RenaissanceRe (RNR) 10-Q 8 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 03, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	RENAISSANCERE HOLDINGS LTD.
Trading Symbol	RNR
Entity Central Index Key	0000913144
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		44,159,306

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
Fixed maturity investments trading, at fair value – amortized cost $9,442,370 at March 31, 2019 (December 31, 2018 – $8,163,962)	$ 9,473,160	$ 8,088,870
Short term investments, at fair value	4,012,815	2,586,520
Equity investments trading, at fair value	389,937	310,252
Other investments, at fair value	878,373	784,933
Investments in other ventures, under equity method	98,563	115,172
Total investments	14,852,848	11,885,747
Cash and cash equivalents	1,021,275	1,107,922
Premiums receivable	2,753,098	1,537,188
Prepaid reinsurance premiums	1,086,027	616,185
Reinsurance recoverable	2,908,343	2,372,221
Accrued investment income	64,615	51,311
Deferred acquisition costs and value of business acquired	841,528	476,661
Receivable for investments sold	411,172	256,416
Other assets	353,543	135,127
Goodwill and other intangible assets	267,151	237,418
Total assets	24,559,600	18,676,196
Liabilities
Reserve for claims and claim expenses	8,391,484	6,076,271
Unearned premiums	3,188,678	1,716,021
Debt	1,191,499	991,127
Reinsurance balances payable	3,009,492	1,902,056
Payable for investments purchased	679,596	380,332
Other liabilities	435,418	513,609
Total liabilities	16,896,167	11,579,416
Commitments and Contingencies
Redeemable noncontrolling interests	2,109,400	2,051,700
Shareholders’ Equity
Preference shares: $1.00 par value – 16,010,000 shares issued and outstanding at March 31, 2019 (December 31, 2018 – 16,010,000)	650,000	650,000
Common shares: $1.00 par value – 44,159,375 shares issued and outstanding at March 31, 2019 (December 31, 2018 – 42,207,390)	44,159	42,207
Additional paid-in capital	543,889	296,099
Accumulated other comprehensive loss	(1,470)	(1,433)
Retained earnings	4,317,455	4,058,207
Total shareholders’ equity attributable to RenaissanceRe	5,554,033	5,045,080
Total liabilities, noncontrolling interests and shareholders’ equity	$ 24,559,600	$ 18,676,196

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturity investments trading, amortized cost	$ 9,442,370	$ 8,163,962
Preference shares, par value (In dollars per share)	$ 1	$ 1
Preference shares, shares issued (In shares)	16,010,000	16,010,000
Preference shares, shares outstanding (In shares)	16,010,000	16,010,000
Common shares, par value (In dollars per share)	$ 1	$ 1
Common shares, shares issued (In shares)	44,159,375	42,207,390
Common shares, shares outstanding (In shares)	44,159,375	42,207,390

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Gross premiums written	$ 1,564,295	$ 1,159,652
Net premiums written	929,031	663,044
Increase in unearned premiums	(379,003)	(222,762)
Net premiums earned	550,028	440,282
Net investment income	81,462	56,476
Net foreign exchange (losses) gains	(2,846)	3,757
Equity in earnings of other ventures	4,661	857
Other income (loss)	3,171	(1,242)
Net realized and unrealized gains (losses) on investments	170,645	(82,144)
Total revenues	807,121	417,986
Expenses
Net claims and claim expenses incurred	227,035	171,703
Acquisition expenses	123,951	97,711
Operational expenses	44,933	41,272
Corporate expenses	38,789	6,733
Interest expense	11,754	11,767
Total expenses	446,462	329,186
Income before taxes	360,659	88,800
Income tax (expense) benefit	(7,531)	3,407
Net income	353,128	92,207
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Net income attributable to RenaissanceRe	282,906	62,308
Dividends on preference shares	(9,189)	(5,595)
Net income available to RenaissanceRe common shareholders	$ 273,717	$ 56,713
Net income available to RenaissanceRe common shareholders per common share – basic (in dollars per share)	$ 6.43	$ 1.42
Net income available to RenaissanceRe common shareholders per common share – diluted (in dollars per share)	6.43	1.42
Dividends per common share (in dollars per share)	$ 0.34	$ 0.33

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Comprehensive income
Net income	$ 353,128	$ 92,207
Change in net unrealized losses on investments	(37)	(30)
Comprehensive income	353,091	92,177
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive income attributable to RenaissanceRe	$ 282,869	$ 62,278

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Preference shares	Common shares	Additional paid-in capital	Accumulated other comprehensive (loss) income	Retained earnings
Beginning balance at Dec. 31, 2017		$ 400,000	$ 40,024	$ 37,355	$ 224	$ 3,913,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares			0	0
Exercise of options and issuance of restricted stock awards			222	1,141
Change in redeemable noncontrolling interests				56
Change in net unrealized (losses) gains on investments					(30)
Net income	$ 92,207					92,207
Net income attributable to redeemable noncontrolling interests	(29,899)					(29,899)
Dividends on common shares	(13,200)					(13,224)
Dividends on preference shares	(5,595)					(5,595)
Ending balance at Mar. 31, 2018	4,436,253	400,000	40,246	38,552	194	3,957,261
Beginning balance at Dec. 31, 2018	5,045,080	650,000	42,207	296,099	(1,433)	4,058,207
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares			1,739	248,259
Exercise of options and issuance of restricted stock awards			213	(466)
Change in redeemable noncontrolling interests				(3)
Change in net unrealized (losses) gains on investments					(37)
Net income	353,128					353,128
Net income attributable to redeemable noncontrolling interests	(70,222)					(70,222)
Dividends on common shares	(14,500)					(14,469)
Dividends on preference shares	(9,189)
Ending balance at Mar. 31, 2019	$ 5,554,033	$ 650,000	$ 44,159	$ 543,889	$ (1,470)	$ 4,317,455

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows provided by (used in) operating activities
Net income	$ 353,128	$ 92,207
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Amortization, accretion and depreciation	(3,606)	13,740
Equity in undistributed earnings of other ventures	5,965	(314)
Net realized and unrealized (gains) losses on investments	(170,645)	82,144
Net unrealized gains included in net investment income	(2,969)	(1,465)
Change in:
Premiums receivable	(578,175)	(380,008)
Prepaid reinsurance premiums	(330,044)	(261,375)
Reinsurance recoverable	12,619	14,309
Deferred acquisition costs	(58,861)	(50,459)
Reserve for claims and claim expenses	(92,303)	(167,681)
Unearned premiums	709,046	484,137
Reinsurance balances payable	837,333	769,858
Other	(304,339)	(632,442)
Net cash provided by (used in) operating activities	377,149	(37,349)
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	4,600,808	2,318,859
Purchases of fixed maturity investments trading	(3,519,277)	(2,312,461)
Net (purchases) sales of equity investments trading	(4,601)	137
Net purchases of short term investments	(1,374,632)	(594,641)
Net purchases of other investments	(51,811)	(98,639)
Net purchases of investments in other ventures	(1,573)	(17,974)
Return of investment from investment in other ventures	11,250	0
Net purchase of the TMR Group Entities	(276,206)	0
Net cash used in investing activities	(616,042)	(704,719)
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	(14,469)	(13,224)
Dividends paid – preference shares	(9,189)	(5,595)
Drawdown of RenaissanceRe Revolving Credit Facility	200,000	0
Net third party redeemable noncontrolling interest share transactions	(16,847)	52,759
Taxes paid on withholding shares	(6,957)	(7,034)
Net cash provided by financing activities	152,538	26,906
Effect of exchange rate changes on foreign currency cash	(292)	1,543
Net decrease in cash and cash equivalents	(86,647)	(713,619)
Cash and cash equivalents, beginning of period	1,107,922	1,361,592
Cash and cash equivalents, end of period	$ 1,021,275	$ 647,973

Organization

Organization	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	ORGANIZATION This report on Form 10-Q should be read in conjunction with the RenaissanceRe’s Annual Report on Form 10-K (“Form 10-K”) for the fiscal year ended December 31, 2018 . RenaissanceRe was formed under the laws of Bermuda on June 7, 1993. Together with its wholly owned and majority-owned subsidiaries and DaVinciRe (as defined below), the Company provides property, casualty and specialty reinsurance and certain insurance solutions to its customers. • On March 22, 2019, the Company’s wholly owned subsidiary, RenaissanceRe Specialty Holdings (UK) Limited, completed its previously announced purchase of all of the share capital of Tokio Millennium Re AG (now known as RenaissanceRe Europe AG) (“RenaissanceRe Europe”), Tokio Millennium Re (UK) Limited (now known as RenaissanceRe (UK) Limited) (“RenaissanceRe UK”), and their respective subsidiaries (collectively, the “TMR Group Entities”) pursuant to a Stock Purchase Agreement by and among the Company, Tokio Marine & Nichido Fire Insurance Co. Ltd. (“Tokio”) and, with respect to certain sections only, Tokio Marine Holdings, Inc. entered into on October 30, 2018 (the “TMR Stock Purchase Agreement”) (the “TMR Stock Purchase”). See “Note 3 . Acquisition of Tokio Millennium Re” for additional information regarding the TMR Stock Purchase. • Renaissance Reinsurance, a Bermuda-domiciled reinsurance company, is the Company’s principal reinsurance subsidiary and provides property, casualty and specialty reinsurance coverages to insurers and reinsurers on a worldwide basis. • Renaissance Reinsurance U.S. Inc. (“Renaissance Reinsurance U.S.”) is a reinsurance company domiciled in the state of Maryland that provides property, casualty and specialty reinsurance coverages to insurers and reinsurers, primarily in the Americas. • RenaissanceRe Underwriting Managers U.S. LLC, a specialty reinsurance agency domiciled in the state of Connecticut, provides specialty treaty reinsurance solutions on both a quota share and excess of loss basis; and writes business on behalf of RenaissanceRe Specialty U.S. Ltd. (“RenaissanceRe Specialty U.S.”), a Bermuda-domiciled reinsurer, which operates subject to U.S. federal income tax, and RenaissanceRe Syndicate 1458 (“Syndicate 1458”). • Syndicate 1458 is the Company’s Lloyd’s syndicate. RenaissanceRe Corporate Capital (UK) Limited (“RenaissanceRe CCL”), a wholly owned subsidiary of RenaissanceRe, is Syndicate 1458’s sole corporate member and RenaissanceRe Syndicate Management Ltd. (“RSML”), a wholly owned subsidiary of RenaissanceRe, is the managing agent for Syndicate 1458. • RenaissanceRe Europe, a Swiss-domiciled reinsurance company, provides property, casualty and specialty reinsurance coverages to insurers and reinsurers on a worldwide basis. • RenaissanceRe UK, a U.K.-domiciled reinsurance company in run-off, provided property, casualty and specialty reinsurance coverages on a worldwide basis. RenaissanceRe UK was placed into run-off effective July 1, 2015, from which date all new and renewal business was written by the U.K. branch of RenaissanceRe Europe. • The Company also manages property, casualty and specialty reinsurance business written on behalf of joint ventures, which include Top Layer Reinsurance Ltd. (“Top Layer Re”), recorded under the equity method of accounting, and DaVinci Reinsurance Ltd. (“DaVinci”). Because the Company owns a noncontrolling equity interest in, but controls a majority of the outstanding voting power of DaVinci’s parent, DaVinciRe Holdings Ltd. (“DaVinciRe”), the results of DaVinci and DaVinciRe are consolidated in the Company’s consolidated financial statements and all significant intercompany transactions have been eliminated. Redeemable noncontrolling interest - DaVinciRe represents the interests of external parties with respect to the net income and shareholders’ equity of DaVinciRe. Renaissance Underwriting Managers, Ltd. (“RUM”), a wholly owned subsidiary of RenaissanceRe, acts as exclusive underwriting manager for these joint ventures in return for fee-based income and profit participation. • RenaissanceRe Medici Fund Ltd. (“Medici”) is an exempted fund, incorporated under the laws of Bermuda. Medici’s objective is to seek to invest substantially all of its assets in various insurance based investment instruments that have returns primarily tied to property catastrophe risk. Third-party investors have subscribed for a portion of the participating, non-voting common shares of Medici. Because the Company owns a noncontrolling equity interest in, but controls a majority of the outstanding voting power of Medici’s parent, RenaissanceRe Fund Holdings Ltd. (“Fund Holdings”), the results of Medici and Fund Holdings are consolidated in the Company’s consolidated financial statements and all significant inter-company transactions have been eliminated. Redeemable noncontrolling interest - Medici represents the interests of external parties with respect to the net income and shareholders’ equity of Medici. • Upsilon RFO Re Ltd., formerly known as Upsilon Reinsurance II Ltd. (“Upsilon RFO”), a Bermuda domiciled special purpose insurer (“SPI”), is a managed joint venture formed by the Company primarily to provide additional capacity to the worldwide aggregate and per-occurrence primary and retrocessional property catastrophe excess of loss market. Upsilon RFO is considered a variable interest entity (“VIE”) and the Company is considered the primary beneficiary. As a result, Upsilon RFO is consolidated by the Company and all significant inter-company transactions have been eliminated. • RenaissanceRe Upsilon Fund Ltd. (“Upsilon Fund”), an exempted Bermuda segregated accounts company, was formed by the Company to provide a fund structure through which third-party investors can invest in reinsurance risk managed by the Company. As a segregated accounts company, Upsilon Fund is permitted to establish segregated accounts to invest in and hold identified pools of assets and liabilities. Each pool of assets and liabilities in each segregated account is structured to be ring-fenced from any claims from the creditors of Upsilon Fund’s general account and from the creditors of other segregated accounts within Upsilon Fund. Third-party investors purchase redeemable, non-voting preference shares linked to specific segregated accounts of Upsilon Fund and own 100% of these shares. Upsilon Fund is an investment company and is considered a VIE. The Company is not considered the primary beneficiary of Upsilon Fund and, as a result, the Company does not consolidate the financial position and results of operations of Upsilon Fund. • Fibonacci Reinsurance Ltd. ("Fibonacci Re"), a Bermuda-domiciled SPI, was formed to provide collateralized capacity to Renaissance Reinsurance and its affiliates. Fibonacci Re raises capital from third-party investors and the Company, via private placements of participating notes which are listed on the Bermuda Stock Exchange. Fibonacci Re is considered a VIE. The Company is not considered the primary beneficiary of Fibonacci Re and, as a result, the Company does not consolidate the financial position and results of operations of Fibonacci Re. • Effective December 22, 2017, the Company and Reinsurance Group of America, Incorporated closed an initiative (“Langhorne”) to source third party capital to support reinsurers targeting large in-force life and annuity blocks. Langhorne Holdings LLC (“Langhorne Holdings”) is a company that owns and manages certain reinsurance entities within Langhorne. Langhorne Partners LLC (“Langhorne Partners”) is the general partner for Langhorne and the entity which manages the third-party investors investing into Langhorne Holdings. The Company concluded that Langhorne Holdings meets the definition of a VIE. The Company is not the primary beneficiary of Langhorne Holdings and as a result, the Company does not consolidate the financial position or results of operations of Langhorne Holdings. The Company concluded that Langhorne Partners is not a VIE. The Company will account for its investments in Langhorne Holdings and Langhorne Partners under the equity method of accounting, one quarter in arrears. • Effective December 17, 2018, the Company formed Vermeer Reinsurance Ltd. (“Vermeer”), an exempted Bermuda reinsurer, with PGGM, a Dutch pension fund manager. Vermeer provides capacity focused on risk remote layers in the U.S. property catastrophe market. Vermeer is managed by RUM in return for a management fee. The Company maintains a majority voting control of Vermeer, while PGGM retains economic benefits. Vermeer is considered a VIE, as it has voting rights that are not proportional to its participating rights and the Company is the primary beneficiary. As a result, the Company consolidates Vermeer and all significant inter-company transactions have been eliminated. The Company does not currently expect its voting or economic interest in Vermeer to fluctuate. •

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES There have been no material changes to the Company’s significant accounting policies as described in its Form 10-K for the year ended December 31, 2018 , except as noted below. BASIS OF PRESENTATION These consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the U.S. (“GAAP”) for interim financial information and in conformity with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the opinion of management, these unaudited consolidated financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation 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 from these statements. Certain comparative information has been reclassified to conform to the current presentation. Because of the seasonality of the Company’s business, the results of operations and cash flows for any interim period will not necessarily be indicative of the results of operations and cash flows for the full fiscal year or subsequent quarters. USE OF ESTIMATES IN FINANCIAL STATEMENTS The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported and disclosed amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates. The major estimates reflected in the Company’s consolidated financial statements include, but are not limited to, the reserve for claims and claim expenses; reinsurance recoverables, including allowances for reinsurance recoverables deemed uncollectible; estimates of written and earned premiums; fair value, including the fair value of investments, financial instruments and derivatives; impairment charges; and the Company’s deferred tax valuation allowance. RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases and subsequently issued a number of other ASUs to amend the guidance, each ultimately reflected in FASB Accounting Standards Codification (“ASC”) Topic Leases . FASB ASC Topic Leases requires, among other items, lessees to recognize lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under the previous guidance. FASB ASC Topic Leases was effective for public business entities for annual and interim periods beginning after December 15, 2018. The Company has adopted FASB ASC Topic Leases through the application of the modified retrospective transition approach. In addition, the Company employed certain practical expedients permitted under the guidance and utilized its incremental borrowing rate in determining the present value of lease payments, not yet paid. The adoption of this guidance did not have a material impact on the Company’s consolidated statements of operations and financial position. The Company determined it was not required to record a cumulative effect adjustment to opening retained earnings as of January 1, 2019. Intra-Entity Transfers of Assets Other Than Inventory In October 2016, the FASB issued ASU No. 2016-16, Intra-Entity Transfers of Assets Other Than Inventory (“ASU 2016-16”). ASU 2016-16 requires entities to recognize the income tax consequences of intra-entity transfers of assets other than inventory when the transfers occur; this is a change from current guidance which prohibits the recognition of current and deferred income taxes until the underlying assets have been sold to outside entities. ASU 2016-16 was effective for public business entities for annual and interim periods beginning after December 15, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated statements of operations and financial position. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS NOT YET ADOPTED Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 modifies the recognition of credit losses by replacing the incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is applicable to financial assets such as loans, debt securities, trade receivables, off-balance sheet credit exposures, reinsurance receivables, and other financial assets that have the contractual right to receive cash. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The Company's invested assets are measured at fair value through net income, and therefore those invested assets would not be impacted by the adoption of ASU 2016-13. The Company has other financial assets, such as reinsurance recoverables, that could be impacted by the adoption of ASU 2016-13. ASU 2016-13 is effective for public business entities that are SEC filers for annual and interim periods beginning after December 15, 2019. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company’s consolidated statements of operations and financial position. Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). Among other things, ASU 2017-04 requires the following: (1) the elimination of step two of the goodwill impairment test; entities will no longer utilize the implied fair value of their assets and liabilities for purposes of testing goodwill for impairment, (2) the quantitative portion of the goodwill impairment test will be performed by comparing the fair value of a reporting unit with its carrying amount; an impairment charge is to be recognized for the excess of carrying amount over fair value, but only to the extent of the amount of goodwill allocated to that reporting unit, and (3) foreign currency translation adjustments are not to be allocated to a reporting unit from an entity’s accumulated other comprehensive income; the reporting unit’s carrying amount should include only the currently translated balances of the assets and liabilities assigned to the reporting unit. ASU 2017-04 is effective for public business entities that are SEC filers for annual periods, or any interim goodwill impairment tests in annual periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company’s consolidated statements of operations and financial position. Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement

Acquisition of Tokio Millennium

Acquisition of Tokio Millennium Re	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisition of Tokio Millennium Re	ACQUISITION OF TOKIO MILLENNIUM RE Overview The aggregate consideration for the TMR Stock Purchase, which closed on March 22, 2019, was $1.6 billion , consisting of cash, RenaissanceRe common shares and a special dividend from the TMR Group Entities, as described in more detail below. The aggregate consideration paid at closing for the TMR Stock Purchase was based on the Company’s good faith estimate of the closing tangible book value of the TMR Group Entities and is subject to post-closing adjustment under the terms of the TMR Stock Purchase Agreement, which we expect to be completed no later than the third quarter of 2019. In connection with the closing of the TMR Stock Purchase, Tokio, RenaissanceRe Europe and RenaissanceRe UK entered into a reserve development agreement whereby RenaissanceRe Europe and RenaissanceRe UK agreed to cede to Tokio, and Tokio agreed to indemnify and reimburse RenaissanceRe Europe and RenaissanceRe UK for, substantially all of RenaissanceRe Europe and RenaissanceRe UK’s adverse development on stated reserves at time of the closing, including unearned premium reserves, subject to certain terms and conditions. The reserve development agreement provides the Company with indemnification on stated reserves, including unearned premium reserves, for RenaissanceRe Europe and RenaissanceRe UK, on a whole-account basis, and takes into consideration adverse performance across the Company’s reportable segments. To the extent the combined performance of acquired reserves for claims and claim expenses or unearned premiums is worse than expected on an aggregate basis across reportable segments, the Company is indemnified under the terms of the reserve development agreement and would expect to collect under the reserve development agreement. At closing, RenaissanceRe Europe and Tokio entered into a retrocessional agreement pursuant to which RenaissanceRe Europe ceded to Tokio all of its liabilities arising from certain stop loss reinsurance contracts RenaissanceRe Europe entered into with third party capital partners which were either in force as of the closing date or which incept prior to December 31, 2021. In connection with the acquisition of the TMR Group Entities, during the first quarter of 2019 , the Company recorded $25.5 million of corporate expenses associated with the acquisition, comprised of $12.9 million of transaction-related costs, $5.9 million of integration-related costs, and $6.7 million of compensation-related costs. Purchase Price The Company's total purchase price for the TMR Group Entities was calculated as follows: Special Dividend Special Dividend paid to common shareholders of Tokio and holders of Tokio equity awards $ 500,000 RenaissanceRe common shares Common shares issued by RenaissanceRe to Tokio 1,739,071 Common share price of RenaissanceRe (1) $ 143.75 Market value of RenaissanceRe common shares issued by RenaissanceRe to Tokio 249,998 Cash consideration Cash consideration paid by RenaissanceRe as acquisition consideration 813,595 Total purchase price 1,563,593 Less: Special Dividend paid to Tokio (500,000 ) Net purchase price $ 1,063,593 (1) RenaissanceRe common share price is based on the 30-day trailing volume weighted average price of $143.7539 as of market close on March 15, 2019, which approximates fair value. Fair Value of Net Assets Acquired and Liabilities Assumed The purchase price was allocated to the acquired assets and liabilities of the Company based on estimated fair values on March 22, 2019, the date the transaction closed, as detailed below. The Company recognized goodwill of $13.1 million primarily attributable to the excess of the purchase price over the fair value of the net assets of the acquired TMR Group Entities. There were no other adjustments to carried goodwill during the period ended March 31, 2019 reflected on the Company’s consolidated balance sheet at March 31, 2019. The Company recognized identifiable finite lived intangible assets of $11.2 million , which will be amortized over a weighted average period of 10.5 years , identifiable indefinite lived intangible assets of $6.8 million , and certain other adjustments to the fair values of the assets acquired, liabilities assumed and shareholders’ equity of the TMR Group Entities at March 22, 2019 as summarized in the table below: Shareholders’ equity of the TMR Group Entities at March 22, 2019 $ 1,032,961 Adjustments for fair value, by applicable balance sheet caption: Net deferred acquisition costs and value of business acquired (56,788 ) Net reserve for claims and claim expenses 67,782 Goodwill and intangible assets at March 22, 2019 of the TMR Group Entities (6,569 ) Total adjustments for fair value by applicable balance sheet caption before tax impact 4,425 Other assets - net deferred tax liability related to fair value adjustments and value of business acquired (2,606 ) Total adjustments for fair value by applicable balance sheet caption, net of tax 1,819 Adjustments for fair value of the identifiable intangible assets: Identifiable indefinite lived intangible assets (insurance licenses) 6,800 Identifiable finite lived intangible assets (top broker relationships and renewal rights) 11,200 Identifiable intangible assets before tax impact 18,000 Other assets - deferred tax liability on identifiable intangible assets (2,281 ) Total adjustments for fair value of the identifiable intangible assets and value of business acquired, net of tax 15,719 Total adjustments for fair value by applicable balance sheet caption, identifiable intangible assets and value of business acquired, net of tax 17,538 Shareholders’ equity of the TMR Group Entities at fair value 1,050,499 Total net purchase price paid by RenaissanceRe 1,063,593 Excess purchase price over the fair value of net assets acquired assigned to goodwill $ 13,094 An explanation of the significant fair value adjustments and related future amortization is as follows: • Net deferred acquisition costs and value of business acquired (“VOBA”) - to reflect the elimination of the TMR Group Entities’ net deferred acquisition costs, partially offset by the establishment of the value of business acquired asset, which represents the present value of the expected underwriting profit within the unearned premiums liability, net of reinsurance, less costs to service the related policies and a risk premium. The adjustment for VOBA will be amortized to acquisition expenses over approximately two years , as the contracts for business in-force as of the acquisition date expire. VOBA at March 22, 2019 and at March 31, 2019 was $287.6 million ; • Reserve for claims and claim expenses - to reflect a decrease related to the present value of the net unpaid claims and claim expenses based on the estimated payout pattern, partially offset by an increase in net claims and claim expenses related to the estimated market based risk margin. The risk margin represents the estimated cost of capital required by a market participant to assume the net claims and claim expenses. This will be amortized using the projected discount and risk margin patterns of the net claims and claims expenses as of the acquisition date; • Identifiable indefinite lived and finite lived intangible assets - to establish the fair value of identifiable intangible assets related to the acquisition of the TMR Group Entities described in detail below; and • Other assets - to reflect the net deferred tax liability on identifiable intangible assets. Identifiable intangible assets at March 22, 2019 and at March 31, 2019, consisted of the following, and are included in goodwill and other intangible assets on the Company’s consolidated balance sheet: Amount Economic Useful Life Top broker relationships $ 10,000 10.0 years Renewal rights 1,200 15.0 years Insurance licenses 6,800 Indefinite Net identifiable intangible assets at March 31, 2019 related to the acquisition of the TMR Group Entities $ 18,000 Amortization from the acquisition date, March 22, 2019, through March 31, 2019 was not material and, as a result, was not included in the Company's consolidated statements of operations for the three months ended March 31, 2019. An explanation of the identifiable intangible assets is as follows: • Top broker relationships - the value of the TMR Group Entities’ relationships with their top four brokers (Marsh & McLennan Companies, Inc., Aon plc, Willis Group Holdings Public Limited Company and Jardine Lloyd Thompson Group plc.) after taking into consideration the expectation of the renewal of these relationships and the associated expenses. These will be amortized on a straight-line basis over the economic useful life as of the acquisition date; • Renewal rights - the value of policy renewal rights after taking into consideration written premium on assumed retention ratios and the insurance cash flows and the associated equity cash flows from these renewal policies over the expected life of the renewals. These will be amortized on a straight-line basis over the economic useful life as of the acquisition date; and • Insurance licenses - the value of insurance licenses acquired which provide the ability to write reinsurance in all 50 states of the U.S. and the District of Columbia. As part of the allocation of the purchase price, included in the adjustment to other assets in the table above is a deferred tax liability of $2.3 million related to the estimated fair value of the intangible assets recorded, as well as a net deferred tax liability of $2.6 million related to certain other adjustments to the fair values of the assets acquired, VOBA, liabilities assumed and shareholders’ equity. Other net deferred tax liabilities recorded primarily relate to differences between financial reporting and tax bases of the acquired assets and liabilities as of the acquisition date, March 22, 2019. The Company estimates that none of the goodwill that was recorded will be deductible for income tax purposes. Financial Results The operating activities of the TMR Group Entities from the closing date, March 22, 2019, through March 31, 2019 were not material, and as a result were not included in the Company’s consolidated statements of operations for the three months ended March 31, 2019. As at March 31, 2019, the Company’s consolidated balance sheet reflects the combined entities. Taxation A net deferred tax liability of $5.7 million was established in conjunction with the acquisition of the TMR Group Entities. A valuation allowance of $35.7 million has been recorded against the TMR Group Entities deferred tax assets, a predominant amount of which was related to the Company’s U.S. operations and was recorded prior to acquisition of the TMR Group Entities. The acquisition of the TMR Group Entities had no effect on the Company’s overall income tax expense in the first quarter of 2019. In addition, the acquisition of the TMR Group Entities had no effect on the Company’s existing valuation allowance condition, as a valuation allowance continues to be provided against a substantial portion of the Company’s deferred tax assets in Ireland, the U.K., Singapore and Switzerland as these operations have produced historical GAAP taxable losses, among other facts. A small valuation allowance continues to be recorded against finite lived tax carryforwards in the U.S. operations. Supplemental Pro Forma Information The following table presents unaudited pro forma consolidated financial information for the three months ended March 31, 2019 and 2018 and assumes the acquisition of the TMR Group Entities occurred on January 1, 2018. The unaudited pro forma consolidated financial information is provided for informational purposes only and is not necessarily, and should not be assumed to be, an indication of the results that would have been achieved had the transaction been completed as of January 1, 2018 or that may be achieved in the future. The unaudited pro forma consolidated financial information does not give consideration to the impact of possible revenue enhancements, expense efficiencies, synergies or asset dispositions that may result from the acquisition of the TMR Group Entities. In addition, unaudited pro forma consolidated financial information does not include the effects of costs associated with any restructuring or integration activities resulting from the acquisition of the TMR Group Entities, as they are nonrecurring. Three months ended March 31, 2019 March 31, 2018 Total revenues $ 1,148,146 $ 725,269 Net income available to RenaissanceRe common shareholders 330,394 27,605 Among other adjustments, and in addition to the fair value adjustments and recognition of goodwill, VOBA and identifiable intangible assets noted above, other material nonrecurring pro forma adjustments directly attributable to the acquisition of the TMR Group Entities principally included certain adjustments to recognize transaction related costs, align accounting policies, and amortize fair value adjustments, VOBA, and identifiable definite lived intangible assets, net of related tax impacts. Defined Benefit Pension Plan The TMR Group Entities have a contributory defined benefit pension plan for certain employees, which was not material to RenaissanceRe’s results of operations, financial condition or cash flows. The plan offers mandatory benefits as prescribed by the applicable law, as well as voluntary benefits. The TMR Group Entities and the members of the plan contribute a defined percentage of salary to the pension arrangement. At retirement, the accumulated contributions are converted into a pension. At March 22, 2019, the net balance sheet liability was $6.1 million , comprising $21.2 million of projected benefit obligation and $15.1 million

Investments

Investments	3 Months Ended
	Mar. 31, 2019
Investments [Abstract]
Investments	INVESTMENTS Fixed Maturity Investments Trading The following table summarizes the fair value of fixed maturity investments trading: March 31, December 31, U.S. treasuries $ 3,097,089 $ 3,331,411 Agencies 182,904 174,883 Municipal 256,967 6,854 Non-U.S. government 687,021 279,818 Non-U.S. government-backed corporate 286,331 160,063 Corporate 2,971,018 2,450,244 Agency mortgage-backed 955,616 817,880 Non-agency mortgage-backed 272,880 278,680 Commercial mortgage-backed 245,323 282,294 Asset-backed 518,011 306,743 Total fixed maturity investments trading (1) $ 9,473,160 $ 8,088,870 (1) Included in total fixed maturity investments trading at March 31, 2019 was $2.2 billion of fixed maturity investments trading acquired as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Contractual maturities of fixed maturity investments trading are described in the following table. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. March 31, 2019 Amortized Cost Fair Value Due in less than one year $ 746,898 $ 744,030 Due after one through five years 5,287,434 5,301,425 Due after five through ten years 1,147,028 1,154,682 Due after ten years 281,009 281,193 Mortgage-backed 1,460,090 1,473,819 Asset-backed 519,911 518,011 Total $ 9,442,370 $ 9,473,160 Equity Investments Trading The following table summarizes the fair value of equity investments trading: March 31, December 31, Financials $ 222,604 $ 200,357 Communications and technology 66,428 42,333 Industrial, utilities and energy 37,574 24,520 Consumer 31,378 20,639 Healthcare 26,867 18,925 Basic materials 5,086 3,478 Total $ 389,937 $ 310,252 Pledged Investments At March 31, 2019 , $6.0 billion of cash and investments at fair value were on deposit with, or in trust accounts for the benefit of, various counterparties, including with respect to the Company’s letter of credit facilities ( December 31, 2018 - $5.7 billion ). Of this amount, $1.9 billion is on deposit with, or in trust accounts for the benefit of, U.S. state regulatory authorities ( December 31, 2018 - $2.0 billion ). Reverse Repurchase Agreements At March 31, 2019 , the Company held $99.9 million ( December 31, 2018 - $3.7 million ) of reverse repurchase agreements. These loans are fully collateralized, are generally outstanding for a short period of time and are presented on a gross basis as part of short term investments on the Company’s consolidated balance sheets. The required collateral for these loans typically includes high-quality, readily marketable instruments at a minimum amount of 102% of the loan principal. Upon maturity, the Company receives principal and interest income. Net Investment Income The components of net investment income are as follows: Three months ended March 31, March 31, Fixed maturity investments $ 61,483 $ 45,643 Short term investments 11,844 5,304 Equity investments 1,027 698 Other investments Private equity investments 2,454 (434 ) Other 7,245 8,023 Cash and cash equivalents 1,517 565 85,570 59,799 Investment expenses (4,108 ) (3,323 ) Net investment income $ 81,462 $ 56,476 Net Realized and Unrealized Gains (Losses) on Investments Net realized and unrealized gains (losses) on investments are as follows: Three months ended March 31, March 31, Gross realized gains $ 24,373 $ 4,583 Gross realized losses (22,943 ) (25,853 ) Net realized gains (losses) on fixed maturity investments 1,430 (21,270 ) Net unrealized gains (losses) on fixed maturity investments trading 103,922 (55,372 ) Net realized and unrealized gains (losses) on investments-related derivatives 13,796 (4,364 ) Net realized (losses) gains on equity investments trading sold during the period (1,161 ) 234 Net unrealized gains (losses) on equity investments trading still held at reporting date 52,658 (1,372 ) Net realized and unrealized gains (losses) on equity investments trading 51,497 (1,138 ) Net realized and unrealized gains (losses) on investments $ 170,645 $ (82,144 )

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The use of fair value to measure certain assets and liabilities with resulting unrealized gains or losses is pervasive within the Company’s consolidated financial statements. Fair value is defined under accounting guidance currently applicable to the Company to be the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between open market participants at the measurement date. The Company recognizes the change in unrealized gains and losses arising from changes in fair value in its consolidated statements of operations. FASB ASC Topic Fair Value Measurements and Disclosures prescribes a fair value hierarchy that prioritizes the inputs to the respective valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to valuation techniques that use at least one significant input that is unobservable (Level 3). The three levels of the fair value hierarchy are described below: • Fair values determined by Level 1 inputs utilize unadjusted quoted prices obtained from active markets for identical assets or liabilities for which the Company has access. The fair value is determined by multiplying the quoted price by the quantity held by the Company; • Fair values determined by Level 2 inputs utilize inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets and liabilities in active markets, and inputs other than quoted prices that are observable for the asset or liability, such as interest rates and yield curves that are observable at commonly quoted intervals, broker quotes and certain pricing indices; and • Level 3 inputs are based all or in part on significant unobservable inputs for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. In these cases, significant management assumptions can be used to establish management’s best estimate of the assumptions used by other market participants in determining the fair value of the asset or liability. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement of the asset or liability. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and the Company considers factors specific to the asset or liability. In order to determine if a market is active or inactive for a security, the Company considers a number of factors, including, but not limited to, the spread between what a seller is asking for a security and what a buyer is bidding for the same security, the volume of trading activity for the security in question, the price of the security compared to its par value (for fixed maturity investments), and other factors that may be indicative of market activity. There have been no material changes in the Company’s valuation techniques, nor have there been any transfers between Level 1 and Level 2, or Level 2 and Level 3 during the period represented by these consolidated financial statements. Below is a summary of the assets and liabilities that are measured at fair value on a recurring basis and also represents the carrying amount on the Company’s consolidated balance sheets: At March 31, 2019 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fixed maturity investments U.S. treasuries $ 3,097,089 $ 3,097,089 $ — $ — Agencies 182,904 — 182,904 — Municipal 256,967 — 256,967 — Non-U.S. government 687,021 — 687,021 — Non-U.S. government-backed corporate 286,331 — 286,331 — Corporate 2,971,018 — 2,971,018 — Agency mortgage-backed 955,616 — 955,616 — Non-agency mortgage-backed 272,880 — 272,880 — Commercial mortgage-backed 245,323 — 245,323 — Asset-backed 518,011 — 518,011 — Total fixed maturity investments 9,473,160 3,097,089 6,376,071 — Short term investments 4,012,815 — 4,012,815 — Equity investments trading 389,937 389,937 — — Other investments Catastrophe bonds 556,380 — 556,380 — Private equity investments (1) 253,566 — — 63,695 Senior secured bank loan funds (1) 15,674 — — — Hedge funds (1) 11,585 — — — Miscellaneous other investments (1) 41,168 — — — Total other investments 878,373 — 556,380 63,695 Other assets and (liabilities) Assumed and ceded (re)insurance contracts (2) 11,827 — — 11,827 Derivatives (3) 5,817 (2,067 ) 7,884 — Total other assets and (liabilities) 17,644 (2,067 ) 7,884 11,827 $ 14,771,929 $ 3,484,959 $ 10,953,150 $ 75,522 (1) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (2) Included in assumed and ceded (re)insurance contracts at March 31, 2019 was $47.6 million of other assets and $35.8 million of other liabilities. Of these amounts, $41.7 million of other assets and $21.7 million of other liabilities was reflected as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (3) See “Note 14 . Derivative Instruments” for additional information related to the fair value by type of contract, of derivatives entered into by the Company. At December 31, 2018 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fixed maturity investments U.S. treasuries $ 3,331,411 $ 3,331,411 $ — $ — Agencies 174,883 — 174,883 — Municipal 6,854 — 6,854 — Non-U.S. government 279,818 — 279,818 — Non-U.S. government-backed corporate 160,063 — 160,063 — Corporate 2,450,244 — 2,450,244 — Agency mortgage-backed 817,880 — 817,880 — Non-agency mortgage-backed 278,680 — 278,680 — Commercial mortgage-backed 282,294 — 282,294 — Asset-backed 306,743 — 306,743 — Total fixed maturity investments 8,088,870 3,331,411 4,757,459 — Short term investments 2,586,520 — 2,586,520 — Equity investments trading 310,252 310,252 — — Other investments Catastrophe bonds 516,571 — 516,571 — Private equity investments (1) 242,647 — — 54,545 Senior secured bank loan funds (1) 14,482 — — — Hedge funds (1) 11,233 — — — Total other investments 784,933 — 516,571 54,545 Other assets and (liabilities) Assumed and ceded (re)insurance contracts (2) (8,359 ) — — (8,359 ) Derivatives (3) 12,399 484 11,915 — Total other assets and (liabilities) 4,040 484 11,915 (8,359 ) $ 11,774,615 $ 3,642,147 $ 7,872,465 $ 46,186 (1) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (2) Included in assumed and ceded (re)insurance contracts at December 31, 2018 was $5.0 million of other assets and $13.3 million of other liabilities. (3) See “Note 14 . Derivative Instruments” for additional information related to the fair value by type of contract, of derivatives entered into by the Company. Level 1 and Level 2 Assets and Liabilities Measured at Fair Value Fixed Maturity Investments Fixed maturity investments included in Level 1 consist of the Company’s investments in U.S. treasuries. Fixed maturity investments included in Level 2 are agencies, municipal, non-U.S. government, non-U.S. government-backed corporate, corporate, agency mortgage-backed, non-agency mortgage-backed, commercial mortgage-backed and asset-backed. The Company’s fixed maturity investments are primarily priced using pricing services, such as index providers and pricing vendors, as well as broker quotations. In general, the pricing vendors provide pricing 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. Observable inputs include benchmark yields, reported trades, broker-dealer quotes, issuer spreads, bids, offers, reference data and industry and economic events. Index pricing generally relies on market traders as the primary source for pricing; however, models are also utilized to provide prices for all index eligible securities. The models use a variety of observable inputs such as benchmark yields, transactional data, dealer runs, broker-dealer quotes and corporate actions. 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 broker quotations to be 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. treasuries Level 1 - At March 31, 2019 , the Company’s U.S. treasuries fixed maturity investments were primarily priced by pricing services and had a weighted average yield to maturity of 2.3% and a weighted average credit quality of AA ( December 31, 2018 - 2.5% and AA, respectively). When pricing these securities, the pricing services utilize daily data from many real time market sources, including active broker dealers. Certain data sources are regularly reviewed for accuracy to attempt to ensure the most reliable price source is used for each issue and maturity date. Agencies Level 2 - At March 31, 2019 , the Company’s agency fixed maturity investments had a weighted average yield to maturity of 2.8% and a weighted average credit quality of AA ( December 31, 2018 - 3.0% and AA, respectively). The issuers of the Company’s agency fixed maturity investments primarily consist of the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and other agencies. Fixed maturity investments included in agencies 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. Municipal Level 2 - At March 31, 2019 , the Company’s municipal fixed maturity investments had a weighted average yield to maturity of 3.4% and a weighted average credit quality of AA ( December 31, 2018 - 4.8% and A, respectively). The Company’s municipal fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information regarding the security from third-party sources such as trustees, paying agents or issuers. 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 over widely accepted market benchmarks. Non-U.S. government Level 2 - At March 31, 2019 , the Company’s non-U.S. government fixed maturity investments had a weighted average yield to maturity of 1.6% and a weighted average credit quality of AA ( December 31, 2018 - 2.7% and AAA, respectively). The issuers of securities in this sector are non-U.S. governments and their respective agencies as well as supranational organizations. Securities held in these sectors are primarily priced by pricing services that 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. Non-U.S. government-backed corporate Level 2 - At March 31, 2019 , the Company’s non-U.S. government-backed corporate fixed maturity investments had a weighted average yield to maturity of 2.1% and a weighted average credit quality of AA ( December 31, 2018 - 2.8% and AA, respectively). Non-U.S. government-backed corporate fixed maturity investments are primarily priced by pricing services that 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 to the respective curve 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. Corporate Level 2 - At March 31, 2019 , the Company’s corporate fixed maturity investments principally consisted of U.S. and international corporations and had a weighted average yield to maturity of 3.6% and a weighted average credit quality of A ( December 31, 2018 - 4.9% and BBB, respectively). 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. Agency mortgage-backed Level 2 - At March 31, 2019 , the Company’s agency mortgage-backed fixed maturity investments included agency residential mortgage-backed securities with a weighted average yield to maturity of 3.1% , a weighted average credit quality of AA and a weighted average life of 5.9 years ( December 31, 2018 - 3.5% , AA and 7.1 years, respectively). The Company’s agency mortgage-backed fixed maturity investments are primarily priced by pricing services using a mortgage pool specific model which utilizes daily inputs from the active to be announced 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. Non-agency mortgage-backed Level 2 - The Company’s non-agency mortgage-backed fixed maturity investments include non-agency prime, non-agency Alt-A and other non-agency residential mortgage-backed securities. At March 31, 2019 , the Company’s non-agency prime residential mortgage-backed fixed maturity investments had a weighted average yield to maturity of 4.2% , a weighted average credit quality of non-investment grade, and a weighted average life of 5.3 years ( December 31, 2018 - 4.4% , non-investment grade and 4.7 years, respectively). The Company’s non-agency Alt-A fixed maturity investments held at March 31, 2019 had a weighted average yield to maturity of 4.2% , a weighted average credit quality of non-investment grade and a weighted average life of 6.8 years ( December 31, 2018 - 4.7% , non-investment grade and 6.3 years, respectively). 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. Commercial mortgage-backed Level 2 - At March 31, 2019 , the Company’s commercial mortgage-backed fixed maturity investments had a weighted average yield to maturity of 3.2% , a weighted average credit quality of AAA, and a weighted average life of 4.6 years ( December 31, 2018 - 3.6% , AAA and 5.0 years, respectively). 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 discount the expected cash flows for each security held in this sector using a spread adjusted benchmark yield based on the characteristics of the security. Asset-backed Level 2 - At March 31, 2019 , the Company’s asset-backed fixed maturity investments had a weighted average yield to maturity of 3.8% , a weighted average credit quality of AAA and a weighted average life of 3.2 years ( December 31, 2018 - 4.3% , AAA and 3.2 years, respectively). The underlying collateral for the Company’s asset-backed fixed maturity investments primarily consists of bank loans, student loans, credit card receivables, auto loans and other receivables. 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. Short Term Investments Level 2 - At March 31, 2019 , the Company’s short term investments had a weighted average yield to maturity of 2.1% and a weighted average credit quality of AAA ( December 31, 2018 - 2.1% and AAA, respectively). The fair value of the Company’s portfolio of short term investments is generally determined using amortized cost which approximates fair value and, in certain cases, in a manner similar to the Company’s fixed maturity investments noted above. Equity Investments, Classified as Trading Level 1 - The fair value of the Company’s portfolio of equity investments, classified as trading is primarily priced by pricing services, reflecting the closing price quoted for the final trading day of the period. When pricing these securities, the pricing services utilize daily data from many real time market sources, including applicable securities exchanges. All data sources are regularly reviewed for accuracy to attempt to ensure the most reliable price source was used for each security. Other investments Catastrophe bonds Level 2 - The Company’s other investments include investments in catastrophe bonds which are recorded at fair value based on broker or underwriter bid indications. Other assets and liabilities Derivatives Level 1 and Level 2 - Other assets and liabilities include certain derivatives entered into by the Company. The fair value of these transactions includes certain exchange traded futures contracts which are considered Level 1, and foreign currency contracts and certain credit derivatives, determined using standard industry valuation models and considered Level 2, as the inputs to the valuation model are based on observable market inputs. For credit derivatives, these inputs include credit spreads, credit ratings of the underlying referenced security, the risk free rate and the contract term. For foreign currency contracts, these inputs include spot rates and interest rate curves. Level 3 Assets and Liabilities Measured at Fair Value Below is a summary of quantitative information regarding the significant unobservable inputs (Level 3) used in determining the fair value of assets and liabilities measured at fair value on a recurring basis: At March 31, 2019 Fair Value (Level 3) Valuation Technique Unobservable Low High Weighted Average or Actual Other investments Private equity investment $ 10,174 External valuation model Indicative pricing n/a n/a $ 101.74 Private equity investments 53,521 Internal valuation model Liquidity discount n/a n/a 12.5 % Total other investments 63,695 Other assets and (liabilities) Assumed and ceded (re)insurance contracts 523 Internal valuation model Bond price $ 100.64 $ 107.97 $ 104.71 Liquidity discount n/a n/a 1.3 % Assumed and ceded (re)insurance contracts (8,356 ) Internal valuation model Net undiscounted cash flows n/a n/a $ 10,413 Expected loss ratio n/a n/a 39.5 % Discount rate n/a n/a 2.2 % Assumed and ceded (re)insurance contracts 19,660 Internal valuation model Expected loss ratio n/a n/a 0.0 % Total other assets and (liabilities) 11,827 Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs $ 75,522 Below is a reconciliation of the beginning and ending balances, for the periods shown, of assets and liabilities measured at fair value on a recurring basis using Level 3 inputs. Interest and dividend income are included in net investment income and are excluded from the reconciliation. Other investments Other assets and (liabilities) Total Balance - January 1, 2019 $ 54,545 $ (8,359 ) $ 46,186 Total realized and unrealized gains Included in other income (loss) (1,111 ) 1,093 (18 ) Total foreign exchange losses (1 ) — (1 ) Purchases 10,262 (897 ) 9,365 Settlements — 20 20 Amounts acquired (1) — 19,970 19,970 Balance - March 31, 2019 $ 63,695 $ 11,827 $ 75,522 (1) Represents the fair value of the other assets acquired from the TMR Group Entities, measured at fair value on a recurring basis using Level 3 inputs at March 22, 2019. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Other assets and (liabilities) Balance - January 1, 2018 $ (2,952 ) Total realized and unrealized gains Included in other income (loss) 206 Purchases (34 ) Balance - March 31, 2018 $ (2,780 ) Other investments Private equity investments Level 3 - At March 31, 2019 , the Company’s other investments included a $10.2 million private equity investment which is recorded at fair value, with the fair value obtained through the receipt of an indicative pricing obtained from the insurance manager of the security. The Company considers the price obtained to be unobservable, as there is little, if any, market activity for this security. This unobservable input in isolation can cause significant increases or decreases in fair value. Generally, an increase in the indicative pricing would result in an increase in the fair value of this private equity investment. Level 3 - At March 31, 2019 , the Company’s other investments included $53.5 million of private equity investments which are recorded at fair value, with the fair value obtained through the use of internal valuation models. The Company measured the fair value of these investments using multiples of net tangible book value of the underlying entity. The significant unobservable inputs used in the fair value measurement of these investments are liquidity discount rates applied to each of the net tangible book value multiples used in the internal valuation models. These unobservable inputs in isolation can cause significant increases or decreases in fair value. The discount rates are applied to each of the comparable net tangible book value multiples which are used to determine fair value. The comparable net tangible book value multiples are observable and based on the trading multiples of public industry peers of the underlying entity. Generally, an increase in the liquidity discount rate would result in a decrease in the fair value of this private equity investment. Other assets and liabilities Assumed and ceded (re)insurance contracts Level 3 - At March 31, 2019 , the Company had a $0.5 million net asset related to an assumed reinsurance contract accounted for at fair value, with the fair value obtained through the use of an internal valuation model. The inputs to the internal valuation model are principally based on indicative pricing obtained from independent brokers and pricing vendors for similarly structured marketable securities. The most significant unobservable inputs include prices for similar marketable securities and a liquidity premium. The Company considers the prices for similar securities to be unobservable, as there is little, if any market activity for these similar assets. In addition, the Company has estimated a liquidity premium that would be required if the Company attempted to effectively exit its position by executing a short sale of these securities. Generally, an increase in the prices for similar marketable securities or a decrease in the liquidity premium would result in an increase in the expected profit and ultimate fair value of this assumed reinsurance contract. Level 3 - At March 31, 2019 , the Company had a $8.4 million net liability related to assumed and ceded (re)insurance contracts accounted for at fair value, with the fair value obtained through the use of an internal valuation model. The inputs to the internal valuation model are principally based on proprietary data as observable market inputs are generally not available. The most significant unobservable inputs include the assumed and ceded expected net cash flows related to the contracts, including the expected premium, acquisition expenses and losses; the expected loss ratio and the relevant discount rate used to present value the net cash flows. The contract period and acquisition expense ratio are considered an observable input as each is defined in the contract. Generally, an increase in the net expected cash flows and expected term of the contract and a decrease in the discount rate, expected loss ratio or acquisition expense ratio, would result in an increase in the expected profit and ultimate fair value of these assumed and ceded (re)insurance contracts. Level 3 - At March 31, 2019 , the Company had a $19.7 million net asset related to assumed and ceded (re)insurance contracts accounted for at fair value, with the fair value obtained through the use of internal valuation models. The inputs to the models are primarily based on the unexpired period of risk and an evaluation of the probability of loss. The fair value of the contracts are sensitive to loss-triggering events. In the event of a loss, the Company would adjust the fair value of the contract to account for a recovery or liability in accordance with the contract terms and the estimate of exposure under the contract. The inputs for the contracts are based on management’s evaluation and are unobservable. Financial Instruments Disclosed, But Not Carried, at Fair Value The Company uses various financial instruments in the normal course of its business. The Company’s insurance contracts are excluded from the fair value of financial instruments accounting guidance, unless the Company elects the fair value option, and therefore, are not included in the amounts discussed herein. The carrying values of cash and cash equivalents, accrued investment income, receivables for investments sold, certain other assets, payables for investments purchased, certain other liabilities, and other financial instruments not included herein approximated their fair values. Debt Included on the Company’s consolidated balance sheet at March 31, 2019 were debt obligations of $1.2 billion ( December 31, 2018 - $991.1 million ). At March 31, 2019 , the Company’s debt obligations included $200.0 million outstanding under the Company’s revolving credit facility. See “Note 8 . Debt and Credit Facilities” for additional information regarding the revolving credit facility. At March 31, 2019 , the fair value of the Company’s debt obligations was $1.2 billion ( December 31, 2018 – $974.7 million ). The fair value of the Company’s debt obligations is determined using indicative market pricing obtained from third-party service providers, which the Company considers Level 2 in the fair value hierarchy. There have been no changes during the period in the Company’s valuation technique used to determine the fair value of the Company’s debt obligations. The Fair Value Option for Financial Assets and Financial Liabilities The Company has elected to account for certain financial assets and financial liabilities at fair value using the guidance under FASB ASC Topic Financial Instruments as the Company believes it represents the most meaningful measurement basis for these assets and liabilities. Below is a summary of the balances the Company has elected to account for at fair value: March 31, December 31, Other investments $ 878,373 $ 784,933 Other assets $ 47,596 $ 4,968 Other liabilities $ 35,769 $ 13,327 Included in net investment income for the three months ended March 31, 2019 were net unrealized gains of $3.0 million , related to the changes in fair value of other investments ( 2018 – gains of $1.5 million ). Included in other income (loss) for the three months ended March 31, 2019 were net unrealized gains of $Nil related to the changes in the fair value of other assets and liabilities ( 2018 - $Nil ). Measuring the Fair Value of Other Investments Using Net Asset Valuations The table below shows the Company’s portfolio of other investments measured using net asset valuations as a practical expedient: At March 31, 2019 Fair Value Unfunded Redemption Frequency Redemption Redemption Private equity investments $ 189,871 $ 381,143 See below See below See below Senior secured bank loan funds 15,674 17,209 See below See below See below Hedge funds 11,585 — See below See below See below Miscellaneous other investments 41,168 — See below See below See below Total other investments measured using net asset valuations $ 258,298 $ 398,352 Private equity investments – A significant portion of the Company’s investments in private equity investments include alternative asset limited partnerships (or similar corporate structures) that invest in certain private equity asset classes including U.S. and global leveraged buyouts, mezzanine investments, distressed securities, real estate, and oil, gas and power. The Company generally has no right to redeem its interest in any of these private equity investments in advance of dissolution of the applicable private equity investment. Instead, the nature of these investm

Reinsurance

Reinsurance	3 Months Ended
	Mar. 31, 2019
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Reinsurance	REINSURANCE The Company purchases reinsurance and other protection to manage its risk portfolio and to reduce its exposure to large losses. The Company currently has in place contracts that provide for recovery of a portion of certain claims and claim expenses, generally in excess of various retentions or on a proportional basis. In addition to loss recoveries, certain of the Company’s ceded reinsurance contracts provide for payments of additional premiums, for reinstatement premiums and for lost no-claims bonuses, which are incurred when losses are ceded to the respective reinsurance contracts. The Company remains liable to the extent that any reinsurer fails to meet its obligations. The following table sets forth the effect of reinsurance and retrocessional activity on premiums written and earned and on net claims and claim expenses incurred: Three months ended March 31, March 31, Premiums written Direct $ 110,968 $ 85,167 Assumed 1,453,327 1,074,485 Ceded (635,264 ) (496,608 ) Net premiums written $ 929,031 $ 663,044 Premiums earned Direct $ 89,814 $ 70,032 Assumed 765,433 605,483 Ceded (305,219 ) (235,233 ) Net premiums earned $ 550,028 $ 440,282 Claims and claim expenses Gross claims and claim expenses incurred $ 338,119 $ 225,742 Claims and claim expenses recovered (111,084 ) (54,039 ) Net claims and claim expenses incurred $ 227,035 $ 171,703 At March 31, 2019 , the Company’s reinsurance recoverable balance was $2.9 billion ( December 31, 2018 - $2.4 billion ). Included in the Company’s reinsurance recoverable balance at March 31, 2019 is $548.7 million of reinsurance recoverable acquired as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Of the Company’s reinsurance recoverable balance at March 31, 2019 , 65.8% is fully collateralized by our reinsurers, 32.1% is recoverable from reinsurers rated A- or higher by major rating agencies and 2.1% is recoverable from reinsurers rated lower than A- by major rating agencies ( December 31, 2018 - 60.8% , 38.0% and 1.2% , respectively). The reinsurers with the three largest balances accounted for 12.0% , 6.9% and 6.5% , respectively, of the Company’s reinsurance recoverable balance at March 31, 2019 ( December 31, 2018 - 15.5% , 6.7% and 6.5% , respectively). The valuation allowance recorded against reinsurance recoverable was $8.5 million at March 31, 2019 ( December 31, 2018 - $9.0 million ). The impact of the acquisition of the TMR Group Entities on the Company’s valuation allowance from the acquisition date, March 22, 2019, through March 31, 2019 was not material and as a result was not reflected in the Company’s consolidated statements of operations and financial position for the quarter ended March 31, 2019. The three largest company-specific components of the valuation allowance represented 17.6% , 13.2% and 12.0% , respectively, of the Company’s total valuation allowance at March 31, 2019 ( December 31, 2018 - 16.2% , 14.8% and 12.3%

Reserve for Claims and Claim Ex

Reserve for Claims and Claim Expenses	3 Months Ended
	Mar. 31, 2019
Insurance Loss Reserves [Abstract]
Reserve for Claims and Claim Expenses	RESERVE FOR CLAIMS AND CLAIM EXPENSES The Company believes the most significant accounting judgment made by management is its estimate of claims and claim expense reserves. Claims and claim expense reserves represent estimates, including actuarial and statistical projections at a given point in time, of the ultimate settlement and administration costs for unpaid claims and claim expenses arising from the insurance and reinsurance contracts the Company sells. The Company establishes its claims and claim expense reserves by taking claims reported to the Company by insureds and ceding companies, but which have not yet been paid (“case reserves”), adding estimates for the anticipated cost of claims incurred but not yet reported to the Company, or incurred but not enough reported to the Company (collectively referred to as “IBNR”) and, if deemed necessary, adding costs for additional case reserves which represent the Company’s estimates for claims related to specific contracts previously reported to the Company which it believes may not be adequately estimated by the client as of that date, or adequately covered in the application of IBNR. The following table summarizes the Company’s claims and claim expense reserves by segment, allocated between case reserves, additional case reserves and IBNR: At March 31, 2019 Case Reserves Additional Case Reserves IBNR Total Property $ 1,243,455 $ 1,598,283 $ 844,681 $ 3,686,419 Casualty and Specialty 1,454,164 121,165 3,125,166 4,700,495 Other 1,404 — 3,166 4,570 Total (1) $ 2,699,023 $ 1,719,448 $ 3,973,013 $ 8,391,484 At December 31, 2018 Property $ 690,718 $ 1,308,307 $ 1,087,229 $ 3,086,254 Casualty and Specialty 771,537 116,877 2,096,979 2,985,393 Other 1,458 — 3,166 4,624 Total $ 1,463,713 $ 1,425,184 $ 3,187,374 $ 6,076,271 (1) Included in the Company’s reserves for claims and claim expenses balance at March 31, 2019 is $2.4 billion of gross reserves for claims and claim expenses, at fair value, acquired as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Activity in the liability for unpaid claims and claim expenses is summarized as follows: Three months ended March 31, 2019 2018 Net reserves as of January 1 $ 3,704,050 $ 3,493,778 Net incurred related to: Current year 231,341 203,038 Prior years (4,306 ) (31,335 ) Total net incurred 227,035 171,703 Net paid related to: Current year 8,149 9,050 Prior years 300,120 328,129 Total net paid 308,269 337,179 Amounts acquired (1) 1,858,775 — Foreign exchange 1,550 12,104 Net reserves as of March 31 5,483,141 3,340,406 Reinsurance recoverable as of March 31 2,908,343 1,572,321 Gross reserves as of March 31 $ 8,391,484 $ 4,912,727 (1) Represents the fair value of the TMR Group Entities reserves for claims and claim expenses, net of reinsurance recoverables, acquired at March 22, 2019. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Prior Year Development of the Reserve for Net Claims and Claim Expenses The Company’s estimates of claims and claim expense reserves are not precise in that, among other things, they are based on predictions of future developments and estimates of future trends and other variable factors. Some, but not all, of the Company’s reserves are further subject to the uncertainty inherent in actuarial methodologies and estimates. Because a reserve estimate is simply an insurer’s estimate at a point in time of its ultimate liability, and because there are numerous factors that affect reserves and claims payments that cannot be determined with certainty in advance, the Company’s ultimate payments will vary, perhaps materially, from its estimates of reserves. If the Company determines in a subsequent period that adjustments to its previously established reserves are appropriate, such adjustments are recorded in the period in which they are identified. On a net basis, the Company’s cumulative favorable or unfavorable development is generally reduced by offsetting changes in its reinsurance recoverables, as well as changes to loss related premiums such as reinstatement premiums and redeemable noncontrolling interest for changes in claims and claim expenses that impact DaVinciRe, all of which generally move in the opposite direction to changes in the Company’s ultimate claims and claim expenses. The following table details the Company’s prior year development by segment of its liability for unpaid claims and claim expenses: Three months ended March 31, 2019 2018 (Favorable) adverse development (Favorable) adverse development Property $ 1,877 $ (27,562 ) Casualty and Specialty (6,202 ) (3,791 ) Other 19 18 Total favorable development of prior accident years net claims and claim expenses $ (4,306 ) $ (31,335 ) Changes to prior year estimated claims reserves increased the Company’s net income by $4.3 million during the three months ended March 31, 2019 , ( 2018 - increased the Company’s net income by $31.3 million ), excluding the consideration of changes in reinstatement, adjustment or other premium items, profit commissions, redeemable noncontrolling interest - DaVinciRe and income tax. Property Segment The following tables detail the development of the Company’s liability for unpaid claims and claim expenses for its Property segment, allocated between large and small catastrophe net claims and claim expenses and attritional net claims and claim expenses, included in the other line item: Three months ended March 31, 2019 (Favorable) adverse development Catastrophe net claims and claim expenses Large catastrophe events 2017 Large Loss Events $ (10,918 ) Other (1,374 ) Total large catastrophe events (12,292 ) Small catastrophe events and attritional loss movements Other small catastrophe events and attritional loss movements 14,169 Total small catastrophe events and attritional loss movements 14,169 Total net adverse development of prior accident years net claims and claim expenses $ 1,877 The net adverse development of prior accident years net claims and claim expenses within the Company’s Property segment in the three months ended March 31, 2019 of $1.9 million was comprised of net favorable development of $12.3 million related to large catastrophe events and net adverse development of $14.2 million related to small catastrophe events. Included in net favorable development of prior accident years net claims and claim expenses from large events was $10.9 million of net decreases in the estimated ultimate losses associated with Hurricanes Harvey, Irma and Maria, the Mexico City Earthquake, the wildfires in California during the fourth quarter of 2017 and certain losses associated with aggregate loss contracts (collectively, the “ 2017 Large Loss Events ”). The Company’s Property segment also experienced net adverse development of $14.2 million associated number of other small catastrophe events and attritional loss movements primarily driven by increases in the estimated ultimate net claims and claim expenses within the Company’s other property class of business. Three months ended March 31, 2018 (Favorable) adverse development Catastrophe net claims and claim expenses Large catastrophe events 2017 Large Loss Events $ (27,109 ) Other (4,258 ) Total large catastrophe events (31,367 ) Small catastrophe events and attritional loss movements Other small catastrophe events and attritional loss movements 3,805 Total small catastrophe events and attritional loss movements 3,805 Total net favorable development of prior accident years net claims and claim expenses $ (27,562 ) The net favorable development of prior accident years net claims and claim expenses within the Company’s Property segment in the three months ended March 31, 2018 of $27.6 million was comprised of net favorable development of $31.4 million related to large catastrophe events and net adverse development of $3.8 million related to small catastrophe events. Included in net favorable development of prior accident years net claims and claim expenses from large events was $27.1 million of net decreases in the estimated ultimate losses associated with Hurricanes Harvey, Irma and Maria, the Mexico City Earthquake, the wildfires in California during the fourth quarter of 2017 and certain losses associated with aggregate loss contracts (collectively, the “ 2017 Large Loss Events ”). In addition, the Company’s Property segment experienced net favorable development of $0.5 million associated with a number of other large and small catastrophe events. Casualty and Specialty Segment The following table details the development of the Company’s liability for unpaid claims and claim expenses for its Casualty and Specialty segment: Three months ended March 31, 2019 2018 (Favorable) adverse development (Favorable) adverse development Actuarial methods $ (6,202 ) $ (3,791 ) Total favorable development of prior accident years net claims and claim expenses $ (6,202 ) $ (3,791 ) The net favorable development of prior accident years net claims and claim expenses within the Company’s Casualty and Specialty segment was $6.2 million and $3.8 million in the three months ended March 31, 2019

Debt and Credit Facilities

Debt and Credit Facilities	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt and Credit Facilities	DEBT AND CREDIT FACILITIES Except as noted below, there have been no material changes to the Company’s debt obligations and credit facilities as described in its Form 10-K for the year ended December 31, 2018 . Debt Obligations A summary of the Company’s debt obligations on its consolidated balance sheets is set forth below: March 31, 2019 December 31, 2018 Fair Value Carrying Value Fair Value Carrying Value 3.450% Senior Notes due 2027 294,450 295,920 283,680 295,797 3.700% Senior Notes due 2025 297,801 297,779 292,557 297,688 5.750% Senior Notes due 2020 256,055 249,683 255,938 249,602 4.750% Senior Notes due 2025 (DaVinciRe) (1) 145,671 148,117 142,539 148,040 Total senior notes 993,977 991,499 974,714 991,127 RenaissanceRe Revolving Credit Facility (2) 200,000 200,000 — — Total debt $ 1,193,977 $ 1,191,499 $ 974,714 $ 991,127 (1) RenaissanceRe owns a noncontrolling economic interest in its joint venture DaVinciRe. Because RenaissanceRe controls a majority of DaVinciRe’s outstanding voting rights, the consolidated financial statements of DaVinciRe are included in the consolidated financial statements of RenaissanceRe. However, RenaissanceRe does not guarantee or provide credit support for DaVinciRe and RenaissanceRe’s financial exposure to DaVinciRe is limited to its investment in DaVinciRe’s shares and counterparty credit risk arising from reinsurance transactions. (2) The drawn amount of the Company’s revolving credit facility is included on the Company’s consolidated balance sheets under debt and is also included in the table below as part of the Company’s significant credit facilities. The amount was drawn in connection with the TMR Stock Purchase. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the TMR Stock Purchase. 3.600% Senior Notes Due 2029 On April 2, 2019, the Company issued $400.0 million of its 3.600% Senior Notes due April 15, 2029 . The net proceeds from this offering were used to repay, in full, the $200.0 million outstanding under the Company’s revolving credit facility at March 31, 2019, which the Company used to partially fund the purchase price for the TMR Stock Purchase, and the remainder of the net proceeds will be used for general corporate purposes. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information regarding the acquisition of the TMR Group Entities and “Note 17 . Subsequent Events” for additional information regarding the issuance, subsequent to March 31, 2019, of the Company’s 3.600% Senior Notes Due 2029. Credit Facilities The outstanding amounts issued or drawn under each of the Company’s significant credit facilities is set forth below: At March 31, 2019 Issued or Drawn RenaissanceRe Revolving Credit Facility (1) $ 200,000 Uncommitted Standby Letter of Credit Facility with Wells Fargo 32,009 Secured Letter of Credit Facility with Citibank Europe 238,956 Renaissance Reinsurance FAL Facility 255,000 Mizuho Letters of Credit (2) 385,975 Mitsubishi Letters of Credit (2) 205,956 Credit Suisse Letter of Credit Facility 75,097 Uncommitted, Unsecured Letter of Credit Facility with Citibank Europe (3) — Total credit facilities in U.S. dollars $ 1,392,993 Specialty Risks FAL Facility (3) £ — Total credit facilities in pound sterling £ — (1) The drawn amount of the Company’s revolving credit facility is included on the Company’s consolidated balance sheet under debt and is also included in the table above as part of the Company’s significant credit facilities. The amount was drawn as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (2) These letters of credit were transferred to the Company in connection with the acquisition of the TMR Group Entities. See below under “TMR Group Entities Letters of Credit” for additional information and “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (3) At March 31, 2019 , no amounts were issued or drawn under these facilities . Uncommitted, Unsecured Letter of Credit Facility with Citibank Europe On March 22, 2019, Renaissance Reinsurance, RenaissanceRe Specialty U.S., Renaissance Reinsurance U.S. and RenaissanceRe Europe and Citibank Europe Plc (“CEP”) entered into a Master Agreement for Issuance of Payment Instruments (the “Master Agreement”) and a Facility Letter for Issuance of Payment Instruments (the “Facility Letter” and, together with the Master Agreement, the “Citi Unsecured Facility”). On April 26, 2019, RenaissanceRe UK Limited (together with Renaissance Reinsurance, RenaissanceRe Specialty U.S., Renaissance Reinsurance U.S. and RenaissanceRe Europe, the “Citi Unsecured Applicants”) became a party to the Citi Unsecured Facility. The Citi Unsecured Facility is an uncommitted, unsecured letter of credit facility pursuant to which CEP or one of its correspondents may issue standby letters of credit or similar instruments in multiple currencies for the account of one or more of the Citi Unsecured Applicants. The obligations of the Citi Unsecured Applicants under the Citi Unsecured Facility are guaranteed by the Company. In the Master Agreement, each Citi Unsecured Applicant makes representations and warranties that are customary for facilities of this type and agrees that it will comply with certain informational and other customary undertakings. The Master Agreement contains events of default customary for facilities of this type. In the case of an event of default under the Citi Unsecured Facility, CEP may exercise certain remedies, including requiring that the relevant Citi Unsecured Applicant pledge cash collateral in an amount equal to the maximum actual and contingent liability of the issuing bank under the letters of credit and similar instruments issued for such Citi Unsecured Applicant under the Citi Unsecured Facility , and taking certain actions with respect to the collateral pledged by such Citi Unsecured Applicant (including the sale thereof). In addition, CEP may require that the relevant Citi Unsecured Applicant pledge cash collateral if certain minimum ratings are not satisfied. Credit Suisse Letter of Credit Facility On March 22, 2019, RenaissanceRe Europe, the Company and Credit Suisse (Switzerland) Ltd. (“CS”) entered into an amended and restated letter of credit facility agreement (the “CS A&R LC Agreement”). The CS A&R LC Agreement is a $125 million committed, unsecured letter of credit facility pursuant to which CS (or any other fronting bank acting on behalf of CS) may issue letters of credit or similar instruments in multiple currencies for the account of RenaissanceRe Europe. The obligations of RenaissanceRe Europe under the CS A&R LC Agreement are guaranteed by the Company. In the CS A&R LC Agreement, RenaissanceRe Europe and the Company make representations, warranties and covenants that are customary for facilities of this type, and agree to comply with certain informational and other customary undertakings. The CS A&R LC Agreement also contains certain financial covenants applicable to the Company, including the requirement to maintain the ratio of consolidated debt to capital of not more than 0.35 :1, to maintain a minimum consolidated net worth initially of approximately $3.0 billion , subject to an annual adjustment, and to maintain the Company’s credit rating with S&P and A.M. Best of at least A-. The CS A&R LC Agreement contains events of default customary for facilities of this type. At any time on or after the occurrence of an event of default, CS may exercise remedies, including canceling the commitment, requiring that RenaissanceRe Europe pledge cash collateral in an amount equal to the maximum liability of the issuing bank under the letters of credit and similar instruments issued under the CS A&R LC Agreement, and demanding that RenaissanceRe Europe procure the release by the beneficiaries of the letters of credit and similar instruments issued under the CS A&R LC Agreement. Renaissance Reinsurance Funds at Lloyd’s Letter of Credit Facility Effective March 7, 2019, the stated amount of the Funds at Lloyd’s letter of credit issued to Renaissance Reinsurance pursuant to the letter of credit facility with Bank of Montreal, CEP and ING Bank N.V., London Branch as lenders, evidenced by a letter of credit reimbursement agreement dated as of November 23, 2015 (the “Renaissance Reinsurance FAL Facility”), was increased from $180.0 million to $255.0 million . TMR Group Entities Letters of Credit

Noncontrolling Interests

Noncontrolling Interests	3 Months Ended
	Mar. 31, 2019
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest [Abstract]
Noncontrolling Interests	NONCONTROLLING INTERESTS A summary of the Company’s redeemable noncontrolling interests on its consolidated balance sheets is set forth below: March 31, December 31, 2018 Redeemable noncontrolling interest - DaVinciRe $ 1,097,245 $ 1,034,946 Redeemable noncontrolling interest - Medici 406,958 416,765 Redeemable noncontrolling interest - Vermeer 605,197 599,989 Redeemable noncontrolling interests $ 2,109,400 $ 2,051,700 A summary of the Company’s redeemable noncontrolling interests on its consolidated statements of operations is set forth below: Three months ended March 31, March 31, Redeemable noncontrolling interest - DaVinciRe $ 62,533 $ 20,953 Redeemable noncontrolling interest - Medici 2,481 8,946 Redeemable noncontrolling interest - Vermeer 5,208 — Net income attributable to redeemable noncontrolling interests $ 70,222 $ 29,899 Redeemable Noncontrolling Interest – DaVinciRe RenaissanceRe owns a noncontrolling economic interest in DaVinciRe; however, because RenaissanceRe controls a majority of DaVinciRe’s outstanding voting rights, the consolidated financial statements of DaVinciRe are included in the consolidated financial statements of the Company. The portion of DaVinciRe’s earnings owned by third parties is recorded in the consolidated statements of operations as net income attributable to redeemable noncontrolling interests. The Company’s noncontrolling economic ownership in DaVinciRe was 22.1% at March 31, 2019 ( December 31, 2018 - 22.1% ). DaVinciRe shareholders are party to a shareholders agreement which provides DaVinciRe shareholders, excluding RenaissanceRe, with certain redemption rights that enable each shareholder to notify DaVinciRe of such shareholder’s desire for DaVinciRe to repurchase up to half of such shareholder’s initial aggregate number of shares held, subject to certain limitations, such as limiting the aggregate of all share repurchase requests to 25% of DaVinciRe’s capital in any given year and satisfying all applicable regulatory requirements. If total shareholder requests exceed 25% of DaVinciRe’s capital, the number of shares repurchased will be reduced among the requesting shareholders pro-rata, based on the amounts desired to be repurchased. Shareholders desiring to have DaVinci repurchase their shares must notify DaVinciRe before March 1 of each year. The repurchase price will be based on GAAP book value as of the end of the year in which the shareholder notice is given, and the repurchase will be effective as of January 1 of the following year. The repurchase price is generally subject to a true-up for potential development on outstanding loss reserves after settlement of all claims relating to the applicable years. The Company expects its noncontrolling economic ownership in DaVinciRe to fluctuate over time. The activity in redeemable noncontrolling interest – DaVinciRe is detailed in the table below: Three months ended March 31, March 31, Beginning balance $ 1,034,946 $ 1,011,659 Redemption of shares from redeemable noncontrolling interest, net of adjustments (234 ) (69 ) Net income attributable to redeemable noncontrolling interest 62,533 20,953 Ending balance $ 1,097,245 $ 1,032,543 Redeemable Noncontrolling Interest - RenaissanceRe Medici Fund Ltd. (“Medici”) Medici is an exempted company incorporated under the laws of Bermuda and its objective is to seek to invest substantially all of its assets in various insurance-based investment instruments that have returns primarily tied to property catastrophe risk. RenaissanceRe owns a noncontrolling economic interest in Medici; however, because RenaissanceRe controls all of Medici’s outstanding voting rights, the financial statements of Medici are included in the consolidated financial statements of the Company. The portion of Medici’s earnings owned by third parties is recorded in the consolidated statements of operations as net income attributable to redeemable noncontrolling interests. Any shareholder may redeem all or any portion of its shares as of the last day of any calendar month, upon at least 30 calendar days’ prior irrevocable written notice to Medici. 2018 During the three months ended March 31, 2018 , third-party investors subscribed for $99.7 million and redeemed $0.7 million of the participating, non-voting common shares of Medici. As a result of these net subscriptions, the Company’s noncontrolling economic ownership in Medici was 17.1% at March 31, 2018 . 2019 During the three months ended March 31, 2019 , third-party investors subscribed for $3.6 million and redeemed $15.9 million of the participating, non-voting common shares of Medici. As a result of these net subscriptions, the Company’s noncontrolling economic ownership in Medici was 17.1% at March 31, 2019 . The Company expects its noncontrolling economic ownership in Medici to fluctuate over time. The activity in redeemable noncontrolling interest – Medici is detailed in the table below: Three months ended March 31, March 31, Beginning balance $ 416,765 $ 284,847 Redemption of shares from redeemable noncontrolling interest, net of adjustments (15,884 ) (711 ) Sale of shares to redeemable noncontrolling interests 3,596 99,739 Net income attributable to redeemable noncontrolling interest 2,481 8,946 Ending balance $ 406,958 $ 392,821 Redeemable Noncontrolling Interest – Vermeer Vermeer is an exempted Bermuda reinsurer that provides capacity focused on risk remote layers in the U.S. property catastrophe market. Vermeer is managed by RUM in return for a management fee. The Company maintains majority voting control of Vermeer, while PGGM retains economic benefits. The Company concluded that Vermeer is a VIE as it has voting rights that are not proportional to its participating rights, and the Company is the primary beneficiary. As a result, the Company consolidates Vermeer and all significant inter-company transactions have been eliminated. The portion of Vermeer’s earnings owned by third parties is recorded in the consolidated statements of operations as net income attributable to redeemable noncontrolling interests. The Company has not provided any financial or other support to Vermeer that it was not contractually required to provide. 2018 During the fourth quarter of 2018, a third-party investor subscribed for $600.0 million of the participating, non-voting common shares of Vermeer and the Company subscribed for $1 thousand of all the voting, non-participating shares of Vermeer. The activity in redeemable noncontrolling interest – Vermeer is detailed in the table below: Three months ended March 31, March 31, Beginning balance $ 599,989 $ — Net income attributable to redeemable noncontrolling interest 5,208 — Ending balance $ 605,197 $ —

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES Upsilon RFO Upsilon RFO is a managed joint venture and a Bermuda domiciled SPI that was formed by the Company primarily to provide additional capacity to the worldwide aggregate and per-occurrence retrocessional property catastrophe excess of loss market. The shareholders (other than the Class A shareholder) participate in substantially all of the profits or losses of Upsilon RFO while their shares remain outstanding. The shareholders (other than the Class A shareholder) indemnify Upsilon RFO against losses relating to insurance risk and therefore these shares have been accounted for as prospective reinsurance under FASB ASC Topic Financial Services - Insurance . Upsilon RFO is considered a VIE as it has insufficient equity capital to finance its activities without additional financial support. The Company is the primary beneficiary of Upsilon RFO as it has the power over the activities that most significantly impact the economic performance of Upsilon RFO and has the obligation to absorb expected losses and the right to receive expected benefits that could be significant to Upsilon RFO, in accordance with the accounting guidance. As a result, the Company consolidates Upsilon RFO and all significant inter-company transactions have been eliminated. Other than its equity investment in Upsilon RFO, the Company has not provided financial or other support to Upsilon RFO that it was not contractually required to provide. 2018 During 2018, $856.7 million of Upsilon RFO non-voting preference shares were issued to existing investors, including $109.8 million to the Company. At December 31, 2018, the Company’s participation in the risks assumed by Upsilon RFO was 14.0% . Payments for certain of the shares issued during 2018 were received by the Company prior to January 1, 2018 were included in other liabilities on the Company’s consolidated balance sheet at December 31, 2017, and in other operating cash flows on the Company’s consolidated statements of cash flows for 2017. During 2018, in connection with the issuance of the non-voting preference shares of Upsilon RFO, other liabilities were reduced by this amount, and reinsurance balances payable were increased by an offsetting amount, with corresponding impacts to other operating cash flows and the change in reinsurance balances payable on the Company consolidated statements of cash flows for 2018. 2019 During the three months ended March 31, 2019 , $502.8 million of Upsilon RFO non-voting preference shares were issued to existing investors, including $100.0 million to the Company. At March 31, 2019 , the Company’s participation in the risks assumed by Upsilon RFO was 16.7% . At March 31, 2019 , the Company’s consolidated balance sheet included total assets and total liabilities of Upsilon RFO of $2.7 billion and $2.7 billion , respectively ( December 31, 2018 - $2.2 billion and $2.2 billion , respectively). Fibonacci Re Fibonacci Re, a Bermuda-domiciled SPI, was formed to provide collateralized capacity to Renaissance Reinsurance and its affiliates. Upon issuance of a series of notes by Fibonacci Re, all of the proceeds from the issuance are deposited into collateral accounts, separated by series, to fund any potential obligation under the reinsurance agreements entered into with Renaissance Reinsurance underlying such series of notes. The outstanding principal amount of each series of notes generally is expected to be returned to holders of such notes upon the expiration of the risk period underlying such notes, unless an event occurs which causes a loss under the applicable series of notes, in which case the amount returned is expected to be reduced by such noteholder’s pro rata share of such loss, as specified in the applicable governing documents of such notes. In addition, holders of such notes are generally entitled to interest payments, payable quarterly, as determined by the applicable governing documents of each series of notes. RUM receives an origination and structuring fee in connection with the formation and operation of Fibonacci Re. The Company concluded that Fibonacci Re meets the definition of a VIE as it does not have sufficient equity capital to finance its activities. The Company evaluated its relationship with Fibonacci Re and concluded it is not the primary beneficiary of Fibonacci Re as it does not have power over the activities that most significantly impact the economic performance of Fibonacci Re. As a result, the Company does not consolidate the financial position or results of operations of Fibonacci Re. The only transactions related to Fibonacci Re that will be recorded in the Company’s consolidated financial statements will be the ceded reinsurance agreements entered into by Renaissance Reinsurance that are accounted for as prospective reinsurance under FASB ASC Topic Financial Services - Insurance, and the fair value of the participating notes owned by the Company. Other than its investment in the participating notes of Fibonacci Re, the Company has not provided financial or other support to Fibonacci Re that it was not contractually required to provide. The fair value of the Company’s investment in the participating notes of Fibonacci Re is included in other investments. Net of third-party investors, the fair value of the Company’s investment in Fibonacci Re was $1.4 million at March 31, 2019 ( December 31, 2018 - $6.0 million ). Renaissance Reinsurance entered into ceded reinsurance contracts with Fibonacci Re with ceded premiums of $6 thousand and ceded premiums earned of $6 thousand during the three months ended March 31, 2019 ( 2018 - $4.1 million and $1.2 million , respectively). During the three months ended March 31, 2019 , Renaissance Reinsurance ceded $5.6 million of net claims and claim expenses to Fibonacci Re and as of March 31, 2019 had a net reinsurance recoverable of $5.6 million from Fibonacci Re. Langhorne The Company and Reinsurance Group of America, Incorporated formed Langhorne, an initiative to source third party capital to support reinsurers targeting large in-force life and annuity blocks. In connection with Langhorne, as of March 31, 2019 the Company has invested $1.6 million in Langhorne Holdings ( December 31, 2018 - $1.3 million ), a company that owns and manages certain reinsurance entities within Langhorne. In addition, as of March 31, 2019 the Company has invested $0.1 million in Langhorne Partners ( December 31, 2018 - $0.1 million ), the general partner for Langhorne and the entity which manages the third-party investors investing into Langhorne Holdings. The Company concluded that Langhorne Holdings meets the definition of a VIE as the voting rights are not proportional with the obligations to absorb losses and rights to receive residual returns. The Company evaluated its relationship with Langhorne Holdings and concluded it is not the primary beneficiary of Langhorne Holdings, as it does not have power over the activities that most significantly impact the economic performance of Langhorne Holdings. As a result, the Company does not consolidate the financial position or results of operations of Langhorne Holdings. The Company separately evaluated Langhorne Partners and concluded that it was not a VIE. The Company accounts for its investments in Langhorne Holdings and Langhorne Partners under the equity method of accounting, one quarter in arrears. The Company anticipates that its absolute investment in Langhorne will increase, perhaps materially, as in-force life and annuity blocks of businesses are written. The Company expects its absolute and relative ownership in Langhorne Partners to remain stable. Other than its current and committed future equity investment in Langhorne, the Company has not provided financial or other support to Langhorne that it was not contractually required to provide. Vermeer Vermeer is an exempted Bermuda reinsurer that provides capacity focused on risk remote layers in the U.S. property catastrophe market. Vermeer is considered a VIE as it has voting rights that are not proportional to its participating rights. The Company is the primary beneficiary of Vermeer as it has the power over the activities that most significantly impact the economic performance of Vermeer and has the obligation to absorb expected losses and the right to receive expected benefits that could be significant to Vermeer, in accordance with the accounting guidance. The portion of Vermeer’s earnings owned by third parties is recorded in the consolidated statements of operations as net income attributable to redeemable noncontrolling interests. See “Note 9 . Noncontrolling Interests” for additional information regarding Vermeer. Other than the Company’s minimal equity investment, it has not provided any financial or other support to Vermeer that it was not contractually required to provide. At March 31, 2019 , the Company’s consolidated balance sheet included total assets and total liabilities of Vermeer of $668.8 million and $63.6 million , respectively ( December 31, 2018 - $600.4 million and $0.4 million , respectively). In addition, the Company’s consolidated balance sheet included redeemable noncontrolling interests associated with Vermeer of $605.2 million at March 31, 2019 ( December 31, 2018 - $600.0 million ). Shima Re Shima Re was acquired on March 22, 2019 in connection with the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Shima Re is a Bermuda domiciled Class 3 insurer registered as a segregated accounts company formed to establish segregated accounts for the purpose of underwriting specified insurance and reinsurance agreements. The obligations of each segregated account are funded through the issuance of non-voting preference shares or principal-at-risk notes to third-party investors. Shima Re writes reinsurance business in areas that include all natural perils, property catastrophe, marine and energy. The maximum exposure of each segregated account is fully collateralized and is funded by cash and term deposits or investments as prescribed by the participant thereto. Shima Re is considered a VIE as it has voting rights that are not proportional to its participating rights. The Company owns the voting shares in the general account of Shima Re and has power over the activities that most significantly impact the economic performance of such general account. As a result, the Company consolidates the financial position and results of operations of the general account. The Company also evaluated its relationship with the segregated accounts of Shima Re and concluded it is not the primary beneficiary of such segregated accounts, as it does not have the obligation to absorb losses of the segregated accounts of Shima Re that could potentially be significant to the segregated assets of Shima Re. As a result, the Company does not consolidate the financial position or results of operations of the segregated accounts. Other than the Company’s investment in the general account of Shima Re, it has not provided any financial or other support to Shima Re that it was not contractually required to provide. Norwood Re Norwood Re was acquired on March 22, 2019 in connection with the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Norwood Re is a Bermuda domiciled SPI registered as a segregated accounts company formed to provide solutions for reinsurance-linked asset investors. Norwood Re is wholly owned by the Norwood Re Purpose Trust. Risks assumed by the segregated accounts of Norwood Re are fronted by or ceded from only one cedant - RenaissanceRe Europe AG and/or its insurance affiliates. The obligations of each segregated account are funded through the issuance of non-voting preference shares to third-party investors. Norwood Re is authorized to write property catastrophe, aviation, crop, terrorism and marine reinsurance. Norwood Re may also write natural catastrophe derivatives. The maximum exposure of each segregated account is fully collateralized and is funded by cash and term deposits or investments as prescribed by the participant thereto.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2019
Stockholders' Equity Note [Abstract]
Shareholders' Equity	SHAREHOLDERS’ EQUITY Dividends The Board of Directors of RenaissanceRe declared dividends, payable to common shareholders of record on March 15, 2019 of $0.34 per common share, and the Company paid the dividends on March 29, 2019. The Board of Directors approved the payment of quarterly dividends on the Series C 6.08% Preference Shares, Series E 5.375% Preference Shares and 5.750% Series F Preference Shares to preference shareholders of record in the amounts and on the quarterly record dates and dividend payment dates set forth in the prospectus supplement and Certificate of Designation for the applicable series of preference shares, unless and until further action is taken by the Board of Directors. The dividend payment dates for the preference shares will be the first day of March, June, September and December of each year (or if this date is not a business day, on the business day immediately following this date). The record dates for the preference share dividends are one day prior to the dividend payment dates. The amount of the dividend on the Series C 6.08% Preference Shares is an amount per share equal to 6.08% of the liquidation preference per annum (the equivalent to $1.52 per share per annum, or $0.38 per share per quarter). The amount of the dividend on the Series E 5.375% Preference Shares is an amount per share equal to 5.375% of the liquidation preference per annum (the equivalent to $1.34375 per share per annum, or $0.3359375 per share per quarter). The amount of the dividend on the 5.750% Series F Preference Shares is an amount per share equal to 5.750% of the liquidation preference per annum (the equivalent to $1,437.50 per 5.750% Series F Preference Share per annum, or $359.375 per 5.750% Series F Preference Share per quarter, or $1.4375 per Depositary Share per annum, or $0.359375 per Depositary Share per quarter). During the three months ended March 31, 2019 , the Company paid $9.2 million in preference share dividends ( 2018 - $5.6 million ) and $14.5 million in common share dividends ( 2018 - $13.2 million ). TMR Stock Purchase On March 22, 2019, in connection with the closing of the TMR Stock Purchase, the Company issued 1,739,071 of its common shares to Tokio as part of the aggregate consideration payable to Tokio under the TMR Stock Purchase Agreement. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Share Repurchases The Company’s share repurchase program may be effected from time to time, depending on market conditions and other factors, through open market purchases and privately negotiated transactions. On November 10, 2017 , RenaissanceRe’s Board of Directors approved a renewal of its authorized share repurchase program for an aggregate amount of up to $500.0 million . Unless terminated earlier by RenaissanceRe’s Board of Directors, the program will expire when the Company has repurchased the full value of the common shares authorized. The Company’s decision to repurchase common shares will depend on, among other matters, the market price of the common shares and the capital requirements of the Company. During the three months ended March 31, 2019 , the Company did no t repurchase any of its common shares. At March 31, 2019 , $500.0 million

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings per common share: Three months ended (common shares in thousands) March 31, March 31, Numerator: Net income available to RenaissanceRe common shareholders $ 273,717 $ 56,713 Amount allocated to participating common shareholders (1) (3,121 ) (546 ) Net income allocated to RenaissanceRe common shareholders $ 270,596 $ 56,167 Denominator: Denominator for basic income per RenaissanceRe common share - weighted average common shares 42,065 39,552 Per common share equivalents of employee stock options and restricted shares 26 47 Denominator for diluted income per RenaissanceRe common share - adjusted weighted average common shares and assumed conversions 42,091 39,599 Net income available to RenaissanceRe common shareholders per common share – basic $ 6.43 $ 1.42 Net income available to RenaissanceRe common shareholders per common share – diluted $ 6.43 $ 1.42 (1)

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2019
Segment Reporting, Measurement Disclosures [Abstract]
Segment Reporting	SEGMENT REPORTING The Company’s reportable segments are defined as follows: (1) Property, which is comprised of catastrophe and other property reinsurance and insurance written on behalf of the Company’s operating subsidiaries and certain joint ventures managed by the Company’s ventures unit, and (2) Casualty and Specialty, which is comprised of casualty and specialty reinsurance and insurance written on behalf of the Company’s operating subsidiaries and certain joint ventures managed by the Company’s ventures unit. In addition to its reportable segments, the Company has an Other category, which primarily includes its strategic investments, investments unit, corporate expenses, capital servicing costs, noncontrolling interests and the remnants of its former Bermuda-based insurance operations. From the acquisition date, March 22, 2019, through March 31, 2019, the results of operations of the TMR Group Entities were not material, and as a result were not included in the Company’s consolidated statements of operations for the three months ended March 31, 2019. In future periods, the results of operations of the TMR Group Entities will be reflected in the Company’s existing reportable segments. The Company’s Property segment is managed by the Chief Underwriting Officer - Property and the Casualty and Specialty segment is managed by the Chief Underwriting Officer - Casualty and Specialty, each of whom operate under the direction of the Company’s Group Chief Underwriting Officer, who in turn reports to the Company’s President and Chief Executive Officer. The Company does not manage its assets by segment; accordingly, net investment income and total assets are not allocated to the segments. A summary of the significant components of the Company’s revenues and expenses by segment is as follows: Three months ended March 31, 2019 Property Casualty and Specialty Other Total Gross premiums written $ 1,032,384 $ 531,911 $ — $ 1,564,295 Net premiums written $ 564,230 $ 364,801 $ — $ 929,031 Net premiums earned $ 290,745 $ 259,283 $ — $ 550,028 Net claims and claim expenses incurred 56,083 170,933 19 227,035 Acquisition expenses 53,739 70,212 — 123,951 Operational expenses 28,544 16,389 — 44,933 Underwriting income (loss) $ 152,379 $ 1,749 $ (19 ) 154,109 Net investment income 81,462 81,462 Net foreign exchange losses (2,846 ) (2,846 ) Equity in earnings of other ventures 4,661 4,661 Other income 3,171 3,171 Net realized and unrealized gains on investments 170,645 170,645 Corporate expenses (38,789 ) (38,789 ) Interest expense (11,754 ) (11,754 ) Income before taxes and redeemable noncontrolling interests 360,659 Income tax expense (7,531 ) (7,531 ) Net income attributable to redeemable noncontrolling interests (70,222 ) (70,222 ) Dividends on preference shares (9,189 ) (9,189 ) Net income available to RenaissanceRe common shareholders $ 273,717 Net claims and claim expenses incurred – current accident year $ 54,206 $ 177,135 $ — $ 231,341 Net claims and claim expenses incurred – prior accident years 1,877 (6,202 ) 19 (4,306 ) Net claims and claim expenses incurred – total $ 56,083 $ 170,933 $ 19 $ 227,035 Net claims and claim expense ratio – current accident year 18.6 % 68.3 % 42.1 % Net claims and claim expense ratio – prior accident years 0.7 % (2.4 )% (0.8 )% Net claims and claim expense ratio – calendar year 19.3 % 65.9 % 41.3 % Underwriting expense ratio 28.3 % 33.4 % 30.7 % Combined ratio 47.6 % 99.3 % 72.0 % Three months ended March 31, 2018 Property Casualty and Specialty Other Total Gross premiums written $ 706,968 $ 452,684 $ — $ 1,159,652 Net premiums written $ 354,077 $ 308,967 $ — $ 663,044 Net premiums earned $ 225,049 $ 215,233 $ — $ 440,282 Net claims and claim expenses incurred 30,607 141,078 18 171,703 Acquisition expenses 40,721 56,990 — 97,711 Operational expenses 26,546 14,593 133 41,272 Underwriting income (loss) $ 127,175 $ 2,572 $ (151 ) 129,596 Net investment income 56,476 56,476 Net foreign exchange gains 3,757 3,757 Equity in earnings of other ventures 857 857 Other loss (1,242 ) (1,242 ) Net realized and unrealized losses on investments (82,144 ) (82,144 ) Corporate expenses (6,733 ) (6,733 ) Interest expense (11,767 ) (11,767 ) Income before taxes and redeemable noncontrolling interests 88,800 Income tax benefit 3,407 3,407 Net income attributable to redeemable noncontrolling interests (29,899 ) (29,899 ) Dividends on preference shares (5,595 ) (5,595 ) Net income available to RenaissanceRe common shareholders $ 56,713 Net claims and claim expenses incurred – current accident year $ 58,169 $ 144,869 $ — $ 203,038 Net claims and claim expenses incurred – prior accident years (27,562 ) (3,791 ) 18 (31,335 ) Net claims and claim expenses incurred – total $ 30,607 $ 141,078 $ 18 $ 171,703 Net claims and claim expense ratio – current accident year 25.8 % 67.3 % 46.1 % Net claims and claim expense ratio – prior accident years (12.2 )% (1.8 )% (7.1 )% Net claims and claim expense ratio – calendar year 13.6 % 65.5 % 39.0 % Underwriting expense ratio 29.9 % 33.3 % 31.6 % Combined ratio 43.5 % 98.8 % 70.6 %

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2019
Summary of Derivative Instruments [Abstract]
Derivative Instruments	DERIVATIVE INSTRUMENTS From time to time, the Company may enter into derivative instruments such as futures, options, swaps, forward contracts and other derivative contracts primarily to manage its foreign currency exposure, obtain exposure to a particular financial market, for yield enhancement, or for trading and to assume risk. The Company’s derivative instruments can be exchange traded or over-the-counter, with over-the-counter derivatives generally traded under International Swaps and Derivatives Association master agreements, which establish the terms of the transactions entered into with the Company’s derivative counterparties. In the event a party becomes insolvent or otherwise defaults on its obligations, a master agreement generally permits the non-defaulting party to accelerate and terminate all outstanding transactions and net the transactions’ marked-to-market values so that a single sum in a single currency will be owed by, or owed to, the non-defaulting party. Effectively, this contractual close-out netting reduces credit exposure from gross to net exposure. Where the Company has entered into master netting agreements with counterparties, or the Company has the legal and contractual right to offset positions, the derivative positions are generally netted by counterparty and are reported accordingly in other assets and other liabilities. The tables below show the gross and net amounts of recognized derivative assets and liabilities at fair value, including the location on the consolidated balance sheets of the Company’s principal derivative instruments: Derivative Assets At March 31, 2019 Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet Balance Sheet Location Collateral Net Amount Interest rate futures $ 1,263 1,206 $ 57 Other assets $ — $ 57 Interest rate swaps 6 — 6 Other assets — 6 Foreign currency forward contracts (1) 10,490 152 10,338 Other assets — 10,338 Foreign currency forward contracts (2) 743 64 679 Other assets — 679 Credit default swaps 121 — 121 Other assets — 121 Total return swaps 600 — 600 Other assets — 600 Total $ 13,223 $ 1,422 $ 11,801 $ — $ 11,801 Derivative Liabilities At March 31, 2019 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet Balance Sheet Location Collateral Pledged Net Amount Interest rate futures $ 3,330 1,206 $ 2,124 Other liabilities $ 2,113 $ 11 Interest rate swaps 71 — 71 Other liabilities 71 — Foreign currency forward contracts (1) 3,011 103 2,908 Other liabilities — 2,908 Foreign currency forward contracts (2) 945 64 881 Other liabilities — 881 Total $ 7,357 $ 1,373 $ 5,984 $ 2,184 $ 3,800 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2) Contracts used to manage foreign currency risks in investment operations. Derivative Assets At December 31, 2018 Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet Balance Sheet Location Collateral Net Amount Interest rate futures $ 2,361 1,660 $ 701 Other assets $ — $ 701 Interest rate swaps 860 — 860 Other assets — 860 Foreign currency forward contracts (1) 16,459 2,260 14,199 Other assets — 14,199 Foreign currency forward contracts (2) 3,194 71 3,123 Other assets — 3,123 Total $ 22,874 $ 3,991 $ 18,883 $ — $ 18,883 Derivative Liabilities At December 31, 2018 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet Balance Sheet Location Collateral Pledged Net Amount Interest rate futures $ 1,887 1,670 $ 217 Other liabilities $ 217 $ — Interest rate swaps 506 — 506 Other liabilities 254 252 Foreign currency forward contracts (1) 4,154 — 4,154 Other liabilities — 4,154 Foreign currency forward contracts (2) 72 71 1 Other liabilities — 1 Credit default swaps 1,606 — 1,606 Other liabilities 1,605 1 Total $ 8,225 $ 1,741 $ 6,484 $ 2,076 $ 4,408 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2) Contracts used to manage foreign currency risks in investment operations. See “Note 4 . Investments” for information on reverse repurchase agreements. The location and amount of the gain (loss) recognized in the Company’s consolidated statements of operations related to its principal derivative instruments are shown in the following table: Location of gain (loss) recognized on derivatives Amount of gain (loss) recognized on derivatives Three months ended March 31, 2019 2018 Interest rate futures Net realized and unrealized gains (losses) on investments $ 8,503 $ (2,337 ) Interest rate swaps Net realized and unrealized gains (losses) on investments 349 (106 ) Foreign currency forward contracts (1) Net foreign exchange (losses) gains 4,442 6,743 Foreign currency forward contracts (2) Net foreign exchange (losses) gains 1,145 (691 ) Credit default swaps Net realized and unrealized gains (losses) on investments 4,410 (1,921 ) Total return swaps Net realized and unrealized gains (losses) on investments 534 — Total $ 19,383 $ 1,688 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2) Contracts used to manage foreign currency risks in investment operations. The Company is not aware of the existence of any credit-risk related contingent features that it believes would be triggered in its derivative instruments that are in a net liability position at March 31, 2019 . Interest Rate Derivatives The Company uses interest rate futures and swaps within its portfolio of fixed maturity investments to manage its exposure to interest rate risk, which may result in increasing or decreasing its exposure to this risk. Interest Rate Futures The fair value of interest rate futures is determined using exchange traded prices. At March 31, 2019 , the Company had $2.6 billion of notional long positions and $343.0 million of notional short positions of primarily Eurodollar, U.S. treasury and non-U.S. dollar futures contracts ( December 31, 2018 - $1.9 billion and $545.8 million , respectively). Interest Rate Swaps The fair value of interest rate swaps is determined using the relevant exchange traded price where available or a discounted cash flow model based on the terms of the contract and inputs, including, where applicable, observable yield curves. At March 31, 2019 , the Company had $26.2 million of notional positions paying a fixed rate and $26.3 million receiving a fixed rate denominated in U.S. dollar swap contracts ( December 31, 2018 - $78.4 million and $32.1 million , respectively). Foreign Currency Derivatives The Company’s functional currency is the U.S. dollar. The Company writes a portion of its business in currencies other than U.S. dollars and may, from time to time, experience foreign exchange gains and losses in the Company’s consolidated financial statements. All changes in exchange rates, with the exception of non-monetary assets and liabilities, are recognized in the Company’s consolidated statements of operations. Underwriting Operations Related Foreign Currency Contracts The Company’s foreign currency policy with regard to its underwriting operations is generally to hold foreign currency assets, including cash, investments and receivables that approximate the foreign currency liabilities, including claims and claim expense reserves and reinsurance balances payable. When necessary, the Company may use foreign currency forward and option contracts to minimize the effect of fluctuating foreign currencies on the value of non-U.S. dollar denominated assets and liabilities associated with its underwriting operations. The fair value of the Company’s underwriting operations related foreign currency contracts is determined using indicative pricing obtained from counterparties or broker quotes. At March 31, 2019 , the Company had outstanding underwriting related foreign currency contracts of $681.9 million in notional long positions and $617.0 million in notional short positions, denominated in U.S. dollars ( December 31, 2018 - $354.1 million and $601.2 million , respectively). Investment Portfolio Related Foreign Currency Forward Contracts The Company’s investment operations are exposed to currency fluctuations through its investments in non-U.S. dollar fixed maturity investments, short term investments and other investments. From time to time, the Company may employ foreign currency forward contracts in its investment portfolio to either assume foreign currency risk or to economically hedge its exposure to currency fluctuations from these investments. The fair value of the Company’s investment portfolio related foreign currency forward contracts is determined using an interpolated rate based on closing forward market rates. At March 31, 2019 , the Company had outstanding investment portfolio related foreign currency contracts of $105.7 million in notional long positions and $38.9 million in notional short positions, denominated in U.S. dollars ( December 31, 2018 - $121.3 million and $42.9 million , respectively). Credit Derivatives The Company’s exposure to credit risk is primarily due to its fixed maturity investments, short term investments, premiums receivable and reinsurance recoverable. From time to time, the Company may purchase credit derivatives to hedge its exposures in the insurance industry, and to assist in managing the credit risk associated with ceded reinsurance. The Company also employs credit derivatives in its investment portfolio to either assume credit risk or hedge its credit exposure. Credit Default Swaps The fair value of the Company’s credit default swaps is determined using industry valuation models, broker bid indications or internal pricing valuation techniques. The fair value of these credit default swaps can change based on a variety of factors including changes in credit spreads, default rates and recovery rates, the correlation of credit risk between the referenced credit and the counterparty, and market rate inputs such as interest rates. At March 31, 2019 , the Company had outstanding credit default swaps of $Nil in notional positions to hedge credit risk and $53.4 million in notional positions to assume credit risk, denominated in U.S. dollars ( December 31, 2018 - $1.0 million and $126.2 million , respectively). Total Return Swaps During the three months ended March 31, 2019, the Company entered into certain total return swap contracts. The Company uses total return swaps as a means to manage spread duration and credit exposure in its investment portfolio. The fair value of the Company’s total return swaps is determined using broker-dealer bid quotations, market-based prices from pricing vendors or valuation models. At March 31, 2019 , the Company had $100.0 million of notional long positions (long credit) and $Nil

Commitments, Contingencies and

Commitments, Contingencies and Other Items	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Other Items	COMMITMENTS, CONTINGENCIES AND OTHER ITEMS There are no material changes from the commitments, contingencies and other items previously disclosed in the Company’s Form 10-K for the year ended December 31, 2018 , other than disclosures associated with the adoption of FASB ASC Topic Leases as outlined below. See “Note 2 . Significant Accounting Policies” for additional information related to the adoption of FASB ASC Topic Leases. Leases The Company’s operating leases primarily relate to office space for its global underwriting platforms, principally in Bermuda, Australia, Ireland, Singapore, Switzerland, the U.K. and the U.S. These leases expire at various dates through 2027 with a weighted average lease term of 1.6 years . Included in other assets and other liabilities at March 31, 2019 is a right-to-use asset of $20.5 million and a lease liability of $20.5 million , respectively, associated with the Company’s operating leases and reflected as a result of the Company’s adoption of FASB ASC Topic Leases ( December 31, 2018 - $Nil and $Nil , respectively). For the three months ended March 31, 2019 , the Company recorded an operating lease expense of $1.7 million included in other income (loss) ( 2018 - $Nil ). The Company’s financing leases primarily relate to office space in Bermuda with an initial lease term of 20 years, ending in 2028 , and a bargain renewal option for an additional 30 years. Included in other assets and other liabilities at March 31, 2019 is a right-to-use asset of $20.4 million and a lease liability of $25.7 million , respectively, associated with the Company’s finance leases and reflected as a result of the Company’s adoption of FASB ASC Topic Leases ( December 31, 2018 - $Nil and $Nil , respectively). For the three months ended March 31, 2019 , the Company recorded interest expense of $0.6 million associated with its finance leases ( 2018 - $0.7 million ) and amortization of its finance leases right-to-use asset of $0.2 million included in other income (loss) ( 2018 - $0.5 million ). Future minimum lease payments under existing operating and finance leases are detailed below, excluding the bargain renewal option on the finance lease related to office space in Bermuda: Future minimum lease payments Operating leases Finance leases 2019 (remaining) $ 5,722 $ 2,498 2020 5,439 3,336 2021 5,052 3,336 2022 4,261 3,336 2023 1,569 2,830 2024 86 2,661 After 2024 211 10,129 Future minimum lease payments under existing leases $ 22,340 $ 28,126 Legal Proceedings

Condensed Consolidating Financi

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries	3 Months Ended
	Mar. 31, 2019
Condensed Consolidating Financial Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]
Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries	CONDENSED CONSOLIDATING FINANCIAL INFORMATION PROVIDED IN CONNECTION WITH OUTSTANDING DEBT OF SUBSIDIARIES The following tables present condensed consolidating balance sheets at March 31, 2019 and December 31, 2018 , condensed consolidating statements of operations and condensed consolidating statements of comprehensive income for the three months ended March 31, 2019 and 2018 , and condensed consolidating statements of cash flows for the three months ended March 31, 2019 and 2018 . Each of RenRe North America Holdings Inc. and RenaissanceRe Finance, Inc. is a 100% owned subsidiary of RenaissanceRe. For additional information related to the terms of the Company’s outstanding debt securities, see “Note 8. Debt and Credit Facilities in the Notes to the Consolidated Financial Statements” in the Company’s Form 10-K for the year ended December 31, 2018 and “Note 8 . Debt and Credit Facilities in the Notes to the Consolidated Financial Statements” included herein. Condensed Consolidating Balance Sheet at March 31, 2019 RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Assets Total investments $ 126,816 $ 110,166 $ 18,385 $ 14,597,481 $ — $ 14,852,848 Cash and cash equivalents 3,070 3,687 5,848 1,008,670 — 1,021,275 Investments in subsidiaries 5,039,057 59,310 1,249,218 — (6,347,585 ) — Due from subsidiaries and affiliates 54,939 101,578 3,765 — (160,282 ) — Premiums receivable — — — 2,753,098 — 2,753,098 Prepaid reinsurance premiums — — — 1,086,027 — 1,086,027 Reinsurance recoverable — — — 2,908,343 — 2,908,343 Accrued investment income (88 ) 231 96 64,376 — 64,615 Deferred acquisition costs — — — 841,528 — 841,528 Receivable for investments sold 926 1 — 410,245 — 411,172 Other assets 766,088 15,528 313,424 (1,793,255 ) 1,051,758 353,543 Goodwill and other intangible assets 119,410 — — 147,741 — 267,151 Total assets $ 6,110,218 $ 290,501 $ 1,590,736 $ 22,024,254 $ (5,456,109 ) $ 24,559,600 Liabilities, Noncontrolling Interests and Shareholders’ Equity Liabilities Reserve for claims and claim expenses $ — $ — $ — $ 8,391,484 $ — $ 8,391,484 Unearned premiums — — — 3,188,678 — 3,188,678 Debt 500,000 — 843,382 148,117 (300,000 ) 1,191,499 Amounts due to subsidiaries and affiliates 25,037 31 112,637 — (137,705 ) — Reinsurance balances payable — — — 3,009,492 — 3,009,492 Payable for investments purchased — — — 679,596 — 679,596 Other liabilities 31,148 288 9,283 395,346 (647 ) 435,418 Total liabilities 556,185 319 965,302 15,812,713 (438,352 ) 16,896,167 Redeemable noncontrolling interests — — — 2,109,400 — 2,109,400 Shareholders’ Equity Total shareholders’ equity 5,554,033 290,182 625,434 4,102,141 (5,017,757 ) 5,554,033 Total liabilities, noncontrolling interests and shareholders’ equity $ 6,110,218 $ 290,501 $ 1,590,736 $ 22,024,254 $ (5,456,109 ) $ 24,559,600 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor, Subsidiary Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Balance Sheet at December 31, 2018 RenaissanceRe Holdings Ltd. (Parent Guarantor) RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-guarantor Subsidiaries) (1) Consolidating Adjustments (2) RenaissanceRe Consolidated Assets Total investments $ 313,360 $ 77,842 $ 28,885 $ 11,465,660 $ — $ 11,885,747 Cash and cash equivalents 3,534 3,350 9,604 1,091,434 — 1,107,922 Investments in subsidiaries 4,414,475 58,458 1,215,663 — (5,688,596 ) — Due from subsidiaries and affiliates 57,039 101,579 — — (158,618 ) — Premiums receivable — — — 1,537,188 — 1,537,188 Prepaid reinsurance premiums — — — 616,185 — 616,185 Reinsurance recoverable — — — 2,372,221 — 2,372,221 Accrued investment income 1,046 310 127 49,828 — 51,311 Deferred acquisition costs — — — 476,661 — 476,661 Receivable for investments sold 203 23,885 — 232,328 — 256,416 Other assets 458,842 22,571 313,636 (1,403,636 ) 743,714 135,127 Goodwill and other intangible assets 120,476 — — 116,942 — 237,418 Total assets $ 5,368,975 $ 287,995 $ 1,567,915 $ 16,554,811 $ (5,103,500 ) $ 18,676,196 Liabilities, Redeemable Noncontrolling Interest and Shareholders’ Equity Liabilities Reserve for claims and claim expenses $ — $ — $ — $ 6,076,271 $ — $ 6,076,271 Unearned premiums — — — 1,716,021 — 1,716,021 Debt 300,000 — 843,086 148,041 (300,000 ) 991,127 Amounts due to subsidiaries and affiliates 6,453 217 102,243 — (108,913 ) — Reinsurance balances payable — — — 1,902,056 — 1,902,056 Payable for investments purchased — 24 — 380,308 — 380,332 Other liabilities 17,442 5,362 13,918 482,422 (5,535 ) 513,609 Total liabilities 323,895 5,603 959,247 10,705,119 (414,448 ) 11,579,416 Redeemable noncontrolling interests — — — 2,051,700 — 2,051,700 Shareholders’ Equity Total shareholders’ equity 5,045,080 282,392 608,668 3,797,992 (4,689,052 ) 5,045,080 Total liabilities, redeemable noncontrolling interest and shareholders’ equity $ 5,368,975 $ 287,995 $ 1,567,915 $ 16,554,811 $ (5,103,500 ) $ 18,676,196 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Statement of Operations for RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Revenues Net premiums earned $ — $ — $ — $ 550,028 $ — $ 550,028 Net investment income 8,277 595 2,060 79,332 (8,802 ) 81,462 Net foreign exchange losses (1 ) — — (2,845 ) — (2,846 ) Equity in earnings of other ventures — — 965 3,696 — 4,661 Other income — — — 3,171 — 3,171 Net realized and unrealized gains on investments 1,002 8,159 109 161,375 — 170,645 Total revenues 9,278 8,754 3,134 794,757 (8,802 ) 807,121 Expenses Net claims and claim expenses incurred — — — 227,035 — 227,035 Acquisition expenses — — — 123,951 — 123,951 Operational expenses 469 11 12,333 42,609 (10,489 ) 44,933 Corporate expenses 38,828 — — (1,922 ) 1,883 38,789 Interest expense 1,883 — 9,252 619 — 11,754 Total expenses 41,180 11 21,585 392,292 (8,606 ) 446,462 (Loss) income before equity in net income of subsidiaries and taxes (31,902 ) 8,743 (18,451 ) 402,465 (196 ) 360,659 Equity in net income of subsidiaries 314,887 828 33,532 — (349,247 ) — Income before taxes 282,985 9,571 15,081 402,465 (349,443 ) 360,659 Income tax (expense) benefit (79 ) (1,805 ) 1,662 (7,309 ) — (7,531 ) Net income 282,906 7,766 16,743 395,156 (349,443 ) 353,128 Net income attributable to redeemable noncontrolling interests — — — (70,222 ) — (70,222 ) Net income attributable to RenaissanceRe 282,906 7,766 16,743 324,934 (349,443 ) 282,906 Dividends on preference shares (9,189 ) — — — — (9,189 ) Net income available to RenaissanceRe common shareholders $ 273,717 $ 7,766 $ 16,743 $ 324,934 $ (349,443 ) $ 273,717 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor, Subsidiary Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Statement of Comprehensive Income for the three months ended March 31, 2019 RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Comprehensive income Net income $ 282,906 $ 7,766 $ 16,743 $ 395,156 $ (349,443 ) $ 353,128 Change in net unrealized losses on investments — — — (37 ) — (37 ) Comprehensive income 282,906 7,766 16,743 395,119 (349,443 ) 353,091 Net income attributable to redeemable noncontrolling interests — — — (70,222 ) — (70,222 ) Comprehensive income attributable to noncontrolling interests — — — (70,222 ) — (70,222 ) Comprehensive income attributable to RenaissanceRe $ 282,906 $ 7,766 $ 16,743 $ 324,897 $ (349,443 ) $ 282,869 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor, Subsidiary Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Statement of Operations for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Revenues Net premiums earned $ — $ — $ — $ 440,282 $ — $ 440,282 Net investment income 6,035 513 1,234 56,305 (7,611 ) 56,476 Net foreign exchange (losses) gains (3 ) — — 3,760 — 3,757 Equity in earnings (losses) of other ventures — — 1,211 (354 ) — 857 Other loss — — — (1,242 ) — (1,242 ) Net realized and unrealized (losses) on investments (661 ) (1,286 ) (259 ) (79,938 ) — (82,144 ) Total revenues 5,371 (773 ) 2,186 418,813 (7,611 ) 417,986 Expenses Net claims and claim expenses incurred — — — 171,703 — 171,703 Acquisition expenses — — — 97,711 — 97,711 Operational expenses 1,313 10 11,070 37,933 (9,054 ) 41,272 Corporate expenses 3,684 — — 3,049 — 6,733 Interest expense 1,108 — 9,252 2,515 (1,108 ) 11,767 Total expenses 6,105 10 20,322 312,911 (10,162 ) 329,186 (Loss) income before equity in net income (loss) of subsidiaries and taxes (734 ) (783 ) (18,136 ) 105,902 2,551 88,800 Equity in net income (loss) of subsidiaries 62,426 834 (3,813 ) — (59,447 ) — Income (loss) before taxes 61,692 51 (21,949 ) 105,902 (56,896 ) 88,800 Income tax benefit 616 221 1,815 755 — 3,407 Net income (loss) 62,308 272 (20,134 ) 106,657 (56,896 ) 92,207 Net income attributable to redeemable noncontrolling interests — — — (29,899 ) — (29,899 ) Net income (loss) attributable to RenaissanceRe 62,308 272 (20,134 ) 76,758 (56,896 ) 62,308 Dividends on preference shares (5,595 ) — — — — (5,595 ) Net income (loss) available (attributable) to RenaissanceRe common shareholders $ 56,713 $ 272 $ (20,134 ) $ 76,758 $ (56,896 ) $ 56,713 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Statement of Comprehensive income (Loss) for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Comprehensive income (loss) Net income (loss) $ 62,308 $ 272 $ (20,134 ) $ 106,657 $ (56,896 ) $ 92,207 Change in net unrealized gains on investments — — — (30 ) — (30 ) Comprehensive income 62,308 272 (20,134 ) 106,627 (56,896 ) 92,177 Net income attributable to redeemable noncontrolling interests — — — (29,899 ) — (29,899 ) Comprehensive income attributable to noncontrolling interests — — — (29,899 ) — (29,899 ) Comprehensive income (loss) attributable to RenaissanceRe $ 62,308 $ 272 $ (20,134 ) $ 76,728 $ (56,896 ) $ 62,278 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Statement of Cash Flows for the three months ended March 31, 2019 RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Consolidated Cash flows (used in) provided by operating activities Net cash (used in) provided by operating activities $ (317,296 ) $ 2,198 $ (21,202 ) $ 713,449 $ 377,149 Cash flows provided by (used in) investing activities Proceeds from sales and maturities of fixed maturity investments trading 277,030 15,655 29,861 4,278,262 4,600,808 Purchases of fixed maturity investments trading (35,909 ) (9,899 ) (14,098 ) (3,459,371 ) (3,519,277 ) Net purchases of equity investments trading — (2,046 ) — (2,555 ) (4,601 ) Net purchases of short term investments (54,622 ) (5,386 ) (4,946 ) (1,309,678 ) (1,374,632 ) Net purchases of other investments — — — (51,811 ) (51,811 ) Net purchases of investments in other ventures — — — (1,573 ) (1,573 ) Return of investment from investments in other ventures — — — 11,250 11,250 Dividends and return of capital from subsidiaries 487,264 — — (487,264 ) — Contributions to subsidiaries (528,416 ) — — 528,416 — Due (from) to subsidiary 2,100 (185 ) 6,629 (8,544 ) — Net purchase of the TMR Group Entities — — — (276,206 ) (276,206 ) Net cash provided by (used in) investing activities 147,447 (1,861 ) 17,446 (779,074 ) (616,042 ) Cash flows provided by (used in) financing activities Dividends paid – RenaissanceRe common shares (14,469 ) — — — (14,469 ) Dividends paid – preference shares (9,189 ) — — — (9,189 ) Drawdown of RenaissanceRe Revolving Credit Facility 200,000 — — — 200,000 Net third party redeemable noncontrolling interest share transactions — — — (16,847 ) (16,847 ) Taxes paid on withholding shares (6,957 ) — — — (6,957 ) Net cash provided by (used in) financing activities 169,385 — — (16,847 ) 152,538 Effect of exchange rate changes on foreign currency cash — — — (292 ) (292 ) Net (decrease) increase in cash and cash equivalents (464 ) 337 (3,756 ) (82,764 ) (86,647 ) Cash and cash equivalents, beginning of period 3,534 3,350 9,604 1,091,434 1,107,922 Cash and cash equivalents, end of period $ 3,070 $ 3,687 $ 5,848 $ 1,008,670 $ 1,021,275 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. Condensed Consolidating Statement of Cash Flows for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-guarantor Subsidiaries) (1) RenaissanceRe Consolidated Cash flows (used in) provided by operating activities Net cash (used in) provided by operating activities $ (6,875 ) $ 659 $ (23,449 ) $ (7,684 ) $ (37,349 ) Cash flows provided by (used in) investing activities Proceeds from sales and maturities of fixed maturity investments trading 119,542 42,793 27,672 2,128,852 2,318,859 Purchases of fixed maturity investments trading (20,216 ) (22,956 ) (12,698 ) (2,256,591 ) (2,312,461 ) Net (purchases) sales of equity investments trading — (21 ) — 158 137 Net sales (purchases) of short term investments 54,728 (4,024 ) (5,925 ) (639,420 ) (594,641 ) Net purchases of other investments — — — (98,639 ) (98,639 ) Net purchases of investments in other ventures — — — (17,974 ) (17,974 ) Dividends and return of capital from subsidiaries 177,250 — — (177,250 ) — Contributions to subsidiaries (150,205 ) (16,500 ) — 166,705 — Due (from) to subsidiaries (154,877 ) 7 14,106 140,764 — Net cash provided by (used in) investing activities 26,222 (701 ) 23,155 (753,395 ) (704,719 ) Cash flows (used in) provided by financing activities Dividends paid – RenaissanceRe common shares (13,224 ) — — — (13,224 ) Dividends paid – preference shares (5,595 ) — — — (5,595 ) Net third party redeemable noncontrolling interest share transactions — — — 52,759 52,759 Taxes paid on withholding shares (7,034 ) — — — (7,034 ) Net cash (used in) provided by financing activities (25,853 ) — — 52,759 26,906 Effect of exchange rate changes on foreign currency cash — — — 1,543 1,543 Net decrease in cash and cash equivalents (6,506 ) (42 ) (294 ) (706,777 ) (713,619 ) Cash and cash equivalents, beginning of period 14,656 139 1,469 1,345,328 1,361,592 Cash and cash equivalents, end of period $ 8,150 $ 97 $ 1,175 $ 638,551 $ 647,973

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS 3.600% Senior Notes Due 2029 On April 2, 2019, the Company issued $400.0 million of its 3.600% Senior Notes due April 15, 2029 , with interest on the notes payable on April 15 and October 15 of each year, commencing on October 15, 2019. The notes are redeemable at the applicable redemption price, subject to the terms described in the indenture for the notes. However, the notes may not be redeemed prior to April 15, 2022 without approval from the Bermuda Monetary Authority (the “BMA”) and may not be redeemed at any time prior to their maturity if enhanced capital requirements, as established by the BMA, would be breached immediately before or after giving effect to the redemption of such notes, unless, in each case, the Company replaces the capital represented by the notes to be redeemed with capital having equal or better capital treatment as the notes under applicable BMA rules. The notes contain various covenants including limitations on mergers and consolidations, and restrictions as to the disposition of, and the placing of liens on, the stock of designated subsidiaries. The net proceeds from this offering were used to repay, in full, the $200.0 million outstanding under the Company’s revolving credit facility at March 31, 2019, which the Company used to partially fund the purchase price for the TMR Stock Purchase, and the remainder of the net proceeds will be used for general corporate purposes.

Significant Accounting Polici_2

Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION These consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the U.S. (“GAAP”) for interim financial information and in conformity with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the opinion of management, these unaudited consolidated financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation 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 from these statements.
Use of Estimates in Financial Statements	USE OF ESTIMATES IN FINANCIAL STATEMENTSThe preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported and disclosed amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates. The major estimates reflected in the Company’s consolidated financial statements include, but are not limited to, the reserve for claims and claim expenses; reinsurance recoverables, including allowances for reinsurance recoverables deemed uncollectible; estimates of written and earned premiums; fair value, including the fair value of investments, financial instruments and derivatives; impairment charges; and the Company’s deferred tax valuation allowance.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted	RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases and subsequently issued a number of other ASUs to amend the guidance, each ultimately reflected in FASB Accounting Standards Codification (“ASC”) Topic Leases . FASB ASC Topic Leases requires, among other items, lessees to recognize lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under the previous guidance. FASB ASC Topic Leases was effective for public business entities for annual and interim periods beginning after December 15, 2018. The Company has adopted FASB ASC Topic Leases through the application of the modified retrospective transition approach. In addition, the Company employed certain practical expedients permitted under the guidance and utilized its incremental borrowing rate in determining the present value of lease payments, not yet paid. The adoption of this guidance did not have a material impact on the Company’s consolidated statements of operations and financial position. The Company determined it was not required to record a cumulative effect adjustment to opening retained earnings as of January 1, 2019. Intra-Entity Transfers of Assets Other Than Inventory In October 2016, the FASB issued ASU No. 2016-16, Intra-Entity Transfers of Assets Other Than Inventory (“ASU 2016-16”). ASU 2016-16 requires entities to recognize the income tax consequences of intra-entity transfers of assets other than inventory when the transfers occur; this is a change from current guidance which prohibits the recognition of current and deferred income taxes until the underlying assets have been sold to outside entities. ASU 2016-16 was effective for public business entities for annual and interim periods beginning after December 15, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated statements of operations and financial position. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS NOT YET ADOPTED Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 modifies the recognition of credit losses by replacing the incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is applicable to financial assets such as loans, debt securities, trade receivables, off-balance sheet credit exposures, reinsurance receivables, and other financial assets that have the contractual right to receive cash. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The Company's invested assets are measured at fair value through net income, and therefore those invested assets would not be impacted by the adoption of ASU 2016-13. The Company has other financial assets, such as reinsurance recoverables, that could be impacted by the adoption of ASU 2016-13. ASU 2016-13 is effective for public business entities that are SEC filers for annual and interim periods beginning after December 15, 2019. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company’s consolidated statements of operations and financial position. Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). Among other things, ASU 2017-04 requires the following: (1) the elimination of step two of the goodwill impairment test; entities will no longer utilize the implied fair value of their assets and liabilities for purposes of testing goodwill for impairment, (2) the quantitative portion of the goodwill impairment test will be performed by comparing the fair value of a reporting unit with its carrying amount; an impairment charge is to be recognized for the excess of carrying amount over fair value, but only to the extent of the amount of goodwill allocated to that reporting unit, and (3) foreign currency translation adjustments are not to be allocated to a reporting unit from an entity’s accumulated other comprehensive income; the reporting unit’s carrying amount should include only the currently translated balances of the assets and liabilities assigned to the reporting unit. ASU 2017-04 is effective for public business entities that are SEC filers for annual periods, or any interim goodwill impairment tests in annual periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company’s consolidated statements of operations and financial position. Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement

Acquisition of Tokio Millenni_2

Acquisition of Tokio Millennium Re (Tables)	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Schedule of Acquisition Purchase Price	The Company's total purchase price for the TMR Group Entities was calculated as follows: Special Dividend Special Dividend paid to common shareholders of Tokio and holders of Tokio equity awards $ 500,000 RenaissanceRe common shares Common shares issued by RenaissanceRe to Tokio 1,739,071 Common share price of RenaissanceRe (1) $ 143.75 Market value of RenaissanceRe common shares issued by RenaissanceRe to Tokio 249,998 Cash consideration Cash consideration paid by RenaissanceRe as acquisition consideration 813,595 Total purchase price 1,563,593 Less: Special Dividend paid to Tokio (500,000 ) Net purchase price $ 1,063,593 (1) RenaissanceRe common share price is based on the 30-day trailing volume weighted average price of $143.7539
Schedule of Fair Value of Net Assets Acquired and Liabilities Assumed	The Company recognized identifiable finite lived intangible assets of $11.2 million , which will be amortized over a weighted average period of 10.5 years , identifiable indefinite lived intangible assets of $6.8 million , and certain other adjustments to the fair values of the assets acquired, liabilities assumed and shareholders’ equity of the TMR Group Entities at March 22, 2019 as summarized in the table below: Shareholders’ equity of the TMR Group Entities at March 22, 2019 $ 1,032,961 Adjustments for fair value, by applicable balance sheet caption: Net deferred acquisition costs and value of business acquired (56,788 ) Net reserve for claims and claim expenses 67,782 Goodwill and intangible assets at March 22, 2019 of the TMR Group Entities (6,569 ) Total adjustments for fair value by applicable balance sheet caption before tax impact 4,425 Other assets - net deferred tax liability related to fair value adjustments and value of business acquired (2,606 ) Total adjustments for fair value by applicable balance sheet caption, net of tax 1,819 Adjustments for fair value of the identifiable intangible assets: Identifiable indefinite lived intangible assets (insurance licenses) 6,800 Identifiable finite lived intangible assets (top broker relationships and renewal rights) 11,200 Identifiable intangible assets before tax impact 18,000 Other assets - deferred tax liability on identifiable intangible assets (2,281 ) Total adjustments for fair value of the identifiable intangible assets and value of business acquired, net of tax 15,719 Total adjustments for fair value by applicable balance sheet caption, identifiable intangible assets and value of business acquired, net of tax 17,538 Shareholders’ equity of the TMR Group Entities at fair value 1,050,499 Total net purchase price paid by RenaissanceRe 1,063,593 Excess purchase price over the fair value of net assets acquired assigned to goodwill $ 13,094
Schedule of Identifiable Intangible Sssets Acquired	Identifiable intangible assets at March 22, 2019 and at March 31, 2019, consisted of the following, and are included in goodwill and other intangible assets on the Company’s consolidated balance sheet: Amount Economic Useful Life Top broker relationships $ 10,000 10.0 years Renewal rights 1,200 15.0 years Insurance licenses 6,800 Indefinite Net identifiable intangible assets at March 31, 2019 related to the acquisition of the TMR Group Entities $ 18,000
Schedule of Business Acquisition, Pro Forma Information	The following table presents unaudited pro forma consolidated financial information for the three months ended March 31, 2019 and 2018 and assumes the acquisition of the TMR Group Entities occurred on January 1, 2018. The unaudited pro forma consolidated financial information is provided for informational purposes only and is not necessarily, and should not be assumed to be, an indication of the results that would have been achieved had the transaction been completed as of January 1, 2018 or that may be achieved in the future. The unaudited pro forma consolidated financial information does not give consideration to the impact of possible revenue enhancements, expense efficiencies, synergies or asset dispositions that may result from the acquisition of the TMR Group Entities. In addition, unaudited pro forma consolidated financial information does not include the effects of costs associated with any restructuring or integration activities resulting from the acquisition of the TMR Group Entities, as they are nonrecurring. Three months ended March 31, 2019 March 31, 2018 Total revenues $ 1,148,146 $ 725,269 Net income available to RenaissanceRe common shareholders 330,394 27,605

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2019
Investments [Abstract]
Schedule of Fair Value of Fixed Maturity and Equity Investments Trading	The following table summarizes the fair value of fixed maturity investments trading: March 31, December 31, U.S. treasuries $ 3,097,089 $ 3,331,411 Agencies 182,904 174,883 Municipal 256,967 6,854 Non-U.S. government 687,021 279,818 Non-U.S. government-backed corporate 286,331 160,063 Corporate 2,971,018 2,450,244 Agency mortgage-backed 955,616 817,880 Non-agency mortgage-backed 272,880 278,680 Commercial mortgage-backed 245,323 282,294 Asset-backed 518,011 306,743 Total fixed maturity investments trading (1) $ 9,473,160 $ 8,088,870 March 31, December 31, Financials $ 222,604 $ 200,357 Communications and technology 66,428 42,333 Industrial, utilities and energy 37,574 24,520 Consumer 31,378 20,639 Healthcare 26,867 18,925 Basic materials 5,086 3,478 Total $ 389,937 $ 310,252
Schedule of Contractual Maturities of Fixed Maturity Investments	Contractual maturities of fixed maturity investments trading are described in the following table. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. March 31, 2019 Amortized Cost Fair Value Due in less than one year $ 746,898 $ 744,030 Due after one through five years 5,287,434 5,301,425 Due after five through ten years 1,147,028 1,154,682 Due after ten years 281,009 281,193 Mortgage-backed 1,460,090 1,473,819 Asset-backed 519,911 518,011 Total $ 9,442,370 $ 9,473,160
Schedule of Net Investment Income	The components of net investment income are as follows: Three months ended March 31, March 31, Fixed maturity investments $ 61,483 $ 45,643 Short term investments 11,844 5,304 Equity investments 1,027 698 Other investments Private equity investments 2,454 (434 ) Other 7,245 8,023 Cash and cash equivalents 1,517 565 85,570 59,799 Investment expenses (4,108 ) (3,323 ) Net investment income $ 81,462 $ 56,476
Schedule of Net Realized and Unrealized Gains (Losses)	Net realized and unrealized gains (losses) on investments are as follows: Three months ended March 31, March 31, Gross realized gains $ 24,373 $ 4,583 Gross realized losses (22,943 ) (25,853 ) Net realized gains (losses) on fixed maturity investments 1,430 (21,270 ) Net unrealized gains (losses) on fixed maturity investments trading 103,922 (55,372 ) Net realized and unrealized gains (losses) on investments-related derivatives 13,796 (4,364 ) Net realized (losses) gains on equity investments trading sold during the period (1,161 ) 234 Net unrealized gains (losses) on equity investments trading still held at reporting date 52,658 (1,372 ) Net realized and unrealized gains (losses) on equity investments trading 51,497 (1,138 ) Net realized and unrealized gains (losses) on investments $ 170,645 $ (82,144 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Below is a summary of the assets and liabilities that are measured at fair value on a recurring basis and also represents the carrying amount on the Company’s consolidated balance sheets: At March 31, 2019 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fixed maturity investments U.S. treasuries $ 3,097,089 $ 3,097,089 $ — $ — Agencies 182,904 — 182,904 — Municipal 256,967 — 256,967 — Non-U.S. government 687,021 — 687,021 — Non-U.S. government-backed corporate 286,331 — 286,331 — Corporate 2,971,018 — 2,971,018 — Agency mortgage-backed 955,616 — 955,616 — Non-agency mortgage-backed 272,880 — 272,880 — Commercial mortgage-backed 245,323 — 245,323 — Asset-backed 518,011 — 518,011 — Total fixed maturity investments 9,473,160 3,097,089 6,376,071 — Short term investments 4,012,815 — 4,012,815 — Equity investments trading 389,937 389,937 — — Other investments Catastrophe bonds 556,380 — 556,380 — Private equity investments (1) 253,566 — — 63,695 Senior secured bank loan funds (1) 15,674 — — — Hedge funds (1) 11,585 — — — Miscellaneous other investments (1) 41,168 — — — Total other investments 878,373 — 556,380 63,695 Other assets and (liabilities) Assumed and ceded (re)insurance contracts (2) 11,827 — — 11,827 Derivatives (3) 5,817 (2,067 ) 7,884 — Total other assets and (liabilities) 17,644 (2,067 ) 7,884 11,827 $ 14,771,929 $ 3,484,959 $ 10,953,150 $ 75,522 (1) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (2) Included in assumed and ceded (re)insurance contracts at March 31, 2019 was $47.6 million of other assets and $35.8 million of other liabilities. Of these amounts, $41.7 million of other assets and $21.7 million of other liabilities was reflected as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (3) See “Note 14 . Derivative Instruments” for additional information related to the fair value by type of contract, of derivatives entered into by the Company. At December 31, 2018 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fixed maturity investments U.S. treasuries $ 3,331,411 $ 3,331,411 $ — $ — Agencies 174,883 — 174,883 — Municipal 6,854 — 6,854 — Non-U.S. government 279,818 — 279,818 — Non-U.S. government-backed corporate 160,063 — 160,063 — Corporate 2,450,244 — 2,450,244 — Agency mortgage-backed 817,880 — 817,880 — Non-agency mortgage-backed 278,680 — 278,680 — Commercial mortgage-backed 282,294 — 282,294 — Asset-backed 306,743 — 306,743 — Total fixed maturity investments 8,088,870 3,331,411 4,757,459 — Short term investments 2,586,520 — 2,586,520 — Equity investments trading 310,252 310,252 — — Other investments Catastrophe bonds 516,571 — 516,571 — Private equity investments (1) 242,647 — — 54,545 Senior secured bank loan funds (1) 14,482 — — — Hedge funds (1) 11,233 — — — Total other investments 784,933 — 516,571 54,545 Other assets and (liabilities) Assumed and ceded (re)insurance contracts (2) (8,359 ) — — (8,359 ) Derivatives (3) 12,399 484 11,915 — Total other assets and (liabilities) 4,040 484 11,915 (8,359 ) $ 11,774,615 $ 3,642,147 $ 7,872,465 $ 46,186 (1) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (2) Included in assumed and ceded (re)insurance contracts at December 31, 2018 was $5.0 million of other assets and $13.3 million of other liabilities. (3) See “Note 14
Schedule of Quantitative Information Used as Level 3 Inputs	Below is a summary of quantitative information regarding the significant unobservable inputs (Level 3) used in determining the fair value of assets and liabilities measured at fair value on a recurring basis: At March 31, 2019 Fair Value (Level 3) Valuation Technique Unobservable Low High Weighted Average or Actual Other investments Private equity investment $ 10,174 External valuation model Indicative pricing n/a n/a $ 101.74 Private equity investments 53,521 Internal valuation model Liquidity discount n/a n/a 12.5 % Total other investments 63,695 Other assets and (liabilities) Assumed and ceded (re)insurance contracts 523 Internal valuation model Bond price $ 100.64 $ 107.97 $ 104.71 Liquidity discount n/a n/a 1.3 % Assumed and ceded (re)insurance contracts (8,356 ) Internal valuation model Net undiscounted cash flows n/a n/a $ 10,413 Expected loss ratio n/a n/a 39.5 % Discount rate n/a n/a 2.2 % Assumed and ceded (re)insurance contracts 19,660 Internal valuation model Expected loss ratio n/a n/a 0.0 % Total other assets and (liabilities) 11,827 Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs $ 75,522
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs	Below is a reconciliation of the beginning and ending balances, for the periods shown, of assets and liabilities measured at fair value on a recurring basis using Level 3 inputs. Interest and dividend income are included in net investment income and are excluded from the reconciliation. Other investments Other assets and (liabilities) Total Balance - January 1, 2019 $ 54,545 $ (8,359 ) $ 46,186 Total realized and unrealized gains Included in other income (loss) (1,111 ) 1,093 (18 ) Total foreign exchange losses (1 ) — (1 ) Purchases 10,262 (897 ) 9,365 Settlements — 20 20 Amounts acquired (1) — 19,970 19,970 Balance - March 31, 2019 $ 63,695 $ 11,827 $ 75,522 (1) Represents the fair value of the other assets acquired from the TMR Group Entities, measured at fair value on a recurring basis using Level 3 inputs at March 22, 2019. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Other assets and (liabilities) Balance - January 1, 2018 $ (2,952 ) Total realized and unrealized gains Included in other income (loss) 206 Purchases (34 ) Balance - March 31, 2018 $ (2,780 )
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs	Below is a reconciliation of the beginning and ending balances, for the periods shown, of assets and liabilities measured at fair value on a recurring basis using Level 3 inputs. Interest and dividend income are included in net investment income and are excluded from the reconciliation. Other investments Other assets and (liabilities) Total Balance - January 1, 2019 $ 54,545 $ (8,359 ) $ 46,186 Total realized and unrealized gains Included in other income (loss) (1,111 ) 1,093 (18 ) Total foreign exchange losses (1 ) — (1 ) Purchases 10,262 (897 ) 9,365 Settlements — 20 20 Amounts acquired (1) — 19,970 19,970 Balance - March 31, 2019 $ 63,695 $ 11,827 $ 75,522 (1) Represents the fair value of the other assets acquired from the TMR Group Entities, measured at fair value on a recurring basis using Level 3 inputs at March 22, 2019. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Other assets and (liabilities) Balance - January 1, 2018 $ (2,952 ) Total realized and unrealized gains Included in other income (loss) 206 Purchases (34 ) Balance - March 31, 2018 $ (2,780 )
Schedule of Balances Elected to Account for at Fair Value	Below is a summary of the balances the Company has elected to account for at fair value: March 31, December 31, Other investments $ 878,373 $ 784,933 Other assets $ 47,596 $ 4,968 Other liabilities $ 35,769 $ 13,327
Schedule of Other Investments Measured Using Net Asset Valuations	The table below shows the Company’s portfolio of other investments measured using net asset valuations as a practical expedient: At March 31, 2019 Fair Value Unfunded Redemption Frequency Redemption Redemption Private equity investments $ 189,871 $ 381,143 See below See below See below Senior secured bank loan funds 15,674 17,209 See below See below See below Hedge funds 11,585 — See below See below See below Miscellaneous other investments 41,168 — See below See below See below Total other investments measured using net asset valuations $ 258,298 $ 398,352

Reinsurance (Tables)

Reinsurance (Tables)	3 Months Ended
	Mar. 31, 2019
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Effect of Reinsurance and Retrocessional Activity on Premiums Written and Earned and on Net Claims and Claim Expenses Incurred	The following table sets forth the effect of reinsurance and retrocessional activity on premiums written and earned and on net claims and claim expenses incurred: Three months ended March 31, March 31, Premiums written Direct $ 110,968 $ 85,167 Assumed 1,453,327 1,074,485 Ceded (635,264 ) (496,608 ) Net premiums written $ 929,031 $ 663,044 Premiums earned Direct $ 89,814 $ 70,032 Assumed 765,433 605,483 Ceded (305,219 ) (235,233 ) Net premiums earned $ 550,028 $ 440,282 Claims and claim expenses Gross claims and claim expenses incurred $ 338,119 $ 225,742 Claims and claim expenses recovered (111,084 ) (54,039 ) Net claims and claim expenses incurred $ 227,035 $ 171,703

Reserve for Claims and Claim _2

Reserve for Claims and Claim Expenses (Tables)	3 Months Ended
	Mar. 31, 2019
Insurance Loss Reserves [Abstract]
Schedule of Liability for Unpaid Claims and Claim Expenses	The following table details the Company’s prior year development by segment of its liability for unpaid claims and claim expenses: Three months ended March 31, 2019 2018 (Favorable) adverse development (Favorable) adverse development Property $ 1,877 $ (27,562 ) Casualty and Specialty (6,202 ) (3,791 ) Other 19 18 Total favorable development of prior accident years net claims and claim expenses $ (4,306 ) $ (31,335 ) Three months ended March 31, 2019 2018 (Favorable) adverse development (Favorable) adverse development Actuarial methods $ (6,202 ) $ (3,791 ) Total favorable development of prior accident years net claims and claim expenses $ (6,202 ) $ (3,791 ) At March 31, 2019 Case Reserves Additional Case Reserves IBNR Total Property $ 1,243,455 $ 1,598,283 $ 844,681 $ 3,686,419 Casualty and Specialty 1,454,164 121,165 3,125,166 4,700,495 Other 1,404 — 3,166 4,570 Total (1) $ 2,699,023 $ 1,719,448 $ 3,973,013 $ 8,391,484 At December 31, 2018 Property $ 690,718 $ 1,308,307 $ 1,087,229 $ 3,086,254 Casualty and Specialty 771,537 116,877 2,096,979 2,985,393 Other 1,458 — 3,166 4,624 Total $ 1,463,713 $ 1,425,184 $ 3,187,374 $ 6,076,271 (1) Included in the Company’s reserves for claims and claim expenses balance at March 31, 2019 is $2.4 billion of gross reserves for claims and claim expenses, at fair value, acquired as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. Activity in the liability for unpaid claims and claim expenses is summarized as follows: Three months ended March 31, 2019 2018 Net reserves as of January 1 $ 3,704,050 $ 3,493,778 Net incurred related to: Current year 231,341 203,038 Prior years (4,306 ) (31,335 ) Total net incurred 227,035 171,703 Net paid related to: Current year 8,149 9,050 Prior years 300,120 328,129 Total net paid 308,269 337,179 Amounts acquired (1) 1,858,775 — Foreign exchange 1,550 12,104 Net reserves as of March 31 5,483,141 3,340,406 Reinsurance recoverable as of March 31 2,908,343 1,572,321 Gross reserves as of March 31 $ 8,391,484 $ 4,912,727 (1) Represents the fair value of the TMR Group Entities reserves for claims and claim expenses, net of reinsurance recoverables, acquired at March 22, 2019. See “Note 3 Three months ended March 31, 2019 (Favorable) adverse development Catastrophe net claims and claim expenses Large catastrophe events 2017 Large Loss Events $ (10,918 ) Other (1,374 ) Total large catastrophe events (12,292 ) Small catastrophe events and attritional loss movements Other small catastrophe events and attritional loss movements 14,169 Total small catastrophe events and attritional loss movements 14,169 Total net adverse development of prior accident years net claims and claim expenses $ 1,877 Three months ended March 31, 2018 (Favorable) adverse development Catastrophe net claims and claim expenses Large catastrophe events 2017 Large Loss Events $ (27,109 ) Other (4,258 ) Total large catastrophe events (31,367 ) Small catastrophe events and attritional loss movements Other small catastrophe events and attritional loss movements 3,805 Total small catastrophe events and attritional loss movements 3,805 Total net favorable development of prior accident years net claims and claim expenses $ (27,562 )

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	A summary of the Company’s debt obligations on its consolidated balance sheets is set forth below: March 31, 2019 December 31, 2018 Fair Value Carrying Value Fair Value Carrying Value 3.450% Senior Notes due 2027 294,450 295,920 283,680 295,797 3.700% Senior Notes due 2025 297,801 297,779 292,557 297,688 5.750% Senior Notes due 2020 256,055 249,683 255,938 249,602 4.750% Senior Notes due 2025 (DaVinciRe) (1) 145,671 148,117 142,539 148,040 Total senior notes 993,977 991,499 974,714 991,127 RenaissanceRe Revolving Credit Facility (2) 200,000 200,000 — — Total debt $ 1,193,977 $ 1,191,499 $ 974,714 $ 991,127 (1) RenaissanceRe owns a noncontrolling economic interest in its joint venture DaVinciRe. Because RenaissanceRe controls a majority of DaVinciRe’s outstanding voting rights, the consolidated financial statements of DaVinciRe are included in the consolidated financial statements of RenaissanceRe. However, RenaissanceRe does not guarantee or provide credit support for DaVinciRe and RenaissanceRe’s financial exposure to DaVinciRe is limited to its investment in DaVinciRe’s shares and counterparty credit risk arising from reinsurance transactions. (2) The drawn amount of the Company’s revolving credit facility is included on the Company’s consolidated balance sheets under debt and is also included in the table below as part of the Company’s significant credit facilities. The amount was drawn in connection with the TMR Stock Purchase. See “Note 3
Schedule of Line of Credit Facilities	The outstanding amounts issued or drawn under each of the Company’s significant credit facilities is set forth below: At March 31, 2019 Issued or Drawn RenaissanceRe Revolving Credit Facility (1) $ 200,000 Uncommitted Standby Letter of Credit Facility with Wells Fargo 32,009 Secured Letter of Credit Facility with Citibank Europe 238,956 Renaissance Reinsurance FAL Facility 255,000 Mizuho Letters of Credit (2) 385,975 Mitsubishi Letters of Credit (2) 205,956 Credit Suisse Letter of Credit Facility 75,097 Uncommitted, Unsecured Letter of Credit Facility with Citibank Europe (3) — Total credit facilities in U.S. dollars $ 1,392,993 Specialty Risks FAL Facility (3) £ — Total credit facilities in pound sterling £ — (1) The drawn amount of the Company’s revolving credit facility is included on the Company’s consolidated balance sheet under debt and is also included in the table above as part of the Company’s significant credit facilities. The amount was drawn as a result of the acquisition of the TMR Group Entities. See “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (2) These letters of credit were transferred to the Company in connection with the acquisition of the TMR Group Entities. See below under “TMR Group Entities Letters of Credit” for additional information and “Note 3 . Acquisition of Tokio Millennium Re” for additional information related to the acquisition of the TMR Group Entities. (3) At March 31, 2019 , no amounts were issued or drawn under these facilities

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	3 Months Ended
	Mar. 31, 2019
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest [Abstract]
Schedule of Redeemable Noncontrolling Interest	The activity in redeemable noncontrolling interest – Medici is detailed in the table below: Three months ended March 31, March 31, Beginning balance $ 416,765 $ 284,847 Redemption of shares from redeemable noncontrolling interest, net of adjustments (15,884 ) (711 ) Sale of shares to redeemable noncontrolling interests 3,596 99,739 Net income attributable to redeemable noncontrolling interest 2,481 8,946 Ending balance $ 406,958 $ 392,821 Three months ended March 31, March 31, Beginning balance $ 1,034,946 $ 1,011,659 Redemption of shares from redeemable noncontrolling interest, net of adjustments (234 ) (69 ) Net income attributable to redeemable noncontrolling interest 62,533 20,953 Ending balance $ 1,097,245 $ 1,032,543 March 31, December 31, 2018 Redeemable noncontrolling interest - DaVinciRe $ 1,097,245 $ 1,034,946 Redeemable noncontrolling interest - Medici 406,958 416,765 Redeemable noncontrolling interest - Vermeer 605,197 599,989 Redeemable noncontrolling interests $ 2,109,400 $ 2,051,700 A summary of the Company’s redeemable noncontrolling interests on its consolidated statements of operations is set forth below: Three months ended March 31, March 31, Redeemable noncontrolling interest - DaVinciRe $ 62,533 $ 20,953 Redeemable noncontrolling interest - Medici 2,481 8,946 Redeemable noncontrolling interest - Vermeer 5,208 — Net income attributable to redeemable noncontrolling interests $ 70,222 $ 29,899 Three months ended March 31, March 31, Beginning balance $ 599,989 $ — Net income attributable to redeemable noncontrolling interest 5,208 — Ending balance $ 605,197 $ —

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings per common share: Three months ended (common shares in thousands) March 31, March 31, Numerator: Net income available to RenaissanceRe common shareholders $ 273,717 $ 56,713 Amount allocated to participating common shareholders (1) (3,121 ) (546 ) Net income allocated to RenaissanceRe common shareholders $ 270,596 $ 56,167 Denominator: Denominator for basic income per RenaissanceRe common share - weighted average common shares 42,065 39,552 Per common share equivalents of employee stock options and restricted shares 26 47 Denominator for diluted income per RenaissanceRe common share - adjusted weighted average common shares and assumed conversions 42,091 39,599 Net income available to RenaissanceRe common shareholders per common share – basic $ 6.43 $ 1.42 Net income available to RenaissanceRe common shareholders per common share – diluted $ 6.43 $ 1.42 (1)

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting, Measurement Disclosures [Abstract]
Schedule of Significant Components of the Company's Revenues and Expenses by Segment	A summary of the significant components of the Company’s revenues and expenses by segment is as follows: Three months ended March 31, 2019 Property Casualty and Specialty Other Total Gross premiums written $ 1,032,384 $ 531,911 $ — $ 1,564,295 Net premiums written $ 564,230 $ 364,801 $ — $ 929,031 Net premiums earned $ 290,745 $ 259,283 $ — $ 550,028 Net claims and claim expenses incurred 56,083 170,933 19 227,035 Acquisition expenses 53,739 70,212 — 123,951 Operational expenses 28,544 16,389 — 44,933 Underwriting income (loss) $ 152,379 $ 1,749 $ (19 ) 154,109 Net investment income 81,462 81,462 Net foreign exchange losses (2,846 ) (2,846 ) Equity in earnings of other ventures 4,661 4,661 Other income 3,171 3,171 Net realized and unrealized gains on investments 170,645 170,645 Corporate expenses (38,789 ) (38,789 ) Interest expense (11,754 ) (11,754 ) Income before taxes and redeemable noncontrolling interests 360,659 Income tax expense (7,531 ) (7,531 ) Net income attributable to redeemable noncontrolling interests (70,222 ) (70,222 ) Dividends on preference shares (9,189 ) (9,189 ) Net income available to RenaissanceRe common shareholders $ 273,717 Net claims and claim expenses incurred – current accident year $ 54,206 $ 177,135 $ — $ 231,341 Net claims and claim expenses incurred – prior accident years 1,877 (6,202 ) 19 (4,306 ) Net claims and claim expenses incurred – total $ 56,083 $ 170,933 $ 19 $ 227,035 Net claims and claim expense ratio – current accident year 18.6 % 68.3 % 42.1 % Net claims and claim expense ratio – prior accident years 0.7 % (2.4 )% (0.8 )% Net claims and claim expense ratio – calendar year 19.3 % 65.9 % 41.3 % Underwriting expense ratio 28.3 % 33.4 % 30.7 % Combined ratio 47.6 % 99.3 % 72.0 % Three months ended March 31, 2018 Property Casualty and Specialty Other Total Gross premiums written $ 706,968 $ 452,684 $ — $ 1,159,652 Net premiums written $ 354,077 $ 308,967 $ — $ 663,044 Net premiums earned $ 225,049 $ 215,233 $ — $ 440,282 Net claims and claim expenses incurred 30,607 141,078 18 171,703 Acquisition expenses 40,721 56,990 — 97,711 Operational expenses 26,546 14,593 133 41,272 Underwriting income (loss) $ 127,175 $ 2,572 $ (151 ) 129,596 Net investment income 56,476 56,476 Net foreign exchange gains 3,757 3,757 Equity in earnings of other ventures 857 857 Other loss (1,242 ) (1,242 ) Net realized and unrealized losses on investments (82,144 ) (82,144 ) Corporate expenses (6,733 ) (6,733 ) Interest expense (11,767 ) (11,767 ) Income before taxes and redeemable noncontrolling interests 88,800 Income tax benefit 3,407 3,407 Net income attributable to redeemable noncontrolling interests (29,899 ) (29,899 ) Dividends on preference shares (5,595 ) (5,595 ) Net income available to RenaissanceRe common shareholders $ 56,713 Net claims and claim expenses incurred – current accident year $ 58,169 $ 144,869 $ — $ 203,038 Net claims and claim expenses incurred – prior accident years (27,562 ) (3,791 ) 18 (31,335 ) Net claims and claim expenses incurred – total $ 30,607 $ 141,078 $ 18 $ 171,703 Net claims and claim expense ratio – current accident year 25.8 % 67.3 % 46.1 % Net claims and claim expense ratio – prior accident years (12.2 )% (1.8 )% (7.1 )% Net claims and claim expense ratio – calendar year 13.6 % 65.5 % 39.0 % Underwriting expense ratio 29.9 % 33.3 % 31.6 % Combined ratio 43.5 % 98.8 % 70.6 %

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Summary of Derivative Instruments [Abstract]
Schedule of Location on Consolidated Balance Sheets and Fair Value of Principal Derivative Instruments	The tables below show the gross and net amounts of recognized derivative assets and liabilities at fair value, including the location on the consolidated balance sheets of the Company’s principal derivative instruments: Derivative Assets At March 31, 2019 Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet Balance Sheet Location Collateral Net Amount Interest rate futures $ 1,263 1,206 $ 57 Other assets $ — $ 57 Interest rate swaps 6 — 6 Other assets — 6 Foreign currency forward contracts (1) 10,490 152 10,338 Other assets — 10,338 Foreign currency forward contracts (2) 743 64 679 Other assets — 679 Credit default swaps 121 — 121 Other assets — 121 Total return swaps 600 — 600 Other assets — 600 Total $ 13,223 $ 1,422 $ 11,801 $ — $ 11,801 Derivative Liabilities At March 31, 2019 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet Balance Sheet Location Collateral Pledged Net Amount Interest rate futures $ 3,330 1,206 $ 2,124 Other liabilities $ 2,113 $ 11 Interest rate swaps 71 — 71 Other liabilities 71 — Foreign currency forward contracts (1) 3,011 103 2,908 Other liabilities — 2,908 Foreign currency forward contracts (2) 945 64 881 Other liabilities — 881 Total $ 7,357 $ 1,373 $ 5,984 $ 2,184 $ 3,800 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2) Contracts used to manage foreign currency risks in investment operations. Derivative Assets At December 31, 2018 Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet Balance Sheet Location Collateral Net Amount Interest rate futures $ 2,361 1,660 $ 701 Other assets $ — $ 701 Interest rate swaps 860 — 860 Other assets — 860 Foreign currency forward contracts (1) 16,459 2,260 14,199 Other assets — 14,199 Foreign currency forward contracts (2) 3,194 71 3,123 Other assets — 3,123 Total $ 22,874 $ 3,991 $ 18,883 $ — $ 18,883 Derivative Liabilities At December 31, 2018 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet Balance Sheet Location Collateral Pledged Net Amount Interest rate futures $ 1,887 1,670 $ 217 Other liabilities $ 217 $ — Interest rate swaps 506 — 506 Other liabilities 254 252 Foreign currency forward contracts (1) 4,154 — 4,154 Other liabilities — 4,154 Foreign currency forward contracts (2) 72 71 1 Other liabilities — 1 Credit default swaps 1,606 — 1,606 Other liabilities 1,605 1 Total $ 8,225 $ 1,741 $ 6,484 $ 2,076 $ 4,408 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2)
Schedule of Gain (Loss) Recognized in Consolidated Statements of Operations Related to Principal Derivative Instruments	The location and amount of the gain (loss) recognized in the Company’s consolidated statements of operations related to its principal derivative instruments are shown in the following table: Location of gain (loss) recognized on derivatives Amount of gain (loss) recognized on derivatives Three months ended March 31, 2019 2018 Interest rate futures Net realized and unrealized gains (losses) on investments $ 8,503 $ (2,337 ) Interest rate swaps Net realized and unrealized gains (losses) on investments 349 (106 ) Foreign currency forward contracts (1) Net foreign exchange (losses) gains 4,442 6,743 Foreign currency forward contracts (2) Net foreign exchange (losses) gains 1,145 (691 ) Credit default swaps Net realized and unrealized gains (losses) on investments 4,410 (1,921 ) Total return swaps Net realized and unrealized gains (losses) on investments 534 — Total $ 19,383 $ 1,688 (1) Contracts used to manage foreign currency risks in underwriting and non-investment operations. (2) Contracts used to manage foreign currency risks in investment operations.

Commitments, Contingencies an_2

Commitments, Contingencies and Other Items (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments Under Existing Operating Leases	Future minimum lease payments under existing operating and finance leases are detailed below, excluding the bargain renewal option on the finance lease related to office space in Bermuda: Future minimum lease payments Operating leases Finance leases 2019 (remaining) $ 5,722 $ 2,498 2020 5,439 3,336 2021 5,052 3,336 2022 4,261 3,336 2023 1,569 2,830 2024 86 2,661 After 2024 211 10,129 Future minimum lease payments under existing leases $ 22,340 $ 28,126
Future Minimum Lease Payments Under Existing Finance Leases	Future minimum lease payments under existing operating and finance leases are detailed below, excluding the bargain renewal option on the finance lease related to office space in Bermuda: Future minimum lease payments Operating leases Finance leases 2019 (remaining) $ 5,722 $ 2,498 2020 5,439 3,336 2021 5,052 3,336 2022 4,261 3,336 2023 1,569 2,830 2024 86 2,661 After 2024 211 10,129 Future minimum lease payments under existing leases $ 22,340 $ 28,126

Condensed Consolidating Finan_2

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Tables)	3 Months Ended
	Mar. 31, 2019
Condensed Consolidating Financial Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]
Condensed Consolidating Balance Sheets	(1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor, Subsidiary Guarantor and Subsidiary Issuer consolidating adjustments. Condensed Consolidating Balance Sheet at December 31, 2018 RenaissanceRe Holdings Ltd. (Parent Guarantor) RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-guarantor Subsidiaries) (1) Consolidating Adjustments (2) RenaissanceRe Consolidated Assets Total investments $ 313,360 $ 77,842 $ 28,885 $ 11,465,660 $ — $ 11,885,747 Cash and cash equivalents 3,534 3,350 9,604 1,091,434 — 1,107,922 Investments in subsidiaries 4,414,475 58,458 1,215,663 — (5,688,596 ) — Due from subsidiaries and affiliates 57,039 101,579 — — (158,618 ) — Premiums receivable — — — 1,537,188 — 1,537,188 Prepaid reinsurance premiums — — — 616,185 — 616,185 Reinsurance recoverable — — — 2,372,221 — 2,372,221 Accrued investment income 1,046 310 127 49,828 — 51,311 Deferred acquisition costs — — — 476,661 — 476,661 Receivable for investments sold 203 23,885 — 232,328 — 256,416 Other assets 458,842 22,571 313,636 (1,403,636 ) 743,714 135,127 Goodwill and other intangible assets 120,476 — — 116,942 — 237,418 Total assets $ 5,368,975 $ 287,995 $ 1,567,915 $ 16,554,811 $ (5,103,500 ) $ 18,676,196 Liabilities, Redeemable Noncontrolling Interest and Shareholders’ Equity Liabilities Reserve for claims and claim expenses $ — $ — $ — $ 6,076,271 $ — $ 6,076,271 Unearned premiums — — — 1,716,021 — 1,716,021 Debt 300,000 — 843,086 148,041 (300,000 ) 991,127 Amounts due to subsidiaries and affiliates 6,453 217 102,243 — (108,913 ) — Reinsurance balances payable — — — 1,902,056 — 1,902,056 Payable for investments purchased — 24 — 380,308 — 380,332 Other liabilities 17,442 5,362 13,918 482,422 (5,535 ) 513,609 Total liabilities 323,895 5,603 959,247 10,705,119 (414,448 ) 11,579,416 Redeemable noncontrolling interests — — — 2,051,700 — 2,051,700 Shareholders’ Equity Total shareholders’ equity 5,045,080 282,392 608,668 3,797,992 (4,689,052 ) 5,045,080 Total liabilities, redeemable noncontrolling interest and shareholders’ equity $ 5,368,975 $ 287,995 $ 1,567,915 $ 16,554,811 $ (5,103,500 ) $ 18,676,196 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Includes Parent Guarantor and Subsidiary Issuer consolidating adjustments.
Condensed Consolidating Statements of Operations	Condensed Consolidating Statement of Operations for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Revenues Net premiums earned $ — $ — $ — $ 440,282 $ — $ 440,282 Net investment income 6,035 513 1,234 56,305 (7,611 ) 56,476 Net foreign exchange (losses) gains (3 ) — — 3,760 — 3,757 Equity in earnings (losses) of other ventures — — 1,211 (354 ) — 857 Other loss — — — (1,242 ) — (1,242 ) Net realized and unrealized (losses) on investments (661 ) (1,286 ) (259 ) (79,938 ) — (82,144 ) Total revenues 5,371 (773 ) 2,186 418,813 (7,611 ) 417,986 Expenses Net claims and claim expenses incurred — — — 171,703 — 171,703 Acquisition expenses — — — 97,711 — 97,711 Operational expenses 1,313 10 11,070 37,933 (9,054 ) 41,272 Corporate expenses 3,684 — — 3,049 — 6,733 Interest expense 1,108 — 9,252 2,515 (1,108 ) 11,767 Total expenses 6,105 10 20,322 312,911 (10,162 ) 329,186 (Loss) income before equity in net income (loss) of subsidiaries and taxes (734 ) (783 ) (18,136 ) 105,902 2,551 88,800 Equity in net income (loss) of subsidiaries 62,426 834 (3,813 ) — (59,447 ) — Income (loss) before taxes 61,692 51 (21,949 ) 105,902 (56,896 ) 88,800 Income tax benefit 616 221 1,815 755 — 3,407 Net income (loss) 62,308 272 (20,134 ) 106,657 (56,896 ) 92,207 Net income attributable to redeemable noncontrolling interests — — — (29,899 ) — (29,899 ) Net income (loss) attributable to RenaissanceRe 62,308 272 (20,134 ) 76,758 (56,896 ) 62,308 Dividends on preference shares (5,595 ) — — — — (5,595 ) Net income (loss) available (attributable) to RenaissanceRe common shareholders $ 56,713 $ 272 $ (20,134 ) $ 76,758 $ (56,896 ) $ 56,713 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Condensed Consolidating Statement of Operations for RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Revenues Net premiums earned $ — $ — $ — $ 550,028 $ — $ 550,028 Net investment income 8,277 595 2,060 79,332 (8,802 ) 81,462 Net foreign exchange losses (1 ) — — (2,845 ) — (2,846 ) Equity in earnings of other ventures — — 965 3,696 — 4,661 Other income — — — 3,171 — 3,171 Net realized and unrealized gains on investments 1,002 8,159 109 161,375 — 170,645 Total revenues 9,278 8,754 3,134 794,757 (8,802 ) 807,121 Expenses Net claims and claim expenses incurred — — — 227,035 — 227,035 Acquisition expenses — — — 123,951 — 123,951 Operational expenses 469 11 12,333 42,609 (10,489 ) 44,933 Corporate expenses 38,828 — — (1,922 ) 1,883 38,789 Interest expense 1,883 — 9,252 619 — 11,754 Total expenses 41,180 11 21,585 392,292 (8,606 ) 446,462 (Loss) income before equity in net income of subsidiaries and taxes (31,902 ) 8,743 (18,451 ) 402,465 (196 ) 360,659 Equity in net income of subsidiaries 314,887 828 33,532 — (349,247 ) — Income before taxes 282,985 9,571 15,081 402,465 (349,443 ) 360,659 Income tax (expense) benefit (79 ) (1,805 ) 1,662 (7,309 ) — (7,531 ) Net income 282,906 7,766 16,743 395,156 (349,443 ) 353,128 Net income attributable to redeemable noncontrolling interests — — — (70,222 ) — (70,222 ) Net income attributable to RenaissanceRe 282,906 7,766 16,743 324,934 (349,443 ) 282,906 Dividends on preference shares (9,189 ) — — — — (9,189 ) Net income available to RenaissanceRe common shareholders $ 273,717 $ 7,766 $ 16,743 $ 324,934 $ (349,443 ) $ 273,717 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2)
Condensed Consolidating Statement of Comprehensive Income (Loss)	Condensed Consolidating Statement of Comprehensive income (Loss) for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Comprehensive income (loss) Net income (loss) $ 62,308 $ 272 $ (20,134 ) $ 106,657 $ (56,896 ) $ 92,207 Change in net unrealized gains on investments — — — (30 ) — (30 ) Comprehensive income 62,308 272 (20,134 ) 106,627 (56,896 ) 92,177 Net income attributable to redeemable noncontrolling interests — — — (29,899 ) — (29,899 ) Comprehensive income attributable to noncontrolling interests — — — (29,899 ) — (29,899 ) Comprehensive income (loss) attributable to RenaissanceRe $ 62,308 $ 272 $ (20,134 ) $ 76,728 $ (56,896 ) $ 62,278 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2) Condensed Consolidating Statement of Comprehensive Income for the three months ended March 31, 2019 RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other Consolidating RenaissanceRe Comprehensive income Net income $ 282,906 $ 7,766 $ 16,743 $ 395,156 $ (349,443 ) $ 353,128 Change in net unrealized losses on investments — — — (37 ) — (37 ) Comprehensive income 282,906 7,766 16,743 395,119 (349,443 ) 353,091 Net income attributable to redeemable noncontrolling interests — — — (70,222 ) — (70,222 ) Comprehensive income attributable to noncontrolling interests — — — (70,222 ) — (70,222 ) Comprehensive income attributable to RenaissanceRe $ 282,906 $ 7,766 $ 16,743 $ 324,897 $ (349,443 ) $ 282,869 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. (2)
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statement of Cash Flows for the three months ended March 31, 2019 RenaissanceRe RenRe North RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Consolidated Cash flows (used in) provided by operating activities Net cash (used in) provided by operating activities $ (317,296 ) $ 2,198 $ (21,202 ) $ 713,449 $ 377,149 Cash flows provided by (used in) investing activities Proceeds from sales and maturities of fixed maturity investments trading 277,030 15,655 29,861 4,278,262 4,600,808 Purchases of fixed maturity investments trading (35,909 ) (9,899 ) (14,098 ) (3,459,371 ) (3,519,277 ) Net purchases of equity investments trading — (2,046 ) — (2,555 ) (4,601 ) Net purchases of short term investments (54,622 ) (5,386 ) (4,946 ) (1,309,678 ) (1,374,632 ) Net purchases of other investments — — — (51,811 ) (51,811 ) Net purchases of investments in other ventures — — — (1,573 ) (1,573 ) Return of investment from investments in other ventures — — — 11,250 11,250 Dividends and return of capital from subsidiaries 487,264 — — (487,264 ) — Contributions to subsidiaries (528,416 ) — — 528,416 — Due (from) to subsidiary 2,100 (185 ) 6,629 (8,544 ) — Net purchase of the TMR Group Entities — — — (276,206 ) (276,206 ) Net cash provided by (used in) investing activities 147,447 (1,861 ) 17,446 (779,074 ) (616,042 ) Cash flows provided by (used in) financing activities Dividends paid – RenaissanceRe common shares (14,469 ) — — — (14,469 ) Dividends paid – preference shares (9,189 ) — — — (9,189 ) Drawdown of RenaissanceRe Revolving Credit Facility 200,000 — — — 200,000 Net third party redeemable noncontrolling interest share transactions — — — (16,847 ) (16,847 ) Taxes paid on withholding shares (6,957 ) — — — (6,957 ) Net cash provided by (used in) financing activities 169,385 — — (16,847 ) 152,538 Effect of exchange rate changes on foreign currency cash — — — (292 ) (292 ) Net (decrease) increase in cash and cash equivalents (464 ) 337 (3,756 ) (82,764 ) (86,647 ) Cash and cash equivalents, beginning of period 3,534 3,350 9,604 1,091,434 1,107,922 Cash and cash equivalents, end of period $ 3,070 $ 3,687 $ 5,848 $ 1,008,670 $ 1,021,275 (1) Includes all other subsidiaries of RenaissanceRe Holdings Ltd. and eliminations. Condensed Consolidating Statement of Cash Flows for the three months ended March 31, 2018 RenaissanceRe RenRe North Inc. RenaissanceRe Finance, Inc. (Subsidiary Issuer) Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-guarantor Subsidiaries) (1) RenaissanceRe Consolidated Cash flows (used in) provided by operating activities Net cash (used in) provided by operating activities $ (6,875 ) $ 659 $ (23,449 ) $ (7,684 ) $ (37,349 ) Cash flows provided by (used in) investing activities Proceeds from sales and maturities of fixed maturity investments trading 119,542 42,793 27,672 2,128,852 2,318,859 Purchases of fixed maturity investments trading (20,216 ) (22,956 ) (12,698 ) (2,256,591 ) (2,312,461 ) Net (purchases) sales of equity investments trading — (21 ) — 158 137 Net sales (purchases) of short term investments 54,728 (4,024 ) (5,925 ) (639,420 ) (594,641 ) Net purchases of other investments — — — (98,639 ) (98,639 ) Net purchases of investments in other ventures — — — (17,974 ) (17,974 ) Dividends and return of capital from subsidiaries 177,250 — — (177,250 ) — Contributions to subsidiaries (150,205 ) (16,500 ) — 166,705 — Due (from) to subsidiaries (154,877 ) 7 14,106 140,764 — Net cash provided by (used in) investing activities 26,222 (701 ) 23,155 (753,395 ) (704,719 ) Cash flows (used in) provided by financing activities Dividends paid – RenaissanceRe common shares (13,224 ) — — — (13,224 ) Dividends paid – preference shares (5,595 ) — — — (5,595 ) Net third party redeemable noncontrolling interest share transactions — — — 52,759 52,759 Taxes paid on withholding shares (7,034 ) — — — (7,034 ) Net cash (used in) provided by financing activities (25,853 ) — — 52,759 26,906 Effect of exchange rate changes on foreign currency cash — — — 1,543 1,543 Net decrease in cash and cash equivalents (6,506 ) (42 ) (294 ) (706,777 ) (713,619 ) Cash and cash equivalents, beginning of period 14,656 139 1,469 1,345,328 1,361,592 Cash and cash equivalents, end of period $ 8,150 $ 97 $ 1,175 $ 638,551 $ 647,973

Organization (Details)

Organization (Details)	3 Months Ended
	Mar. 31, 2019
RenaissanceRe Upsilon Fund Ltd. | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Percent of segregated funds owned by third party investors	100.00%

Acquisition of Tokio Millenni_3

Acquisition of Tokio Millennium Re (Overview) (Details) - TMR Group Entities - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 22, 2019
Business Acquisition [Line Items]
Net purchase price		$ 1,563,593
Corporate expenses associated with the acquisition	$ 25,500
Transaction-related costs
Business Acquisition [Line Items]
Corporate expenses associated with the acquisition	12,900
Integration-related costs
Business Acquisition [Line Items]
Corporate expenses associated with the acquisition	5,900
Compensation-related costs
Business Acquisition [Line Items]
Corporate expenses associated with the acquisition	$ 6,700

Investments (Schedule of Fair V

Investments (Schedule of Fair Value of Fixed Maturity Investments Trading) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Investment [Line Items]
Total fixed maturity investments trading	$ 9,473,160	$ 8,088,870
U.S. treasuries
Investment [Line Items]
Total fixed maturity investments trading	3,097,089	3,331,411
Agencies
Investment [Line Items]
Total fixed maturity investments trading	182,904	174,883
Municipal
Investment [Line Items]
Total fixed maturity investments trading	256,967	6,854
Non-U.S. government
Investment [Line Items]
Total fixed maturity investments trading	687,021	279,818
Non-U.S. government-backed corporate
Investment [Line Items]
Total fixed maturity investments trading	286,331	160,063
Corporate
Investment [Line Items]
Total fixed maturity investments trading	2,971,018	2,450,244
Agency mortgage-backed
Investment [Line Items]
Total fixed maturity investments trading	955,616	817,880
Non-agency mortgage-backed
Investment [Line Items]
Total fixed maturity investments trading	272,880	278,680
Commercial mortgage-backed
Investment [Line Items]
Total fixed maturity investments trading	245,323	282,294
Asset-backed
Investment [Line Items]
Total fixed maturity investments trading	518,011	$ 306,743
TMR Group Entities
Investment [Line Items]
Total fixed maturity investments trading	$ 2,200,000

Acquisition of Tokio Millenni_4

Acquisition of Tokio Millennium Re (Purchase Price) (Details) - TMR Group Entities - USD ($) $ / shares in Units, $ in Thousands	Mar. 22, 2019	Mar. 14, 2019
Business Acquisition [Line Items]
Special Dividend paid to common shareholders of Tokio and holders of Tokio equity awards	$ 500,000
Common shares issued by RenaissanceRe to Tokio (in share)	1,739,071
Common share price of RenaissanceRe (in dollars per share)	$ 143.75	$ 143.7539
Market value of RenaissanceRe common shares issued by RenaissanceRe to Tokio	$ 249,998
Cash consideration paid by RenaissanceRe as acquisition consideration	813,595
Total purchase price	1,563,593
Less: Special Dividend paid to Tokio	(500,000)
Net purchase price	$ 1,063,593
Common share price, trading volume, term	30 days

Investments (Schedule of Contra

Investments (Schedule of Contractual Maturities of Fixed Maturity Investments) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Amortized Cost
Due in less than one year	$ 746,898
Due after one through five years	5,287,434
Due after five through ten years	1,147,028
Due after ten years	281,009
Amortized Cost	9,442,370	$ 8,163,962
Fair Value
Due in less than one year	744,030
Due after one through five years	5,301,425
Due after five through ten years	1,154,682
Due after ten years	281,193
Fair Value	9,473,160	8,088,870
Mortgage-backed
Amortized Cost
Amortized Cost	1,460,090
Fair Value
Fair Value	1,473,819
Asset-backed
Amortized Cost
Amortized Cost	519,911
Fair Value
Fair Value	$ 518,011	$ 306,743

Acquisition of Tokio Millenni_5

Acquisition of Tokio Millennium Re Acquisition of Tokio Millennium Re (Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - TMR Group Entities $ in Thousands	Mar. 22, 2019USD ($)	Mar. 31, 2019USD ($)state
Business Acquisition [Line Items]
Goodwill	$ 13,094
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 11,200
Acquired finite-lived intangibles, weighted average amortization period	10 years 6 months
Identifiable indefinite lived intangible assets (insurance licenses)	$ 6,800
Value of business acquired, amortization period	2 years
Value of business acquired	$ 287,600
Deferred tax liability related to the estimated fair value of the intangible assets recorded	2,281
Deferred tax liability related to other adjustments	2,606
Insurance licenses
Business Acquisition [Line Items]
Identifiable indefinite lived intangible assets (insurance licenses)	$ 6,800	$ 6,800
Number of states, ability to write reinsurance | state		50

Investments (Schedule of Fair_2

Investments (Schedule of Fair Value of Equity Investments Trading) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	$ 389,937	$ 310,252
Financials
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	222,604	200,357
Communications and technology
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	66,428	42,333
Industrial, utilities and energy
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	37,574	24,520
Consumer
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	31,378	20,639
Healthcare
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	26,867	18,925
Basic materials
Debt and Equity Securities, FV-NI [Line Items]
Equity investments trading	$ 5,086	$ 3,478

Acquisition of Tokio Millenni_6

Acquisition of Tokio Millennium Re (Schedule of Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - TMR Group Entities - USD ($) $ in Thousands	Mar. 22, 2019	Mar. 31, 2019
Business Acquisition [Line Items]
Shareholders’ equity of the TMR Group Entities at March 22, 2019	$ 1,032,961
Adjustments for fair value, by applicable balance sheet caption:
Net deferred acquisition costs and value of business acquired	(56,788)
Net reserve for claims and claim expenses	67,782
Goodwill and intangible assets at March 22, 2019 of the TMR Group Entities	(6,569)
Total adjustments for fair value by applicable balance sheet caption before tax impact	4,425
Other assets - net deferred tax liability related to fair value adjustments and value of business acquired	(2,606)
Total adjustments for fair value by applicable balance sheet caption, net of tax	1,819
Adjustments for fair value of the identifiable intangible assets:
Identifiable indefinite lived intangible assets (insurance licenses)	6,800
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	11,200
Identifiable intangible assets before tax impact	18,000	$ 18,000
Other assets - deferred tax liability on identifiable intangible assets	(2,281)
Total adjustments for fair value of the identifiable intangible assets and value of business acquired, net of tax	15,719
Total adjustments for fair value by applicable balance sheet caption, identifiable intangible assets and value of business acquired, net of tax	17,538
Shareholders’ equity of the TMR Group Entities at fair value	1,050,499
Total net purchase price paid by RenaissanceRe	1,063,593
Excess purchase price over the fair value of net assets acquired assigned to goodwill	13,094
Insurance licenses
Adjustments for fair value of the identifiable intangible assets:
Identifiable indefinite lived intangible assets (insurance licenses)	6,800	$ 6,800
Top Broker Relationships and Renewal Rights
Adjustments for fair value of the identifiable intangible assets:
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 11,200

Investments (Pledged Investment

Investments (Pledged Investments) (Details) - USD ($) $ in Billions	Mar. 31, 2019	Dec. 31, 2018
Investments [Abstract]
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of various counterparties	$ 6	$ 5.7
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of U.S. state regulatory authorities	$ 1.9	$ 2

Acquisition of Tokio Millenni_7

Acquisition of Tokio Millennium RE (Identifiable Intangible Assets) (Details) - TMR Group Entities - USD ($) $ in Thousands	Mar. 22, 2019	Mar. 31, 2019
Business Acquisition [Line Items]
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 11,200
Intangible assets acquired	6,800
Net identifiable intangible assets at March 31, 2019 related to the acquisition of the TMR Group Entities	$ 18,000	$ 18,000
Economic Useful Life	10 years 6 months
Top broker relationships
Business Acquisition [Line Items]
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 10,000	$ 10,000
Economic Useful Life	10 years	10 years
Renewal rights
Business Acquisition [Line Items]
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 1,200	$ 1,200
Economic Useful Life	15 years	15 years
Insurance licenses
Business Acquisition [Line Items]
Intangible assets acquired	$ 6,800	$ 6,800

Investments (Reverse Purchase A

Investments (Reverse Purchase Agreements) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Value of reverse repurchase agreements	$ 99.9	$ 3.7
Minimum required collateral for reverse repurchase agreements, expressed as a percentage of loan principal	102.00%

Acquisition of Tokio Millenni_8

Acquisition of Tokio Millennium Re (Taxation) (Details) - TMR Group Entities $ in Millions	Mar. 22, 2019USD ($)
Business Acquisition [Line Items]
Other assets - net deferred tax liability related to fair value adjustments and value of business acquired	$ 5.7
Deferred tax assets, valuation allowance	$ 35.7

Investments (Schedule of Net In

Investments (Schedule of Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	$ 85,570	$ 59,799
Investment expenses	(4,108)	(3,323)
Net investment income	81,462	56,476
Fixed maturity investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	61,483	45,643
Short term investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	11,844	5,304
Equity investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	1,027	698
Private equity investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	2,454	(434)
Other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	7,245	8,023
Cash and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income before investment expenses	$ 1,517	$ 565

Acquisition of Tokio Millenni_9

Acquisition of Tokio Millennium Re (Supplemental Pro Forma Information) (Details) - TMR Group Entities - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Total revenues	$ 1,148,146	$ 725,269
Net income available to RenaissanceRe common shareholders	$ 330,394	$ 27,605

Investments (Schedule of Net Re

Investments (Schedule of Net Realized and Unrealized (Losses) Gains on Investments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Gain (Loss) on Securities [Line Items]
Net realized and unrealized gains (losses) on investments	$ 170,645	$ (82,144)
Fixed maturity investments
Gain (Loss) on Securities [Line Items]
Gross realized gains	24,373	4,583
Gross realized losses	(22,943)	(25,853)
Net realized gains (losses) on fixed maturity investments	1,430	(21,270)
Net unrealized gains (losses) on fixed maturity investments trading	103,922	(55,372)
Derivatives
Gain (Loss) on Securities [Line Items]
Net realized and unrealized gains (losses) on investments-related derivatives	13,796	(4,364)
Equity investments
Gain (Loss) on Securities [Line Items]
Net realized (losses) gains on equity investments trading sold during the period	(1,161)	234
Net unrealized gains (losses) on equity investments trading still held at reporting date	52,658	(1,372)
Net realized and unrealized gains (losses) on equity investments trading	$ 51,497	$ (1,138)

Acquisition of Tokio Millenn_10

Acquisition of Tokio Millennium Re (Defined Benefit Pension Plan) (Details) - Pension Plan - TMR Group Entities $ in Millions	Mar. 22, 2019USD ($)
Business Acquisition [Line Items]
Net balance sheet liability	$ 6.1
Projected benefit obligation	21.2
Plan assets at fair value	$ 15.1

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	$ 9,473,160	$ 8,088,870
Equity investments trading	389,937	310,252
Other investments	878,373	784,933
Other assets	47,596	4,968
Other liabilities	(35,769)	(13,327)
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	9,473,160	8,088,870
Short term investments	4,012,815	2,586,520
Equity investments trading	389,937	310,252
Other investments	878,373	784,933
Other assets	17,644	4,040
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	14,771,929	11,774,615
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	3,097,089	3,331,411
Short term investments	0	0
Equity investments trading	389,937	310,252
Other investments	0	0
Other assets		484
Other liabilities	(2,067)
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	3,484,959	3,642,147
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	6,376,071	4,757,459
Short term investments	4,012,815	2,586,520
Equity investments trading	0	0
Other investments	556,380	516,571
Other assets	7,884	11,915
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	10,953,150	7,872,465
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Short term investments	0	0
Equity investments trading	0	0
Other investments	63,695	54,545
Other assets	11,827
Other liabilities		(8,359)
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	75,522	46,186
Fair Value, Measurements, Recurring | U.S. treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	3,097,089	3,331,411
Fair Value, Measurements, Recurring | U.S. treasuries | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	3,097,089	3,331,411
Fair Value, Measurements, Recurring | U.S. treasuries | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | U.S. treasuries | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	182,904	174,883
Fair Value, Measurements, Recurring | Agencies | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Agencies | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	182,904	174,883
Fair Value, Measurements, Recurring | Agencies | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	256,967	6,854
Fair Value, Measurements, Recurring | Municipal | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Municipal | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	256,967	6,854
Fair Value, Measurements, Recurring | Municipal | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	687,021	279,818
Fair Value, Measurements, Recurring | Non-U.S. government | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-U.S. government | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	687,021	279,818
Fair Value, Measurements, Recurring | Non-U.S. government | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-U.S. government-backed corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	286,331	160,063
Fair Value, Measurements, Recurring | Non-U.S. government-backed corporate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-U.S. government-backed corporate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	286,331	160,063
Fair Value, Measurements, Recurring | Non-U.S. government-backed corporate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	2,971,018	2,450,244
Fair Value, Measurements, Recurring | Corporate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Corporate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	2,971,018	2,450,244
Fair Value, Measurements, Recurring | Corporate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Agency mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	955,616	817,880
Fair Value, Measurements, Recurring | Agency mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Agency mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	955,616	817,880
Fair Value, Measurements, Recurring | Agency mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-agency mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	272,880	278,680
Fair Value, Measurements, Recurring | Non-agency mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Non-agency mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	272,880	278,680
Fair Value, Measurements, Recurring | Non-agency mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	245,323	282,294
Fair Value, Measurements, Recurring | Commercial mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Commercial mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	245,323	282,294
Fair Value, Measurements, Recurring | Commercial mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	518,011	306,743
Fair Value, Measurements, Recurring | Asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Asset-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	518,011	306,743
Fair Value, Measurements, Recurring | Asset-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0	0
Fair Value, Measurements, Recurring | Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	556,380	516,571
Fair Value, Measurements, Recurring | Catastrophe bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Catastrophe bonds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	556,380	516,571
Fair Value, Measurements, Recurring | Catastrophe bonds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	253,566	242,647
Fair Value, Measurements, Recurring | Private equity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Private equity investments | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Private equity investments | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	63,695	54,545
Fair Value, Measurements, Recurring | Senior secured bank loan funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	15,674	14,482
Fair Value, Measurements, Recurring | Senior secured bank loan funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Senior secured bank loan funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Senior secured bank loan funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	11,585	11,233
Fair Value, Measurements, Recurring | Hedge funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Hedge funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Hedge funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Fair Value, Measurements, Recurring | Miscellaneous other investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0
Fair Value, Measurements, Recurring | Miscellaneous other investments | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0
Fair Value, Measurements, Recurring | Miscellaneous other investments | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	11,827
Other liabilities		(8,359)
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	11,827
Other liabilities		(8,359)
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Unobservable Inputs (Level 3) | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	47,600	5,000
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Unobservable Inputs (Level 3) | Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other liabilities	(35,800)	(13,300)
Fair Value, Measurements, Recurring | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	5,817	12,399
Fair Value, Measurements, Recurring | Derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets		484
Other liabilities	(2,067)
Fair Value, Measurements, Recurring | Derivatives | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	7,884	11,915
Fair Value, Measurements, Recurring | Derivatives | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	$ 0
TMR Group Entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	2,200,000
TMR Group Entities | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Unobservable Inputs (Level 3) | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	41,700
TMR Group Entities | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Significant Unobservable Inputs (Level 3) | Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other liabilities	$ (21,700)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) £ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Mar. 31, 2019GBP (£)	Dec. 31, 2018USD ($)	Jun. 30, 2015USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	$ 878,373,000			$ 784,933,000
Other assets	47,596,000			4,968,000
Other liabilities	35,769,000			13,327,000
Debt	1,191,499,000			991,127,000
Credit facilities outstanding	1,392,993,000		£ 0
Long-term debt, fair value	1,193,977,000			974,714,000
Net unrealized gains (losses) recognized in earnings	2,969,000	$ 1,465,000
Net investment income | Other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net unrealized gains (losses) recognized in earnings	3,000,000	1,500,000
Other income (loss) | Other assets and (liabilities)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net unrealized gains (losses) recognized in earnings	0	$ 0
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	878,373,000			784,933,000
Other assets	17,644,000			4,040,000
Fair Value, Measurements, Recurring | Private equity investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	253,566,000			242,647,000
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	63,695,000			54,545,000
Other assets	11,827,000
Other liabilities				8,359,000
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Private equity investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	63,695,000			$ 54,545,000
Significant Unobservable Inputs (Level 3) | External valuation model | Fair Value, Measurements, Recurring | Private equity investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	10,174,000
Significant Unobservable Inputs (Level 3) | Internal valuation model | Fair Value, Measurements, Recurring | Private equity investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments	53,521,000
Significant Unobservable Inputs (Level 3) | Internal valuation model | Fair Value, Measurements, Recurring | Assumed reinsurance contract
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	500,000
Other liabilities	8,356,000
Significant Unobservable Inputs (Level 3) | Internal valuation model | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contract
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	19,660,000
Fair Value Measured at Net Asset Value Per Share
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment fair value	$ 258,298,000
U.S. treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	2.30%		2.30%	2.50%
Agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	2.80%		2.80%	3.00%
Municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.40%		3.40%	4.80%
Non-U.S. government
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	1.60%		1.60%	2.70%
Non-U.S. government-backed corporate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	2.10%		2.10%	2.80%
Corporate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.60%		3.60%	4.90%
Agency mortgage-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.10%		3.10%	3.50%
Weighted average life	5 years 10 months 24 days	7 years 1 month 6 days
Non-agency prime residential mortgage-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	4.20%		4.20%	4.40%
Weighted average life	5 years 3 months 18 days	4 years 8 months 12 days
Alt-A non-agency mortgage-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	4.20%		4.20%	4.70%
Weighted average life	6 years 9 months 18 days	6 years 3 months 18 days
Commercial mortgage-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.20%		3.20%	3.60%
Weighted average life	4 years 7 months 6 days	5 years
Asset-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.80%		3.80%	4.30%
Weighted average life	3 years 2 months 12 days	3 years 2 months 12 days
Short term investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	2.10%		2.10%	2.10%
Private equity investments | Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liquidation period for fund assets	7 years
Private equity investments | Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liquidation period for fund assets	10 years
Private equity investments | Fair Value Measured at Net Asset Value Per Share
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment fair value	$ 189,871,000
Senior secured bank loan funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment in closed end fund	$ 15,700,000
Senior secured bank loan funds | Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liquidation period for fund assets	4 years
Senior secured bank loan funds | Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liquidation period for fund assets	5 years
Senior secured bank loan funds | Fair Value Measured at Net Asset Value Per Share
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment fair value	$ 15,674,000
Hedge funds | Fair Value Measured at Net Asset Value Per Share
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment fair value	11,585,000
Miscellaneous other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment fair value	41,168,000				$ 41,168,000
RenaissanceRe Revolving Credit Facility | Line of Credit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facilities outstanding	$ 200,000,000

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Information Used as Level 3 Inputs) (Details) $ in Thousands	Mar. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	$ 878,373	$ 784,933
Other liabilities	(35,769)	(13,327)
Total other assets and (liabilities)	47,596	4,968
Fair Value, Measurements, Recurring
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	878,373	784,933
Total other assets and (liabilities)	17,644	4,040
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	14,771,929	11,774,615
Fair Value, Measurements, Recurring | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	63,695	54,545
Other liabilities		(8,359)
Total other assets and (liabilities)	11,827
Total other assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs	75,522	46,186
Fair Value, Measurements, Recurring | Private equity investments
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	253,566	242,647
Fair Value, Measurements, Recurring | Private equity investments | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	63,695	54,545
Fair Value, Measurements, Recurring | Private equity investments | External valuation model | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	10,174
Fair Value, Measurements, Recurring | Private equity investments | Internal valuation model | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other investments	53,521
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other liabilities		(8,359)
Total other assets and (liabilities)	11,827
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other liabilities		$ (8,359)
Total other assets and (liabilities)	11,827
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group one | Internal valuation model | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Total other assets and (liabilities)	523
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group two | Internal valuation model | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other liabilities	(8,356)
Total other assets and (liabilities)	500
Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group three | Internal valuation model | Fair Value (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Total other assets and (liabilities)	$ 19,660
Indicative pricing | Fair Value, Measurements, Recurring | Private equity investments | External valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs | $ / shares	101.74
Liquidity discount | Fair Value, Measurements, Recurring | Private equity investments | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs | $ / shares	0.125
Liquidity discount | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group one | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs	0.013
Bond price | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group one | Internal valuation model | Fair Value (Level 3) | Low
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs | $ / shares	100.64
Bond price | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group one | Internal valuation model | Fair Value (Level 3) | High
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs | $ / shares	107.97
Bond price | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group one | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs | $ / shares	104.71
Net undiscounted cash flows | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group two | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs	10,413,000
Expected loss ratio | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group two | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs	0.395
Expected loss ratio | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group three | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs	0
Discount rate | Fair Value, Measurements, Recurring | Assumed and ceded (re)insurance contracts, group two | Internal valuation model | Fair Value (Level 3) | Weighted Average or Actual
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Significant observable and unobservable inputs	0.022

Fair Value Measurements (Asse_2

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Total realized and unrealized gains
Amounts acquired	$ 19,970
Other assets and (liabilities)
Total realized and unrealized gains
Amounts acquired	19,970
Fair Value (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	46,186
Total realized and unrealized gains
Purchases	9,365
Settlements	20
Balance at end of the period	75,522
Fair Value (Level 3) | Fair Value, Measurements, Recurring | Other income (loss)
Total realized and unrealized gains
Included in other income (loss)	(18)
Total foreign exchange losses	(1)
Fair Value (Level 3) | Fair Value, Measurements, Recurring | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	54,545
Total realized and unrealized gains
Purchases	10,262
Settlements	0
Amounts acquired	0
Balance at end of the period	63,695
Fair Value (Level 3) | Fair Value, Measurements, Recurring | Other investments | Other income (loss)
Total realized and unrealized gains
Included in other income (loss)	(1,111)
Total foreign exchange losses	(1)
Fair Value (Level 3) | Fair Value, Measurements, Recurring | Other assets and (liabilities)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	(8,359)	$ (2,952)
Total realized and unrealized gains
Purchases	(897)	(34)
Settlements	20
Balance at end of the period	11,827	(2,780)
Fair Value (Level 3) | Fair Value, Measurements, Recurring | Other assets and (liabilities) | Other income (loss)
Total realized and unrealized gains
Included in other income (loss)	1,093	$ 206
Total foreign exchange losses	$ 0

Fair Value Measurements (Summar

Fair Value Measurements (Summary of the Balances Company Has Elected to Account For at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Other investments	$ 878,373	$ 784,933
Other assets	47,596	4,968
Other liabilities	$ 35,769	$ 13,327

Fair Value Measurements (Compan

Fair Value Measurements (Company's Portfolio of Other Investments Measured Using Net Asset Valuations) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jun. 30, 2015
Miscellaneous other investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 41,168	$ 41,168
Unfunded Commitments		$ 0
Fair Value Measured at Net Asset Value Per Share
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	258,298
Unfunded Commitments	398,352
Fair Value Measured at Net Asset Value Per Share | Private equity investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	189,871
Unfunded Commitments	381,143
Fair Value Measured at Net Asset Value Per Share | Senior secured bank loan funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	15,674
Unfunded Commitments	17,209
Fair Value Measured at Net Asset Value Per Share | Hedge funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	11,585
Unfunded Commitments	$ 0

Reinsurance (Effect of Reinsura

Reinsurance (Effect of Reinsurance and Retrocessional Activity on Premiums Written and Earned and on Net Claims and Claim Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Premiums written
Direct	$ 110,968	$ 85,167
Assumed	1,453,327	1,074,485
Ceded	(635,264)	(496,608)
Net premiums written	929,031	663,044
Premiums earned
Direct	89,814	70,032
Assumed	765,433	605,483
Ceded	(305,219)	(235,233)
Net premiums earned	550,028	440,282
Claims and claim expenses
Gross claims and claim expenses incurred	338,119	225,742
Claims and claim expenses recovered	(111,084)	(54,039)
Net claims and claim expenses incurred	$ 227,035	$ 171,703

Reinsurance (Narrative) (Detail

Reinsurance (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Ceded Credit Risk [Line Items]
Reinsurance recoverable	$ 2,908,343	$ 1,572,321	$ 2,372,221
Allowance for reinsurance recoverable
Ceded Credit Risk [Line Items]
Valuation allowances and reserves balance	$ 8,500		$ 9,000
Customer Concentration Risk, Customer One | Reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	12.00%	15.50%
Customer Concentration Risk, Customer One | Allowance for reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	17.60%	16.20%
Customer Concentration Risk, Customer Two | Reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	6.90%	6.70%
Customer Concentration Risk, Customer Two | Allowance for reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	13.20%	14.80%
Customer Concentration Risk, Customer Three | Reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	6.50%	6.50%
Customer Concentration Risk, Customer Three | Allowance for reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	12.00%	12.30%
Ceded Credit Risk, Secured | Reinsurer Concentration Risk | Reinsurance recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	65.80%	60.80%
Ceded Credit Risk, Unsecured | Reinsurer Concentration Risk | Reinsurance recoverable | Standard & Poor's, A- Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	32.10%	38.00%
Ceded Credit Risk, Unsecured | Reinsurer Concentration Risk | Reinsurance recoverable | Standard & Poor's, BBB Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	2.10%	1.20%
TMR Group Entities
Ceded Credit Risk [Line Items]
Reinsurance recoverable	$ 548,700

Reserve for Claims and Claim _3

Reserve for Claims and Claim Expenses (Claims and Claim Expense Reserves by Segment) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Case Reserves	$ 2,699,023	$ 1,463,713
Additional Case Reserves	1,719,448	1,425,184
IBNR	3,973,013	3,187,374
Gross reserve for claims and claim expenses	8,391,484	6,076,271	$ 4,912,727
Other
Liability for Claims and Claims Adjustment Expense [Line Items]
Case Reserves	1,404	1,458
Additional Case Reserves	0	0
IBNR	3,166	3,166
Gross reserve for claims and claim expenses	4,570	4,624
Property | Operating Segments
Liability for Claims and Claims Adjustment Expense [Line Items]
Case Reserves	1,243,455	690,718
Additional Case Reserves	1,598,283	1,308,307
IBNR	844,681	1,087,229
Gross reserve for claims and claim expenses	3,686,419	3,086,254
Casualty and Specialty | Operating Segments
Liability for Claims and Claims Adjustment Expense [Line Items]
Case Reserves	1,454,164	771,537
Additional Case Reserves	121,165	116,877
IBNR	3,125,166	2,096,979
Gross reserve for claims and claim expenses	4,700,495	$ 2,985,393
TMR Group Entities
Liability for Claims and Claims Adjustment Expense [Line Items]
Gross reserve for claims and claim expenses	$ 2,400,000

Reserve for Claims and Claim _4

Reserve for Claims and Claim Expenses (Schedule of Liability for Unpaid Claims and Claims Adjustment Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net reserves as of January 1	$ 3,704,050	$ 3,493,778
Net incurred related to:
Current year	231,341	203,038
Prior years	(4,306)	(31,335)
Total net incurred	227,035	171,703
Net paid related to:
Current year	8,149	9,050
Prior years	300,120	328,129
Total net paid	308,269	337,179
Foreign exchange	1,550	12,104
Amounts acquired	1,858,775	0
Net reserves as of March 31	5,483,141	3,340,406
Reinsurance recoverable as of March 31	2,908,343	1,572,321
Gross reserves as of March 31	$ 8,391,484	$ 4,912,727

Reserve for Claims and Claim _5

Reserve for Claims and Claim Expenses (Prior Year Development of the Reserve for Net Claims and Claim Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	$ (4,306)	$ (31,335)
Other
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	19	18
Property
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	1,877	(27,562)
Property | Large catastrophe events
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	(12,292)	(31,367)
Property | 2017 Large Loss Events
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	(10,918)	(27,109)
Property | Other
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	(1,374)	(4,258)
Property | Small catastrophe events and attritional loss movements
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	14,169	3,805
Property | Other small catastrophe events and attritional loss movements
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	14,169	3,805
Property | Other Large and Small Catastrophe Events
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years		(500)
Casualty and Specialty
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	(6,202)	(3,791)
Casualty and Specialty | Actuarial methods
Liability for Catastrophe Claims [Line Items]
Net claims and claim expenses incurred – prior accident years	$ (6,202)	$ (3,791)

Debt and Credit Facilities (Sum

Debt and Credit Facilities (Summary of Debt Obligations) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Fair Value	$ 1,193,977	$ 974,714
Carrying Value	$ 1,191,499	991,127
3.450% Senior Notes due 2027
Debt Instrument [Line Items]
Stated interest rate	3.45%
3.700% Senior Notes due 2025
Debt Instrument [Line Items]
Stated interest rate	3.70%
5.750% Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate	5.75%
4.750% Senior Notes due 2025 (DaVinciRe)
Debt Instrument [Line Items]
Stated interest rate	4.75%
Senior Notes
Debt Instrument [Line Items]
Fair Value	$ 993,977	974,714
Carrying Value	991,499	991,127
Senior Notes | 3.450% Senior Notes due 2027 | RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	294,450	283,680
Carrying Value	295,920	295,797
Senior Notes | 3.700% Senior Notes due 2025 | RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	297,801	292,557
Carrying Value	297,779	297,688
Senior Notes | 5.750% Senior Notes due 2020 | RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	256,055	255,938
Carrying Value	249,683	249,602
Senior Notes | 4.750% Senior Notes due 2025 (DaVinciRe) | DaVinciRe Holdings Ltd.
Debt Instrument [Line Items]
Fair Value	145,671	142,539
Carrying Value	148,117	148,040
RenaissanceRe Revolving Credit Facility | Line of Credit | RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	200,000	0
Carrying Value	$ 200,000	$ 0

Debt and Credit Facilities (Deb

Debt and Credit Facilities (Debt Obligations) (Details) - Subsequent Event - Senior Notes - 3.600% Senior Notes Due 2029	Apr. 02, 2019USD ($)
Debt Instrument [Line Items]
Stated interest rate	3.60%
Face amount	$ 400,000,000
Repayments of lines of credit	$ 200,000,000

Debt and Credit Facilities (Sch

Debt and Credit Facilities (Schedule of Credit Facilities) (Details) - Mar. 31, 2019 £ in Thousands, $ in Thousands	USD ($)	GBP (£)
Line of Credit Facility [Line Items]
Credit facilities outstanding	$ 1,392,993	£ 0
Specialty Risks FAL Facility | Line of Credit
Line of Credit Facility [Line Items]
Credit facilities outstanding | £		£ 0
RenaissanceRe Revolving Credit Facility | Line of Credit
Line of Credit Facility [Line Items]
Credit facilities outstanding	200,000
Letter of Credit | Renaissance Reinsurance FAL Facility
Line of Credit Facility [Line Items]
Credit facilities outstanding	255,000
Letter of Credit | Wells Fargo | Uncommitted Standby Letter of Credit Facility
Line of Credit Facility [Line Items]
Credit facilities outstanding	32,009
Letter of Credit | Citibank Europe PLC
Line of Credit Facility [Line Items]
Credit facilities outstanding	0
Letter of Credit | Citibank Europe PLC | Bilateral Facility
Line of Credit Facility [Line Items]
Credit facilities outstanding	238,956
Letter of Credit | Mizuho Bank, Ltd.
Line of Credit Facility [Line Items]
Credit facilities outstanding	385,975
Letter of Credit | The Bank of Tokyo-Mitsubishi UFJ Ltd.
Line of Credit Facility [Line Items]
Credit facilities outstanding	205,956
Letter of Credit | Credit Suisse (Switzerland) Ltd.
Line of Credit Facility [Line Items]
Credit facilities outstanding	$ 75,097

Debt and Credit Facilities Debt

Debt and Credit Facilities Debt and Credit Facilities (Credit Facilities) (Details) - Letter of Credit	Mar. 22, 2019USD ($)	Mar. 07, 2019USD ($)	Nov. 23, 2015USD ($)
Credit Suisse (Switzerland) Ltd.
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 125,000,000
Ratio of indebtedness to net capital	0.35
Minimum net worth required for compliance	$ 3,000,000,000
Bank Of Montreal, CEP and ING Bank N.V., London Branch
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 255,000,000	$ 180,000,000

Noncontrolling Interests (Detai

Noncontrolling Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 2,109,400	$ 2,051,700
Net income attributable to redeemable noncontrolling interests	$ 70,222		$ 29,899
DaVinci Reinsurance Ltd.
Redeemable Noncontrolling Interest [Line Items]
Parent company ownership in redeemable noncontrolling interest	22.10%	22.10%
RenaissanceRe Medici Fund Ltd.
Redeemable Noncontrolling Interest [Line Items]
Parent company ownership in redeemable noncontrolling interest	17.10%	17.10%
DaVinciRe Holdings Ltd.
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 1,097,245	$ 1,034,946	1,032,543	$ 1,011,659
Net income attributable to redeemable noncontrolling interests	62,533		20,953
Redemption of shares from redeemable noncontrolling interest	$ 234		69
DaVinciRe Holdings Ltd. | Maximum
Redeemable Noncontrolling Interest [Line Items]
Share repurchase requests, limit	25.00%
RenaissanceRe Medici Fund Ltd.
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 406,958	416,765	392,821	284,847
Net income attributable to redeemable noncontrolling interests	$ 2,481		8,946
Redemption provision, notice period	30 days
Sale of shares to redeemable noncontrolling interest	$ 3,596		99,739
Redemption of shares from redeemable noncontrolling interest	15,884		711
Vermeer Reinsurance Ltd.
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	605,197	599,989	0	$ 0
Net income attributable to redeemable noncontrolling interests	$ 5,208		$ 0
Participating, Non-voting Common Shares | Vermeer Reinsurance Ltd.
Redeemable Noncontrolling Interest [Line Items]
Sale of shares to redeemable noncontrolling interest		600,000
Voting, Non-participating Shares | Vermeer Reinsurance Ltd.
Redeemable Noncontrolling Interest [Line Items]
Sale of shares to redeemable noncontrolling interest		$ 1

Noncontrolling Interests (Sched

Noncontrolling Interests (Schedule of Redeemable Noncontrolling Interest) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Activity in redeemable noncontrolling interest
Beginning balance	$ 2,051,700
Net income attributable to redeemable noncontrolling interest	70,222	$ 29,899
Ending balance	2,109,400
DaVinciRe Holdings Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	1,034,946	1,011,659
Redemption of shares from redeemable noncontrolling interest, net of adjustments	(234)	(69)
Net income attributable to redeemable noncontrolling interest	62,533	20,953
Ending balance	1,097,245	1,032,543
RenaissanceRe Medici Fund Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	416,765	284,847
Redemption of shares from redeemable noncontrolling interest, net of adjustments	(15,884)	(711)
Sale of shares to redeemable noncontrolling interests	3,596	99,739
Net income attributable to redeemable noncontrolling interest	2,481	8,946
Ending balance	406,958	392,821
Vermeer Reinsurance Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	599,989	0
Net income attributable to redeemable noncontrolling interest	5,208	0
Ending balance	$ 605,197	$ 0

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Assets	$ 24,559,600		$ 18,676,196
Liabilities	16,896,167		11,579,416
Ceded premiums written	635,264	$ 496,608
Ceded premiums earned	305,219	235,233
Investments in other ventures, under equity method	98,563		115,172
Redeemable noncontrolling interests	2,109,400		2,051,700
Upsilon RFO Re Ltd. | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	2,700,000		2,200,000
Liabilities	2,700,000		2,200,000
Upsilon RFO Re Ltd. | Variable Interest Entity, Primary Beneficiary | Non-Voting Preference Shares
Variable Interest Entity [Line Items]
Contributions to subsidiaries	100,000		109,800
Upsilon RFO Re Ltd. | Variable Interest Entity, Primary Beneficiary | Third party investor | Non-Voting Preference Shares
Variable Interest Entity [Line Items]
Contributions to subsidiaries	$ 502,800		$ 856,700
Upsilon RFO Re Ltd. | Variable Interest Entity, Primary Beneficiary | RenaissanceRe Holdings Ltd.
Variable Interest Entity [Line Items]
Variable interest entity, ownership percentage	16.70%		14.00%
Renaissance Reinsurance Ltd. | Variable Interest Entity, Not Primary Beneficiary | Fibonacci Reinsurance Ltd.
Variable Interest Entity [Line Items]
Ceded premiums written	$ 6	4,100
Ceded premiums earned	6	1,200
Ceded Net Claims And Claim Expenses	5,600
Net reinsurance recoverable	5,600
Fibonacci Reinsurance Ltd. | Variable Interest Entity, Not Primary Beneficiary | Other investments
Variable Interest Entity [Line Items]
Investment in participating notes	1,400		$ 6,000
Langhorne Holdings LLC | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Investments in other ventures, under equity method	1,600		1,300
Langhorne Partners | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Investments in other ventures, under equity method	100		100
Vermeer Reinsurance Ltd.
Variable Interest Entity [Line Items]
Redeemable noncontrolling interests	605,197	$ 0	599,989	$ 0
Vermeer Reinsurance Ltd. | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	668,800		600,400
Liabilities	63,600		400
Redeemable noncontrolling interests	$ 605,200		$ 600,000

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($)	Mar. 29, 2019	Mar. 15, 2019	Jun. 30, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Nov. 10, 2017
Class of Stock [Line Items]
Dividends per common share (in dollars per share)				$ 0.34	$ 0.33
Dividends paid per common share (in dollars per share)	$ 0.33
Dividends declared and paid, preference shares				$ 9,189,000	$ 5,595,000
Dividends declared and paid, common shares				$ 14,500,000	$ 13,200,000
Shares issued (in shares)				16,010,000		16,010,000
Common Shares
Class of Stock [Line Items]
Dividends per common share (in dollars per share)		$ 0.34
Share repurchase program, authorized amount							$ 500,000,000
Share repurchase program, shares repurchased (in shares)				0
Share repurchase program, remaining authorized aggregate amount				$ 500,000,000
Series C Preference Shares
Class of Stock [Line Items]
Dividend rate, percentage				6.08%
Liquidation preference per annum (in dollars per share)				$ 1.52
Liquidation preference quarterly (in dollars per share)				$ 0.38
Series E Preference Shares
Class of Stock [Line Items]
Dividend rate, percentage				5.375%
Liquidation preference per annum (in dollars per share)				$ 1.34375
Liquidation preference quarterly (in dollars per share)				$ 0.3359375
Series F Preference Shares
Class of Stock [Line Items]
Dividend rate, percentage			5.75%
Liquidation preference per annum (in dollars per share)			$ 1,437.50
Liquidation preference quarterly (in dollars per share)			359.375
Depositary Shares
Class of Stock [Line Items]
Liquidation preference per annum (in dollars per share)			1.4375
Liquidation preference quarterly (in dollars per share)			$ 0.359375

Earnings Per Share (Computation

Earnings Per Share (Computation of Basic and Diluted Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income available to RenaissanceRe common shareholders	$ 273,717	$ 56,713
Amount allocated to participating common shareholders	(3,121)	(546)
Net income allocated to RenaissanceRe common shareholders	$ 270,596	$ 56,167
Denominator:
Denominator for basic income per RenaissanceRe common share - weighted average common shares (in shares)	42,065	39,552
Per common share equivalents of employee stock options and restricted shares (in shares)	26	47
Denominator for diluted income per RenaissanceRe common share - adjusted weighted average common shares and assumed conversions (in shares)	42,091	39,599
Net income available to RenaissanceRe common shareholders per common share – basic (in dollars per share)	$ 6.43	$ 1.42
Net income available to RenaissanceRe common shareholders per common share – diluted (in dollars per share)	$ 6.43	$ 1.42

Segment Reporting (Schedule of

Segment Reporting (Schedule of Significant Components of the Company's Revenues and Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Gross premiums written	$ 1,564,295	$ 1,159,652
Net premiums written	929,031	663,044
Net premiums earned	550,028	440,282
Net claims and claim expenses incurred	227,035	171,703
Acquisition expenses	123,951	97,711
Operational expenses	44,933	41,272
Underwriting income (loss)	154,109	129,596
Net investment income	81,462	56,476
Net foreign exchange (losses) gains	(2,846)	3,757
Equity in earnings of other ventures	4,661	857
Other income (loss)	3,171	(1,242)
Net realized and unrealized gains (losses) on investments	170,645	(82,144)
Corporate expenses	(38,789)	(6,733)
Interest expense	(11,754)	(11,767)
Income before taxes	360,659	88,800
Income tax (expense) benefit	(7,531)	3,407
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Dividends on preference shares	(9,189)	(5,595)
Net income available to RenaissanceRe common shareholders	273,717	56,713
Net claims and claim expenses incurred – current accident year	231,341	203,038
Net claims and claim expenses incurred – prior accident years	(4,306)	(31,335)
Total net incurred	$ 227,035	$ 171,703
Net claims and claim expense ratio – current accident year	42.10%	46.10%
Net claims and claim expense ratio – prior accident years	(0.80%)	(7.10%)
Net claims and claim expense ratio – calendar year	41.30%	39.00%
Underwriting expense ratio	30.70%	31.60%
Combined ratio	72.00%	70.60%
Other
Segment Reporting Information [Line Items]
Gross premiums written	$ 0	$ 0
Net premiums written	0	0
Net premiums earned	0	0
Net claims and claim expenses incurred	19	18
Acquisition expenses	0	0
Operational expenses	0	133
Underwriting income (loss)	(19)	(151)
Net investment income	81,462	56,476
Net foreign exchange (losses) gains	(2,846)	3,757
Equity in earnings of other ventures	4,661	857
Other income (loss)	3,171	(1,242)
Net realized and unrealized gains (losses) on investments	170,645	(82,144)
Corporate expenses	(38,789)	(6,733)
Interest expense	(11,754)	(11,767)
Income tax (expense) benefit	(7,531)	3,407
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Dividends on preference shares	(9,189)	(5,595)
Net claims and claim expenses incurred – current accident year	0	0
Net claims and claim expenses incurred – prior accident years	19	18
Total net incurred	19	18
Property
Segment Reporting Information [Line Items]
Net claims and claim expenses incurred – prior accident years	1,877	(27,562)
Property | Operating Segments
Segment Reporting Information [Line Items]
Gross premiums written	1,032,384	706,968
Net premiums written	564,230	354,077
Net premiums earned	290,745	225,049
Net claims and claim expenses incurred	56,083	30,607
Acquisition expenses	53,739	40,721
Operational expenses	28,544	26,546
Underwriting income (loss)	152,379	127,175
Net claims and claim expenses incurred – current accident year	54,206	58,169
Net claims and claim expenses incurred – prior accident years	1,877	(27,562)
Total net incurred	$ 56,083	$ 30,607
Net claims and claim expense ratio – current accident year	18.60%	25.80%
Net claims and claim expense ratio – prior accident years	0.70%	(12.20%)
Net claims and claim expense ratio – calendar year	19.30%	13.60%
Underwriting expense ratio	28.30%	29.90%
Combined ratio	47.60%	43.50%
Casualty and Specialty
Segment Reporting Information [Line Items]
Net claims and claim expenses incurred – prior accident years	$ (6,202)	$ (3,791)
Casualty and Specialty | Operating Segments
Segment Reporting Information [Line Items]
Gross premiums written	531,911	452,684
Net premiums written	364,801	308,967
Net premiums earned	259,283	215,233
Net claims and claim expenses incurred	170,933	141,078
Acquisition expenses	70,212	56,990
Operational expenses	16,389	14,593
Underwriting income (loss)	1,749	2,572
Net claims and claim expenses incurred – current accident year	177,135	144,869
Net claims and claim expenses incurred – prior accident years	(6,202)	(3,791)
Total net incurred	$ 170,933	$ 141,078
Net claims and claim expense ratio – current accident year	68.30%	67.30%
Net claims and claim expense ratio – prior accident years	(2.40%)	(1.80%)
Net claims and claim expense ratio – calendar year	65.90%	65.50%
Underwriting expense ratio	33.40%	33.30%
Combined ratio	99.30%	98.80%

Derivative Instruments (Consoli

Derivative Instruments (Consolidated Balance Sheets and Fair Value of the Principal Derivative Instruments) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other assets
Derivative Assets
Gross Amounts of Recognized Assets	$ 13,223	$ 22,874
Gross Amounts Offset in the Balance Sheet	1,422	3,991
Net Amounts of Assets Presented in the Balance Sheet	11,801	18,883
Collateral	0	0
Net Amount	11,801	18,883
Other assets | Interest rate futures
Derivative Assets
Gross Amounts of Recognized Assets	1,263	2,361
Gross Amounts Offset in the Balance Sheet	1,206	1,660
Net Amounts of Assets Presented in the Balance Sheet	57	701
Collateral	0	0
Net Amount	57	701
Other assets | Interest rate swaps
Derivative Assets
Gross Amounts of Recognized Assets	6	860
Gross Amounts Offset in the Balance Sheet	0	0
Net Amounts of Assets Presented in the Balance Sheet	6	860
Collateral	0	0
Net Amount	6	860
Other assets | Foreign currency forward contracts, underwriting and non-investment operations
Derivative Assets
Gross Amounts of Recognized Assets	10,490	16,459
Gross Amounts Offset in the Balance Sheet	152	2,260
Net Amounts of Assets Presented in the Balance Sheet	10,338	14,199
Collateral	0	0
Net Amount	10,338	14,199
Other assets | Foreign currency forward contracts, investment operations
Derivative Assets
Gross Amounts of Recognized Assets	743	3,194
Gross Amounts Offset in the Balance Sheet	64	71
Net Amounts of Assets Presented in the Balance Sheet	679	3,123
Collateral	0	0
Net Amount	679	3,123
Other assets | Credit default swaps
Derivative Assets
Gross Amounts of Recognized Assets	121
Gross Amounts Offset in the Balance Sheet	0
Net Amounts of Assets Presented in the Balance Sheet	121
Collateral	0
Net Amount	121
Other assets | Total return swaps
Derivative Assets
Gross Amounts of Recognized Assets	600
Gross Amounts Offset in the Balance Sheet	0
Net Amounts of Assets Presented in the Balance Sheet	600
Collateral	0
Net Amount	600
Other liabilities
Derivative Liabilities
Gross Amounts of Recognized Liabilities	7,357	8,225
Gross Amounts Offset in the Balance Sheet	1,373	1,741
Net Amounts of Liabilities Presented in the Balance Sheet	5,984	6,484
Collateral Pledged	2,184	2,076
Net Amount	3,800	4,408
Other liabilities | Interest rate futures
Derivative Liabilities
Gross Amounts of Recognized Liabilities	3,330	1,887
Gross Amounts Offset in the Balance Sheet	1,206	1,670
Net Amounts of Liabilities Presented in the Balance Sheet	2,124	217
Collateral Pledged	2,113	217
Net Amount	11	0
Other liabilities | Interest rate swaps
Derivative Liabilities
Gross Amounts of Recognized Liabilities	71	506
Gross Amounts Offset in the Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Balance Sheet	71	506
Collateral Pledged	71	254
Net Amount	0	252
Other liabilities | Foreign currency forward contracts, underwriting and non-investment operations
Derivative Liabilities
Gross Amounts of Recognized Liabilities	3,011	4,154
Gross Amounts Offset in the Balance Sheet	103	0
Net Amounts of Liabilities Presented in the Balance Sheet	2,908	4,154
Collateral Pledged	0	0
Net Amount	2,908	4,154
Other liabilities | Foreign currency forward contracts, investment operations
Derivative Liabilities
Gross Amounts of Recognized Liabilities	945	72
Gross Amounts Offset in the Balance Sheet	64	71
Net Amounts of Liabilities Presented in the Balance Sheet	881	1
Collateral Pledged	0	0
Net Amount	$ 881	1
Other liabilities | Credit default swaps
Derivative Liabilities
Gross Amounts of Recognized Liabilities		1,606
Gross Amounts Offset in the Balance Sheet		0
Net Amounts of Liabilities Presented in the Balance Sheet		1,606
Collateral Pledged		1,605
Net Amount		$ 1

Derivative Instruments (Gain (L

Derivative Instruments (Gain (Loss) Recognized in the Consolidated Statements of Operations Related to its Derivative Instruments) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	$ 19,383	$ 1,688
Net realized and unrealized gains (losses) on investments | Interest rate futures
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	8,503	(2,337)
Net realized and unrealized gains (losses) on investments | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	349	(106)
Net realized and unrealized gains (losses) on investments | Credit default swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	4,410	(1,921)
Net foreign exchange (losses) gains | Foreign currency forward contracts, underwriting and non-investment operations
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	4,442	6,743
Net foreign exchange (losses) gains | Foreign currency forward contracts, investment operations
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	1,145	(691)
Net foreign exchange (losses) gains | Total return swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized on derivatives	$ 534	$ 0

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details) - Not Designated as Hedging Instrument - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Interest rate futures | Long
Derivative [Line Items]
Notional amount	$ 2,600,000,000	$ 1,900,000,000
Interest rate futures | Short
Derivative [Line Items]
Notional amount	343,000,000	545,800,000
Interest rate swaps | US Dollars | Paying a Fixed Rate
Derivative [Line Items]
Notional amount	26,200,000	78,400,000
Interest rate swaps | US Dollars | Receiving a Fixed Rate
Derivative [Line Items]
Notional amount	26,300,000	32,100,000
Foreign currency forward contracts, underwriting and non-investment operations | Long
Derivative [Line Items]
Notional amount	681,900,000	354,100,000
Foreign currency forward contracts, underwriting and non-investment operations | Short
Derivative [Line Items]
Notional amount	617,000,000	601,200,000
Foreign currency forward contracts, investment operations | Long
Derivative [Line Items]
Notional amount	105,700,000	121,300,000
Foreign currency forward contracts, investment operations | Short
Derivative [Line Items]
Notional amount	38,900,000	42,900,000
Credit default swaps | Long
Derivative [Line Items]
Notional amount	0	1,000,000
Credit default swaps | Short
Derivative [Line Items]
Notional amount	53,400,000	$ 126,200,000
Total return swaps | Long
Derivative [Line Items]
Notional amount	100,000,000
Total return swaps | Short
Derivative [Line Items]
Notional amount	$ 0

Commitments, Contingencies an_3

Commitments, Contingencies and Other Items Commitments, Contingencies and Other Items (Leases) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease, weighted average lease term	1 year 7 months 6 days
Operating lease, right-of-use asset	$ 20.5
Operating lease, liability	20.5
Operating lease, expense	$ 1.7
Lessee, operating lease, term of contract	20 years
Lessee, operating lease, renewal term	30 years
Other assets
Lessee, Lease, Description [Line Items]
Finance lease, right-of-use asset	$ 20.4
Other liabilities
Lessee, Lease, Description [Line Items]
Finance lease, liability	25.7
Other Operating Income (Expense), Net
Lessee, Lease, Description [Line Items]
Finance lease, interest expense	0.6	$ 0.7
Finance lease, right-of-use asset, amortization	$ 0.2	$ 0.5

Commitments, Contingencies an_4

Commitments, Contingencies and Other Items - Future Minimum Lease Payments Under Existing Operating and Finance Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating leases
2019 (remaining)	$ 5,722
2020	5,439
2021	5,052
2022	4,261
2023	1,569
2024	86
After 2024	211
Future minimum lease payments under existing leases	22,340
Finance leases
2019 (remaining)	2,498
2020	3,336
2021	3,336
2022	3,336
2023	2,830
2024	2,661
After 2024	10,129
Future minimum lease payments under existing leases	$ 28,126

Condensed Consolidating Finan_3

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Assets
Total investments	$ 14,852,848	$ 11,885,747
Cash and cash equivalents	1,021,275	1,107,922	$ 647,973	$ 1,361,592
Investments in subsidiaries	0	0
Due from subsidiaries and affiliates	0	0
Premiums receivable	2,753,098	1,537,188
Prepaid reinsurance premiums	1,086,027	616,185
Reinsurance recoverable	2,908,343	2,372,221	1,572,321
Accrued investment income	64,615	51,311
Deferred acquisition costs and value of business acquired	841,528	476,661
Receivable for investments sold	411,172	256,416
Other assets	353,543	135,127
Goodwill and other intangible assets	267,151	237,418
Total assets	24,559,600	18,676,196
Liabilities
Reserve for claims and claim expenses	8,391,484	6,076,271	4,912,727
Unearned premiums	3,188,678	1,716,021
Debt	1,191,499	991,127
Amounts due to subsidiaries and affiliates	0	0
Reinsurance balances payable	3,009,492	1,902,056
Payable for investments purchased	679,596	380,332
Other liabilities	435,418	513,609
Total liabilities	16,896,167	11,579,416
Redeemable noncontrolling interests	2,109,400	2,051,700
Shareholders’ Equity
Total shareholders’ equity	5,554,033	5,045,080	4,436,253
Total liabilities, noncontrolling interests and shareholders’ equity	24,559,600	18,676,196
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Assets
Total investments	110,166	77,842
Cash and cash equivalents	3,687	3,350	97	139
Investments in subsidiaries	59,310	58,458
Due from subsidiaries and affiliates	101,578	101,579
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	231	310
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	1	23,885
Other assets	15,528	22,571
Goodwill and other intangible assets	0	0
Total assets	290,501	287,995
Liabilities
Reserve for claims and claim expenses	0	0
Unearned premiums	0	0
Debt	0	0
Amounts due to subsidiaries and affiliates	31	217
Reinsurance balances payable	0	0
Payable for investments purchased	0	24
Other liabilities	288	5,362
Total liabilities	319	5,603
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	290,182	282,392
Total liabilities, noncontrolling interests and shareholders’ equity	290,501	287,995
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Assets
Total investments	18,385	28,885
Cash and cash equivalents	5,848	9,604	1,175	1,469
Investments in subsidiaries	1,249,218	1,215,663
Due from subsidiaries and affiliates	3,765	0
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	96	127
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	0	0
Other assets	313,424	313,636
Goodwill and other intangible assets	0	0
Total assets	1,590,736	1,567,915
Liabilities
Reserve for claims and claim expenses	0	0
Unearned premiums	0	0
Debt	843,382	843,086
Amounts due to subsidiaries and affiliates	112,637	102,243
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	9,283	13,918
Total liabilities	965,302	959,247
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	625,434	608,668
Total liabilities, noncontrolling interests and shareholders’ equity	1,590,736	1,567,915
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Assets
Total investments	126,816	313,360
Cash and cash equivalents	3,070	3,534	8,150	14,656
Investments in subsidiaries	5,039,057	4,414,475
Due from subsidiaries and affiliates	54,939	57,039
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	(88)	1,046
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	926	203
Other assets	766,088	458,842
Goodwill and other intangible assets	119,410	120,476
Total assets	6,110,218	5,368,975
Liabilities
Reserve for claims and claim expenses	0	0
Unearned premiums	0	0
Debt	500,000	300,000
Amounts due to subsidiaries and affiliates	25,037	6,453
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	31,148	17,442
Total liabilities	556,185	323,895
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	5,554,033	5,045,080
Total liabilities, noncontrolling interests and shareholders’ equity	6,110,218	5,368,975
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-Guarantor Subsidiaries)
Assets
Total investments	14,597,481	11,465,660
Cash and cash equivalents	1,008,670	1,091,434	$ 638,551	$ 1,345,328
Investments in subsidiaries	0	0
Due from subsidiaries and affiliates	0	0
Premiums receivable	2,753,098	1,537,188
Prepaid reinsurance premiums	1,086,027	616,185
Reinsurance recoverable	2,908,343	2,372,221
Accrued investment income	64,376	49,828
Deferred acquisition costs and value of business acquired	841,528	476,661
Receivable for investments sold	410,245	232,328
Other assets	(1,793,255)	(1,403,636)
Goodwill and other intangible assets	147,741	116,942
Total assets	22,024,254	16,554,811
Liabilities
Reserve for claims and claim expenses	8,391,484	6,076,271
Unearned premiums	3,188,678	1,716,021
Debt	148,117	148,041
Amounts due to subsidiaries and affiliates	0	0
Reinsurance balances payable	3,009,492	1,902,056
Payable for investments purchased	679,596	380,308
Other liabilities	395,346	482,422
Total liabilities	15,812,713	10,705,119
Redeemable noncontrolling interests	2,109,400	2,051,700
Shareholders’ Equity
Total shareholders’ equity	4,102,141	3,797,992
Total liabilities, noncontrolling interests and shareholders’ equity	22,024,254	16,554,811
Consolidating Adjustments
Assets
Total investments	0	0
Cash and cash equivalents	0	0
Investments in subsidiaries	(6,347,585)	(5,688,596)
Due from subsidiaries and affiliates	(160,282)	(158,618)
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	0	0
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	0	0
Other assets	1,051,758	743,714
Goodwill and other intangible assets	0	0
Total assets	(5,456,109)	(5,103,500)
Liabilities
Reserve for claims and claim expenses	0	0
Unearned premiums	0	0
Debt	(300,000)	(300,000)
Amounts due to subsidiaries and affiliates	(137,705)	(108,913)
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	(647)	(5,535)
Total liabilities	(438,352)	(414,448)
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	(5,017,757)	(4,689,052)
Total liabilities, noncontrolling interests and shareholders’ equity	$ (5,456,109)	$ (5,103,500)

Condensed Consolidating Finan_4

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Net premiums earned	$ 550,028	$ 440,282
Net investment income	81,462	56,476
Net foreign exchange (losses) gains	(2,846)	3,757
Equity in earnings of other ventures	4,661	857
Other income (loss)	3,171	(1,242)
Net realized and unrealized gains (losses) on investments	170,645	(82,144)
Total revenues	807,121	417,986
Expenses
Net claims and claim expenses incurred	227,035	171,703
Acquisition expenses	123,951	97,711
Operational expenses	44,933	41,272
Corporate expenses	38,789	6,733
Interest expense	11,754	11,767
Total expenses	446,462	329,186
Income (loss) before equity in net income (loss) of subsidiaries and taxes	360,659	88,800
Equity in net income (loss) of subsidiaries	0	0
Income before taxes	360,659	88,800
Income tax (expense) benefit	(7,531)	3,407
Net income	353,128	92,207
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Net income attributable to RenaissanceRe	282,906	62,308
Dividends on preference shares	(9,189)	(5,595)
Net income available to RenaissanceRe common shareholders	273,717	56,713
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Revenues
Net premiums earned	0	0
Net investment income	595	513
Net foreign exchange (losses) gains	0	0
Equity in earnings of other ventures	0	0
Other income (loss)	0	0
Net realized and unrealized gains (losses) on investments	8,159	(1,286)
Total revenues	8,754	(773)
Expenses
Net claims and claim expenses incurred	0	0
Acquisition expenses	0	0
Operational expenses	11	10
Corporate expenses	0	0
Interest expense	0	0
Total expenses	11	10
Income (loss) before equity in net income (loss) of subsidiaries and taxes	8,743	(783)
Equity in net income (loss) of subsidiaries	828	834
Income before taxes	9,571	51
Income tax (expense) benefit	(1,805)	221
Net income	7,766	272
Net income attributable to redeemable noncontrolling interests	0	0
Net income attributable to RenaissanceRe	7,766	272
Dividends on preference shares	0	0
Net income available to RenaissanceRe common shareholders	7,766	272
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Revenues
Net premiums earned	0	0
Net investment income	2,060	1,234
Net foreign exchange (losses) gains	0	0
Equity in earnings of other ventures	965	1,211
Other income (loss)	0	0
Net realized and unrealized gains (losses) on investments	109	(259)
Total revenues	3,134	2,186
Expenses
Net claims and claim expenses incurred	0	0
Acquisition expenses	0	0
Operational expenses	12,333	11,070
Corporate expenses	0	0
Interest expense	9,252	9,252
Total expenses	21,585	20,322
Income (loss) before equity in net income (loss) of subsidiaries and taxes	(18,451)	(18,136)
Equity in net income (loss) of subsidiaries	33,532	(3,813)
Income before taxes	15,081	(21,949)
Income tax (expense) benefit	1,662	1,815
Net income	16,743	(20,134)
Net income attributable to redeemable noncontrolling interests	0	0
Net income attributable to RenaissanceRe	16,743	(20,134)
Dividends on preference shares	0	0
Net income available to RenaissanceRe common shareholders	16,743	(20,134)
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Revenues
Net premiums earned	0	0
Net investment income	8,277	6,035
Net foreign exchange (losses) gains	(1)	(3)
Equity in earnings of other ventures	0	0
Other income (loss)	0	0
Net realized and unrealized gains (losses) on investments	1,002	(661)
Total revenues	9,278	5,371
Expenses
Net claims and claim expenses incurred	0	0
Acquisition expenses	0	0
Operational expenses	469	1,313
Corporate expenses	38,828	3,684
Interest expense	1,883	1,108
Total expenses	41,180	6,105
Income (loss) before equity in net income (loss) of subsidiaries and taxes	(31,902)	(734)
Equity in net income (loss) of subsidiaries	314,887	62,426
Income before taxes	282,985	61,692
Income tax (expense) benefit	(79)	616
Net income	282,906	62,308
Net income attributable to redeemable noncontrolling interests	0	0
Net income attributable to RenaissanceRe	282,906	62,308
Dividends on preference shares	(9,189)	(5,595)
Net income available to RenaissanceRe common shareholders	273,717	56,713
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-Guarantor Subsidiaries)
Revenues
Net premiums earned	550,028	440,282
Net investment income	79,332	56,305
Net foreign exchange (losses) gains	(2,845)	3,760
Equity in earnings of other ventures	3,696	(354)
Other income (loss)	3,171	(1,242)
Net realized and unrealized gains (losses) on investments	161,375	(79,938)
Total revenues	794,757	418,813
Expenses
Net claims and claim expenses incurred	227,035	171,703
Acquisition expenses	123,951	97,711
Operational expenses	42,609	37,933
Corporate expenses	(1,922)	3,049
Interest expense	619	2,515
Total expenses	392,292	312,911
Income (loss) before equity in net income (loss) of subsidiaries and taxes	402,465	105,902
Equity in net income (loss) of subsidiaries	0	0
Income before taxes	402,465	105,902
Income tax (expense) benefit	(7,309)	755
Net income	395,156	106,657
Net income attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Net income attributable to RenaissanceRe	324,934	76,758
Dividends on preference shares	0	0
Net income available to RenaissanceRe common shareholders	324,934	76,758
Consolidating Adjustments
Revenues
Net premiums earned	0	0
Net investment income	(8,802)	(7,611)
Net foreign exchange (losses) gains	0	0
Equity in earnings of other ventures	0	0
Other income (loss)	0	0
Net realized and unrealized gains (losses) on investments	0	0
Total revenues	(8,802)	(7,611)
Expenses
Net claims and claim expenses incurred	0	0
Acquisition expenses	0	0
Operational expenses	(10,489)	(9,054)
Corporate expenses	1,883	0
Interest expense	0	(1,108)
Total expenses	(8,606)	(10,162)
Income (loss) before equity in net income (loss) of subsidiaries and taxes	(196)	2,551
Equity in net income (loss) of subsidiaries	(349,247)	(59,447)
Income before taxes	(349,443)	(56,896)
Income tax (expense) benefit	0	0
Net income	(349,443)	(56,896)
Net income attributable to redeemable noncontrolling interests	0	0
Net income attributable to RenaissanceRe	(349,443)	(56,896)
Dividends on preference shares	0	0
Net income available to RenaissanceRe common shareholders	$ (349,443)	$ (56,896)

Condensed Consolidating Finan_5

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Statement of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Net income	$ 353,128	$ 92,207
Change in net unrealized losses on investments	(37)	(30)
Comprehensive income	353,091	92,177
Net (income) loss attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive (income) loss attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive income attributable to RenaissanceRe	282,869	62,278
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net income	7,766	272
Change in net unrealized losses on investments	0	0
Comprehensive income	7,766	272
Net (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive income attributable to RenaissanceRe	7,766	272
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net income	16,743	(20,134)
Change in net unrealized losses on investments	0	0
Comprehensive income	16,743	(20,134)
Net (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive income attributable to RenaissanceRe	16,743	(20,134)
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Net income	282,906	62,308
Change in net unrealized losses on investments	0	0
Comprehensive income	282,906	62,308
Net (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive income attributable to RenaissanceRe	282,906	62,308
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-Guarantor Subsidiaries)
Condensed Financial Statements, Captions [Line Items]
Net income	395,156	106,657
Change in net unrealized losses on investments	(37)	(30)
Comprehensive income	395,119	106,627
Net (income) loss attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive (income) loss attributable to redeemable noncontrolling interests	(70,222)	(29,899)
Comprehensive income attributable to RenaissanceRe	324,897	76,728
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net income	(349,443)	(56,896)
Change in net unrealized losses on investments	0	0
Comprehensive income	(349,443)	(56,896)
Net (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive (income) loss attributable to redeemable noncontrolling interests	0	0
Comprehensive income attributable to RenaissanceRe	$ (349,443)	$ (56,896)

Condensed Consolidating Finan_6

Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows (used in) provided by operating activities
Net cash (used in) provided by operating activities	$ 377,149	$ (37,349)
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	4,600,808	2,318,859
Purchases of fixed maturity investments trading	(3,519,277)	(2,312,461)
Net purchases of equity investments trading	(4,601)	137
Net purchases of short term investments	(1,374,632)	(594,641)
Net purchases of other investments	(51,811)	(98,639)
Net purchases of investments in other ventures	(1,573)	(17,974)
Return of investment from investment in other ventures	11,250	0
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	0	0
Net purchase of the TMR Group Entities	(276,206)	0
Net cash used in investing activities	(616,042)	(704,719)
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	(14,469)	(13,224)
Dividends paid – preference shares	(9,189)	(5,595)
Drawdown of RenaissanceRe Revolving Credit Facility	200,000	0
Net third party redeemable noncontrolling interest share transactions	(16,847)	52,759
Taxes paid on withholding shares	(6,957)	(7,034)
Net cash provided by financing activities	152,538	26,906
Effect of exchange rate changes on foreign currency cash	(292)	1,543
Net decrease in cash and cash equivalents	(86,647)	(713,619)
Cash and cash equivalents, beginning of period	1,107,922	1,361,592
Cash and cash equivalents, end of period	1,021,275	647,973
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash (used in) provided by operating activities	2,198	659
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	15,655	42,793
Purchases of fixed maturity investments trading	(9,899)	(22,956)
Net purchases of equity investments trading	(2,046)	(21)
Net purchases of short term investments	(5,386)	(4,024)
Net purchases of other investments	0	0
Net purchases of investments in other ventures	0	0
Return of investment from investment in other ventures	0
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	(16,500)
Due (from) to subsidiary	(185)	7
Net purchase of the TMR Group Entities	0
Net cash used in investing activities	(1,861)	(701)
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
Drawdown of RenaissanceRe Revolving Credit Facility	0
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	0	0
Net cash provided by financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	337	(42)
Cash and cash equivalents, beginning of period	3,350	139
Cash and cash equivalents, end of period	3,687	97
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash (used in) provided by operating activities	(21,202)	(23,449)
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	29,861	27,672
Purchases of fixed maturity investments trading	(14,098)	(12,698)
Net purchases of equity investments trading	0	0
Net purchases of short term investments	(4,946)	(5,925)
Net purchases of other investments	0	0
Net purchases of investments in other ventures	0	0
Return of investment from investment in other ventures	0
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	6,629	14,106
Net purchase of the TMR Group Entities	0
Net cash used in investing activities	17,446	23,155
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
Drawdown of RenaissanceRe Revolving Credit Facility	0
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	0	0
Net cash provided by financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	(3,756)	(294)
Cash and cash equivalents, beginning of period	9,604	1,469
Cash and cash equivalents, end of period	5,848	1,175
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Cash flows (used in) provided by operating activities
Net cash (used in) provided by operating activities	(317,296)	(6,875)
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	277,030	119,542
Purchases of fixed maturity investments trading	(35,909)	(20,216)
Net purchases of equity investments trading	0	0
Net purchases of short term investments	(54,622)	54,728
Net purchases of other investments	0	0
Net purchases of investments in other ventures	0	0
Return of investment from investment in other ventures	0
Dividends and return of capital from subsidiaries	487,264	177,250
Contributions to subsidiaries	(528,416)	(150,205)
Due (from) to subsidiary	2,100	(154,877)
Net purchase of the TMR Group Entities	0
Net cash used in investing activities	147,447	26,222
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	(14,469)	(13,224)
Dividends paid – preference shares	(9,189)	(5,595)
Drawdown of RenaissanceRe Revolving Credit Facility	200,000
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	(6,957)	(7,034)
Net cash provided by financing activities	169,385	(25,853)
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	(464)	(6,506)
Cash and cash equivalents, beginning of period	3,534	14,656
Cash and cash equivalents, end of period	3,070	8,150
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries and Eliminations (Non-Guarantor Subsidiaries)
Cash flows (used in) provided by operating activities
Net cash (used in) provided by operating activities	713,449	(7,684)
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	4,278,262	2,128,852
Purchases of fixed maturity investments trading	(3,459,371)	(2,256,591)
Net purchases of equity investments trading	(2,555)	158
Net purchases of short term investments	(1,309,678)	(639,420)
Net purchases of other investments	(51,811)	(98,639)
Net purchases of investments in other ventures	(1,573)	(17,974)
Return of investment from investment in other ventures	11,250
Dividends and return of capital from subsidiaries	(487,264)	(177,250)
Contributions to subsidiaries	528,416	166,705
Due (from) to subsidiary	(8,544)	140,764
Net purchase of the TMR Group Entities	(276,206)
Net cash used in investing activities	(779,074)	(753,395)
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
Drawdown of RenaissanceRe Revolving Credit Facility	0
Net third party redeemable noncontrolling interest share transactions	(16,847)	52,759
Taxes paid on withholding shares	0	0
Net cash provided by financing activities	(16,847)	52,759
Effect of exchange rate changes on foreign currency cash	(292)	1,543
Net decrease in cash and cash equivalents	(82,764)	(706,777)
Cash and cash equivalents, beginning of period	1,091,434	1,345,328
Cash and cash equivalents, end of period	$ 1,008,670	$ 638,551

Subsequent Events (Details)

Subsequent Events (Details) - Senior Notes - 3.600% Senior Notes Due 2029 - Subsequent Event	Apr. 02, 2019USD ($)
Subsequent Event [Line Items]
Stated interest rate	3.60%
Face amount	$ 400,000,000
Repayments of lines of credit	$ 200,000,000