with or without call or prepayment penalties. June 30, 2017 December 31, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Managed fixed maturities Due in one year or less $ 497,473 $ 492,256 $ 350,733 $ 346,161 Due after one year through five years 2,464,093 2,461,870 2,954,856 2,933,146 Due after five years through ten years 456,793 459,311 430,365 426,647 Due after ten years 70,551 72,317 128,508 125,927 3,488,910 3,485,754 3,864,462 3,831,881 Asset-backed and mortgage-backed securities 1,631,940 1,627,935 1,562,651 1,552,818 Total managed fixed maturities $ 5,120,850 $ 5,113,689 $ 5,427,113 $ 5,384,699 Non-managed catastrophe bonds Due in one year or less $ 33,662 $ 32,441 $ 43,664 $ 45,418 Due after one year through five years 263,300 265,735 112,572 111,656 Due after five years through ten years 6,750 6,778 1,250 1,257 Due after ten years — — — — Total non-managed fixed maturities 303,712 304,954 157,486 158,331 Total fixed maturities $ 5,424,562 $ 5,418,643 $ 5,584,599 $ 5,543,030
Other investments	The following tables set forth certain information regarding the Company’s other investment portfolio as at June 30, 2017 and December 31, 2016 : June 30, 2017 Fair Value Investments with redemption restrictions Investments without redemption restrictions Redemption frequency (a) Redemption notice period (a) Hedge funds 18,303 18,303 — Private equity investments 100,391 100,391 — Fixed income investment funds 268,110 237,986 30,124 Daily Daily to 2 days Overseas deposits 57,874 57,874 — Mutual funds 3,940 — 3,940 Daily Daily Total other investments $ 448,618 $ 414,554 $ 34,064 December 31, 2016 Fair Value Investments with redemption restrictions Investments without redemption restrictions Redemption frequency (a) Redemption notice period (a) Fund of hedge funds $ 955 $ 955 $ — Hedge funds 17,381 17,381 — Private equity investments 82,627 82,627 — Fixed income investment funds 249,275 218,333 30,942 Daily 2 days Overseas deposits 50,106 50,106 — Mutual funds 5,368 — 5,368 Daily Daily Total other investments $ 405,712 $ 369,402 $ 36,310 (a) The redemption frequency and notice periods only apply to investments without redemption restrictions.
Reconciliation of beginning and ending investment in affiliate balances	The following table presents a reconciliation of the Company’s beginning and ending investments in investment affiliates for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Investments in investment affiliates, beginning of period $ 94,697 $ 84,135 $ 100,431 $ 87,673 Net capital (distributions) contributions (786 ) 15,732 (11,708 ) 16,307 Income (loss) from investment affiliates 9,466 (589 ) 14,654 (4,702 ) Investments in investment affiliates, end of period $ 103,377 $ 99,278 $ 103,377 $ 99,278
Schedule of equity method investments	The following table presents the Company’s investments in investment affiliates as at June 30, 2017 and December 31, 2016 : June 30, 2017 Investment at cost Voting ownership % Equity ownership % Carrying value Aquiline II $ 33,349 — % 8.1 % $ 52,010 Aquiline III 37,969 — % 9.0 % 50,153 Aquiline Tech 1,214 — % 16.4 % 1,214 Total investments in investment affiliates $ 72,532 $ 103,377 December 31, 2016 Investment at cost Voting ownership % Equity ownership % Carrying value Aquiline II $ 46,871 — % 8.1 % $ 61,999 Aquiline III 37,969 — % 9.0 % 38,432 Total investments in investment affiliates $ 84,840 $ 100,431
Net investment income	Net investment income was derived from the following sources: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Managed investments Fixed maturities and short-term investments $ 31,312 $ 30,621 $ 62,983 $ 58,638 Other investments 7,571 8,026 14,441 8,898 Cash and cash equivalents and restricted cash 616 380 1,226 1,245 Securities lending income 7 12 20 17 Total gross investment income 39,506 39,039 78,670 68,798 Investment expenses (1,443 ) (2,190 ) (4,415 ) (4,026 ) Total managed net investment income $ 38,063 $ 36,849 $ 74,255 $ 64,772 Non managed investments Fixed maturities and short-term investments $ 4,500 $ 1,977 $ 7,560 $ 3,272 Restricted cash, cash and cash equivalents 1,678 431 2,640 674 Total non-managed net investment income 6,178 2,408 10,200 3,946 Total net investment income $ 44,241 $ 39,257 $ 84,455 $ 68,718
Analysis of net realized gains and the change in net unrealized gains (losses) on investments	The following table sets forth an analysis of net realized gains and the change in net unrealized gains on investments: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Managed fixed maturities, short-term and other investments Gross realized gains $ 5,175 $ 3,306 $ 7,865 $ 6,523 Gross realized (losses) (2,906 ) (786 ) (8,488 ) (5,089 ) Net realized gains (losses) on investments 2,269 2,520 (623 ) 1,434 Change in net unrealized gains on investments 15,942 30,052 30,291 77,130 Total net realized and change in net unrealized gains on managed investments $ 18,211 $ 32,572 $ 29,668 $ 78,564 Non-managed fixed maturities, short-term and other investments Gross realized gains $ 5 $ 204 $ 1,733 $ 715 Gross realized (losses) — — — (9 ) Net realized gains on investments 5 204 1,733 706 Change in net unrealized gains (losses) on investments 379 1,376 (622 ) 1,742 Total net realized and change in net unrealized gains on non-managed investments 384 1,580 1,111 2,448 Total net realized and change in net unrealized gains on total investments $ 18,595 $ 34,152 $ 30,779 $ 81,012

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair value hierarchy - allocation of investments	At June 30, 2017 , the Company’s investments were allocated between Levels 1, 2 and 3 as follows: Level 1 Level 2 Level 3 Fair value based on NAV practical expedient (a) Total Managed investments U.S. government and government agency $ — $ 646,436 $ — $ — $ 646,436 Non-U.S. government and government agency — 292,504 — — 292,504 U.S. states, municipalities and political subdivisions — 227,949 — — 227,949 Agency residential mortgage-backed securities — 783,006 — — 783,006 Non-agency residential mortgage-backed securities — 26,683 — — 26,683 U.S. corporate — 1,386,484 — — 1,386,484 Non-U.S. corporate — 379,480 — — 379,480 Bank loans — 328,729 224,172 — 552,901 Asset-backed securities — 466,135 35,921 — 502,056 Commercial mortgage-backed securities — 316,190 — — 316,190 Total fixed maturities — 4,853,596 260,093 — 5,113,689 Short-term investments 248,439 7,077 — — 255,516 Other investments Hedge funds — — — 18,303 18,303 Private equity investments — — — 100,391 100,391 Fixed income investment funds — 30,137 16,400 221,573 268,110 Overseas deposits — — — 57,874 57,874 Mutual funds — 3,940 — — 3,940 Total other investments — 34,077 16,400 398,141 448,618 Investments in investment affiliates (b) — — — — 103,377 Total managed investments $ 248,439 $ 4,894,750 $ 276,493 $ 398,141 $ 5,921,200 Non-managed investments Catastrophe bonds $ — $ 236,929 $ 68,025 $ — $ 304,954 Short-term investments 2,615,837 — — — 2,615,837 Total non-managed investments 2,615,837 236,929 68,025 — 2,920,791 Total investments $ 2,864,276 $ 5,131,679 $ 344,518 $ 398,141 $ 8,841,991 (a) In accordance with ASC Topic 820 “Fair Value Measurements,” investments measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (b) In accordance with ASC Topic 825 “Financial Instruments,” the Company’s investments in investment affiliates have not been classified in the fair value hierarchy. At December 31, 2016 , the Company’s investments were allocated between Levels 1, 2 and 3 as follows: Level 1 Level 2 Level 3 Fair value based on NAV practical expedient (a) Total Managed investments U.S. government and government agency $ — $ 804,126 $ — $ — $ 804,126 Non-U.S. government and government agency — 240,791 — — 240,791 U.S. states, municipalities and political subdivisions — 271,830 — — 271,830 Agency residential mortgage-backed securities — 679,595 — — 679,595 Non-agency residential mortgage-backed securities — 15,477 — — 15,477 U.S. corporate — 1,534,508 — — 1,534,508 Non-U.S. corporate — 410,227 — — 410,227 Bank loans — 323,903 246,496 — 570,399 Asset-backed securities — 502,883 23,931 — 526,814 Commercial mortgage-backed securities — 330,932 — — 330,932 Total fixed maturities — 5,114,272 270,427 — 5,384,699 Short-term investments 209,651 18,735 — — 228,386 Other investments Fund of hedge funds — — — 955 955 Hedge funds — — — 17,381 17,381 Private equity investments — — — 82,627 82,627 Fixed income investment funds — 30,941 12,168 206,166 249,275 Overseas deposits — — — 50,106 50,106 Mutual funds — 5,368 — — 5,368 Total other investments — 36,309 12,168 357,235 405,712 Investments in investment affiliates (b) — — — — 100,431 Total managed investments $ 209,651 $ 5,169,316 $ 282,595 $ 357,235 $ 6,119,228 Non-managed investments Catastrophe bonds $ — $ 109,956 $ 48,375 $ — $ 158,331 Short-term investments 2,567,784 — — — 2,567,784 Total non-managed investments 2,567,784 109,956 48,375 — 2,726,115 Total investments $ 2,777,435 $ 5,279,272 $ 330,970 $ 357,235 $ 8,845,343 (a) In accordance with ASC Topic 820 “Fair Value Measurements,” investments measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (b) In accordance with ASC Topic 825 “Financial Instruments,” the Company’s investments in investment affiliates have not been classified in the fair value hierarchy.
Reconciliation of beginning and ending balances for all Level 3 investments measured at fair value on recurring basis	The following table presents a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, 2017 Bank Loans Catastrophe Bonds Fixed Income Investment Funds Asset Backed Securities Total Level 3 investments, beginning of period $ 236,694 $ 72,676 $ 12,560 $ 23,882 $ 345,812 Purchases 16,757 5,000 3,432 11,053 36,242 Sales — — — (53 ) (53 ) Settlements (28,893 ) (10,216 ) 408 — (38,701 ) Net realized gains — 216 — — 216 Change in net unrealized (losses) gains (386 ) 349 — 49 12 Amortization — — — 990 990 Level 3 investments, end of period $ 224,172 $ 68,025 $ 16,400 $ 35,921 $ 344,518 Three Months Ended June 30, 2016 Bank Loans Catastrophe Bonds Asset Backed Securities Total Level 3 investments, beginning of period $ 255,011 $ 37,105 $ — $ 292,116 Purchases 8,885 — 12,383 21,268 Settlements (17,784 ) — — (17,784 ) Change in net unrealized (losses) gains (2,964 ) 413 — (2,551 ) Level 3 investments, end of period $ 243,148 $ 37,518 $ 12,383 $ 293,049 Six Months Ended June 30, 2017 Bank Loans Catastrophe Bonds Fixed Income Investment Funds Asset Backed Securities Total Level 3 investments—beginning of period $ 246,496 $ 48,375 $ 12,168 $ 23,931 $ 330,970 Purchases 39,933 66,091 3,432 11,053 120,509 Sales — — — (53 ) (53 ) Settlements (62,003 ) (48,996 ) 800 — (110,199 ) Net realized gains — 3,350 — — 3,350 Change in net unrealized (losses) (254 ) (795 ) — — (1,049 ) Amortization — — — 990 990 Level 3 investments—end of period $ 224,172 $ 68,025 $ 16,400 $ 35,921 $ 344,518 Six Months Ended June 30, 2016 Bank Loans Catastrophe Bonds Asset Backed Securities Total Level 3 investments—beginning of period $ 232,337 $ 13,500 $ — $ 245,837 Purchases 50,988 23,272 12,383 86,643 Sales (2,389 ) — — (2,389 ) Settlements (34,033 ) (125 ) — (34,158 ) Change in net unrealized (losses) gains (3,755 ) 871 — (2,884 ) Level 3 investments—end of period $ 243,148 $ 37,518 $ 12,383 $ 293,049

Variable interest entities (Tab

Variable interest entities (Tables)	6 Months Ended
	Jun. 30, 2017
Variable Interest Entities Disclosure [Abstract]
Summary of notes payable to variable interest entities	The following tables present a reconciliation of the beginning and ending notes payable to AlphaCat investors for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, 2017 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 343,256 $ 103,320 $ 446,576 Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund 423,269 — 423,269 Issuance of notes payable to AlphaCat investors 267,867 68,880 336,747 Redemption of notes payable to AlphaCat investors (140,150 ) — (140,150 ) Foreign exchange gains (283 ) — (283 ) Notes payable to AlphaCat investors, end of period $ 893,959 $ 172,200 $ 1,066,159 Three Months Ended June 30, 2016 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 261,793 $ 61,717 $ 323,510 Issuance of notes payable to AlphaCat investors 102,817 32,609 135,426 Redemption of notes payable to AlphaCat investors (88,079 ) — (88,079 ) Foreign exchange losses 125 — 125 Notes payable to AlphaCat investors, end of period $ 276,656 $ 94,326 $ 370,982 Six Months Ended June 30, 2017 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 278,202 $ — $ 278,202 Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund 423,269 — 423,269 Issuance of notes payable to AlphaCat investors 541,877 172,200 714,077 Redemption of notes payable to AlphaCat investors (349,106 ) — (349,106 ) Foreign exchange gains (283 ) — (283 ) Notes payable to AlphaCat investors, end of period $ 893,959 $ 172,200 $ 1,066,159 Six Months Ended June 30, 2016 Variable Funding Notes Structured Notes Total Notes payable to AlphaCat investors, beginning of period $ 75,493 $ — $ 75,493 Issuance of notes payable to AlphaCat investors 298,105 94,326 392,431 Redemption of notes payable to AlphaCat investors (97,684 ) — (97,684 ) Foreign exchange losses 742 — 742 Notes payable to AlphaCat investors, end of period $ 276,656 $ 94,326 $ 370,982
Total assets and liabilities of the Company's consolidated VIEs	The following table presents the total assets and total liabilities of the Company’s consolidated VIEs, excluding intercompany eliminations, as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Total Assets Total Liabilities Total Assets Total Liabilities AlphaCat sidecars $ 29,330 $ 3,455 $ 40,041 $ 3,206 AlphaCat ILS funds - Lower Risk (a) 951,428 951,428 13,371 1,498,276 42,457 AlphaCat ILS funds - Higher Risk (a) 1,037,568 207,300 972,633 381,332 AlphaCat Re and AlphaCat Master Fund 2,828,096 2,827,926 2,510,415 2,510,245 BetaCat ILS funds 146,098 278 82,471 30,663 (a) Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit.

Noncontrolling interest (Tables

Noncontrolling interest (Tables)	6 Months Ended
	Jun. 30, 2017
Noncontrolling Interest [Abstract]
Reconciliation of beginning and ending balances of noncontrolling interest and redeemable noncontrolling interest	The following tables present a reconciliation of the beginning and ending balances of redeemable noncontrolling interests and noncontrolling interests for the three and six months ended June 30, 2017 and 2016 : Redeemable noncontrolling interests Noncontrolling interests Total Three Months Ended June 30, Three Months Ended June 30, Three Months Ended June 30, 2017 2016 2017 2016 2017 2016 Balance, beginning of period $ 1,657,630 $ 1,409,037 $ 330,597 $ 157,223 $ 1,988,227 $ 1,566,260 Issuance of shares 106,501 112,500 103,320 59,349 209,821 171,849 Adjustment to noncontrolling interests as a result of deconsolidation (459,021 ) — — — (459,021 ) — Income attributable to noncontrolling interests 28,555 17,230 15,095 3,963 43,650 21,193 Redemption of shares / distributions (82,005 ) (6,484 ) (33,354 ) (8,381 ) (115,359 ) (14,865 ) Balance, end of period $ 1,251,660 $ 1,532,283 $ 415,658 $ 212,154 $ 1,667,318 $ 1,744,437 Redeemable noncontrolling interests Noncontrolling interests Total Six Months Ended June 30, Six Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 2017 2016 Balance, beginning of period $ 1,528,001 $ 1,111,714 $ 165,977 $ 154,662 $ 1,693,978 $ 1,266,376 Issuance of shares 210,200 381,250 258,300 171,674 468,500 552,924 Adjustment to noncontrolling interests as a result of deconsolidation (459,021 ) — — — (459,021 ) — Income attributable to noncontrolling interests 54,485 45,803 31,737 12,921 86,222 58,724 Redemption of shares / distributions (82,005 ) (6,484 ) (40,356 ) (127,103 ) (122,361 ) (133,587 ) Balance, end of period $ 1,251,660 $ 1,532,283 $ 415,658 $ 212,154 $ 1,667,318 $ 1,744,437

Derivative instruments (Tables)

Derivative instruments (Tables)	6 Months Ended
	Jun. 30, 2017
Derivative [Line Items]
Location and amount of gains and losses related to derivative instruments reported on in the comprehensive income and earnings	The following table provides the total impact on other comprehensive income (loss) and earnings relating to the derivative instruments formally designated as cash flow hedges along with the impact of the related hedged items for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, Interest rate swap contracts 2017 2016 2017 2016 Amount of effective portion recognized in other comprehensive income $ 2,217 $ 2,694 $ 4,376 $ 6,350 Amount of effective portion subsequently reclassified to earnings $ (2,073 ) $ (2,758 ) $ (4,330 ) $ (5,656 ) Amount of ineffective portion excluded from effectiveness testing $ (144 ) $ 64 $ (46 ) $ (694 )
Not designated as hedging instruments
Derivative [Line Items]
Location and fair value amount of derivative instruments reported on the balance sheet	The following table summarizes information on the classification and amount of the fair value of derivatives not designated as hedging instruments for accounting purposes within the Company’s Consolidated Balance Sheets as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Derivatives not designated as hedging instruments Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Foreign currency forward contracts $ 223,018 $ 1,972 $ 6,325 $ 181,375 $ 2,351 $ 3,421 Interest rate swap contracts $ 150,000 $ 330 $ 648 $ — $ — $ — (a) Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses, respectively, within the Company’s consolidated balance sheets.
Location and amount of gains and losses related to derivative instruments reported on in the income statement	The following table summarizes information on the classification and net impact on earnings, recognized in the Company’s Consolidated Statements of Income and Comprehensive Income relating to the foreign currency forward and interest rate swap contracts that were not designated as hedging instruments for accounting purposes during the three and six months ended June 30, 2017 and 2016 : Derivatives not designated as hedging instruments Classification of (losses) gains recognized in earnings Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Foreign currency forward contracts Foreign exchange (losses) gains $ (6,525 ) $ 896 $ (6,072 ) $ (1,117 ) Foreign currency forward contracts Other (loss) income $ (874 ) $ 84 $ (979 ) $ 120 Interest rate swap contracts Change in unrealized losses on investments $ (319 ) $ — $ (319 ) $ —
Designated as hedging instruments
Derivative [Line Items]
Location and fair value amount of derivative instruments reported on the balance sheet	The following table summarizes information on the classification and amount of the fair value of derivatives designated as hedging instruments for accounting purposes on the Consolidated Balance Sheets as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Derivatives designated as hedging instruments Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Notional Exposure Asset Derivative at Fair Value (a) Liability Derivative at Fair Value (a) Interest rate swap contracts $ 552,263 $ 20 $ 1,409 $ 552,263 $ 20 $ 1,479 (a) Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses, respectively, within the Company’s consolidated balance sheets.

Reserve for losses and loss e33

Reserve for losses and loss expenses (Tables)	6 Months Ended
	Jun. 30, 2017
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Summary of reserve for losses and loss expenses	The following table summarizes the total reserve for losses and loss expenses as at June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 Case reserves $ 1,236,799 $ 1,237,772 IBNR 2,068,392 1,757,423 Total reserve for losses and loss expenses $ 3,305,191 $ 2,995,195
Reserve for losses and loss expenses	The following table represents an analysis of paid and unpaid losses and loss expenses incurred and a reconciliation of the beginning and ending unpaid losses and loss expenses for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Reserve for losses and loss expenses, beginning of period $ 3,052,745 $ 2,980,300 $ 2,995,195 $ 2,996,567 Loss reserves recoverable (451,856 ) (370,689 ) (430,421 ) (350,586 ) Net reserves for losses and loss expenses, beginning of period 2,600,889 2,609,611 2,564,774 2,645,981 Net reserves acquired (a) 23,753 — 23,753 — Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in: Current year 339,439 369,911 670,255 648,097 Prior years (43,290 ) (62,781 ) (104,521 ) (116,520 ) Total net incurred losses and loss expenses 296,149 307,130 565,734 531,577 Less net losses and loss expenses paid in respect of losses occurring in: Current year (42,758 ) (45,882 ) (50,456 ) (61,655 ) Prior years (193,265 ) (176,775 ) (431,354 ) (430,079 ) Total net paid losses (236,023 ) (222,657 ) (481,810 ) (491,734 ) Foreign exchange losses (gains) 20,216 (14,354 ) 32,533 (6,094 ) Net reserve for losses and loss expenses, end of period 2,704,984 2,679,730 2,704,984 2,679,730 Loss reserves recoverable 600,207 442,987 600,207 442,987 Reserve for losses and loss expenses, end of period $ 3,305,191 $ 3,122,717 $ 3,305,191 $ 3,122,717 (a) Equals net reserves acquired of $42,575 less net reserves commuted at closing of $18,822 . Incurred losses and loss expenses comprise: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Gross losses and loss expenses $ 415,013 $ 397,863 $ 761,808 $ 667,716 Reinsurance recoverable (118,864 ) (90,733 ) (196,074 ) (136,139 ) Net incurred losses and loss expenses $ 296,149 $ 307,130 $ 565,734 $ 531,577
Prior year development by segment and line of business	The net favorable development on prior years by segment and line of business for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended June 30, 2017 Property Marine Specialty Liability Total Validus Re $ (671 ) $ (16,313 ) $ (6,115 ) $ — $ (23,099 ) Talbot (4,894 ) (17,056 ) 6,074 — (15,876 ) Western World (479 ) — — 16 (463 ) AlphaCat (3,097 ) — (755 ) — (3,852 ) Net (favorable) adverse development $ (9,141 ) $ (33,369 ) $ (796 ) $ 16 $ (43,290 ) The net favorable loss reserve development on prior accident years of $43.3 million during the three months ended June 30, 2017 was primarily due to favorable development on attritional losses. Three Months Ended June 30, 2016 Property Marine Specialty Liability Total Validus Re $ (9,468 ) $ (10,018 ) $ (11,391 ) $ — $ (30,877 ) Talbot (10,094 ) (8,928 ) (9,306 ) — (28,328 ) Western World (1,582 ) — — (1,576 ) (3,158 ) AlphaCat (296 ) — (122 ) — (418 ) Net favorable development $ (21,440 ) $ (18,946 ) $ (20,819 ) $ (1,576 ) $ (62,781 ) The net favorable loss reserve development on prior accident years of $62.8 million during the three months ended June 30, 2016 was primarily due to favorable development on attritional losses. Six Months Ended June 30, 2017 Property Marine Specialty Liability Total Validus Re $ (4,242 ) $ (31,742 ) $ (15,895 ) $ — $ (51,879 ) Talbot (11,228 ) (33,052 ) (410 ) — (44,690 ) Western World (3,302 ) — — 2,620 (682 ) AlphaCat (7,492 ) — 222 — (7,270 ) Net (favorable) adverse development $ (26,264 ) $ (64,794 ) $ (16,083 ) $ 2,620 $ (104,521 ) The net favorable loss reserve development on prior accident years of $104.5 million during the six months ended June 30, 2017 was primarily due to favorable development on attritional losses. Six Months Ended June 30, 2016 Property Marine Specialty Liability Total Validus Re $ (32,300 ) $ (6,463 ) $ (17,798 ) $ — $ (56,561 ) Talbot (28,540 ) (5,964 ) (16,544 ) — (51,048 ) Western World (2,023 ) — — (5,561 ) (7,584 ) AlphaCat (477 ) — (850 ) — (1,327 ) Net favorable development $ (63,340 ) $ (12,427 ) $ (35,192 ) $ (5,561 ) $ (116,520 ) The net favorable development of $116.5 million for the six months ended June 30, 2016 was primarily due to favorable development on attritional losses.

Reinsurance (Tables)

Reinsurance (Tables)	6 Months Ended
	Jun. 30, 2017
Reinsurance Disclosures [Abstract]
Schedule of reinsurance recoverable	The Company’s reinsurance balances recoverable at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Loss reserves recoverable on unpaid: Case reserves $ 176,416 $ 165,328 IBNR 423,791 265,093 Total loss reserves recoverable 600,207 430,421 Paid losses recoverable 35,675 35,247 Total reinsurance balances recoverable $ 635,882 $ 465,668
Reinsurance recoverables by reinsurer	Reinsurance balances recoverable by reinsurer as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Reinsurance Recoverable % of Total Reinsurance Recoverable % of Total Top 10 reinsurers $ 521,027 81.9 % $ 395,308 84.9 % Other reinsurers’ balances > $1 million 106,432 16.8 % 66,944 14.4 % Other reinsurers’ balances < $1 million 8,423 1.3 % 3,416 0.7 % Total $ 635,882 100.0 % $ 465,668 100.0 % The following tables show the reinsurance balances recoverable due from, and the ratings associated with, the Company’s top ten reinsurers as at June 30, 2017 and December 31, 2016 : June 30, 2017 Top 10 Reinsurers Rating Reinsurance Recoverable % of Total Munich Re AA- $ 96,997 15.2 % Lloyd's Syndicates A+ 84,742 13.2 % Fully collateralized reinsurers NR 80,558 12.7 % Swiss Re AA- 77,928 12.3 % Everest Re A+ 54,565 8.6 % Hannover Re AA- 48,037 7.6 % Federal Crop Insurance Corporation (a) 29,009 4.6 % Transatlantic Re A+ 23,066 3.6 % XL Catlin A+ 16,062 2.5 % Helvetia Group A 10,063 1.6 % Total $ 521,027 81.9 % (a) The Company participates in a crop reinsurance program sponsored by the U.S. federal government. The Company remains obligated for amounts ceded in the event that its reinsurers or retrocessionaires do not meet their obligations, except for amounts ceded to the U.S. federal government in the agriculture line of business. December 31, 2016 Top 10 Reinsurers Rating Reinsurance Recoverable % of Total Lloyd's Syndicates A+ $ 84,419 18.2 % Swiss Re AA- 84,044 18.1 % Fully collateralized reinsurers NR 83,088 17.8 % Hannover Re AA- 50,603 10.9 % Everest Re A+ 36,912 7.9 % Munich Re AA- 18,214 3.9 % Transatlantic Re A+ 10,593 2.3 % Hamilton Re A- 10,343 2.2 % Toa Re A+ 9,510 2.0 % National Indemnity Company AA+ 7,582 1.6 % Total $ 395,308 84.9 %

Share capital (Tables)

Share capital (Tables)	6 Months Ended
	Jun. 30, 2017
Stockholders' Equity Note [Abstract]
Summary of preferred shares issued and outstanding	The following table is a summary of the preferred share activity during the six months ended June 30, 2017 and 2016 : Six Months Ended June 30, 2017 2016 Preferred shares issued and outstanding, beginning of period 6,000 — Preferred shares issued 10,000 6,000 Preferred shares issued and outstanding, end of period 16,000 6,000
Summary of common shares issued and outstanding	The following table is a summary of the common share activity during the six months ended June 30, 2017 and 2016 : Six Months Ended June 30, 2017 2016 Common shares issued, beginning of period 161,279,976 160,570,772 Restricted share awards vested, net of shares withheld 597,021 601,890 Restricted share units vested, net of shares withheld 14,948 18,486 Options exercised — 13,635 Performance share awards vested, net of shares withheld 42,410 48,088 Common shares issued, end of period 161,934,355 161,252,871 Treasury shares, end of period (82,415,774 ) (80,480,633 ) Common shares outstanding, end of period 79,518,581 80,772,238

Stock plans (Tables)

Stock plans (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options, activity during the period	Activity with respect to options for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Options Weighted Average Grant Date Fair Value Weighted Average Grant Date Exercise Price Options Weighted Average Grant Date Fair Value Weighted Average Grant Date Exercise Price Options outstanding, beginning of period 26,136 $ 6.78 $ 23.48 65,401 $ 7.74 $ 20.17 Options exercised — — — (14,044 ) 7.69 17.02 Options outstanding, end of period 26,136 $ 6.78 $ 23.48 51,357 $ 7.75 $ 21.03
Restricted shares awards, activity during the period	Activity with respect to unvested restricted share awards for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Restricted Share Awards Weighted Average Grant Date Fair Value Restricted Share Awards Weighted Average Grant Date Fair Value Restricted share awards outstanding, beginning of period 2,469,982 $ 40.89 2,739,446 $ 38.25 Restricted share awards granted 481,619 53.42 534,905 48.69 Restricted share awards vested (803,764 ) 41.31 (783,523 ) 37.32 Restricted share awards forfeited (39,617 ) 41.98 (8,317 ) 37.94 Restricted share awards outstanding, end of period 2,108,220 $ 43.58 2,482,511 $ 40.79
Restricted share units, activity during the period	Activity with respect to unvested restricted share units for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Restricted Share Units Weighted Average Grant Date Fair Value Restricted Share Units Weighted Average Grant Date Fair Value Restricted share units outstanding, beginning of period 112,808 $ 40.95 114,337 $ 38.47 Restricted share units granted 12,236 53.40 20,129 48.69 Restricted share units vested (18,241 ) 41.66 (23,982 ) 38.18 Restricted share units issued in lieu of cash dividends 1,468 40.98 1,629 38.47 Restricted share units outstanding, end of period 108,271 $ 42.24 112,113 $ 40.37
Performance share awards, activity during the period	Activity with respect to unvested performance share awards for the six months ended June 30, 2017 and 2016 was as follows: Six Months Ended June 30, 2017 2016 Performance Share Awards Weighted Average Grant Date Fair Value Performance Share Awards Weighted Average Grant Date Fair Value Performance share awards outstanding, beginning of period 285,820 $ 44.53 172,594 $ 40.70 Performance share awards granted 107,209 53.40 121,844 48.69 Performance share awards vested (52,639 ) 37.33 (57,581 ) 36.11 Performance share awards conversion adjustment (26,322 ) 36.82 45,517 36.82 Performance share awards outstanding, end of period 314,068 $ 49.37 282,374 $ 44.46
Total share compensation expenses	The breakdown of share compensation expenses by award type for the periods indicated was as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Restricted share awards $ 9,745 $ 9,517 $ 18,789 $ 18,646 Restricted share units 327 377 642 688 Performance share awards 1,074 833 1,206 2,630 Total $ 11,146 $ 10,727 $ 20,637 $ 21,964

Debt and financing arrangemen37

Debt and financing arrangements (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Summary of outstanding debentures and senior notes payable	The Company’s outstanding debentures and senior notes payable as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Deferrable debentures 2006 Junior Subordinated $ 150,000 $ 150,000 2007 Junior Subordinated 139,800 139,800 Flagstone 2006 Junior Subordinated 134,850 133,676 Flagstone 2007 Junior Subordinated 113,750 113,750 Total debentures payable 538,400 537,226 2010 Senior notes payable 250,000 250,000 Less: Unamortized debt issuance costs (4,537 ) (4,638 ) Total senior notes payable 245,463 245,362 Total debentures and senior notes payable $ 783,863 $ 782,588
Summary of outstanding credit and other facilities	The Company’s outstanding credit and other facilities as at June 30, 2017 and December 31, 2016 were as follows: June 30, 2017 December 31, 2016 Commitment Drawn and outstanding Commitment Drawn and outstanding Credit and other facilities $85,000 syndicated unsecured letter of credit facility $ 85,000 $ — $ 85,000 $ — $300,000 syndicated secured letter of credit facility 300,000 87,718 300,000 90,252 $24,000 secured bi-lateral letter of credit facility 24,000 5,648 24,000 4,553 $20,000 AlphaCat Re secured letter of credit facility (a) — — 20,000 20,000 $25,000 IPC bi-lateral facility 25,000 5,535 25,000 5,842 $236,000 Flagstone bi-lateral facility 236,000 102,190 236,000 144,392 Total credit and other facilities $ 670,000 $ 201,091 $ 690,000 $ 265,039 (a) The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017.
Summary of key terms of debentures and senior notes	The following table summarizes the key terms of the Company’s senior notes and junior subordinated deferrable debentures: Description Issuance date Issued Maturity date Interest Rate as at Interest payments due Issuance Date June 30, 2017 2006 Junior Subordinated Deferrable Debentures June 15, 2006 $ 150,000 June 15, 2036 9.069 % (a) 5.831 % (e) Quarterly Flagstone 2006 Junior Subordinated Deferrable Debentures August 23, 2006 $ 134,850 September 15, 2036 3.540 % (b) 6.463 % (e) Quarterly 2007 Junior Subordinated Deferrable Debentures June 21, 2007 $ 200,000 June 15, 2037 8.480 % (c) 5.180 % (e) Quarterly Flagstone 2007 Junior Subordinated Deferrable Debentures June 8, 2007 $ 100,000 July 30, 2037 3.000 % (b) 5.900 % (e) Quarterly Flagstone 2007 Junior Subordinated Deferrable Debentures September 20, 2007 $ 25,000 September 15, 2037 3.100 % (b) 5.983 % (e) Quarterly 2010 Senior Notes due 2040 January 26, 2010 $ 250,000 January 26, 2040 8.875 % (d) 8.875 % (d) Semi-annually in arrears (a) Fixed interest rate for 5 years , floating interest rate of three-month LIBOR plus 3.550% thereafter, reset quarterly. (b) Floating interest rate of three-month LIBOR plus amount stated, reset quarterly. (c) Fixed interest rate for 5 years , floating interest rate of three-month LIBOR plus 2.950% thereafter, reset quarterly. (d) Fixed interest rate. (e) Fixed interest rate as a result of interest rate swap contracts entered into by the Company.
Investments and cash pledged as collateral under credit facilities	The Company has pledged cash and investments as collateral under the Company’s credit facilities in the total amount of $404,516 (December 31, 2016 : $442,184 ) as detailed in the table below: Cash and investments pledged as collateral June 30, 2017 December 31, 2016 $300,000 syndicated secured letter of credit facility $ 147,048 $ 157,597 $24,000 secured bi-lateral letter of credit facility 33,353 48,097 AlphaCat Re secured letter of credit facility (a) — 20,032 $236,000 Flagstone bi-lateral facility 224,115 216,458 Total cash and investments pledged as collateral $ 404,516 $ 442,184 (a) The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017.
Components of finance expenses	Finance expenses consist of interest on the junior subordinated deferrable debentures and senior notes, the amortization of debt offering costs, credit facility fees, bank charges, Talbot Funds at Lloyds (“FAL”) facility, AlphaCat financing fees and other charges as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 2006 Junior Subordinated Deferrable Debentures $ 2,211 $ 2,211 $ 4,398 $ 4,422 2007 Junior Subordinated Deferrable Debentures 1,831 1,830 3,641 3,661 Flagstone 2006 Junior Subordinated Deferrable Debentures 2,248 2,244 4,469 4,489 Flagstone 2007 Junior Subordinated Deferrable Debentures 1,751 1,766 3,474 3,533 2010 Senior Notes due 2040 5,598 5,597 11,195 11,194 Credit facilities 403 235 621 896 Bank and other charges 131 206 282 213 AlphaCat fees (a) 36 77 72 961 Total finance expenses $ 14,209 $ 14,166 $ 28,152 $ 29,369 (a) Includes finance expenses incurred by AlphaCat Managers Ltd. in relation to fund raising for the AlphaCat sidecars, the AlphaCat ILS funds and AlphaCat direct.

Accumulated other comprehensi38

Accumulated other comprehensive loss (Tables)	6 Months Ended
	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of changes in accumulated other comprehensive loss	The changes in accumulated other comprehensive loss, by component for the three and six months ended June 30, 2017 and 2016 was as follows: Three Months Ended June 30, 2017 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (21,677 ) $ (82 ) $ (694 ) $ (22,453 ) Other comprehensive income (loss), net of tax 1,489 1,184 (144 ) 2,529 Balance, net of tax, end of period $ (20,188 ) $ 1,102 $ (838 ) $ (19,924 ) Three Months Ended June 30, 2016 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (13,862 ) $ 251 $ (1,827 ) $ (15,438 ) Other comprehensive (loss) income, net of tax (3,287 ) 479 64 (2,744 ) Balance, net of tax, end of period $ (17,149 ) $ 730 $ (1,763 ) $ (18,182 ) Six Months Ended June 30, 2017 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (22,274 ) $ (150 ) $ (792 ) $ (23,216 ) Other comprehensive income (loss), net of tax 2,086 1,252 (46 ) 3,292 Balance, net of tax, end of period $ (20,188 ) $ 1,102 $ (838 ) $ (19,924 ) Six Months Ended June 30, 2016 Foreign currency translation adjustment Minimum pension liability Cash flow hedge Total Balance, net of tax, beginning of period $ (11,834 ) $ 334 $ (1,069 ) $ (12,569 ) Other comprehensive (loss) income, net of tax (5,315 ) 396 (694 ) (5,613 ) Balance, net of tax, end of period $ (17,149 ) $ 730 $ (1,763 ) $ (18,182 )

Commitments and contingencies (

Commitments and contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Unfunded investment commitments	As at June 30, 2017 and December 31, 2016 , the Company had total unfunded investment commitments related to the following: Unfunded investment commitments June 30, 2017 December 31, 2016 Fixed maturity investments (a) $ 25,238 $ 28,499 Other investments (b) 119,495 156,134 Investments in investment affiliates (c) 84,046 64,071 AlphaCat ILS Fund — 10,000 Total unfunded investment commitments $ 228,779 $ 258,704 (a) The Company has an outstanding commitment to participate in certain secured loan facilities through participation agreements with an established loan originator. (b) The Company’s total capital commitments related to other investments as at June 30, 2017 was $313,000 ( December 31, 2016 : $308,000 ). (c) Refer to Note 4 (c), “Investments in Investment Affiliates.”

Earnings per share (Tables)

Earnings per share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per share	The following table sets forth the computation of basic earnings per common share and earnings per diluted common share for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Basic earnings per common share Net income available to Validus common shareholders $ 101,095 $ 94,963 $ 195,656 $ 261,773 Weighted average number of common shares outstanding 79,270,561 81,950,833 79,202,116 82,386,047 Basic earnings per share available to Validus common shareholders $ 1.28 $ 1.16 $ 2.47 $ 3.18 Earnings per diluted common share Net income available to Validus common shareholders $ 101,095 $ 94,963 $ 195,656 $ 261,773 Weighted average number of common shares outstanding 79,270,561 81,950,833 79,202,116 82,386,047 Share equivalents: Stock options 14,739 33,796 15,059 34,837 Unvested restricted shares 1,587,151 1,388,374 1,644,823 1,364,775 Weighted average number of diluted common shares outstanding 80,872,451 83,373,003 80,861,998 83,785,659 Earnings per diluted share available to Validus common shareholders $ 1.25 $ 1.14 $ 2.42 $ 3.12

Segment information (Tables)

Segment information (Tables)	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Summary of results of operating segments and Corporate	The following tables summarize the results of our operating segments and “Corporate and Investments”: Three Months Ended June 30, Six Months Ended June 30, Validus Re Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 296,997 $ 285,810 $ 917,519 $ 977,478 Reinsurance premiums ceded (11,387 ) (3,196 ) (120,200 ) (95,691 ) Net premiums written 285,610 282,614 797,319 881,787 Change in unearned premiums (45,003 ) (35,492 ) (338,300 ) (390,834 ) Net premiums earned 240,607 247,122 459,019 490,953 Other insurance related income (loss) 58 150 136 (165 ) Total underwriting revenues 240,665 247,272 459,155 490,788 Underwriting deductions Losses and loss expenses 104,685 132,139 190,839 215,007 Policy acquisition costs 47,158 42,564 88,414 84,823 General and administrative expenses 19,274 17,872 36,106 35,051 Share compensation expenses 2,663 2,775 5,140 5,676 Total underwriting deductions 173,780 195,350 320,499 340,557 Underwriting income $ 66,885 $ 51,922 $ 138,656 $ 150,231 Selected ratios Ratio of net to gross premiums written 96.2 % 98.9 % 86.9 % 90.2 % Losses and loss expense ratio 43.5 % 53.5 % 41.6 % 43.8 % Policy acquisition cost ratio 19.6 % 17.2 % 19.3 % 17.3 % General and administrative expense ratio (a) 9.1 % 8.4 % 8.9 % 8.3 % Expense ratio 28.7 % 25.6 % 28.2 % 25.6 % Combined ratio 72.2 % 79.1 % 69.8 % 69.4 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, Talbot Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 262,477 $ 296,067 $ 509,652 $ 562,384 Reinsurance premiums ceded (24,977 ) (27,161 ) (117,801 ) (114,619 ) Net premiums written 237,500 268,906 391,851 447,765 Change in unearned premiums (45,626 ) (67,357 ) (4,912 ) (39,424 ) Net premiums earned 191,874 201,549 386,939 408,341 Other insurance related income 65 279 820 290 Total underwriting revenues 191,939 201,828 387,759 408,631 Underwriting deductions Losses and loss expenses 93,389 109,310 199,801 209,411 Policy acquisition costs 44,305 43,613 87,581 87,956 General and administrative expenses 35,582 39,061 74,025 77,596 Share compensation expenses 3,155 3,270 5,982 6,792 Total underwriting deductions 176,431 195,254 367,389 381,755 Underwriting income $ 15,508 $ 6,574 $ 20,370 $ 26,876 Selected ratios Ratio of net to gross premiums written 90.5 % 90.8 % 76.9 % 79.6 % Losses and loss expense ratio 48.7 % 54.2 % 51.6 % 51.3 % Policy acquisition cost ratio 23.1 % 21.6 % 22.6 % 21.5 % General and administrative expense ratio (a) 20.2 % 21.1 % 20.7 % 20.7 % Expense ratio 43.3 % 42.7 % 43.3 % 42.2 % Combined ratio 92.0 % 96.9 % 94.9 % 93.5 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, Western World Segment Information 2017 2016 2017 2016 Underwriting revenues Gross premiums written $ 131,068 $ 86,971 $ 303,111 $ 150,930 Reinsurance premiums ceded (23,180 ) (5,006 ) (28,798 ) (9,145 ) Net premiums written 107,888 81,965 274,313 141,785 Change in unearned premiums 22,806 (16,309 ) (46,347 ) (14,630 ) Net premiums earned 130,694 65,656 227,966 127,155 Other insurance related income 663 189 904 477 Total underwriting revenues 131,357 65,845 228,870 127,632 Underwriting deductions Losses and loss expenses 97,008 44,229 171,933 83,875 Policy acquisition costs 19,230 15,410 39,466 29,610 General and administrative expenses 18,316 11,458 29,070 23,533 Share compensation expenses 609 542 1,301 1,123 Total underwriting deductions 135,163 71,639 241,770 138,141 Underwriting loss $ (3,806 ) $ (5,794 ) $ (12,900 ) $ (10,509 ) Selected ratios Ratio of net to gross premiums written 82.3 % 94.2 % 90.5 % 93.9 % Losses and loss expense ratio 74.2 % 67.4 % 75.4 % 66.0 % Policy acquisition cost ratio 14.7 % 23.5 % 17.3 % 23.3 % General and administrative expense ratio (a) 14.5 % 18.2 % 13.4 % 19.3 % Expense ratio 29.2 % 41.7 % 30.7 % 42.6 % Combined ratio 103.4 % 109.1 % 106.1 % 108.6 % (a) The general and administrative expense ratio includes share compensation expenses. Three Months Ended June 30, Six Months Ended June 30, AlphaCat Segment Information 2017 2016 2017 2016 Fee revenues Third party $ 5,549 $ 3,091 $ 10,193 $ 7,818 Related party 644 328 1,275 1,219 Total fee revenues 6,193 3,419 11,468 9,037 Expenses General and administrative expenses 3,549 2,751 7,393 4,233 Share compensation expenses 83 133 165 274 Finance expenses 44 75 75 883 Tax expense 135 — 134 — Foreign exchange losses 1 4 — 12 Total expenses 3,812 2,963 7,767 5,402 Income before investments from AlphaCat Funds and Sidecars 2,381 456 3,701 3,635 Investment income (loss) from AlphaCat Funds and Sidecars (a) AlphaCat Sidecars (21 ) 541 (133 ) 665 AlphaCat ILS Funds - Lower Risk (b) 1,301 2,075 3,490 4,582 AlphaCat ILS Funds - Higher Risk (b) 2,600 692 4,967 3,128 BetaCat ILS Funds 263 1,113 631 1,676 PaCRe — — — (23 ) Validus’ share of investment income from AlphaCat Funds and Sidecars 4,143 4,421 8,955 10,028 Validus’ share of AlphaCat segment income $ 6,524 $ 4,877 $ 12,656 $ 13,663 Supplemental information Gross premiums written AlphaCat Sidecars $ — $ (14 ) $ 66 $ (66 ) AlphaCat ILS Funds - Lower Risk (b) 53,632 50,234 106,540 110,192 AlphaCat ILS Funds - Higher Risk (b) 43,672 42,010 137,208 138,330 AlphaCat Direct (c) 8,378 6,675 26,794 17,797 Total gross premiums written $ 105,682 $ 98,905 $ 270,608 $ 266,253 (a) The investment income from the AlphaCat funds and sidecars is based on equity accounting. (b) Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit. (c) AlphaCat Direct includes direct investments from third party investors in AlphaCat Re. Three Months Ended June 30, Six Months Ended June 30, Corporate and Investments 2017 2016 2017 2016 Investment income Managed net investment income (a) $ 38,063 $ 36,849 $ 74,255 $ 64,772 Corporate expenses General and administrative expenses 18,847 17,872 36,024 34,055 Share compensation expenses 4,636 4,007 8,049 8,099 Finance expenses (b) 14,149 13,979 28,013 28,320 Dividends on preferred shares 2,203 — 4,406 — Tax (benefit) expense (1,122 ) 1,706 (4,670 ) (412 ) Total Corporate expenses 38,713 37,564 71,822 70,062 Other items Net realized gains (losses) on managed investments (b) 2,269 2,520 (623 ) 1,434 Change in net unrealized gains on managed investments (b) 15,942 30,052 30,291 77,130 Income (loss) from investment affiliate 9,466 (589 ) 14,654 (4,702 ) Foreign exchange (losses) gains (b) (7,323 ) 6,621 (6,220 ) 12,695 Other income 174 79 268 756 Transaction expenses (4,427 ) — (4,427 ) — Total other items 16,101 38,683 33,943 87,313 Total Corporate and Investments $ 15,451 $ 37,968 $ 36,376 $ 82,023 (a) Managed net investment income excludes the components which are included in the Company’s share of AlphaCat, net realized and change in unrealized gains on managed investments and income (loss) from investment affiliates. (b) These items exclude the components which are included in Validus’ share of AlphaCat and amounts which are consolidated from VIEs. The following tables reconcile the results of our operating segments along with our corporate and investments function to the Consolidated results of the Company for the periods indicated: Three Months Ended June 30, 2017 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 296,997 $ 262,477 $ 131,068 $ 105,682 $ — $ (3,322 ) $ 792,902 Reinsurance premiums ceded (11,387 ) (24,977 ) (23,180 ) — — 3,322 (56,222 ) Net premiums written 285,610 237,500 107,888 105,682 — — 736,680 Change in unearned premiums (45,003 ) (45,626 ) 22,806 (37,830 ) — — (105,653 ) Net premiums earned 240,607 191,874 130,694 67,852 — — 631,027 Other insurance related income 58 65 663 5,874 — (5,495 ) 1,165 Total underwriting revenues 240,665 191,939 131,357 73,726 — (5,495 ) 632,192 Underwriting deductions Losses and loss expenses 104,685 93,389 97,008 1,067 — — 296,149 Policy acquisition costs 47,158 44,305 19,230 7,165 — (590 ) 117,268 General and administrative expenses 19,274 35,582 18,316 9,768 18,847 (5,438 ) 96,349 Share compensation expenses 2,663 3,155 609 83 4,636 — 11,146 Total underwriting deductions 173,780 176,431 135,163 18,083 23,483 (6,028 ) 520,912 Underwriting income (loss) $ 66,885 $ 15,508 $ (3,806 ) $ 55,643 $ (23,483 ) $ 533 $ 111,280 Other items (a) — — — 183 7,501 — 7,684 Dividends on preferred shares — — — — (2,203 ) — (2,203 ) Net investment income — — — 6,178 38,063 — 44,241 Transaction expenses — — — — (4,427 ) — (4,427 ) (Income) attributable to AlphaCat investors — — — (11,830 ) — — (11,830 ) Net (income) attributable to noncontrolling interest — — — (43,650 ) — — (43,650 ) Segmental income (loss) $ 66,885 $ 15,508 $ (3,806 ) $ 6,524 $ 15,451 $ 533 Net income available to Validus common shareholders $ 101,095 (a) Other items includes finance expenses, tax benefit (expense), foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Three Months Ended June 30, 2016 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 285,810 $ 296,067 $ 86,971 $ 98,905 $ — $ (3,711 ) $ 764,042 Reinsurance premiums ceded (3,196 ) (27,161 ) (5,006 ) (4,577 ) — 3,711 (36,229 ) Net premiums written 282,614 268,906 81,965 94,328 — — 727,813 Change in unearned premiums (35,492 ) (67,357 ) (16,309 ) (34,932 ) — — (154,090 ) Net premiums earned 247,122 201,549 65,656 59,396 — — 573,723 Other insurance related income 150 279 189 3,401 — (3,274 ) 745 Total underwriting revenues 247,272 201,828 65,845 62,797 — (3,274 ) 574,468 Underwriting deductions Losses and loss expenses 132,139 109,310 44,229 21,452 — — 307,130 Policy acquisition costs 42,564 43,613 15,410 6,530 — (151 ) 107,966 General and administrative expenses 17,872 39,061 11,458 6,561 17,872 (3,136 ) 89,688 Share compensation expenses 2,775 3,270 542 133 4,007 — 10,727 Total underwriting deductions 195,350 195,254 71,639 34,676 21,879 (3,287 ) 515,511 Underwriting income (loss) $ 51,922 $ 6,574 $ (5,794 ) $ 28,121 $ (21,879 ) $ 13 $ 58,957 Other items (a) — — — 1,058 22,998 — 24,056 Dividends on preferred shares — — — — — — — Net investment income — — — 3,005 36,849 (597 ) 39,257 (Income) attributable to AlphaCat investors — — — (6,114 ) — — (6,114 ) Net (income) attributable to noncontrolling interest — — — (21,193 ) — — (21,193 ) Segmental income (loss) $ 51,922 $ 6,574 $ (5,794 ) $ 4,877 $ 37,968 $ (584 ) Net income available to Validus common shareholders $ 94,963 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Six Months Ended June 30, 2017 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 917,519 $ 509,652 $ 303,111 $ 270,608 $ — $ (17,131 ) $ 1,983,759 Reinsurance premiums ceded (120,200 ) (117,801 ) (28,798 ) (6,660 ) — 17,131 (256,328 ) Net premiums written 797,319 391,851 274,313 263,948 — — 1,727,431 Change in unearned premiums (338,300 ) (4,912 ) (46,347 ) (131,469 ) — — (521,028 ) Net premiums earned 459,019 386,939 227,966 132,479 — — 1,206,403 Other insurance related income 136 820 904 11,035 — (10,494 ) 2,401 Total underwriting revenues 459,155 387,759 228,870 143,514 — (10,494 ) 1,208,804 Underwriting deductions Losses and loss expenses 190,839 199,801 171,933 3,161 — — 565,734 Policy acquisition costs 88,414 87,581 39,466 14,066 — (631 ) 228,896 General and administrative expenses 36,106 74,025 29,070 19,409 36,024 (10,361 ) 184,273 Share compensation expenses 5,140 5,982 1,301 165 8,049 — 20,637 Total underwriting deductions 320,499 367,389 241,770 36,801 44,073 (10,992 ) 999,540 Underwriting income (loss) $ 138,656 $ 20,370 $ (12,900 ) $ 106,713 $ (44,073 ) $ 498 $ 209,264 Other items (a) — — — 1,298 15,027 — 16,325 Dividends on preferred shares — — — — (4,406 ) — (4,406 ) Net investment income — — — 10,200 74,255 — 84,455 Transaction expenses — — — — (4,427 ) — (4,427 ) (Income) attributable to AlphaCat investors — — — (19,333 ) — — (19,333 ) Net (income) attributable to noncontrolling interest — — — (86,222 ) — — (86,222 ) Segmental income (loss) $ 138,656 $ 20,370 $ (12,900 ) $ 12,656 $ 36,376 $ 498 Net income available to Validus common shareholders $ 195,656 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss). Six Months Ended June 30, 2016 Validus Re Segment Talbot Segment Western World Segment AlphaCat Segment and Consolidated VIEs Corporate and Investments Eliminations Total Underwriting revenues Gross premiums written $ 977,478 $ 562,384 $ 150,930 $ 266,253 $ — $ (20,212 ) $ 1,936,833 Reinsurance premiums ceded (95,691 ) (114,619 ) (9,145 ) (4,821 ) — 20,212 (204,064 ) Net premiums written 881,787 447,765 141,785 261,432 — — 1,732,769 Change in unearned premiums (390,834 ) (39,424 ) (14,630 ) (142,890 ) — — (587,778 ) Net premiums earned 490,953 408,341 127,155 118,542 — — 1,144,991 Other insurance related (loss) income (165 ) 290 477 9,066 — (8,187 ) 1,481 Total underwriting revenues 490,788 408,631 127,632 127,608 — (8,187 ) 1,146,472 Underwriting deductions Losses and loss expenses 215,007 209,411 83,875 23,284 — — 531,577 Policy acquisition costs 84,823 87,956 29,610 12,687 — 83 215,159 General and administrative expenses 35,051 77,596 23,533 14,017 34,055 (8,356 ) 175,896 Share compensation expenses 5,676 6,792 1,123 274 8,099 — 21,964 Total underwriting deductions 340,557 381,755 138,141 50,262 42,154 (8,273 ) 944,596 Underwriting income (loss) $ 150,231 $ 26,876 $ (10,509 ) $ 77,346 $ (42,154 ) $ 86 $ 201,876 Other items (a) — — — 1,212 59,405 — 60,617 Dividends on preferred shares — — — — — — — Net investment income — — — 4,543 64,772 (597 ) 68,718 (Income) attributable to AlphaCat investors — — — (10,714 ) — — (10,714 ) Net (income) attributable to noncontrolling interest — — — (58,724 ) — — (58,724 ) Segmental income (loss) $ 150,231 $ 26,876 $ (10,509 ) $ 13,663 $ 82,023 $ (511 ) Net income available to Validus common shareholders $ 261,773 (a) Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss).
Gross premiums written allocated to the territory of coverage exposure	The following tables set forth the gross premiums written by operating segment allocated to the territory of coverage exposure for the periods indicated: Gross Premiums Written Three Months Ended June 30, 2017 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 100,312 $ 34,470 $ 131,068 $ 70,048 $ (3,443 ) $ 332,455 41.9 % Worldwide excluding United States (a) 4,537 32,627 — 870 114 38,148 4.7 % Australia and New Zealand 3,264 1,848 — 2,003 40 7,155 0.9 % Europe 748 5,857 — (15 ) 275 6,865 0.9 % Latin America and Caribbean 11,874 24,800 — 46 (1,411 ) 35,309 4.5 % Japan 39,305 3,381 — 2,662 (6 ) 45,342 5.7 % Canada 3,155 1,111 — 130 (4 ) 4,392 0.6 % Rest of the world (b) 4,877 23,168 — — 105 28,150 3.6 % Sub-total, non United States 67,760 92,792 — 5,696 (887 ) 165,361 20.9 % Worldwide including United States (a) 53,524 30,735 — 29,937 1,006 115,202 14.5 % Other locations non-specific (c) 75,401 104,480 — 1 2 179,884 22.7 % Total $ 296,997 $ 262,477 $ 131,068 $ 105,682 $ (3,322 ) $ 792,902 100.0 % Gross Premiums Written Three Months Ended June 30, 2016 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 129,087 $ 39,135 $ 86,971 $ 37,338 $ (417 ) $ 292,114 38.2 % Worldwide excluding United States (a) 16,975 30,028 — 6,496 (136 ) 53,363 7.0 % Australia and New Zealand 1,926 2,063 — 867 21 4,877 0.6 % Europe 3,267 6,855 — (145 ) 216 10,193 1.3 % Latin America and Caribbean 5,992 27,597 — — (2,511 ) 31,078 4.1 % Japan 39,053 3,965 — 1,721 (7 ) 44,732 5.9 % Canada 1,821 2,470 — 223 (36 ) 4,478 0.6 % Rest of the world (b) 3,259 29,806 — — (457 ) 32,608 4.3 % Sub-total, non United States 72,293 102,784 — 9,162 (2,910 ) 181,329 23.8 % Worldwide including United States (a) 35,561 34,198 — 52,394 (380 ) 121,773 15.9 % Other locations non-specific (c) 48,869 119,950 — 11 (4 ) 168,826 22.1 % Total $ 285,810 $ 296,067 $ 86,971 $ 98,905 $ (3,711 ) $ 764,042 100.0 % Gross Premiums Written Six Months Ended June 30, 2017 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 314,180 $ 63,555 $ 303,111 $ 98,251 $ (4,323 ) $ 774,774 39.1 % Worldwide excluding United States (a) 38,605 66,958 — 7,905 (539 ) 112,929 5.7 % Australia and New Zealand 4,195 5,030 — 2,003 (110 ) 11,118 0.6 % Europe 30,364 17,572 — 451 (430 ) 47,957 2.3 % Latin America and Caribbean 21,216 48,977 — 46 (4,283 ) 65,956 3.3 % Japan 40,466 5,206 — 3,855 (36 ) 49,491 2.5 % Canada 4,870 2,248 — 130 (49 ) 7,199 0.4 % Rest of the world (b) 18,782 46,440 — — (1,577 ) 63,645 3.2 % Sub-total, non United States 158,498 192,431 — 14,390 (7,024 ) 358,295 18.0 % Worldwide including United States (a) 155,945 58,092 — 153,246 (5,784 ) 361,499 18.2 % Other locations non-specific (c) 288,896 195,574 — 4,721 — 489,191 24.7 % Total $ 917,519 $ 509,652 $ 303,111 $ 270,608 $ (17,131 ) $ 1,983,759 100.0 % Gross Premiums Written Six Months Ended June 30, 2016 Validus Re Talbot Western World AlphaCat Eliminations Total % United States $ 424,481 $ 65,245 $ 150,930 $ 62,729 $ (1,555 ) $ 701,830 36.2 % Worldwide excluding United States (a) 47,239 65,532 — 22,507 (611 ) 134,667 7.0 % Australia and New Zealand 6,849 4,375 — 4,949 (113 ) 16,060 0.8 % Europe 25,734 20,716 — 3,306 (708 ) 49,048 2.5 % Latin America and Caribbean 19,574 51,404 — — (5,537 ) 65,441 3.4 % Japan 39,925 4,582 — 3,221 (31 ) 47,697 2.5 % Canada 3,497 3,562 — 223 (87 ) 7,195 0.4 % Rest of the world (b) 19,947 57,290 — — (2,342 ) 74,895 3.9 % Sub-total, non United States 162,765 207,461 — 34,206 (9,429 ) 395,003 20.5 % Worldwide including United States (a) 147,338 62,652 — 167,767 (9,214 ) 368,543 19.0 % Other locations non-specific (c) 242,894 227,026 — 1,551 (14 ) 471,457 24.3 % Total $ 977,478 $ 562,384 $ 150,930 $ 266,253 $ (20,212 ) $ 1,936,833 100.0 % (a) Represents risks in two or more geographic zones. (b) Represents risks in one geographic zone. (c) The Other locations non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable since these exposures can span multiple geographic areas and, in some instances, are not fixed locations.

Business combination - Fair val

Business combination - Fair value of net assets acquired (Details) $ in Thousands	May 01, 2017USD ($)StatesAgent	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Transaction expenses		$ 4,427	$ 0	$ 4,427	$ 0
Net loss reserves	$ 42,575
Goodwill		$ 227,701		$ 227,701		$ 196,758
Crop Risk Services
Business Acquisition [Line Items]
Number of agents | Agent	1,170
Number of states | States	36
Total purchase price	$ 185,576
Cash and cash equivalents	1,653
Premiums receivable	564,453
Prepaid reinsurance premiums	227,157
Other assets	157,146
Assets acquired	950,409
Reinsurance balances payable	294,201
Unearned premiums	406,649
Net loss reserves	42,575
Other liabilities	122,715
Liabilities acquired	866,140
Excess purchase price	101,307
Total intangible assets	63,921
Goodwill	30,943
Deferred tax arising on Goodwill	$ 6,443
Crop Risk Services | Intangible asset - Distribution channels
Business Acquisition [Line Items]
Estimated useful life	10 years
Total intangible assets	$ 52,898
Crop Risk Services | Intangible asset - Brand name
Business Acquisition [Line Items]
Estimated useful life	10 years
Total intangible assets	$ 9,568
Crop Risk Services | Intangible asset - Technology
Business Acquisition [Line Items]
Estimated useful life	2 years
Total intangible assets	$ 1,455

Business combination - Reconcil

Business combination - Reconciliation of carrying amount of goodwill and intangible assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Goodwill And Other Intangible Assets [Line Items]
Goodwill, beginning of period	$ 196,758
Additions	30,943
Goodwill, end of period	227,701
Finite lived intangible assets, beginning of period	11,424
Indefinite lived intangible assets, beginning of period	104,168
Intangible assets, beginning of period	115,592
Additions, finite lived	63,921
Amortization	(3,995)	$ (2,832)
Finite lived intangible assets, end of period	71,350
Indefinite lived intangible assets, end of period	104,168
Intangible assets, end of period	175,518
Talbot
Goodwill And Other Intangible Assets [Line Items]
Goodwill, beginning of period	20,393
Additions	0
Goodwill, end of period	20,393
Intangible assets, beginning of period	93,924
Additions, finite lived	0
Amortization	(2,081)
Intangible assets, end of period	91,843
Western World
Goodwill And Other Intangible Assets [Line Items]
Goodwill, beginning of period	176,365
Additions	30,943
Goodwill, end of period	207,308
Intangible assets, beginning of period	21,668
Additions, finite lived	63,921
Amortization	(1,914)
Intangible assets, end of period	$ 83,675

Business combination - Suppleme

Business combination - Supplemental pro forma information (Details) - Crop Risk Services $ in Thousands	2 Months Ended
	Jun. 30, 2017USD ($)
Business Acquisition [Line Items]
Net premiums written	$ 6,988
Net premiums earned	50,044
Total underwriting deductions	44,780
Underwriting income, before general and administrative expenses	$ 5,264

Investments (Amortized cost or

Investments (Amortized cost or cost and fair value of investments) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		$ 5,424,562	$ 5,584,599
Short-term investments, at amortized cost or cost		2,871,126	2,796,358
Other investments, at amortized cost or cost		416,996	380,130
Investments in investment affiliates, at cost		72,532	84,840
Total investments		8,785,216	8,845,927
Fixed maturities, at fair value		5,418,643	5,543,030
Short-term investments, at fair value		2,871,353	2,796,170
Other investments, at fair value		448,618	405,712
Investments in investment affiliates, at fair value		103,377	100,431
Total investments		8,841,991	8,845,343
Managed investments
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		5,120,850	5,427,113
Short-term investments, at amortized cost or cost		255,289	228,574
Other investments, at amortized cost or cost		416,996	380,130
Investments in investment affiliates, at cost	[1]	72,532	84,840
Total investments		5,865,667	6,120,657
Fixed maturities, at fair value		5,113,689	5,384,699
Short-term investments, at fair value		255,516	228,386
Other investments, at fair value		448,618	405,712
Investments in investment affiliates, at fair value	[1]	103,377	100,431
Total investments		5,921,200	6,119,228
Managed investments | U.S. government and government agency
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		649,214	809,392
Fixed maturities, at fair value		646,436	804,126
Managed investments | Non-U.S. government and government agency
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		293,002	245,651
Fixed maturities, at fair value		292,504	240,791
Managed investments | U.S. states, municipalities and political subdivisions
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		227,047	271,742
Fixed maturities, at fair value		227,949	271,830
Managed investments | Agency residential mortgage-backed securities
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		786,784	684,490
Fixed maturities, at fair value		783,006	679,595
Managed investments | Non-agency residential mortgage-backed securities
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		26,745	15,858
Fixed maturities, at fair value		26,683	15,477
Managed investments | U.S. corporate
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		1,378,884	1,540,036
Fixed maturities, at fair value		1,386,484	1,534,508
Managed investments | Non-U.S. corporate
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		380,317	418,520
Fixed maturities, at fair value		379,480	410,227
Managed investments | Bank loans
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		560,446	579,121
Fixed maturities, at fair value		552,901	570,399
Managed investments | Asset-backed securities
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		500,679	528,563
Fixed maturities, at fair value		502,056	526,814
Managed investments | Commercial mortgage-backed securities
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		317,732	333,740
Fixed maturities, at fair value		316,190	330,932
Managed investments | Fund of hedge funds
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		0	1,457
Other investments, at fair value		0	955
Managed investments | Hedge funds
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		11,292	11,292
Other investments, at fair value		18,303	17,381
Managed investments | Private equity investments
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		79,871	66,383
Other investments, at fair value		100,391	82,627
Managed investments | Fixed income investment funds
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		266,041	247,967
Other investments, at fair value		268,110	249,275
Managed investments | Overseas deposits
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		57,874	50,106
Other investments, at fair value		57,874	50,106
Managed investments | Mutual funds
Amortized cost (or cost) and estimated fair value of investments
Other investments, at amortized cost or cost		1,918	2,925
Other investments, at fair value		3,940	5,368
Non-managed investments
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		303,712	157,486
Short-term investments, at amortized cost or cost		2,615,837	2,567,784
Total investments		2,919,549	2,725,270
Fixed maturities, at fair value		304,954	158,331
Short-term investments, at fair value		2,615,837	2,567,784
Total investments		2,920,791	2,726,115
Non-managed investments | Catastrophe bonds
Amortized cost (or cost) and estimated fair value of investments
Fixed maturities, at amortized cost or cost		303,712	157,486
Fixed maturities, at fair value		$ 304,954	$ 158,331
[1]	The Company’s investments in investment affiliates have been treated as equity method investments with the corresponding gains and losses recorded inincome as “Income (loss) from investment affiliates.”

Investments (Fixed maturities b

Investments (Fixed maturities by investment rating) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fixed Maturities
Fair value	$ 5,418,643	$ 5,543,030
Percentage of total	100.00%	100.00%
Managed investments
Fixed Maturities
Fair value	$ 5,113,689	$ 5,384,699
Percentage of total	94.40%	97.10%
Managed investments | Total investment grade fixed maturities
Fixed Maturities
Fair value	$ 4,494,243	$ 4,766,696
Percentage of total	82.90%	86.00%
Managed investments | Total investment grade fixed maturities | AAA
Fixed Maturities
Fair value	$ 2,318,254	$ 2,405,597
Percentage of total	42.80%	43.40%
Managed investments | Total investment grade fixed maturities | AA
Fixed Maturities
Fair value	$ 463,060	$ 538,289
Percentage of total	8.50%	9.70%
Managed investments | Total investment grade fixed maturities | A rating
Fixed Maturities
Fair value	$ 1,009,366	$ 1,081,949
Percentage of total	18.60%	19.50%
Managed investments | Total investment grade fixed maturities | BBB
Fixed Maturities
Fair value	$ 703,563	$ 740,861
Percentage of total	13.00%	13.40%
Managed investments | Total non-investment grade fixed maturities
Fixed Maturities
Fair value	$ 619,446	$ 618,003
Percentage of total	11.50%	11.10%
Managed investments | Total non-investment grade fixed maturities | BB
Fixed Maturities
Fair value	$ 229,023	$ 213,568
Percentage of total	4.20%	3.90%
Managed investments | Total non-investment grade fixed maturities | B
Fixed Maturities
Fair value	$ 176,743	$ 177,737
Percentage of total	3.30%	3.20%
Managed investments | Total non-investment grade fixed maturities | CCC
Fixed Maturities
Fair value	$ 11,114	$ 13,371
Percentage of total	0.20%	0.20%
Managed investments | Total non-investment grade fixed maturities | NR
Fixed Maturities
Fair value	$ 202,566	$ 213,327
Percentage of total	3.80%	3.80%
Non-managed investments
Fixed Maturities
Fair value	$ 304,954	$ 158,331
Percentage of total	5.60%	2.90%
Non-managed investments | Total non-investment grade fixed maturities | BB
Fixed Maturities
Fair value	$ 28,177	$ 29,731
Percentage of total	0.40%	0.60%
Non-managed investments | Total non-investment grade fixed maturities | B
Fixed Maturities
Fair value	$ 2,781	$ 4,524
Percentage of total	0.10%	0.10%
Non-managed investments | Total non-investment grade fixed maturities | NR
Fixed Maturities
Fair value	$ 273,996	$ 124,076
Percentage of total	5.10%	2.20%

Investments (Maturity profile o

Investments (Maturity profile of fixed maturity investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Maturity profile
Amortized cost	$ 5,424,562	$ 5,584,599
Fair value	5,418,643	5,543,030
Managed investments
Maturity profile
Amortized cost	5,120,850	5,427,113
Fair value	5,113,689	5,384,699
Managed investments | Fixed maturities trading securities allocated to contractual maturity
Maturity profile
Amortized cost	3,488,910	3,864,462
Fair value	3,485,754	3,831,881
Managed investments | Due in one year or less | Fixed maturities trading securities allocated to contractual maturity
Maturity profile
Amortized cost	497,473	350,733
Fair value	492,256	346,161
Managed investments | Due after one year through five years | Fixed maturities trading securities allocated to contractual maturity
Maturity profile
Amortized cost	2,464,093	2,954,856
Fair value	2,461,870	2,933,146
Managed investments | Due after five years through ten years | Fixed maturities trading securities allocated to contractual maturity
Maturity profile
Amortized cost	456,793	430,365
Fair value	459,311	426,647
Managed investments | Due after ten years | Fixed maturities trading securities allocated to contractual maturity
Maturity profile
Amortized cost	70,551	128,508
Fair value	72,317	125,927
Managed investments | Asset backed and mortgaged backed securities
Maturity profile
Amortized cost	1,631,940	1,562,651
Fair value	1,627,935	1,552,818
Non-managed investments
Maturity profile
Amortized cost	303,712	157,486
Fair value	304,954	158,331
Non-managed investments | Due in one year or less
Maturity profile
Amortized cost	33,662	43,664
Fair value	32,441	45,418
Non-managed investments | Due after one year through five years
Maturity profile
Amortized cost	263,300	112,572
Fair value	265,735	111,656
Non-managed investments | Due after five years through ten years
Maturity profile
Amortized cost	6,750	1,250
Fair value	6,778	1,257
Non-managed investments | Due after ten years
Maturity profile
Amortized cost	0	0
Fair value	$ 0	$ 0

Investments (Other investments)

Investments (Other investments) (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Other investments, at fair value		$ 448,618	$ 405,712
Managed investments
Investment [Line Items]
Other investments, at fair value		448,618	405,712
Managed investments | Fund of hedge funds
Investment [Line Items]
Other investments, at fair value		0	955
Managed investments | Hedge funds
Investment [Line Items]
Other investments, at fair value		18,303	17,381
Managed investments | Private equity investments
Investment [Line Items]
Other investments, at fair value		100,391	82,627
Managed investments | Fixed income investment funds
Investment [Line Items]
Other investments, at fair value		268,110	249,275
Managed investments | Overseas deposits
Investment [Line Items]
Other investments, at fair value		57,874	50,106
Managed investments | Mutual funds
Investment [Line Items]
Other investments, at fair value		3,940	5,368
Recurring | Managed investments
Investment [Line Items]
Other investments, at fair value		448,618	405,712
Recurring | Managed investments | Fund of hedge funds
Investment [Line Items]
Other investments, at fair value			955
Recurring | Managed investments | Hedge funds
Investment [Line Items]
Other investments, at fair value		18,303	17,381
Recurring | Managed investments | Private equity investments
Investment [Line Items]
Other investments, at fair value		100,391	82,627
Recurring | Managed investments | Fixed income investment funds
Investment [Line Items]
Other investments, at fair value		268,110	249,275
Recurring | Managed investments | Overseas deposits
Investment [Line Items]
Other investments, at fair value		57,874	50,106
Recurring | Managed investments | Mutual funds
Investment [Line Items]
Other investments, at fair value		3,940	5,368
Recurring | Managed investments | Subject to redemption restriction
Investment [Line Items]
Other investments, at fair value		414,554	369,402
Recurring | Managed investments | Subject to redemption restriction | Fund of hedge funds
Investment [Line Items]
Other investments, at fair value			955
Recurring | Managed investments | Subject to redemption restriction | Hedge funds
Investment [Line Items]
Other investments, at fair value		18,303	17,381
Recurring | Managed investments | Subject to redemption restriction | Private equity investments
Investment [Line Items]
Other investments, at fair value		100,391	82,627
Recurring | Managed investments | Subject to redemption restriction | Fixed income investment funds
Investment [Line Items]
Other investments, at fair value		237,986	218,333
Recurring | Managed investments | Subject to redemption restriction | Overseas deposits
Investment [Line Items]
Other investments, at fair value		57,874	50,106
Recurring | Managed investments | Subject to redemption restriction | Mutual funds
Investment [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Not subject to redemption restriction
Investment [Line Items]
Other investments, at fair value		34,064	36,310
Recurring | Managed investments | Not subject to redemption restriction | Fund of hedge funds
Investment [Line Items]
Other investments, at fair value			0
Recurring | Managed investments | Not subject to redemption restriction | Hedge funds
Investment [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Not subject to redemption restriction | Private equity investments
Investment [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Not subject to redemption restriction | Fixed income investment funds
Investment [Line Items]
Other investments, at fair value		$ 30,124	$ 30,942
Redemption frequency		Daily	Daily
Redemption notice period	[1]		2 days
Recurring | Managed investments | Not subject to redemption restriction | Fixed income investment funds | Minimum
Investment [Line Items]
Redemption notice period	[1]	1 day
Recurring | Managed investments | Not subject to redemption restriction | Fixed income investment funds | Maximum
Investment [Line Items]
Redemption notice period	[1]	2 days
Recurring | Managed investments | Not subject to redemption restriction | Overseas deposits
Investment [Line Items]
Other investments, at fair value		$ 0	$ 0
Recurring | Managed investments | Not subject to redemption restriction | Mutual funds
Investment [Line Items]
Other investments, at fair value		$ 3,940	$ 5,368
Redemption frequency		Daily	Daily
Redemption notice period	[1]	1 day	1 day
[1]	The redemption frequency and notice periods only apply to investments without redemption restrictions.

Investments (Investment affilia

Investments (Investment affiliate rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Equity Method Investments [Line Items]
Investments in affiliates, beginning of period			$ 100,431
Income (loss) from investment affiliates	$ 9,466	$ (589)	14,654	$ (4,702)
Investments in affiliates, end of period	103,377		103,377
Investment affiliate
Schedule of Equity Method Investments [Line Items]
Investments in affiliates, beginning of period	94,697	84,135	100,431	87,673
Net capital contributions	(786)	15,732	(11,708)	16,307
Income (loss) from investment affiliates	9,466	(589)	14,654	(4,702)
Investments in affiliates, end of period	$ 103,377	$ 99,278	$ 103,377	$ 99,278

Investments (Investment affil50

Investments (Investment affiliate details) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Mar. 31, 2017	Mar. 20, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Investments in investment affiliates, at cost		$ 72,532			$ 84,840
Investments in affiliates		103,377			100,431
Aquiline Financial Services Fund II LP
Schedule of Equity Method Investments [Line Items]
Remaining capital commitment		3,229			2,040
Aquiline Financial Services Fund III LP
Schedule of Equity Method Investments [Line Items]
Remaining capital commitment		62,031			62,031
Aquiline Tech
Schedule of Equity Method Investments [Line Items]
Remaining capital commitment		18,786		$ 20,000
Investment affiliate
Schedule of Equity Method Investments [Line Items]
Investments in affiliates		103,377	$ 94,697		100,431	$ 99,278	$ 84,135	$ 87,673
Investment affiliate | Aquiline Financial Services Fund II LP
Schedule of Equity Method Investments [Line Items]
Investments in investment affiliates, at cost		$ 33,349			$ 46,871
Voting ownership %		0.00%			0.00%
Equity ownership %		8.10%			8.10%
Investments in affiliates		$ 52,010			$ 61,999
Investment affiliate | Aquiline Financial Services Fund III LP
Schedule of Equity Method Investments [Line Items]
Investments in investment affiliates, at cost		$ 37,969			$ 37,969
Voting ownership %		0.00%			0.00%
Equity ownership %		9.00%			9.00%
Investments in affiliates		$ 50,153			$ 38,432
Investment affiliate | Aquiline Tech
Schedule of Equity Method Investments [Line Items]
Investments in investment affiliates, at cost		$ 1,214
Voting ownership %		0.00%
Equity ownership %		16.40%
Investments in affiliates		$ 1,214
Managed investments
Schedule of Equity Method Investments [Line Items]
Investments in investment affiliates, at cost	[1]	72,532			84,840
Investments in affiliates	[1]	$ 103,377			$ 100,431
[1]	The Company’s investments in investment affiliates have been treated as equity method investments with the corresponding gains and losses recorded inincome as “Income (loss) from investment affiliates.”

Investments (Components of net

Investments (Components of net investment income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net investment income
Net investment income	$ 44,241	$ 39,257	$ 84,455	$ 68,718
Managed investments
Net investment income
Total gross investment income	39,506	39,039	78,670	68,798
Investment expenses	(1,443)	(2,190)	(4,415)	(4,026)
Net investment income	38,063	36,849	74,255	64,772
Managed investments | Fixed maturities and short term investments
Net investment income
Total gross investment income	31,312	30,621	62,983	58,638
Managed investments | Other investments
Net investment income
Total gross investment income	7,571	8,026	14,441	8,898
Managed investments | Restricted cash, cash and cash equivalents
Net investment income
Total gross investment income	616	380	1,226	1,245
Managed investments | Securities lending income
Net investment income
Total gross investment income	7	12	20	17
Non-managed investments
Net investment income
Net investment income	6,178	2,408	10,200	3,946
Non-managed investments | Fixed maturities and short term investments
Net investment income
Total gross investment income	4,500	1,977	7,560	3,272
Non-managed investments | Restricted cash, cash and cash equivalents
Net investment income
Total gross investment income	$ 1,678	$ 431	$ 2,640	$ 674

Investments (Realized and unrea

Investments (Realized and unrealized gains) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fixed Maturities Short Term And Other Investments And Cash Equivalents [Abstract]
Net realized gains (losses) on investments	$ 2,274	$ 2,724	$ 1,110	$ 2,140
Change in net unrealized gains on investments	16,321	31,428	29,669	78,872
Total net realized and change in net unrealized gains (losses) on investments	18,595	34,152	30,779	81,012
Managed investments
Fixed Maturities Short Term And Other Investments And Cash Equivalents [Abstract]
Gross realized gains	5,175	3,306	7,865	6,523
Gross realized losses	(2,906)	(786)	(8,488)	(5,089)
Net realized gains (losses) on investments	2,269	2,520	(623)	1,434
Change in net unrealized gains on investments	15,942	30,052	30,291	77,130
Total net realized and change in net unrealized gains (losses) on investments	18,211	32,572	29,668	78,564
Non-managed investments
Fixed Maturities Short Term And Other Investments And Cash Equivalents [Abstract]
Gross realized gains	5	204	1,733	715
Gross realized losses	0	0	0	(9)
Net realized gains (losses) on investments	5	204	1,733	706
Change in net unrealized gains on investments	379	1,376	(622)	1,742
Total net realized and change in net unrealized gains (losses) on investments	$ 384	$ 1,580	$ 1,111	$ 2,448

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)funds	Dec. 31, 2016USD ($)
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other investments, at fair value	$ 448,618	$ 405,712
Cash, cash equivalents, restricted cash and investments pledged as collateral	5,221,174	5,173,966
Investments held in trust	5,156,173	5,068,092
Investments and cash pledged as collateral	$ 404,516	442,184
Minimum
Schedule of Trading Securities and Other Trading Assets [Line Items]
Remaining liquidation period	5 years
Maximum
Schedule of Trading Securities and Other Trading Assets [Line Items]
Remaining liquidation period	10 years
Managed investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other investments, at fair value	$ 448,618	405,712
Recurring | Managed investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other investments, at fair value	448,618	405,712
Recurring | Managed investments | Subject to redemption restriction
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other investments, at fair value	$ 414,554	369,402
Recurring | Managed investments | Subject to redemption restriction | Investment fund A
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other investments number of funds | funds	1
Other investments, at fair value	$ 192,437	$ 184,749
Redemption restriction period	2 years

Fair value measurements (Fair v

Fair value measurements (Fair value hierarchy) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		$ 5,418,643	$ 5,543,030
Short-term investments, at fair value		2,871,353	2,796,170
Other investments, at fair value		448,618	405,712
Investments in affiliates		103,377	100,431
Total investments		8,841,991	8,845,343
Managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		5,113,689	5,384,699
Short-term investments, at fair value		255,516	228,386
Other investments, at fair value		448,618	405,712
Investments in affiliates	[1]	103,377	100,431
Total investments		5,921,200	6,119,228
Managed investments | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		646,436	804,126
Managed investments | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		292,504	240,791
Managed investments | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		227,949	271,830
Managed investments | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		783,006	679,595
Managed investments | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		26,683	15,477
Managed investments | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		1,386,484	1,534,508
Managed investments | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		379,480	410,227
Managed investments | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		552,901	570,399
Managed investments | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		502,056	526,814
Managed investments | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		316,190	330,932
Managed investments | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	955
Managed investments | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		18,303	17,381
Managed investments | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		100,391	82,627
Managed investments | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		268,110	249,275
Managed investments | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		57,874	50,106
Managed investments | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		3,940	5,368
Non-managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		304,954	158,331
Short-term investments, at fair value		2,615,837	2,567,784
Total investments		2,920,791	2,726,115
Non-managed investments | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		304,954	158,331
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		8,841,991	8,845,343
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		2,864,276	2,777,435
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		5,131,679	5,279,272
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		344,518	330,970
Recurring | Managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		5,113,689	5,384,699
Short-term investments, at fair value		255,516	228,386
Other investments, at fair value		448,618	405,712
Total investments		5,921,200	6,119,228
Recurring | Managed investments | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		646,436	804,126
Recurring | Managed investments | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		292,504	240,791
Recurring | Managed investments | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		227,949	271,830
Recurring | Managed investments | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		783,006	679,595
Recurring | Managed investments | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		26,683	15,477
Recurring | Managed investments | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		1,386,484	1,534,508
Recurring | Managed investments | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		379,480	410,227
Recurring | Managed investments | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		552,901	570,399
Recurring | Managed investments | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		502,056	526,814
Recurring | Managed investments | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		316,190	330,932
Recurring | Managed investments | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value			955
Recurring | Managed investments | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		18,303	17,381
Recurring | Managed investments | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		100,391	82,627
Recurring | Managed investments | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		268,110	249,275
Recurring | Managed investments | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		57,874	50,106
Recurring | Managed investments | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		3,940	5,368
Recurring | Managed investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Short-term investments, at fair value		248,439	209,651
Other investments, at fair value		0	0
Total investments		248,439	209,651
Recurring | Managed investments | Level 1 | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 1 | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value			0
Recurring | Managed investments | Level 1 | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 1 | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 1 | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 1 | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 1 | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		4,853,596	5,114,272
Short-term investments, at fair value		7,077	18,735
Other investments, at fair value		34,077	36,309
Total investments		4,894,750	5,169,316
Recurring | Managed investments | Level 2 | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		646,436	804,126
Recurring | Managed investments | Level 2 | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		292,504	240,791
Recurring | Managed investments | Level 2 | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		227,949	271,830
Recurring | Managed investments | Level 2 | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		783,006	679,595
Recurring | Managed investments | Level 2 | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		26,683	15,477
Recurring | Managed investments | Level 2 | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		1,386,484	1,534,508
Recurring | Managed investments | Level 2 | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		379,480	410,227
Recurring | Managed investments | Level 2 | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		328,729	323,903
Recurring | Managed investments | Level 2 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		466,135	502,883
Recurring | Managed investments | Level 2 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		316,190	330,932
Recurring | Managed investments | Level 2 | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value			0
Recurring | Managed investments | Level 2 | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 2 | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 2 | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		30,137	30,941
Recurring | Managed investments | Level 2 | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 2 | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		3,940	5,368
Recurring | Managed investments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		260,093	270,427
Short-term investments, at fair value		0	0
Other investments, at fair value		16,400	12,168
Total investments		276,493	282,595
Recurring | Managed investments | Level 3 | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		224,172	246,496
Recurring | Managed investments | Level 3 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		35,921	23,931
Recurring | Managed investments | Level 3 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Managed investments | Level 3 | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value			0
Recurring | Managed investments | Level 3 | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 3 | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 3 | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		16,400	12,168
Recurring | Managed investments | Level 3 | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Managed investments | Level 3 | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value		0	0
Recurring | Non-managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, at fair value		2,615,837	2,567,784
Total investments		2,920,791	2,726,115
Recurring | Non-managed investments | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		304,954	158,331
Recurring | Non-managed investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, at fair value		2,615,837	2,567,784
Total investments		2,615,837	2,567,784
Recurring | Non-managed investments | Level 1 | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		0	0
Recurring | Non-managed investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, at fair value		0	0
Total investments		236,929	109,956
Recurring | Non-managed investments | Level 2 | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		236,929	109,956
Recurring | Non-managed investments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, at fair value		0	0
Total investments		68,025	48,375
Recurring | Non-managed investments | Level 3 | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value		68,025	48,375
Recurring | Fair value based on NAV practical expedient
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	[2]	398,141	357,235
Recurring | Fair value based on NAV practical expedient | Managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Short-term investments, at fair value	[2]	0	0
Other investments, at fair value	[2]	398,141	357,235
Total investments	[2]	398,141	357,235
Recurring | Fair value based on NAV practical expedient | Managed investments | U.S. government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Non-US government and government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | U.S. states, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Non-Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Managed investments | Fund of hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]		955
Recurring | Fair value based on NAV practical expedient | Managed investments | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]	18,303	17,381
Recurring | Fair value based on NAV practical expedient | Managed investments | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]	100,391	82,627
Recurring | Fair value based on NAV practical expedient | Managed investments | Fixed income investment funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]	221,573	206,166
Recurring | Fair value based on NAV practical expedient | Managed investments | Overseas deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]	57,874	50,106
Recurring | Fair value based on NAV practical expedient | Managed investments | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments, at fair value	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Non-managed investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments, at fair value	[2]	0	0
Total investments	[2]	0	0
Recurring | Fair value based on NAV practical expedient | Non-managed investments | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	[2]	$ 0	$ 0
[1]	The Company’s investments in investment affiliates have been treated as equity method investments with the corresponding gains and losses recorded inincome as “Income (loss) from investment affiliates.”
[2]	In accordance with ASC Topic 820 “Fair Value Measurements,” investments measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.

Fair value measurements (Level

Fair value measurements (Level 3 rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period		$ 0
Settlements		0
Recurring | Level 3
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period	$ 345,812	292,116	$ 330,970	$ 245,837
Purchases	36,242	21,268	120,509	86,643
Sales	(53)		(53)	(2,389)
Settlements	(38,701)	(17,784)	(110,199)	(34,158)
Net realized losses	216		3,350
Change in net unrealized (losses) gains	12	(2,551)	(1,049)	(2,884)
Amortization	990		990
Level 3 investments - end of period	344,518	293,049	344,518	293,049
Recurring | Level 3 | Bank loan portfolio
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period	236,694	255,011	246,496	232,337
Purchases	16,757	8,885	39,933	50,988
Sales	0		0	(2,389)
Settlements	(28,893)	(17,784)	(62,003)	(34,033)
Net realized losses	0		0
Change in net unrealized (losses) gains	(386)	(2,964)	(254)	(3,755)
Amortization	0		0
Level 3 investments - end of period	224,172	243,148	224,172	243,148
Recurring | Level 3 | Catastrophe bonds
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period	72,676	37,105	48,375	13,500
Purchases	5,000	0	66,091	23,272
Sales	0		0	0
Settlements	(10,216)	0	(48,996)	(125)
Net realized losses	216		3,350
Change in net unrealized (losses) gains	349	413	(795)	871
Amortization	0		0
Level 3 investments - end of period	68,025	37,518	68,025	37,518
Recurring | Level 3 | Fixed income investment funds
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period	12,560		12,168
Purchases	3,432		3,432
Sales	0		0
Settlements	408		800
Net realized losses	0		0
Change in net unrealized (losses) gains	0		0
Amortization	0		0
Level 3 investments - end of period	16,400		16,400
Recurring | Level 3 | Asset-backed securities
Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis
Level 3 investments - beginning of period	23,882		23,931	0
Purchases	11,053	12,383	11,053	12,383
Sales	(53)		(53)	0
Settlements	0		0	0
Net realized losses	0		0
Change in net unrealized (losses) gains	49	0	0	0
Amortization	990		990
Level 3 investments - end of period	$ 35,921	$ 12,383	$ 35,921	$ 12,383

Fair value measurements (Narrat

Fair value measurements (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	$ 8,841,991	$ 8,845,343
Managed investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	5,921,200	6,119,228
Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	$ 8,841,991	8,845,343
Recurring | Hedge fund side pocket
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	3 months
Recurring | Hedge funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	3 months
Recurring | Minimum | Private equity investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	3 months
Recurring | Minimum | Fixed income investment funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	1 month
Recurring | Maximum | Private equity investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	6 months
Recurring | Maximum | Fixed income investment funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment Time Lag Reporting	3 months
Recurring | Managed investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	$ 5,921,200	6,119,228
Recurring | Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	344,518	330,970
Recurring | Level 3 | Managed investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Trading Securities	$ 276,493	$ 282,595
Ratio of Level 3 investments to total investments (percent)	4.70%	4.60%

Variable interest entities (Not

Variable interest entities (Notes payable to AlphaCat investors) (Details) - Variable interest entities, primary beneficiary - AlphaCat ILS funds - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Variable Interest Entity [Line Items]
Notes payable to AlphaCat investors, beginning of period	$ 446,576	$ 323,510	$ 278,202	$ 75,493	$ 75,493
Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund	423,269		423,269
Issuance of notes payable to AlphaCat investors	336,747	135,426	714,077	392,431
Redemption of notes payable to AlphaCat investors	(140,150)	(88,079)	(349,106)	(97,684)
Foreign exchange gains	(283)	125	(283)	742
Notes payable to AlphaCat investors, end of period	1,066,159	370,982	1,066,159	370,982	278,202
Variable Funding Notes
Variable Interest Entity [Line Items]
Notes payable to AlphaCat investors, beginning of period	343,256	261,793	278,202	75,493	75,493
Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund	423,269		423,269
Issuance of notes payable to AlphaCat investors	267,867	102,817	541,877	298,105
Redemption of notes payable to AlphaCat investors	(140,150)	(88,079)	(349,106)	(97,684)
Foreign exchange gains	(283)	125	(283)	742
Notes payable to AlphaCat investors, end of period	893,959	276,656	893,959	276,656	278,202
Structured Notes
Variable Interest Entity [Line Items]
Notes payable to AlphaCat investors, beginning of period	103,320	61,717	0	0	0
Notes payable to AlphaCat investors recognized on deconsolidation of AlphaCat ILS fund	0		0
Issuance of notes payable to AlphaCat investors	68,880	32,609	172,200	94,326
Redemption of notes payable to AlphaCat investors	0	0	0	0
Foreign exchange gains	0	0	0	0
Notes payable to AlphaCat investors, end of period	$ 172,200	$ 94,326	$ 172,200	$ 94,326	$ 0

Variable interest entities (Ass

Variable interest entities (Assets and liabilities of consolidated VIEs) (Details) - Variable interest entities, primary beneficiary - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
AlphaCat sidecars
Variable Interest Entity [Line Items]
Total assets		$ 29,330	$ 40,041
Total liabilities		3,455	3,206
AlphaCat ILS funds - Lower Risk
Variable Interest Entity [Line Items]
Total assets	[1]	951,428	1,498,276
Total liabilities	[1]	13,371	42,457
AlphaCat ILS funds - Higher Risk
Variable Interest Entity [Line Items]
Total assets	[1]	1,037,568	972,633
Total liabilities	[1]	207,300	381,332
AlphaCat Re and AlphaCat Master Fund
Variable Interest Entity [Line Items]
Total assets		2,828,096	2,510,415
Total liabilities		2,827,926	2,510,245
BetaCat ILS funds
Variable Interest Entity [Line Items]
Total assets		146,098	82,471
Total liabilities		$ 278	$ 30,663
[1]	Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit.

Variable interest entities (Nar

Variable interest entities (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017USD ($)fundssubsidiaries	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)fundssubsidiaries	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Variable Interest Entity [Line Items]
Loss on deconsolidation of AlphaCat ILS fund			$ (402)	$ 0
(Income) attributable to AlphaCat investors	$ 11,830	$ 6,114	19,333	10,714
Accounts payable and accrued expenses
Variable Interest Entity [Line Items]
(Income) attributable to AlphaCat investors			$ 63,352	17,068
Variable interest entities, primary beneficiary
Variable Interest Entity [Line Items]
Variable funding notes, typical minimum duration			12 months
AlphaCat ILS funds | Variable interest entities, primary beneficiary
Variable Interest Entity [Line Items]
Variable Interest Entity Redemption Of Notes Payable To AlphaCat Investors	$ 140,150	88,079	$ 349,106	$ 97,684
Risk profile percentage			7.00%
AlphaCat ILS funds | Variable interest entities, primary beneficiary | Accounts payable and accrued expenses
Variable Interest Entity [Line Items]
Variable Interest Entity Redemption Of Notes Payable To AlphaCat Investors					$ 1,000
ILS fund issuing structured notes
Variable Interest Entity [Line Items]
Number of AlphaCat ILS funds | funds	1		1
BetaCat ILS funds | Variable interest entities, primary beneficiary
Variable Interest Entity [Line Items]
Number of consolidated VIE BetaCat ILS funds | subsidiaries	2		2
Structured Notes
Variable Interest Entity [Line Items]
Structured notes interest rate percentage			7.00%	8.00%
Structured Notes | AlphaCat ILS funds | Variable interest entities, primary beneficiary
Variable Interest Entity [Line Items]
Variable Interest Entity Redemption Of Notes Payable To AlphaCat Investors	$ 0	$ 0	$ 0	$ 0

Noncontrolling interest (Detail

Noncontrolling interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Noncontrolling Interest [Line Items]
Balance, beginning of period	$ 1,988,227	$ 1,566,260	$ 1,693,978	$ 1,266,376
Issuance of shares	209,821	171,849	468,500	552,924
Adjustment to noncontrolling interests as a result of deconsolidation	(459,021)	0	(459,021)	0
Income attributable to noncontrolling interest	43,650	21,193	86,222	58,724
Redemption of shares	(115,359)	(14,865)	(122,361)	(133,587)
Balance, end of period	1,667,318	1,744,437	1,667,318	1,744,437
Redeemable noncontrolling interest
Noncontrolling Interest [Line Items]
Balance, beginning of period	1,657,630	1,409,037	1,528,001	1,111,714
Issuance of shares	106,501	112,500	210,200	381,250
Adjustment to noncontrolling interests as a result of deconsolidation	(459,021)	0	(459,021)	0
Income attributable to noncontrolling interest	28,555	17,230	54,485	45,803
Redemption of shares	(82,005)	(6,484)	(82,005)	(6,484)
Balance, end of period	1,251,660	1,532,283	1,251,660	1,532,283
Balances payable to noncontrolling interests	74,200		74,200		$ 71,530
Noncontrolling interest
Noncontrolling Interest [Line Items]
Balance, beginning of period	330,597	157,223	165,977	154,662
Issuance of shares	103,320	59,349	258,300	171,674
Adjustment to noncontrolling interests as a result of deconsolidation	0	0	0	0
Income attributable to noncontrolling interest	15,095	3,963	31,737	12,921
Distributions	(33,354)	(8,381)	(40,356)	(127,103)
Balance, end of period	415,658	$ 212,154	415,658	$ 212,154
Balances payable to noncontrolling interests	$ 0		$ 0		$ 16,144

Derivative instruments (Amount

Derivative instruments (Amount and balance sheet location) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Not designated as hedging instruments | Foreign exchange contracts
Summary of derivatives
Net Notional Exposure		$ 223,018	$ 181,375
Not designated as hedging instruments | Foreign exchange contracts | Other assets
Summary of derivatives
Fair value, derivative assets	[1]	1,972	2,351
Not designated as hedging instruments | Foreign exchange contracts | Accounts payable and accrued expenses
Summary of derivatives
Fair value, derivative liabilities	[1]	6,325	3,421
Not designated as hedging instruments | Interest rate swap contracts
Summary of derivatives
Net Notional Exposure		150,000	0
Not designated as hedging instruments | Interest rate swap contracts | Other assets
Summary of derivatives
Fair value, derivative assets	[1]	330	0
Not designated as hedging instruments | Interest rate swap contracts | Accounts payable and accrued expenses
Summary of derivatives
Fair value, derivative liabilities	[1]	648	0
Designated as hedging instruments | Interest rate swap contracts
Summary of derivatives
Net Notional Exposure		552,263	552,263
Designated as hedging instruments | Interest rate swap contracts | Other assets
Summary of derivatives
Fair value, derivative assets		20	20
Designated as hedging instruments | Interest rate swap contracts | Accounts payable and accrued expenses
Summary of derivatives
Fair value, derivative liabilities		$ 1,409	$ 1,479
[1]	Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses, respectively, within the Company’s consolidated balance sheets.

Derivative instruments (Amoun62

Derivative instruments (Amount included in statement of operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Not designated as hedging instruments | Foreign exchange gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in earnings	$ (6,525)	$ 896	$ (6,072)	$ (1,117)
Not designated as hedging instruments | Other income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in earnings	(874)	84	(979)	120
Not designated as hedging instruments | Gain (Loss) on Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in earnings	(319)	0	(319)	0
Designated as hedging instruments | Cash flow hedge | Interest rate swap contracts
Derivative instruments designated as a cash flow hedge
Amount of ineffective portion excluded from effectiveness testing	(144)	64	(46)	(694)
Designated as hedging instruments | Cash flow hedge | Interest rate swap contracts | Other comprehensive income
Derivative instruments designated as a cash flow hedge
Amount of effective portion recognized in other comprehensive income	2,217	2,694	4,376	6,350
Designated as hedging instruments | Cash flow hedge | Interest rate swap contracts | Finance expenses
Derivative instruments designated as a cash flow hedge
Amount of effective portion subsequently reclassified to earnings	$ (2,073)	$ (2,758)	$ (4,330)	$ (5,656)

Reserve for losses and loss e63

Reserve for losses and loss expenses (Components of reserves for losses and loss expenses) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
Case reserves	$ 1,236,799		$ 1,237,772
IBNR	2,068,392		1,757,423
Reserve for losses and loss expenses	$ 3,305,191	$ 3,052,745	$ 2,995,195	$ 3,122,717	$ 2,980,300	$ 2,996,567

Reserve for losses and loss e64

Reserve for losses and loss expenses (Reserve rollforward) (Details) - USD ($) $ in Thousands		May 01, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reserve for paid losses and unpaid loss expenses
Reserve for losses and loss expenses, beginning of period			$ 3,052,745	$ 2,980,300	$ 2,995,195	$ 2,996,567
Loss reserves recoverable, beginning of period			(451,856)	(370,689)	(430,421)	(350,586)
Net reserves for losses and loss expenses, beginning of period			2,600,889	2,609,611	2,564,774	2,645,981
Net reserves acquired	[1]		23,753	0	23,753	0
Increase (decrease) in net losses and loss expenses incurred in respect of losses occurring in:
Current year			339,439	369,911	670,255	648,097
Prior years			(43,290)	(62,781)	(104,521)	(116,520)
Total incurred losses and loss expenses			296,149	307,130	565,734	531,577
Less net losses and loss expenses paid in respect of losses occurring in:
Current year			(42,758)	(45,882)	(50,456)	(61,655)
Prior years			(193,265)	(176,775)	(431,354)	(430,079)
Total net paid losses			(236,023)	(222,657)	(481,810)	(491,734)
Foreign exchange loss			20,216	(14,354)	32,533	(6,094)
Net reserve for losses and loss expenses, end of period			2,704,984	2,679,730	2,704,984	2,679,730
Loss reserves recoverable, end of period			600,207	442,987	600,207	442,987
Reserve for losses and loss expenses, end of period			3,305,191	3,122,717	3,305,191	3,122,717
Components of incurred losses and loss expenses
Gross losses and loss expenses			415,013	397,863	761,808	667,716
Reinsurance recoverable			(118,864)	(90,733)	(196,074)	(136,139)
Net incurred losses and loss expenses			$ 296,149	$ 307,130	$ 565,734	$ 531,577
Net loss reserves		$ 42,575
Commutation of reserves		$ 18,822
[1]	Equals net reserves acquired of $42,575 less net reserves commuted at closing of $18,822.

Reserve for losses and loss e65

Reserve for losses and loss expenses (Prior year development) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	$ (43,290)	$ (62,781)	$ (104,521)	$ (116,520)
Validus Re
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(23,099)	(30,877)	(51,879)	(56,561)
Talbot
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(15,876)	(28,328)	(44,690)	(51,048)
Western World
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(463)	(3,158)	(682)	(7,584)
AlphaCat
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(3,852)	(418)	(7,270)	(1,327)
Property
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(9,141)	(21,440)	(26,264)	(63,340)
Property | Validus Re
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(671)	(9,468)	(4,242)	(32,300)
Property | Talbot
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(4,894)	(10,094)	(11,228)	(28,540)
Property | Western World
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(479)	(1,582)	(3,302)	(2,023)
Property | AlphaCat
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(3,097)	(296)	(7,492)	(477)
Marine
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(33,369)	(18,946)	(64,794)	(12,427)
Marine | Validus Re
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(16,313)	(10,018)	(31,742)	(6,463)
Marine | Talbot
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(17,056)	(8,928)	(33,052)	(5,964)
Specialty
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(796)	(20,819)	(16,083)	(35,192)
Specialty | Validus Re
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(6,115)	(11,391)	(15,895)	(17,798)
Specialty | Talbot
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	6,074	(9,306)	(410)	(16,544)
Specialty | AlphaCat
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	(755)	(122)	222	(850)
Liability
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	16	(1,576)	2,620	(5,561)
Liability | Western World
Increase (decrease) in net reserves for losses and loss expenses in respect of losses occurring in:
Net (favorable) adverse development on prior years	$ 16	$ (1,576)	$ 2,620	$ (5,561)

Reinsurance (Components of rein

Reinsurance (Components of reinsurance) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
Outstanding losses	$ 176,416		$ 165,328
IBNR	423,791		265,093
Total loss reserves recoverable	600,207	$ 451,856	430,421	$ 442,987	$ 370,689	$ 350,586
Paid losses recoverable	35,675		35,247
Total reinsurance balances recoverable	$ 635,882		$ 465,668

Reinsurance (Ceded credit risk)

Reinsurance (Ceded credit risk) (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2017	Dec. 31, 2016
Ceded Credit Risk [Line Items]
Provision for uncollectible reinsurance relating to losses recoverable		$ 6,741	$ 5,153
Reinsurance Recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 635,882	$ 465,668
Percentage of total		100.00%	100.00%
Reinsurance Recoverable | A- or better
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 630,821	$ 461,369
Percentage of total		99.20%	99.10%
Reinsurance Recoverable | Top 10 reinsurers
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 521,027	$ 395,308
Percentage of total		81.90%	84.90%
Reinsurance Recoverable | Top 10 reinsurers | Munich Re | AA- rating
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 96,997	$ 18,214
Percentage of total		15.20%	3.90%
Reinsurance Recoverable | Top 10 reinsurers | Lloyds Syndicates | A plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 84,742	$ 84,419
Percentage of total		13.20%	18.20%
Reinsurance Recoverable | Top 10 reinsurers | Fully collateralized reinsurers | NR
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 80,558	$ 83,088
Percentage of total		12.70%	17.80%
Reinsurance Recoverable | Top 10 reinsurers | Swiss Re | AA- rating
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 77,928	$ 84,044
Percentage of total		12.30%	18.10%
Reinsurance Recoverable | Top 10 reinsurers | Everest Re | A plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 54,565	$ 36,912
Percentage of total		8.60%	7.90%
Reinsurance Recoverable | Top 10 reinsurers | Hannover Re | AA- rating
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 48,037	$ 50,603
Percentage of total		7.60%	10.90%
Reinsurance Recoverable | Top 10 reinsurers | Federal Crop Insurance Corporation
Ceded Credit Risk [Line Items]
Reinsurance recoverable	[1]	$ 29,009
Percentage of total	[1]	4.60%
Reinsurance Recoverable | Top 10 reinsurers | Transatlantic Re | A plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 23,066	$ 10,593
Percentage of total		3.60%	2.30%
Reinsurance Recoverable | Top 10 reinsurers | XL Catlin | A plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 16,062
Percentage of total		2.50%
Reinsurance Recoverable | Top 10 reinsurers | Helvetia Group | A rating
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 10,063
Percentage of total		1.60%
Reinsurance Recoverable | Top 10 reinsurers | Hamilton Re | A- rating
Ceded Credit Risk [Line Items]
Reinsurance recoverable			$ 10,343
Percentage of total			2.20%
Reinsurance Recoverable | Top 10 reinsurers | Toa Re | A plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable			$ 9,510
Percentage of total			2.00%
Reinsurance Recoverable | Top 10 reinsurers | National Indemnity | AA plus
Ceded Credit Risk [Line Items]
Reinsurance recoverable			$ 7,582
Percentage of total			1.60%
Reinsurance Recoverable | Other reinsurers' balances greater than $1 million
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 106,432	$ 66,944
Percentage of total		16.80%	14.40%
Reinsurance Recoverable | Other reinsurers' balances less than $1 million
Ceded Credit Risk [Line Items]
Reinsurance recoverable		$ 8,423	$ 3,416
Percentage of total		1.30%	0.70%
[1]	The Company participates in a crop reinsurance program sponsored by the U.S. federal government. The Company remains obligated for amounts ceded in the event that its reinsurers or retrocessionaires do not meet their obligations, except for amounts ceded to the U.S. federal government in the agriculture line of business.

Share capital (Preferred stock)

Share capital (Preferred stock) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 12, 2017	Jun. 13, 2016	Jun. 30, 2017	Jun. 30, 2016
Preferred shares - Shareholders' Equity
Net proceeds on issuance of preferred shares			$ 241,686	$ 144,852
Preferred shares, shares issued, beginning of period			6,000	0
Preferred shares, shares outstanding, beginning of period			6,000	0
Preferred shares issued			10,000	6,000
Preferred shares, shares issued, end of period			16,000	6,000
Preferred shares, shares outstanding, end of period			16,000	6,000
Series A preferred shares
Preferred shares - Shareholders' Equity
Preferred shares, dividend rate, percentage		5.875%
Proportionate interest of Series A Preferred shares, per depositary share		0.10%
Preferred stock, par or stated value per share		$ 0.175
Preferred stock, liquidation preference, per share		$ 25,000
Preferred shares, shares issued, beginning of period			6,000
Preferred shares issued		6,000
Preferred shares, shares issued, end of period			6,000
Series A depositary share equivalent
Preferred shares - Shareholders' Equity
Preferred shares equivalent depositary shares number		6,000,000
Preferred stock, liquidation preference, per share		$ 25
Series B preferred shares
Preferred shares - Shareholders' Equity
Preferred shares, dividend rate, percentage	5.80%
Proportionate interest of Series A Preferred shares, per depositary share	0.10%
Preferred stock, par or stated value per share	$ 0.175
Preferred stock, liquidation preference, per share	$ 25,000
Net proceeds on issuance of preferred shares	$ 241,686
Preferred shares issued	10,000
Preferred shares, shares issued, end of period			10,000
Series B preferred shares | On or after June 15, 2022
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	$ 25,000
Series B preferred shares | Prior to redemption in the event of amalgamation, consolidation, merger or similar
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	26,000
Series B preferred shares | Prior to redemption if change in tax law or capital disqualification event
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	$ 25,000
Series B depositary share equivalent
Preferred shares - Shareholders' Equity
Preferred shares equivalent depositary shares number	10,000,000
Preferred stock, liquidation preference, per share	$ 25
Series B depositary share equivalent | On or after June 15, 2022
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	25
Series B depositary share equivalent | Prior to redemption in the event of amalgamation, consolidation, merger or similar
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	26
Series B depositary share equivalent | Prior to redemption if change in tax law or capital disqualification event
Preferred shares - Shareholders' Equity
Preferred shares, redemption price per share	$ 25

Share capital (Common stock) (D

Share capital (Common stock) (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 03, 2015	Jun. 30, 2017	Jun. 30, 2016
Share Capital (Narrative)
Authorized share capital		571,428,571
Common shares, par value		$ 0.175
Common stock voting rights		one vote per share
Restriction on percentage of voting power		9.09%
Share repurchases
Common share repurchase authorization	$ 750,000
Share repurchase program, cumulative shares repurchased		80,776,802
Shares repurchased, cumulative	$ 2,274,401	$ 2,718,402
Remaining share repurchase authorization amount		$ 305,999
Summary of common shares issued and outstanding
Common shares issued, beginning balance		161,279,976	160,570,772
Options exercised		0	13,635
Common shares issued, ending balance		161,934,355	161,252,871
Treasury shares, ending balance		(82,415,774)	(80,480,633)
Common shares outstanding, ending balance		79,518,581	80,772,238
Restricted share awards
Summary of common shares issued and outstanding
Vested, net of shares withheld		597,021	601,890
Restricted share units
Summary of common shares issued and outstanding
Vested, net of shares withheld		14,948	18,486
Performance shares
Summary of common shares issued and outstanding
Vested, net of shares withheld		42,410	48,088

Share capital (Dividends) (Deta

Share capital (Dividends) (Details) - $ / shares	3 Months Ended				6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Class of Stock [Line Items]
Cash dividends declared per share - common shares	$ 0.38	$ 0.38	$ 0.35	$ 0.35	$ 0.76	$ 0.70
Series A depositary share equivalent
Class of Stock [Line Items]
Cash dividends declared per share - preferred shares	$ 0.3671875	$ 0.3671875

Stock plans (Options activity)

Stock plans (Options activity) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Options activities:
Options outstanding, beginning balance (in shares)	26,136	65,401
Options exercised during period (in shares)	0	(14,044)
Options outstanding, ending balance (in shares)	26,136	51,357
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 6.78	$ 7.74
Weighted average grant date fair value, options exercised (in dollars per share)	0	7.69
Weighted average grant date fair value, ending balance (in dollars per share)	6.78	7.75
Weighted Average Grant Date Exercise Price
Weighted average grant date exercise price, beginning balance (in dollars per share)	23.48	20.17
Weighted average grant date exercise price, options exercised (in dollars per share)	0	17.02
Weighted average grant date exercise price, ending balance (in dollars per share)	$ 23.48	$ 21.03

Stock plans (Other awards activ

Stock plans (Other awards activity) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Restricted share awards
Activities
Beginning balance (in shares)	2,469,982	2,739,446
Granted (in shares)	481,619	534,905
Vested (in shares)	(803,764)	(783,523)
Forfeited (in shares)	(39,617)	(8,317)
Ending balance (in shares)	2,108,220	2,482,511
Weighted average grant date fair value
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 40.89	$ 38.25
Weighted average grant date fair value, granted (in dollars per share)	53.42	48.69
Weighted average grant date fair value, vested (in dollars per share)	41.31	37.32
Weighted average grant date fair value, forfeited (in dollars per share)	41.98	37.94
Weighted average grant date fair value, ending balance (in dollars per share)	$ 43.58	$ 40.79
Restricted share units
Activities
Beginning balance (in shares)	112,808	114,337
Granted (in shares)	12,236	20,129
Vested (in shares)	(18,241)	(23,982)
Issued in lieu of cash dividends (in shares)	1,468	1,629
Ending balance (in shares)	108,271	112,113
Weighted average grant date fair value
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 40.95	$ 38.47
Weighted average grant date fair value, granted (in dollars per share)	53.40	48.69
Weighted average grant date fair value, vested (in dollars per share)	41.66	38.18
Weighted average grant date fair value, issued in lieu of cash dividends (in dollars per share)	40.98	38.47
Weighted average grant date fair value, ending balance (in dollars per share)	$ 42.24	$ 40.37
Performance shares
Activities
Beginning balance (in shares)	285,820	172,594
Granted (in shares)	107,209	121,844
Vested (in shares)	(52,639)	(57,581)
Conversion adjustment (in shares)	(26,322)	45,517
Ending balance (in shares)	314,068	282,374
Weighted average grant date fair value
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 44.53	$ 40.70
Weighted average grant date fair value, granted (in dollars per share)	53.40	48.69
Weighted average grant date fair value, vested (in dollars per share)	37.33	36.11
Weighted average grant date fair value, conversion adjustment (in dollars per share)	36.82	36.82
Weighted average grant date fair value, ending balance (in dollars per share)	$ 49.37	$ 44.46

Stock plans (Components of shar

Stock plans (Components of share compensation expenses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Total share compensation expenses
Share compensation expenses	$ 11,146	$ 10,727	$ 20,637	$ 21,964
Restricted share awards
Total share compensation expenses
Share compensation expenses	9,745	9,517	18,789	18,646
Restricted share units
Total share compensation expenses
Share compensation expenses	327	377	642	688
Performance shares
Total share compensation expenses
Share compensation expenses	$ 1,074	$ 833	$ 1,206	$ 2,630

Stock plans (Narrative) (Detail

Stock plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Stock plans (other details)
Number of shares reserved for issuance under the LTIP and STIP	2,753,292		2,753,292
Remaining number of shares reserved for issuance	714,817		714,817
Share compensation expenses	$ 11,146	$ 10,727	$ 20,637	$ 21,964
Options exercised during period (in shares)			0	(14,044)
Share Based Compensation Arrangement By Share Based Payment Award Options Exercised In Period Weighted Average Grant Date Fair Value			$ 0	$ 7.69
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price			$ 0	$ 17.02
Options
Stock plans (other details)
Life of options			10 years
Restricted share awards
Stock plans (other details)
Share compensation expenses	9,745	9,517	$ 18,789	$ 18,646
Unrecognized share compensation expenses	63,931		$ 63,931		$ 58,804
Weighted average period of recognizing share based compensation expenses			2 years 7 months 9 days		2 years 3 months 3 days
Restricted share units
Stock plans (other details)
Share compensation expenses	327	377	$ 642	688
Unrecognized share compensation expenses	2,558		$ 2,558		$ 2,542
Weighted average period of recognizing share based compensation expenses			2 years 7 months 17 days		2 years 6 months 21 days
Performance shares
Stock plans (other details)
Share compensation expenses	1,074	$ 833	$ 1,206	$ 2,630
Unrecognized share compensation expenses	$ 10,250		$ 10,250		$ 6,902
Weighted average period of recognizing share based compensation expenses			2 years 4 months 2 days		2 years 21 days
Performance share awards performance period			3 years

Debt and financing arrangemen75

Debt and financing arrangements (Summary of outstanding debentures and senior notes payable) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt Instruments [Line Items]
Debentures payable	$ 538,400	$ 537,226
Debt instrument, commitment	250,000	250,000
Less: Unamortized debt issuance costs	(4,537)	(4,638)
Total senior notes payable	245,463	245,362
Debentures payable	783,863	782,588
2006 Junior Subordinated
Debt Instruments [Line Items]
Debentures payable	150,000	150,000
Debt instrument, commitment	150,000
2007 Junior Subordinated
Debt Instruments [Line Items]
Debentures payable	139,800	139,800
Debt instrument, commitment	200,000
Flagstone 2006 Junior Subordinated
Debt Instruments [Line Items]
Debentures payable	134,850	133,676
Debt instrument, commitment	134,850
Flagstone 2007 Junior Subordinated
Debt Instruments [Line Items]
Debentures payable	$ 113,750	$ 113,750

Debt and financing arrangemen76

Debt and financing arrangements (Credit facilities outstanding) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Commitment		$ 670,000	$ 690,000
Drawn and outstanding		201,091	265,039
$85,000 syndicated unsecured letter of credit facility
Line of Credit Facility [Line Items]
Commitment		85,000	85,000
Drawn and outstanding		0	0
$300,000 syndicated secured letter of credit facility
Line of Credit Facility [Line Items]
Commitment		300,000	300,000
Drawn and outstanding		87,718	90,252
$24,000 secured bi-lateral letter of credit facility
Line of Credit Facility [Line Items]
Commitment		24,000	24,000
Drawn and outstanding		5,648	4,553
$20,000 AlphaCat Re secured letter of credit facility
Line of Credit Facility [Line Items]
Commitment	[1]	0	20,000
Drawn and outstanding	[1]	0	20,000
$25,000 IPC bi-lateral facility
Line of Credit Facility [Line Items]
Commitment		25,000	25,000
Drawn and outstanding		5,535	5,842
$236,000 Flagstone bi-lateral facility
Line of Credit Facility [Line Items]
Commitment		236,000	236,000
Drawn and outstanding		$ 102,190	$ 144,392
[1]	The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017.

Debt and financing arrangemen77

Debt and financing arrangements (Summary of key terms of senior notes and debentures) (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2017	Dec. 31, 2016
Debt Instruments [Line Items]
Commitment		$ 250,000	$ 250,000
2010 Senior Notes Due 2040
Debt Instruments [Line Items]
Issuance date		Jan. 26, 2010
Commitment		$ 250,000
Maturity date		Jan. 26, 2040
Interest payments due		Semi-annually in arrears
Payments expected to be made after 2022		$ 250,000
Junior Subordinated Debt
Debt Instruments [Line Items]
Payments expected to be made after 2022		$ 538,400
2006 Junior Subordinated
Debt Instruments [Line Items]
Issuance date		Jun. 15, 2006
Commitment		$ 150,000
Maturity date		Jun. 15, 2036
Interest payments due		Quarterly
Interest rate term		5 years
2006 Junior Subordinated | Three month LIBOR
Debt Instruments [Line Items]
Spread on variable rate (in percent)		3.55%
Flagstone 2006 Junior Subordinated
Debt Instruments [Line Items]
Issuance date		Aug. 23, 2006
Commitment		$ 134,850
Maturity date		Sep. 15, 2036
Interest payments due		Quarterly
2007 Junior Subordinated
Debt Instruments [Line Items]
Issuance date		Jun. 21, 2007
Commitment		$ 200,000
Maturity date		Jun. 15, 2037
Interest payments due		Quarterly
Interest rate term		5 years
2007 Junior Subordinated | Three month LIBOR
Debt Instruments [Line Items]
Spread on variable rate (in percent)		2.95%
Flagstone 2007 Due July 30 2037
Debt Instruments [Line Items]
Issuance date		Jun. 8, 2007
Commitment		$ 100,000
Maturity date		Jul. 30, 2037
Interest payments due		Quarterly
Flagstone 2007 Due September 15 2037
Debt Instruments [Line Items]
Issuance date		Sep. 20, 2007
Commitment		$ 25,000
Maturity date		Sep. 15, 2037
Interest payments due		Quarterly
At Issuance | 2010 Senior Notes Due 2040
Debt Instruments [Line Items]
Fixed interest rate (in percent)	[1]	8.875%
At Issuance | 2006 Junior Subordinated
Debt Instruments [Line Items]
Fixed interest rate (in percent)	[2]	9.069%
At Issuance | Flagstone 2006 Junior Subordinated | Three month LIBOR
Debt Instruments [Line Items]
Spread on variable rate (in percent)	[3]	3.54%
At Issuance | 2007 Junior Subordinated
Debt Instruments [Line Items]
Fixed interest rate (in percent)	[4]	8.48%
At Issuance | Flagstone 2007 Due July 30 2037 | Three month LIBOR
Debt Instruments [Line Items]
Spread on variable rate (in percent)	[3]	3.00%
At Issuance | Flagstone 2007 Due September 15 2037 | Three month LIBOR
Debt Instruments [Line Items]
Spread on variable rate (in percent)	[3]	3.10%
Outstanding | 2010 Senior Notes Due 2040
Debt Instruments [Line Items]
Fixed interest rate (in percent)	[1]	8.875%
Outstanding | 2006 Junior Subordinated
Debt Instruments [Line Items]
Effective percentage	[5]	5.831%
Outstanding | Flagstone 2006 Junior Subordinated
Debt Instruments [Line Items]
Effective percentage	[5]	6.463%
Outstanding | 2007 Junior Subordinated
Debt Instruments [Line Items]
Effective percentage	[5]	5.18%
Outstanding | Flagstone 2007 Due July 30 2037
Debt Instruments [Line Items]
Effective percentage	[5]	5.90%
Outstanding | Flagstone 2007 Due September 15 2037
Debt Instruments [Line Items]
Effective percentage	[5]	5.983%
[1]	Fixed interest rate.
[2]	Fixed interest rate for 5 years, floating interest rate of three-month LIBOR plus 3.550% thereafter, reset quarterly.
[3]	Floating interest rate of three-month LIBOR plus amount stated, reset quarterly.
[4]	Fixed interest rate for 5 years, floating interest rate of three-month LIBOR plus 2.950% thereafter, reset quarterly.
[5]	Fixed interest rate as a result of interest rate swap contracts entered into by the Company.

Debt and financing arrangemen78

Debt and financing arrangements (Investments pledged as collateral) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investments and cash pledged as collateral		$ 404,516	$ 442,184
$300,000 syndicated secured letter of credit facility
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investments and cash pledged as collateral		147,048	157,597
$24,000 secured bi-lateral letter of credit facility
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investments and cash pledged as collateral		33,353	48,097
AlphaCat Re secured letter of credit facility (a)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investments and cash pledged as collateral	[1]	0	20,032
$236,000 Flagstone bi-lateral facility
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investments and cash pledged as collateral		$ 224,115	$ 216,458
[1]	The Company terminated its AlphaCat Re secured letter of credit facility on January 6, 2017.

Debt and financing arrangemen79

Debt and financing arrangements (Components of finance expenses) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016
Debt Instruments [Line Items]
Finance expenses	$ 14,209		$ 14,166		$ 28,152	$ 29,369
2006 Junior Subordinated
Debt Instruments [Line Items]
Finance expenses	2,211		2,211		4,398	4,422
2007 Junior Subordinated
Debt Instruments [Line Items]
Finance expenses	1,831		1,830		3,641	3,661
Flagstone 2006 Junior Subordinated
Debt Instruments [Line Items]
Finance expenses	2,248		2,244		4,469	4,489
Flagstone 2007 Junior Subordinated
Debt Instruments [Line Items]
Finance expenses	1,751		1,766		3,474	3,533
2010 Senior Notes Due 2040
Debt Instruments [Line Items]
Finance expenses	5,598		5,597		11,195	11,194
Credit facilities
Debt Instruments [Line Items]
Finance expenses	403		235		621	896
Bank and other charges
Debt Instruments [Line Items]
Finance expenses	131		206		282	213
AlphaCat fees
Debt Instruments [Line Items]
Finance expenses	$ 36	[1]	$ 77	[1]	$ 72	$ 961
[1]	Includes finance expenses incurred by AlphaCat Managers Ltd. in relation to fund raising for the AlphaCat sidecars, the AlphaCat ILS funds and AlphaCat direct.

Accumulated other comprehensi80

Accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax			$ 4,004,268
Total shareholders' equity	$ 4,627,089	$ 4,078,410	4,627,089	$ 4,078,410
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax	(22,453)	(15,438)	(23,216)	(12,569)
Net current period other comprehensive loss, net of tax	2,529	(2,744)	3,292	(5,613)
Total shareholders' equity	(19,924)	(18,182)	(19,924)	(18,182)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax	(21,677)	(13,862)	(22,274)	(11,834)
Net current period other comprehensive loss, net of tax	1,489	(3,287)	2,086	(5,315)
Total shareholders' equity	(20,188)	(17,149)	(20,188)	(17,149)
Minimum pension liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax	(82)	251	(150)	334
Net current period other comprehensive loss, net of tax	1,184	479	1,252	396
Total shareholders' equity	1,102	730	1,102	730
Cash flow hedge
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax	(694)	(1,827)	(792)	(1,069)
Net current period other comprehensive loss, net of tax	(144)	64	(46)	(694)
Total shareholders' equity	$ (838)	$ (1,763)	$ (838)	$ (1,763)

Commitments and contingencies81

Commitments and contingencies (Lloyd's syndicate) (Details) - 6 months ended Jun. 30, 2017 - Lloyd's Syndicate 1183 £ in Thousands, $ in Thousands	USD ($)	GBP (£)
Funds at Lloyd's and Lloyd's Central Fund
Maximum premium levies assessable, percent	3.00%	3.00%
Estimated underwriting capacity | £		£ 600,000
Exchange rate	£1 equals $1.30	£1 equals $1.30
Maximum premium levies assessable, amount	$ 23,400
2017 Underwriting Year
Loss Contingencies [Line Items]
Components of required capital	583,600
2016 Underwriting year
Loss Contingencies [Line Items]
Components of required capital	$ 617,000

Commitments and contingencies82

Commitments and contingencies (Other commitments) (Details) - USD ($) $ in Thousands		May 01, 2017	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Investment commitment
Other Commitments [Line Items]
Capital commitment			$ 313,000	$ 313,000	$ 308,000
Remaining commitment			228,779	228,779	258,704
Investment commitment | Investments in investment affiliates
Other Commitments [Line Items]
Remaining commitment	[1]		84,046	84,046	64,071
Investment commitment | AlphaCat ILS funds
Other Commitments [Line Items]
Remaining commitment			0	0	10,000
Investment commitment | Fixed maturity investments
Other Commitments [Line Items]
Remaining commitment	[2]		25,238	25,238	28,499
Investment commitment | Other investments
Other Commitments [Line Items]
Remaining commitment	[3]		119,495	119,495	$ 156,134
Marketing services agreement
Other Commitments [Line Items]
Annual fee for services commitment		$ 2,000
Services commitment period		7 years
Services commitment extension period		3 years
Marketing expense			$ 333	$ 333
[1]	Refer to Note 4(c), “Investments in Investment Affiliates.”
[2]	The Company has an outstanding commitment to participate in certain secured loan facilities through participation agreements with an established loan originator.
[3]	The Company’s total capital commitments related to other investments as at June 30, 2017 was $313,000 (December 31, 2016: $308,000).

Related party transactions (Det

Related party transactions (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Investments in affiliates		$ 103,377,000		$ 103,377,000		$ 100,431,000
Group Ark Insurance Holdings Ltd
Related Party Transaction [Line Items]
Gross premiums written			$ 65,000		$ 1,971,000
Reinsurance premiums ceded			(17,000)		0
Earned premium adjustments			473,000		999,000
Premiums receivable						292,000
Loss reserves recoverable						798,000
Wellington Insurance Company
Related Party Transaction [Line Items]
Gross premiums written		1,144,000	0	4,118,000	0
Earned premium adjustments		1,676,000	0	2,537,000	0
Premiums receivable		3,531,000		3,531,000		666,000
Investment affiliate
Related Party Transaction [Line Items]
Investments in affiliates						100,431,000
Partnership fees incurred		130,000	$ 440,000	486,000	$ 440,000
Investment commitment
Related Party Transaction [Line Items]
Remaining commitment		228,779,000		228,779,000		258,704,000
Investment commitment | Investment affiliate
Related Party Transaction [Line Items]
Remaining commitment	[1]	$ 84,046,000		$ 84,046,000		$ 64,071,000
[1]	Refer to Note 4(c), “Investments in Investment Affiliates.”

Earnings per share (Details)

Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic earnings per share
Net income available to Validus common shareholders	$ 101,095	$ 94,963	$ 195,656	$ 261,773
Weighted average number of common shares outstanding	79,270,561	81,950,833	79,202,116	82,386,047
Basic earnings per share available to common shareholders	$ 1.28	$ 1.16	$ 2.47	$ 3.18
Earnings per diluted share
Net income available to Validus common shareholders	$ 101,095	$ 94,963	$ 195,656	$ 261,773
Weighted average number of common shares outstanding	79,270,561	81,950,833	79,202,116	82,386,047
Weighted average number of diluted common shares outstanding	80,872,451	83,373,003	80,861,998	83,785,659
Earnings per diluted share available to common shareholders	$ 1.25	$ 1.14	$ 2.42	$ 3.12
Other details:
Anti-dilutive securities excluded from the calculation of diluted earnings per share	412,603	507,262	207,054	253,631
Stock options
Earnings per diluted share
Share equivalents	14,739	33,796	15,059	34,837
Unvested restricted shares
Earnings per diluted share
Share equivalents	1,587,151	1,388,374	1,644,823	1,364,775

Segment information (Summary of

Segment information (Summary of results of operating and other segments) (Details) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2017USD ($)		Jun. 30, 2016USD ($)		Jun. 30, 2017USD ($)segments	Jun. 30, 2016USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segments						4
Underwriting revenues
Gross premiums written		$ 792,902		$ 764,042		$ 1,983,759	$ 1,936,833
Reinsurance premiums ceded		(56,222)		(36,229)		(256,328)	(204,064)
Net premiums written		736,680		727,813		1,727,431	1,732,769
Change in unearned premiums		(105,653)		(154,090)		(521,028)	(587,778)
Net premiums earned		631,027		573,723		1,206,403	1,144,991
Other insurance related income (loss)		1,165		745		2,401	1,481
Segmental revenues		632,192		574,468		1,208,804	1,146,472
Underwriting deductions
Losses and loss expenses		296,149		307,130		565,734	531,577
Policy acquisition costs		117,268		107,966		228,896	215,159
General and administrative expenses		96,349		89,688		184,273	175,896
Share compensation expenses		11,146		10,727		20,637	21,964
Total underwriting deductions		520,912		515,511		999,540	944,596
Segmental income		111,280		58,957		209,264	201,876
Other items		7,684	[1]	24,056	[1]	16,325	60,617
Dividends on preferred shares		(2,203)		0		(4,406)
Net investment income		44,241		39,257		84,455	68,718
Transaction expenses		(4,427)		0		(4,427)	0
(Income) attributable to AlphaCat investors		(11,830)		(6,114)		(19,333)	(10,714)
Net (income) attributable to noncontrolling interest		(43,650)		(21,193)		(86,222)	(58,724)
Finance expenses		14,209		14,166		28,152	29,369
Tax (benefit) expense		(987)		1,706		(4,536)	(412)
Net realized gains on investments		2,274		2,724		1,110	2,140
Change in net unrealized gains on managed investments (b)		16,321		31,428		29,669	78,872
Income (loss) from investment affiliates		9,466		(589)		14,654	(4,702)
Foreign exchange gains (losses)		7,329		(6,286)		5,760	(12,531)
Net income available to Validus		103,298		94,963		200,062	261,773
Selected ratios:
Net income available to Validus common shareholders		101,095		94,963		195,656	261,773
Corporate and investment
Underwriting deductions
Dividends on preferred shares						0
Operating Segments | Validus Re
Underwriting revenues
Gross premiums written		296,997		285,810		917,519	977,478
Reinsurance premiums ceded		(11,387)		(3,196)		(120,200)	(95,691)
Net premiums written		285,610		282,614		797,319	881,787
Change in unearned premiums		(45,003)		(35,492)		(338,300)	(390,834)
Net premiums earned		240,607		247,122		459,019	490,953
Other insurance related income (loss)		58		150		136	(165)
Segmental revenues		240,665		247,272		459,155	490,788
Underwriting deductions
Losses and loss expenses		104,685		132,139		190,839	215,007
Policy acquisition costs		47,158		42,564		88,414	84,823
General and administrative expenses		19,274		17,872		36,106	35,051
Share compensation expenses		2,663		2,775		5,140	5,676
Total underwriting deductions		173,780		195,350		320,499	340,557
Segmental income		66,885		51,922		138,656	150,231
Validus share of segmental income		$ 66,885		$ 51,922		$ 138,656	$ 150,231
Selected ratios:
Net premiums written / Gross premiums written		96.20%		98.90%		86.90%	90.20%
Losses and loss expenses		43.50%		53.50%		41.60%	43.80%
Policy acquisition costs		19.60%		17.20%		19.30%	17.30%
General and administrative expenses	[2]	9.10%		8.40%		8.90%	8.30%
Expense ratio		28.70%		25.60%		28.20%	25.60%
Combined ratio		72.20%		79.10%		69.80%	69.40%
Operating Segments | Talbot Segment
Underwriting revenues
Gross premiums written		$ 262,477		$ 296,067		$ 509,652	$ 562,384
Reinsurance premiums ceded		(24,977)		(27,161)		(117,801)	(114,619)
Net premiums written		237,500		268,906		391,851	447,765
Change in unearned premiums		(45,626)		(67,357)		(4,912)	(39,424)
Net premiums earned		191,874		201,549		386,939	408,341
Other insurance related income (loss)		65		279		820	290
Segmental revenues		191,939		201,828		387,759	408,631
Underwriting deductions
Losses and loss expenses		93,389		109,310		199,801	209,411
Policy acquisition costs		44,305		43,613		87,581	87,956
General and administrative expenses		35,582		39,061		74,025	77,596
Share compensation expenses		3,155		3,270		5,982	6,792
Total underwriting deductions		176,431		195,254		367,389	381,755
Segmental income		15,508		6,574		20,370	26,876
Validus share of segmental income		$ 15,508		$ 6,574		$ 20,370	$ 26,876
Selected ratios:
Net premiums written / Gross premiums written		90.50%		90.80%		76.90%	79.60%
Losses and loss expenses		48.70%		54.20%		51.60%	51.30%
Policy acquisition costs		23.10%		21.60%		22.60%	21.50%
General and administrative expenses	[2]	20.20%		21.10%		20.70%	20.70%
Expense ratio		43.30%		42.70%		43.30%	42.20%
Combined ratio		92.00%		96.90%		94.90%	93.50%
Operating Segments | Western World
Underwriting revenues
Gross premiums written		$ 131,068		$ 86,971		$ 303,111	$ 150,930
Reinsurance premiums ceded		(23,180)		(5,006)		(28,798)	(9,145)
Net premiums written		107,888		81,965		274,313	141,785
Change in unearned premiums		22,806		(16,309)		(46,347)	(14,630)
Net premiums earned		130,694		65,656		227,966	127,155
Other insurance related income (loss)		663		189		904	477
Segmental revenues		131,357		65,845		228,870	127,632
Underwriting deductions
Losses and loss expenses		97,008		44,229		171,933	83,875
Policy acquisition costs		19,230		15,410		39,466	29,610
General and administrative expenses		18,316		11,458		29,070	23,533
Share compensation expenses		609		542		1,301	1,123
Total underwriting deductions		135,163		71,639		241,770	138,141
Segmental income		(3,806)		(5,794)		(12,900)	(10,509)
Validus share of segmental income		$ (3,806)		$ (5,794)		$ (12,900)	$ (10,509)
Selected ratios:
Net premiums written / Gross premiums written		82.30%		94.20%		90.50%	93.90%
Losses and loss expenses		74.20%		67.40%		75.40%	66.00%
Policy acquisition costs		14.70%		23.50%		17.30%	23.30%
General and administrative expenses	[2]	14.50%		18.20%		13.40%	19.30%
Expense ratio		29.20%		41.70%		30.70%	42.60%
Combined ratio		103.40%		109.10%		106.10%	108.60%
Operating Segments | AlphaCat
Underwriting revenues
Gross premiums written		$ 105,682		$ 98,905		$ 270,608	$ 266,253
Third party management fees		5,549		3,091		10,193	7,818
Related party management fees		644		328		1,275	1,219
Segmental revenues		6,193		3,419		11,468	9,037
Underwriting deductions
General and administrative expenses		3,549		2,751		7,393	4,233
Share compensation expenses		83		133		165	274
Total underwriting deductions		3,812		2,963		7,767	5,402
Segmental income		2,381		456		3,701	3,635
Net investment income	[3]	4,143		4,421		8,955	10,028
Finance expenses		44		75		75	883
Tax (benefit) expense		135		0		134
Foreign exchange gains (losses)		1		4		0	12
Operating Segments | AlphaCat | AlphaCat sidecars
Underwriting revenues
Gross premiums written		0		(14)		66	(66)
Underwriting deductions
Net investment income	[3]	(21)		541		(133)	665
Operating Segments | AlphaCat | AlphaCat ILS funds - Lower Risk
Underwriting revenues
Gross premiums written	[4]	53,632		50,234		106,540	110,192
Underwriting deductions
Net investment income	[3],[4]	1,301		2,075		3,490	4,582
Operating Segments | AlphaCat | AlphaCat ILS funds - Higher Risk
Underwriting revenues
Gross premiums written	[4]	43,672		42,010		137,208	138,330
Underwriting deductions
Net investment income	[3],[4]	2,600		692		4,967	3,128
Operating Segments | AlphaCat | BetaCat ILS funds
Underwriting deductions
Net investment income	[3]	263		1,113		631	1,676
Operating Segments | AlphaCat | PaCRe funds
Underwriting deductions
Net investment income	[3]	0		0		0	(23)
Operating Segments | AlphaCat | AlphaCat direct
Underwriting revenues
Gross premiums written	[5]	8,378		6,675		26,794	17,797
Operating Segments | AlphaCat And Consolidated Variable Interest Entities
Underwriting revenues
Gross premiums written		105,682		98,905		270,608	266,253
Reinsurance premiums ceded		0		(4,577)		(6,660)	(4,821)
Net premiums written		105,682		94,328		263,948	261,432
Change in unearned premiums		(37,830)		(34,932)		(131,469)	(142,890)
Net premiums earned		67,852		59,396		132,479	118,542
Other insurance related income (loss)		5,874		3,401		11,035	9,066
Segmental revenues		73,726		62,797		143,514	127,608
Underwriting deductions
Losses and loss expenses		1,067		21,452		3,161	23,284
Policy acquisition costs		7,165		6,530		14,066	12,687
General and administrative expenses		9,768		6,561		19,409	14,017
Share compensation expenses		83		133		165	274
Total underwriting deductions		18,083		34,676		36,801	50,262
Segmental income		55,643		28,121		106,713	77,346
Other items		183	[1]	1,058	[1]	1,298	1,212
Net investment income		6,178		3,005		10,200	4,543
(Income) attributable to AlphaCat investors		(11,830)		(6,114)		(19,333)	(10,714)
Net (income) attributable to noncontrolling interest		(43,650)		(21,193)		(86,222)	(58,724)
Validus share of segmental income		6,524		4,877		12,656	13,663
Operating Segments | Corporate and investment
Underwriting deductions
General and administrative expenses		18,847		17,872		36,024	34,055
Share compensation expenses		4,636		4,007		8,049	8,099
Total underwriting deductions		23,483		21,879		44,073	42,154
Segmental income		(23,483)		(21,879)		(44,073)	(42,154)
Other items		7,501	[1]	22,998	[1]	15,027	59,405
Dividends on preferred shares		(2,203)		0		(4,406)	0
Net investment income	[6]	38,063		36,849		74,255	64,772
Transaction expenses		(4,427)		0		(4,427)	0
Finance expenses	[6]	14,149		13,979		28,013	28,320
Tax (benefit) expense		(1,122)		1,706		(4,670)	(412)
Total expenses		38,713		37,564		71,822	70,062
Validus share of segmental income		15,451		37,968		36,376	82,023
Net realized gains on investments	[6]	2,269		2,520		(623)	1,434
Change in net unrealized gains on managed investments (b)	[6]	15,942		30,052		30,291	77,130
Income (loss) from investment affiliates		9,466		(589)		14,654	(4,702)
Foreign exchange gains (losses)	[6]	7,323		(6,621)		6,220	(12,695)
Other income		174		79		268	756
Total other items		16,101		38,683		33,943	87,313
Eliminations
Underwriting revenues
Gross premiums written		(3,322)		(3,711)		(17,131)	(20,212)
Reinsurance premiums ceded		3,322		3,711		17,131	20,212
Net premiums written						0	0
Change in unearned premiums						0	0
Net premiums earned						0	0
Other insurance related income (loss)		(5,495)		(3,274)		(10,494)	(8,187)
Segmental revenues		(5,495)		(3,274)		(10,494)	(8,187)
Underwriting deductions
Losses and loss expenses						0	0
Policy acquisition costs		(590)		(151)		(631)	83
General and administrative expenses		(5,438)		(3,136)		(10,361)	(8,356)
Total underwriting deductions		(6,028)		(3,287)		(10,992)	(8,273)
Segmental income		533		13		498	86
Net investment income		0		(597)		0	(597)
Validus share of segmental income		$ 533		$ (584)		$ 498	$ (511)
[1]	Other items includes finance expenses, tax expenses, foreign exchange gains (losses), net realized and change in net unrealized gains (losses) on investments, income from investment and operating affiliates and other income (loss).
[2]	The general and administrative expense ratio includes share compensation expenses.
[3]	The investment income from the AlphaCat funds and sidecars is based on equity accounting.
[4]	Lower risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of less than 7%, whereas higher risk AlphaCat ILS funds have a maximum permitted portfolio expected loss of greater than 7%. Expected loss represents the average annual loss over the set of simulation scenarios divided by the total limit.
[5]	AlphaCat Direct includes direct investments from third party investors in AlphaCat Re.
[6]	These items exclude the components which are included in Validus’ share of AlphaCat and amounts which are consolidated from VIEs.

Segment information (Gross prem

Segment information (Gross premiums written by geographic location and segment) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 792,902		$ 764,042		$ 1,983,759	$ 1,936,833
Percent of gross premiums written	100.00%		100.00%		100.00%	100.00%
United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 332,455		$ 292,114		$ 774,774	$ 701,830
Percent of gross premiums written	41.90%		38.20%		39.10%	36.20%
Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 38,148	[1]	$ 53,363	[1]	$ 112,929	$ 134,667
Percent of gross premiums written	4.70%	[1]	7.00%	[1]	5.70%	7.00%
Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 7,155		$ 4,877		$ 11,118	$ 16,060
Percent of gross premiums written	0.90%		0.60%		0.60%	0.80%
Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 6,865		$ 10,193		$ 47,957	$ 49,048
Percent of gross premiums written	0.90%		1.30%		2.30%	2.50%
Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 35,309		$ 31,078		$ 65,956	$ 65,441
Percent of gross premiums written	4.50%		4.10%		3.30%	3.40%
Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 45,342		$ 44,732		$ 49,491	$ 47,697
Percent of gross premiums written	5.70%		5.90%		2.50%	2.50%
Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 4,392		$ 4,478		$ 7,199	$ 7,195
Percent of gross premiums written	0.60%		0.60%		0.40%	0.40%
Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 28,150	[2]	$ 32,608	[2]	$ 63,645	$ 74,895
Percent of gross premiums written	3.60%	[2]	4.30%	[2]	3.20%	3.90%
Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 165,361		$ 181,329		$ 358,295	$ 395,003
Percent of gross premiums written	20.90%		23.80%		18.00%	20.50%
Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 115,202	[1]	$ 121,773	[1]	$ 361,499	$ 368,543
Percent of gross premiums written	14.50%	[1]	15.90%	[1]	18.20%	19.00%
Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 179,884	[3]	$ 168,826	[3]	$ 489,191	$ 471,457
Percent of gross premiums written	22.70%	[3]	22.10%	[3]	24.70%	24.30%
Operating Segments | Validus Re
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 296,997		$ 285,810		$ 917,519	$ 977,478
Operating Segments | Validus Re | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	100,312		129,087		314,180	424,481
Operating Segments | Validus Re | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	4,537	[1]	16,975	[1]	38,605	47,239
Operating Segments | Validus Re | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	3,264		1,926		4,195	6,849
Operating Segments | Validus Re | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	748		3,267		30,364	25,734
Operating Segments | Validus Re | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	11,874		5,992		21,216	19,574
Operating Segments | Validus Re | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	39,305		39,053		40,466	39,925
Operating Segments | Validus Re | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	3,155		1,821		4,870	3,497
Operating Segments | Validus Re | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	4,877	[2]	3,259	[2]	18,782	19,947
Operating Segments | Validus Re | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	67,760		72,293		158,498	162,765
Operating Segments | Validus Re | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	53,524	[1]	35,561	[1]	155,945	147,338
Operating Segments | Validus Re | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	75,401	[3]	48,869	[3]	288,896	242,894
Operating Segments | Talbot Segment
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	262,477		296,067		509,652	562,384
Operating Segments | Talbot Segment | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	34,470		39,135		63,555	65,245
Operating Segments | Talbot Segment | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	32,627	[1]	30,028	[1]	66,958	65,532
Operating Segments | Talbot Segment | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	1,848		2,063		5,030	4,375
Operating Segments | Talbot Segment | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	5,857		6,855		17,572	20,716
Operating Segments | Talbot Segment | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	24,800		27,597		48,977	51,404
Operating Segments | Talbot Segment | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	3,381		3,965		5,206	4,582
Operating Segments | Talbot Segment | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	1,111		2,470		2,248	3,562
Operating Segments | Talbot Segment | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	23,168	[2]	29,806	[2]	46,440	57,290
Operating Segments | Talbot Segment | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	92,792		102,784		192,431	207,461
Operating Segments | Talbot Segment | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	30,735	[1]	34,198	[1]	58,092	62,652
Operating Segments | Talbot Segment | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	104,480	[3]	119,950	[3]	195,574	227,026
Operating Segments | Western World
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	131,068		86,971		303,111	150,930
Operating Segments | Western World | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	131,068		86,971		303,111	150,930
Operating Segments | Western World | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0	[1]	0	[1]	0	0
Operating Segments | Western World | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0	[2]	0	[2]	0	0
Operating Segments | Western World | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0		0		0	0
Operating Segments | Western World | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0	[1]	0	[1]	0	0
Operating Segments | Western World | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0	[3]	0	[3]	0	0
Operating Segments | AlphaCat
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	105,682		98,905		270,608	266,253
Operating Segments | AlphaCat | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	70,048		37,338		98,251	62,729
Operating Segments | AlphaCat | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	870	[1]	6,496	[1]	7,905	22,507
Operating Segments | AlphaCat | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	2,003		867		2,003	4,949
Operating Segments | AlphaCat | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(15)		(145)		451	3,306
Operating Segments | AlphaCat | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	46		0		46	0
Operating Segments | AlphaCat | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	2,662		1,721		3,855	3,221
Operating Segments | AlphaCat | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	130		223		130	223
Operating Segments | AlphaCat | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	0	[2]	0	[2]	0	0
Operating Segments | AlphaCat | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	5,696		9,162		14,390	34,206
Operating Segments | AlphaCat | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	29,937	[1]	52,394	[1]	153,246	167,767
Operating Segments | AlphaCat | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	1	[3]	11	[3]	4,721	1,551
Operating Segments | AlphaCat And Consolidated Variable Interest Entities
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	105,682		98,905		270,608	266,253
Eliminations
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(3,322)		(3,711)		(17,131)	(20,212)
Eliminations | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(3,443)		(417)		(4,323)	(1,555)
Eliminations | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	114	[1]	(136)	[1]	(539)	(611)
Eliminations | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	40		21		(110)	(113)
Eliminations | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	275		216		(430)	(708)
Eliminations | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(1,411)		(2,511)		(4,283)	(5,537)
Eliminations | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(6)		(7)		(36)	(31)
Eliminations | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(4)		(36)		(49)	(87)
Eliminations | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	105	[2]	(457)	[2]	(1,577)	(2,342)
Eliminations | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	(887)		(2,910)		(7,024)	(9,429)
Eliminations | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	1,006	[1]	(380)	[1]	(5,784)	(9,214)
Eliminations | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	$ 2	[3]	$ (4)	[3]	$ 0	$ (14)
[1]	Represents risks in two or more geographic zones.
[2]	Represents risks in one geographic zone.
[3]	The Other locations non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable since these exposures can span multiple geographic areas and, in some instances, are not fixed locations.