AmTrust Financial Services (AFSIP) 10-Q 9 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	AFSI
Entity Registrant Name	AMTRUST FINANCIAL SERVICES, INC.
Entity Central Index Key	1,365,555
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		196,026,575

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investments:
Fixed maturity securities, available-for-sale, at fair value (amortized cost $7,483,972; $7,315,041)	$ 7,621,536	$ 7,398,134
Fixed maturity securities, trading, at fair value (amortized cost $34,300; $29,081)	32,174	33,782
Equity securities, available-for-sale, at fair value (cost $87,416; $126,670)	104,540	137,162
Equity securities, trading, at fair value (cost $88,746; $76,163)	81,112	81,960
Short-term investments	7,141	0
Equity investment in unconsolidated subsidiaries – related party	0	151,332
Other investments (related party $57,346; $72,328)	140,643	152,187
Total investments	7,987,146	7,954,557
Cash and cash equivalents	766,121	567,771
Restricted cash and cash equivalents	879,478	713,338
Accrued interest and dividends	63,797	54,680
Premiums receivable, net	2,920,325	2,802,167
Reinsurance recoverable (related party $2,606,929; $2,452,242)	6,062,987	4,329,521
Prepaid reinsurance premium (related party $1,227,769; $1,133,485)	2,181,851	1,994,092
Other assets (related party $275,116; $189,223; recorded at fair value $298,701; $356,856)	1,985,826	1,712,165
Deferred policy acquisition costs	1,192,417	928,920
Property and equipment, net	458,342	314,332
Goodwill	790,421	686,565
Intangible assets	538,648	556,560
Total assets	25,827,359	22,614,668
LIABILITIES
Loss and loss adjustment expense reserves	12,086,644	10,140,716
Unearned premiums	5,322,203	4,880,066
Ceded reinsurance premiums payable (related party $366,215; $633,638)	799,659	804,882
Funds held under reinsurance treaties	122,983	70,868
Note payable on collateral loan – related party	167,975	167,975
Securities sold but not yet purchased, at fair value	56,181	36,394
Securities sold under agreements to repurchase, at contract value	0	160,270
Accrued expenses and other liabilities (recorded at fair value $146,628; $76,840)	1,950,971	1,651,626
Deferred gain on retroactive reinsurance	337,054	0
Debt (net of debt issuance cost of $15,323, $15,960)	1,287,744	1,234,900
Total liabilities	22,131,414	19,147,697
Commitments and contingencies
Redeemable non-controlling interest	1,484	1,358
Stockholders’ equity:
Common stock, $0.01 par value; 500,000 shares authorized; 210,751 and 196,455 issued in 2017 and 2016, respectively; 195,996 and 170,508 outstanding in 2017 and 2016, respectively	2,108	1,965
Preferred stock, $0.01 par value; 10,000 shares authorized; 5,399 issued and outstanding; $913,750 aggregated liquidation preference in 2017 and 2016, respectively	913,750	913,750
Additional paid-in capital	1,633,978	1,384,922
Treasury stock at cost; 14,755 and 25,947 shares in 2017 and 2016, respectively	(242,270)	(310,883)
Accumulated other comprehensive income (loss), net of tax	42,417	(125,722)
Retained earnings	1,163,177	1,405,071
Total AmTrust Financial Services, Inc. equity	3,513,160	3,269,103
Non-controlling interest	181,301	196,510
Total stockholders’ equity	3,694,461	3,465,613
Total liabilities and stockholders' equity	$ 25,827,359	$ 22,614,668

Consolidated Balance Sheets (u3

Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fixed maturities, available-for-sale, amortized cost	$ 7,484,353	$ 7,315,041
Fixed maturities, trading, amortized cost	34,300	29,081
Equity securities, available-for-sale, cost	87,416	126,670
Trading securities, cost basis	88,746	76,163
Other investments	140,643	152,187
Reinsurance recoverable	6,062,987	4,329,521
Prepaid reinsurance premium	2,181,851	1,994,092
Other assets, fair value	298,701	356,856
Other assets	1,985,826	1,712,165
Ceded reinsurance premiums payable	799,659	804,882
Accrued expenses and other current liabilities	146,628	76,840
Debt issuance costs, Net	$ 15,323	$ 15,960
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, issued (in shares)	210,751,000	196,455,000
Common stock, outstanding (in shares)	195,996,000	170,508,000
Liquidation preference	$ 913,750	$ 913,750
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred Stock, shares issued	5,399,000	5,399,000
Preferred stock, shares outstanding (in shares)	5,399,000	5,399,000
Treasury stock at cost (in shares)	14,755,000	25,947,000
Related Party Transactions
Other investments	$ 57,346	$ 72,328
Reinsurance recoverable	2,606,929	2,452,242
Prepaid reinsurance premium	1,227,769	1,133,485
Other assets	275,116	189,223
Ceded reinsurance premiums payable	$ 366,215	$ 633,638

Consolidated Statements of Inco

Consolidated Statements of Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Premium income:
Net written premium	$ 1,175,757	$ 1,216,050	$ 3,891,725		$ 3,705,165
Change in unearned premium	17,120	(19,814)	(95,607)		(252,895)
Net earned premium	1,192,877	1,196,236	3,796,118		3,452,270
Service and fee income (related parties - three months $55,931; $19,367 and nine months $81,221; $61,137)	180,505	133,857	486,447		386,968
Net investment income	61,103	59,919	173,654		160,079
Net realized gain on investments	24,520	8,230	56,590		31,304
Total revenues	1,459,005	1,398,242	4,512,809		4,030,621
Expenses:
Loss and loss adjustment expense	1,266,118	811,048	3,130,930		2,310,514
Acquisition costs and other underwriting expenses (net of ceding commission - related party - three months $136,316; $158,216 and nine months $448,249; $440,561)	337,086	303,992	1,038,496		870,937
Other	177,350	139,251	540,063		402,862
Total expenses	1,780,554	1,254,291	4,709,489		3,584,313
(Loss) income before other income (loss), (benefit) provision for income taxes, equity in earnings of unconsolidated subsidiaries and non-controlling interest	(321,549)	143,951	(196,680)		446,308
Other income (loss):
Interest expense (net of interest income - related party - three months $1,169; $2,061 and nine months $3,487; $6,436)	(22,873)	(22,124)	(70,703)		(55,910)
(Loss) gain on investment in life settlement contracts net of profit commission	(924)	5,485	6,425		28,891
Foreign currency loss	(62,819)	(10,880)	(139,735)		(78,108)
Gain on acquisition	0	0	0		48,775
Gain on sale of policy management system	186,755	0	186,755	[1]	0	[1]
Total other income (loss)	100,139	(27,519)	(17,258)		(56,352)
(Loss) income before (benefit) provision for income taxes, equity in earnings of unconsolidated subsidiaries and non-controlling interest	(221,410)	116,432	(213,938)		389,956
(Benefit) provision for income taxes	(62,588)	23,185	(60,959)		65,952
(Loss) income before equity in earnings of unconsolidated subsidiaries	(158,822)	93,247	(152,979)		324,004
Equity in earnings of unconsolidated subsidiary – related parties	0	1,954	73,488		12,532
Net (loss) income	(158,822)	95,201	(79,491)		336,536
Net income (loss) attributable to non-controlling interest and redeemable non-controlling interest of subsidiaries	718	(2,975)	(17,010)		(12,809)
Net (loss) income attributable to AmTrust Financial Services, Inc.	(158,104)	92,226	(96,501)		323,727
Dividends on preferred stock	(16,571)	(11,576)	(49,713)		(31,943)
Net (loss) income attributable to AmTrust common stockholders	$ (174,675)	$ 80,650	$ (146,214)		$ 291,784
Earnings per common share: (usd per share)
Basic earnings per share (usd per share)	$ (0.89)	$ 0.47	$ (0.80)		$ 1.68
Diluted earnings per share (usd per share)	(0.89)	0.47	(0.80)		1.67
Dividends declared per common share (usd per share)	$ 0.17	$ 0.17	$ 0.51		$ 0.47
[1]	) 2017 amounts relate to the sale of the personal lines policy management system to National General Holdings Corp. See Note 10 for more information.

Consolidated Statements of Inc5

Consolidated Statements of Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Service and fee income	$ 180,505	$ 486,447	$ 386,968
Interest Income form related party	1,169	3,487	2,061	$ 6,436
Related Party Transactions
Service and fee income	55,931	81,221	19,367	61,137
Ceding commission - earned	$ 136,316	$ 448,249	$ 158,216	$ 440,561

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ (158,822)	$ 95,201	$ (79,491)	$ 336,536
Other comprehensive income, net of tax:
Foreign currency translation adjustments	50,709	(30,145)	127,235	(110,148)
Change in fair value of interest rate swap	25	253	145	540
Unrealized gain on securities:
Gross unrealized holding gain	17,175	23,741	115,235	328,409
Tax (benefit) expense arising during period	(2,615)	7,118	20,346	113,890
Net unrealized holding gain	19,790	16,623	94,889	214,519
Reclassification adjustments for investment gain included in net income, net of tax: Other-than-temporary impairment loss	0	5,989	0	16,526
Reclassification adjustments for investment gain included in net income, net of tax: Other net realized (gain) loss on investments	(23,272)	(9,388)	(54,130)	(34,519)
Total reclassification adjustments for investment gains included in net (loss) income, net of tax	(23,272)	(3,399)	(54,130)	(17,993)
Other comprehensive income (loss), net of tax	47,252	(16,668)	168,139	86,918
Comprehensive (loss) income	(111,570)	78,533	88,648	423,454
Less: Comprehensive (loss) income attributable to redeemable non-controlling interest and non-controlling interest	(718)	2,975	17,010	12,809
Comprehensive (loss) income attributable to AmTrust Financial Services, Inc.	$ (110,852)	$ 75,558	$ 71,638	$ 410,645

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income		$ (79,491)	$ 336,536
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization		118,687	97,314
Net amortization of bond premium or discount		13,296	21,983
Equity earnings on investment in unconsolidated subsidiaries	[1]	(73,488)	(12,532)
Gain on investment in life settlement contracts, net		(6,425)	(28,891)
Net realized gain on investments		(56,590)	(57,721)
Non-cash write-down of investments		19,303	26,417
Discount on notes payable		4,776	4,420
Stock based compensation		18,793	17,433
Bad debt expense		19,739	15,199
Foreign currency loss		139,735	78,108
Gain on sale of policy management system	[2]	186,755	0
Gain on acquisition		0	(48,775)
Changes in assets - (increase) decrease:
Premiums and notes receivables		(63,888)	(299,778)
Reinsurance recoverable		(1,685,050)	(363,087)
Deferred policy acquisition costs		(248,351)	(229,289)
Prepaid reinsurance premiums		(185,368)	(486,506)
Other assets		(166,903)	307,499
Changes in liabilities - increase (decrease):
Ceded reinsurance premium payable		93,841	316,497
Loss and loss adjustment expense reserve		1,564,468	1,189,411
Unearned premiums		283,950	513,482
Funds held under reinsurance treaties		1,101	(7,487)
Accrued expenses and other liabilities		400,378	(509,573)
Net cash (used in) provided by operating activities		(74,242)	880,660
Cash flows from investing activities:
Purchases of fixed maturities, available-for-sale		(1,603,933)	(1,839,005)
Purchases of equity securities, available-for-sale		(51,416)	(129,716)
Purchase of equity securities, trading		(386,561)	(150,654)
Purchase of other investments		(18,806)	(15,391)
Sales, maturities, paydowns of fixed maturities, available-for-sale		1,704,224	1,537,296
Sales of equity securities, available-for-sale		193,466	110,895
Sales of equity securities, trading		379,933	155,502
Sales of other investments		50,793	3,371
Net sale of short term investments		(7,336)	(125,907)
Net sale (purchase) of securities sold but not purchased		19,787	(14,848)
Payment of life settlement contracts		(16,473)	(15,880)
Receipt of life settlement contract proceeds		48,714	38,247
Acquisition of subsidiaries, net of cash received	[3]	(97,786)	(139,038)
Sale of equity method investment	[1]	211,290	0
Change in restricted cash and cash equivalents		(156,138)	(176,428)
Purchase of property and equipment		(193,249)	(111,708)
Sale of life settlement contracts	[4]	90,000	0
Sale of policy management system	[2]	57,040	0
Net cash provided by (used in) investing activities		223,549	(873,264)
Cash flows from financing activities:
Repurchase agreements, net		(160,270)	0
Secured loan agreements borrowings		108,234	45,809
Secured loan agreements payments		(9,272)	(5,372)
Promissory notes payments		(52,343)	0
Convertible senior notes settlement		0	(10)
Financing fees		(197)	0
Common stock issuance		298,747	276
Common stock repurchase		0	(152,395)
Preferred stock issuance		0	417,264
Contingent consideration payments		(16,611)	(34,839)
Non-controlling interest capital contributions from consolidated subsidiaries, net		(31,398)	(5,984)
Stock option exercise and other		271	(6,819)
Dividends distributed on common stock		(91,382)	(78,501)
Dividends distributed on preferred stock		(49,713)	(31,943)
Net cash (used in) provided by financing activities		(3,934)	147,486
Effect of exchange rate changes on cash		52,977	(25,453)
Net increase in cash and cash equivalents		198,350	129,429
Cash and cash equivalents, beginning of the year		567,771	1,003,916
Cash and cash equivalents, end of the period		$ 766,121	$ 1,133,345
[1]	2017 amounts relate to the sale of shares of National General Holding Corp. See Note 10 for more information.
[2]	) 2017 amounts relate to the sale of the personal lines policy management system to National General Holdings Corp. See Note 10 for more information.
[3]	Primarily relates to the acquisitions of AmeriHeath Casualty Insurance Company, PDP Group, Inc., and other immaterial subsidiaries. See Note 11 for more information.
[4]	2017 Amounts relate to the sale of life settlement contracts from Tiger Capital LLC's portfolio. See Note 5 for more information.

Basis of Reporting

Basis of Reporting	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Reporting	Basis of Reporting The accompanying unaudited interim consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial statements and with the instructions to Form 10-Q and Article 10 of Regulation S-X and, therefore, do not include all of the information and footnotes required by GAAP for complete financial statements. These interim statements should be read in conjunction with the consolidated financial statements and notes thereto included in the AmTrust Financial Services, Inc. (“AmTrust” or the “Company”) Annual Report on Form 10-K for the year ended December 31, 2016 , previously filed with the Securities and Exchange Commission (“SEC”) on April 4, 2017 ("Form 10-K"). These interim consolidated financial statements reflect all adjustments that are, in the opinion of management, necessary for a fair presentation of the results for the interim period and all such adjustments are of a normal recurring nature. The results of operations for the interim period are not necessarily indicative, if annualized, of those to be expected for the full year. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. A detailed description of the Company’s significant accounting policies and management judgments is located in the audited consolidated financial statements for the year ended December 31, 2016 , included in the Company’s Form 10-K filed with the SEC. All material inter-company transactions and accounts have been eliminated in the consolidated financial statements. To facilitate period-to-period comparisons, certain reclassifications have been made to prior period consolidated financial statement amounts to conform to current period presentation. As previously disclosed, on March 14, 2017 , the Audit Committee of our Board of Directors, in consultation with management and our current and former independent registered public accounting firms, concluded that our previously issued Consolidated Financial Statements for fiscal years 2015 and 2014 , along with each of the four quarters included in fiscal year 2015 as well as the first three quarters of fiscal year 2016 , needed to be restated. Accordingly, within this report, we have included restated unaudited quarterly financial statements for the three and nine months periods ended September 30, 2016 . See our Form 10-K for the year ended December 31, 2016 and Quarterly Report on Form 10-Q/A for the period ended September 30, 2016 for more information. During the three months ended September 30, 2017, the Company identified and corrected errors that originated in prior periods primarily related to the misclassification of certain service and fee income as other underwriting expense and an overstatement of net earned premium with a corresponding overstatement of acquisition costs. In accordance with ASC 250, Accounting Changes and Error Correction s, and SEC guidance, the Company evaluated the materiality of the errors from both quantitative and qualitative perspectives. Based on this analysis, the Company concluded that the errors were immaterial to its financial position, results of operations and cash flows for any previously reported quarterly financial statements or for the current period in which they were corrected. As a result of these correction of errors for the three months ended September 30, 2017, service and fee income increased $37,895 , net earned premiums decreased $39,170 , acquisition costs and other underwriting expense decreased $3,622 , and other expenses were increased $7,740 . The errors had no impact on the Company's previously reported net income.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements With the exception of those discussed below, there have been no recent accounting pronouncements or changes in accounting pronouncements during the nine months ended September 30, 2017 , as compared to those described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2016 , that are of significance, or potential significance, to the Company. Recent Accounting Standards, Adopted In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, classification on the statement of cash flows, and accounting for forfeitures. The adoption of this guidance on January 1, 2017 did not have a material effect on the Company's results of operations, financial position or cash flows. In March 2016, the FASB issued ASU 2016-07, Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting , which eliminates the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. The guidance requires the equity method investor to add the cost of acquiring additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted this guidance on a prospective basis. The adoption of this guidance on January 1, 2017 did not have a material effect on the Company's results of operations, financial position or cash flows. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments , which clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. An entity performing the assessment under the amended guidance in this ASU is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence prescribed by Topic 815. The Company adopted this guidance on a modified retrospective basis. The adoption of this guidance on January 1, 2017 did not have a material effect on the Company's results of operations, financial position or cash flows. In March 2016, the FASB issued ASU 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships , which clarifies that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted this guidance on a modified retrospective basis. The adoption of this guidance on January 1, 2017 did not have a material effect on the Company's results of operations, financial position or cash flows. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business , which clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The guidance specifies that when substantially all of the fair value of gross assets acquired is concentrated in a single asset (or a group of similar assets), the assets acquired would not represent a business. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. The guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. Early adoption is permitted and prospective application is required. The Company early adopted this guidance effective January 1, 2017. The adoption of this guidance did not have a material impact on the Company's results of operations, financial position or cash flows. Recent Accounting Standards, Not Yet Adopted In March 2017, the FASB issued ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities . The new guidance shortens the amortization period for the premium on callable debt securities to the earliest call date. The amortization period for the discount on callable debt securities is not changed by the new guidance, and continues to be amortized to maturity. The new guidance more closely aligns interest income recorded on debt securities held at a premium or a discount with the economics of the underlying instrument. The guidance is effective for annual periods beginning after December 15, 2018, including interim periods within those periods. Early adoption is permitted, including adoption in an interim period. If an entity early adopts in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Company is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures. In March 2017, the FASB issued ASU 2017-07, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires that an employer present service cost in the same line item or items as other current employee compensation costs, and present the remaining components of net benefit cost in one or more separate line items outside of income from operations (if that subtotal is presented). In addition, this ASU limits the components of net benefit cost eligible to be capitalized to service cost. This guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those annual periods. This standard is not expected to have a material impact on the Company's financial position, results of operations or cash flows. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The ASU requires lessees to put most leases on their balance sheets as a lease liability with a corresponding right-of-use asset, but continue to recognize the related leasing expense within net income. The definition of a lease was modified to exemplify the concept of control over an asset identified in the lease. Lease classification criteria remains substantially similar to criteria in current lease guidance. The guidance defines which payments can be used in determining lease classification. For short-term leases with a term of 12 months or less, lessees can make a policy election not to recognize lease assets and lease liabilities. Lessor accounting is largely unchanged. Leveraged leases that commenced before the effective date of the new guidance are grandfathered. New disclosures are required, and certain practical expedients are allowed upon adoption. This accounting and disclosure guidance will be effective for interim and annual reporting periods beginning after December 15, 2018 and should be implemented using the modified retrospective approach. Early adoption is permitted. The Company is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures. In February 2017, the FASB issued ASU 2017-05, Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets, which clarifies that ASC 610-20 applies to the derecognition of nonfinancial assets and in substance nonfinancial assets unless other specific guidance applies. As a result, the new guidance will not apply to the derecognition of businesses, nonprofit activities, or financial assets (including equity method investments), or to revenue transactions (contracts with customers). The new guidance also clarifies that an in substance nonfinancial asset is an asset or group of assets for which substantially all of the fair value consists of nonfinancial assets and the group or subsidiary is not a business. In addition, transfers of nonfinancial assets to another entity in exchange for a noncontrolling ownership interest in that entity will be accounted for under ASC 610-20, removing specific guidance on such partial exchanges from ASC 845, Nonmonetary Transactions . As a result of the new guidance, the guidance specific to real estate sales in ASC 360-20 will be eliminated. As such, sales and partial sales of real estate assets will now be subject to the same derecognition model as all other nonfinancial assets. This guidance is effective for fiscal years beginning after December 15, 2017, including interim reporting periods within that reporting period. Early adoption is permitted, but only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment , which simplifies the accounting for goodwill impairment charges. Under the current guidance, if the fair value of a reporting unit is lower than its carrying amount, an entity calculates any impairment charge by comparing the implied fair value of goodwill with its carrying amount. The implied fair value of goodwill is calculated by deducting the fair value of all assets and liabilities of the reporting unit from the reporting unit’s fair value. Under the new guidance, an entity will record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value not to exceed the amount of goodwill allocated to that reporting unit. The guidance is effective in fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual and interim goodwill impairment testing dates after January 1, 2017. The Company is evaluating the requirements of this guidance and the potential impact on the Company’s financial position and results of operations. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , which requires an entity to recognize revenue for the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard is effective on January 1, 2018, and may be applied retrospectively or through a cumulative effect adjustment to retained earnings at the date of adoption. The new guidance does not apply to insurance contracts, leases, financial instruments, and certain other agreements that are within the scope of other GAAP guidance. The Company is currently assessing its revenue streams to identify any contracts with customers that may be in-scope of the new standard. The Company has selected a sample of in-scope contracts for review (“key contracts”) to identify any potential impact on revenue recognition. The Company plans to identify and group the remaining contracts with customers with similar terms and features based on the conclusions developed in the review of the key contracts and to identify additional contracts with customers that may have unique terms and features that require a separate assessment. The Company is also assessing the impact on costs to obtain or fulfill contracts with customers, and which transition method to apply upon adoption on January 1, 2018. The Company is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures.

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	Investments (a) Available-for-Sale Securities The cost or amortized cost, gross unrealized gains and losses, and estimated fair value of fixed maturity and equity securities classified as available-for-sale as of September 30, 2017 and December 31, 2016 , are presented below: As of September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities: U.S. treasury securities $ 319,333 $ 1,080 $ (1,528 ) $ 318,885 U.S. government agencies 48,605 26 (481 ) 48,150 Municipal bonds 894,106 15,459 (3,772 ) 905,793 Foreign government 184,507 4,013 (1,404 ) 187,116 Corporate bonds: Finance 1,579,758 45,733 (2,413 ) 1,623,078 Industrial 2,184,009 60,640 (6,306 ) 2,238,343 Utilities 365,563 10,140 (964 ) 374,739 Commercial mortgage-backed securities 461,972 4,480 (5,461 ) 460,991 Residential mortgage-backed securities: Agency backed 801,586 13,362 (4,054 ) 810,894 Non-agency backed 5,677 3 (31 ) 5,649 Collateralized loan / debt obligation 617,392 9,323 (367 ) 626,348 Asset backed securities 21,464 114 (28 ) 21,550 Total fixed maturity securities $ 7,483,972 $ 164,373 $ (26,809 ) $ 7,621,536 Equity Securities: Common stock $ 87,416 $ 19,418 $ (2,294 ) $ 104,540 As of December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities: U.S. treasury securities $ 331,036 $ 1,235 $ (1,617 ) $ 330,654 U.S. government agencies 63,467 282 (17 ) 63,732 Municipal bonds 860,444 9,603 (15,877 ) 854,170 Foreign government 149,365 4,237 (726 ) 152,876 Corporate bonds: Finance 1,535,606 38,404 (7,722 ) 1,566,288 Industrial 2,222,843 62,133 (17,115 ) 2,267,861 Utilities 195,607 4,433 (1,210 ) 198,830 Commercial mortgage-backed securities 178,092 2,464 (2,562 ) 177,994 Residential mortgage-backed securities: Agency backed 1,210,229 13,685 (13,529 ) 1,210,385 Non-agency backed 61,646 586 (1,003 ) 61,229 Collateralized loan / debt obligations 476,767 8,389 (751 ) 484,405 Asset backed securities 29,939 31 (260 ) 29,710 Total fixed maturity securities $ 7,315,041 $ 145,482 $ (62,389 ) $ 7,398,134 Equity Securities: Preferred stock $ 4,044 $ — $ (59 ) $ 3,985 Common stock 122,626 12,899 (2,348 ) 133,177 Total equity securities $ 126,670 $ 12,899 $ (2,407 ) $ 137,162 Investments in foreign government securities include securities issued by national entities as well as instruments that are unconditionally guaranteed by such entities. As of September 30, 2017 , the Company's foreign government securities were issued or guaranteed primarily by governments in Europe, Canada and Israel. Proceeds from the sale of investments in available-for-sale securities were approximately $757,709 and $647,928 , respectively, during the three months ended September 30, 2017 and 2016 , and were approximately $1,897,690 and $1,648,193 , respectively, for the nine months ended September 30, 2017 and 2016 . A summary of the Company’s available-for-sale fixed maturity securities as of September 30, 2017 and December 31, 2016 , by contractual maturity, is shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. September 30, 2017 December 31, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 185,841 $ 186,532 $ 319,275 $ 319,882 Due after one through five years 1,748,551 1,788,962 2,956,429 2,998,711 Due after five through ten years 3,176,390 3,246,584 1,645,211 1,683,112 Due after ten years 465,099 474,026 437,452 432,702 Mortgage and asset backed securities 1,908,091 1,925,432 1,956,674 1,963,727 Total fixed maturity securities $ 7,483,972 $ 7,621,536 $ 7,315,041 $ 7,398,134 The tables below summarize the gross unrealized losses of our available-for-sale fixed maturity and equity securities by length of time the security has continuously been in an unrealized loss position as of September 30, 2017 and December 31, 2016 : Less Than 12 Months 12 Months or More Total As of September 30, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed Maturity Securities: U.S. treasury securities $ 257,511 $ (1,452 ) $ 6,263 $ (76 ) $ 263,774 $ (1,528 ) U.S. government agencies 43,352 (481 ) — — 43,352 (481 ) Municipal bonds 291,908 (2,778 ) 42,088 (994 ) 333,996 (3,772 ) Foreign government 75,485 (1,315 ) 9,258 (89 ) 84,743 (1,404 ) Corporate bonds: Finance 184,303 (1,589 ) 65,061 (824 ) 249,364 (2,413 ) Industrial 347,521 (4,169 ) 86,507 (2,137 ) 434,028 (6,306 ) Utilities 62,260 (494 ) 23,913 (470 ) 86,173 (964 ) Commercial mortgage-backed securities 252,831 (4,784 ) 9,674 (677 ) 262,505 (5,461 ) Residential mortgage-backed securities: Agency backed 253,181 (3,998 ) 2,264 (56 ) 255,445 (4,054 ) Non-agency backed 3,206 (9 ) 2,322 (22 ) 5,528 (31 ) Collateralized loan / debt obligations 69,034 (367 ) — — 69,034 (367 ) Asset backed securities 5,797 (6 ) 1,008 (22 ) 6,805 (28 ) Total fixed maturity securities $ 1,846,389 $ (21,442 ) $ 248,358 $ (5,367 ) $ 2,094,747 $ (26,809 ) Equity Securities: Common stock $ 16,245 $ (2,294 ) $ — $ — $ 16,245 $ (2,294 ) Less Than 12 Months 12 Months or More Total As of December 31, 2016 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed Maturity Securities: U.S. treasury securities $ 293,155 $ (1,613 ) $ 22,989 $ (4 ) $ 316,144 $ (1,617 ) U.S. government agencies 7,866 (17 ) — — 7,866 (17 ) Municipal bonds 519,578 (15,207 ) 15,742 (670 ) 535,320 (15,877 ) Foreign government 128,863 (688 ) 12,659 (38 ) 141,522 (726 ) Corporate bonds: Finance 1,071,982 (7,210 ) 16,840 (512 ) 1,088,822 (7,722 ) Industrial 1,200,129 (13,648 ) 114,035 (3,467 ) 1,314,164 (17,115 ) Utilities 119,488 (423 ) 10,391 (787 ) 129,879 (1,210 ) Commercial mortgage-backed securities 71,780 (1,654 ) 10,910 (908 ) 82,690 (2,562 ) Residential mortgage-backed securities: Agency backed 718,098 (13,469 ) 8,144 (60 ) 726,242 (13,529 ) Non-agency backed 24,372 (869 ) 4,462 (134 ) 28,834 (1,003 ) Collateralized loan / debt obligations 97,923 (433 ) 32,937 (318 ) 130,860 (751 ) Asset backed securities 9,220 (124 ) 4,926 (136 ) 14,146 (260 ) Total fixed maturity securities $ 4,262,454 $ (55,355 ) $ 254,035 $ (7,034 ) $ 4,516,489 $ (62,389 ) Equity Securities: Preferred stock $ 529 $ (30 ) $ — $ (29 ) $ 529 $ (59 ) Common stock 46,254 (1,394 ) 9,991 (954 ) 56,245 (2,348 ) Total equity securities $ 46,783 $ (1,424 ) $ 9,991 $ (983 ) $ 56,774 $ (2,407 ) There are 1,499 and 2,125 securities at September 30, 2017 and December 31, 2016 , respectively, that account for the gross unrealized loss, none of which is deemed by the Company to be other-than-temporarily impaired ("OTTI"). At September 30, 2017 , the Company determined that the unrealized losses on fixed maturity securities were primarily due to market interest rate movements since their date of purchase. On a quarterly basis, the Company analyzes securities in an unrealized loss position for OTTI. The Company considers an investment to be impaired when it has been in an unrealized loss position greater than a de minimis threshold for over 12 months, excluding securities backed by the U.S. government (e.g., U.S. treasury securities or agency-backed residential mortgage-backed securities). Additionally, the Company reviews whether any of the impaired positions related to securities for which OTTI was previously recognized, and whether the Company intends to sell any of the securities in an unrealized loss position. Once the Company completes the analysis described above, each security is further evaluated to assess whether the decline in the fair value of any investment below its cost basis is deemed other-than-temporary. The Company considers many factors in completing its quarterly review of securities with unrealized losses for OTTI. For equity securities, the Company considers the length of time and the extent to which the fair value has been below cost, the financial condition and near-term prospects of the issuer, including any specific events that may influence the operations of the issuer, and the intent and ability of the Company to retain its investment for a period of time sufficient to allow for any anticipated recovery in fair value. For fixed maturity securities, the Company considers among other things, the length of time and the extent to which the fair value has been less than the amortized cost basis, adverse conditions and near-term prospects for improvement specifically related to the issuer, industry or geographic area, the historical and implied volatility of the fair value of the security, any information obtained from regulators and rating agencies, the issuer’s capital strength and the payment structure of the security and the likelihood the issuer will be able to make payments in the future (or the historical failure of the issuer to make scheduled interest or principal payments or payment of dividends). For equity securities, a decline in fair value that is considered to be other-than-temporary is recognized in net income based on the fair value of the security at the time of assessment, resulting in a new cost basis for the security. For fixed maturity securities where the Company intends to sell the security or it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost, a decline in fair value is considered to be other-than-temporary and is recognized in net income based on the fair value of the security at the time of assessment, resulting in a new cost basis for the security. If the decline in fair value of a fixed maturity security below its amortized cost is considered to be other-than-temporary based upon other considerations, the Company compares the estimated present value of the cash flows expected to be collected to the amortized cost of the security. The extent to which the estimated present value of the cash flows expected to be collected is less than the amortized cost of the security represents the credit-related portion of the other-than-temporary impairment, which is recognized in net income, resulting in a new cost basis for the security. Any remaining decline in fair value represents the non-credit portion of the other-than-temporary impairment, which is recognized in other comprehensive income (loss). There were no credit-related OTTI charges for the three and nine months ended September 30, 2017 . (b) Trading Securities The amortized cost, estimated fair value and gross unrealized gains and losses of trading securities as of September 30, 2017 and December 31, 2016 are presented in the tables below: As of September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities U.S. Treasury securities $ 10,050 $ — $ (140 ) $ 9,910 Corporate bonds: Industrial 23,955 643 (2,699 ) 21,899 Utilities 295 70 — 365 Total Fixed Maturity Securities $ 34,300 $ 713 $ (2,839 ) $ 32,174 Common stock $ 88,746 $ 3,960 $ (11,594 ) $ 81,112 As of December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities Corporate bonds: Industrial $ 24,151 $ 4,379 $ — $ 28,530 Utilities 4,930 322 — 5,252 Total Fixed Maturity Securities $ 29,081 $ 4,701 $ — $ 33,782 Common stock $ 76,163 $ 9,842 $ (4,045 ) $ 81,960 Proceeds from the sale of investments in trading securities were approximately $70,518 and $47,177 , respectively, during the three months ended September 30, 2017 and 2016 , and were approximately $379,933 and $155,502 , respectively, during the nine months ended September 30, 2017 and 2016 . The table below shows the portion of trading gains and losses for the period related to trading securities still held during the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net (losses) and gains recognized during the period on trading securities $ (2,241 ) $ 995 $ (17,481 ) $ 3,428 Less: Net (losses) and gains recognized during the period on trading securities sold during the period (1,584 ) 812 (933 ) 8,199 Unrealized (losses) and gains recognized during the reporting period on trading securities still held at the reporting date $ (657 ) $ 183 $ (16,548 ) $ (4,771 ) (c) Investment Income Net investment income for the three and nine months ended September 30, 2017 and 2016 was derived from the following sources: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Fixed maturity securities, available-for-sale $ 60,478 $ 59,712 $ 187,128 $ 152,140 Equity securities, available-for-sale 469 465 2,038 6,927 Fixed maturity securities, trading 473 — 1,505 — Equity securities, trading (141 ) (40 ) (121 ) (318 ) Cash and short term investments 5,695 410 8,977 2,182 Other invested assets (1) (664 ) — (15,665 ) — 66,310 60,547 183,862 160,931 Less: Investment expenses (5,207 ) (628 ) (10,208 ) (852 ) $ 61,103 $ 59,919 $ 173,654 $ 160,079 (1) Includes losses from equity method investments. (d) Realized Gains and Losses The tables below summarize the gross and net realized gains and (losses) for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2017 Gross Gains Gross Losses Net Gains (Losses) Gross Gains Gross Losses Net Gains (Losses) Fixed maturity securities, available-for-sale $ 15,577 $ (1,132 ) $ 14,445 $ 38,024 $ (3,188 ) $ 34,836 Equity securities, available-for-sale 9,122 (295 ) 8,827 21,633 (1,894 ) 19,739 Fixed maturity securities, trading 1,723 — 1,723 6,695 (9,548 ) (2,853 ) Equity securities, trading 6,204 (10,168 ) (3,964 ) 14,691 (29,319 ) (14,628 ) Other investments 3,489 — 3,489 19,516 (20 ) 19,496 $ 36,115 $ (11,595 ) $ 24,520 $ 100,559 $ (43,969 ) $ 56,590 Three Months Ended September 30, Nine Months Ended September 30, 2016 2016 Gross Gains Gross Losses Net Gains (Losses) Gross Gains Gross Losses Net Gains (Losses) Fixed maturity securities, available-for-sale $ 17,535 $ (2,582 ) $ 14,953 $ 57,346 $ (4,199 ) $ 53,147 Equity securities, available-for-sale 553 (1,126 ) (573 ) 1,821 (1,862 ) (41 ) Equity securities, trading 2,897 (1,902 ) 995 17,824 (14,396 ) 3,428 Other investments 3,449 (1,133 ) 2,316 1,189 (2 ) 1,187 Write-down of other invested assets — (6,440 ) (6,440 ) — (19,977 ) (19,977 ) Write-down of equity securities, available-for-sale — (3,021 ) (3,021 ) — (6,440 ) (6,440 ) $ 24,434 $ (16,204 ) $ 8,230 $ 78,180 $ (46,876 ) $ 31,304 On June 9, 2017 , the Company announced that it entered into agreements to sell 10,586 common shares of National General Holdings Corp. (“NGHC”), a related party, at a price of $20.00 per share (representing a discount of 8.3% to NGHC's common stock closing market price on the Nasdaq Stock Exchange on June 8, 2017 ). The sale was completed through separate, privately negotiated purchase agreements with unaffiliated third parties and resulted in a $68,425 realized gain, which is reflected in the Equity in earnings of unconsolidated subsidiaries - related parties caption on the Consolidated Statements of Income. (f) Restricted Cash and Investments The Company, in order to conduct business in certain states, is required to maintain letters of credit or assets on deposit to support state mandated regulatory requirements and certain third party agreements. The Company also utilizes trust accounts to collateralize business with its reinsurance counterparties. These assets are primarily in the form of cash and certain investment grade securities. The fair values of the Company's restricted assets as of September 30, 2017 and December 31, 2016 are as follows: September 30, 2017 December 31, 2016 Restricted cash and cash equivalents $ 879,478 $ 713,338 Restricted investments - fixed maturity securities at fair value 2,861,413 2,126,216 Total restricted cash, cash equivalents, and investments $ 3,740,891 $ 2,839,554 (g) Other Securities sold but not yet purchased are securities that the Company has sold, but does not own, in anticipation of a decline in the market value of the security. For more information related to these agreements, please see Note 4 to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016. The Company’s liability for securities to be delivered is measured at their fair value and was $56,181 and $36,394 as of September 30, 2017 and December 31, 2016 , respectively. From time to time, the Company enters into repurchase agreements that are subject to a master netting arrangement, which are accounted for as collateralized borrowing transactions and are recorded at contract amounts. The Company receives cash or securities that it invests or holds in short term or fixed income securities. As of September 30, 2017 , the Company had no outstanding repurchase agreements. As of December 31, 2016, the Company had thirteen repurchase agreements with an outstanding principal amount of $160,270 , which approximates fair value, at interest rates between 0.75% and 0.90% . The Company had approximately $175,700 of collateral pledged in support of these agreements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The following tables present the level within the fair value hierarchy at which the Company’s financial assets and financial liabilities are measured on a recurring basis as of September 30, 2017 and December 31, 2016 : As of September 30, 2017 Total Level 1 Level 2 Level 3 Financial Assets: U.S. treasury securities $ 328,795 $ 328,795 $ — $ — U.S. government agencies 48,150 — 48,150 — Municipal bonds 905,793 — 905,164 629 Foreign government 187,116 — 187,116 — Corporate bonds and other bonds: Finance 1,623,078 — 1,615,636 7,442 Industrial 2,260,242 — 2,258,428 1,814 Utilities 375,104 — 375,104 — Commercial mortgage-backed securities 460,991 — 437,559 23,432 Residential mortgage-backed securities: Agency backed 810,894 — 810,894 — Non-agency backed 5,649 — 5,649 — Collateralized loan / debt obligations 626,348 — 626,348 — Asset-backed securities 21,550 — 20,759 791 Equity securities, available-for-sale 104,540 104,540 — — Equity securities, trading 81,112 79,001 411 1,700 Life settlement contracts 298,701 — — 298,701 Total Financial Assets $ 8,138,063 $ 512,336 $ 7,291,218 $ 334,509 Financial Liabilities: Securities sold but not yet purchased, at fair value $ 56,181 $ 42,512 $ 13,669 $ — Life settlement contract profit commission 5,927 — — 5,927 Contingent consideration 84,520 — — 84,520 Total Financial Liabilities $ 146,628 $ 42,512 $ 13,669 $ 90,447 As of December 31, 2016 Total Level 1 Level 2 Level 3 Financial Assets: U.S. treasury securities $ 330,654 $ 330,654 $ — $ — U.S. government agencies 63,732 — 63,732 — Municipal bonds 854,170 — 854,170 — Foreign government 152,876 — 149,298 3,578 Corporate bonds and other bonds: Finance 1,566,288 — 1,559,800 6,488 Industrial 2,296,391 — 2,291,351 5,040 Utilities 204,082 — 199,503 4,579 Commercial mortgage-backed securities 177,994 — 177,994 — Residential mortgage-backed securities: Agency backed 1,210,385 — 1,186,315 24,070 Non-agency backed 61,229 — 58,109 3,120 Collateralized loan / debt obligations 484,405 — 484,405 — Asset-backed securities 29,710 — 29,710 — Equity securities, available-for-sale 137,162 66,228 49,618 21,316 Equity securities, trading 81,960 78,827 — 3,133 Life settlement contracts 356,856 — — 356,856 Total Financial Assets $ 8,007,894 $ 475,709 $ 7,104,005 $ 428,180 Financial Liabilities: Securities sold but not yet purchased, at fair value $ 36,394 $ 36,394 $ — $ — Fixed maturity securities sold but not yet purchased 160,270 — 160,270 — Life settlement contract profit commission 4,940 — — 4,940 Contingent consideration (as restated) 71,657 — — 71,657 Derivatives 243 — 243 — Total Financial Liabilities $ 273,504 $ 36,394 $ 160,513 $ 76,597 Transfers between Level 1 and Level 2 for all periods presented are due to changes in the availability of observable market information and re-evaluation of the observability of pricing inputs. During the nine month period ended September 30, 2017 , there was a $35,818 transfer from Level 2 to Level 1. The following table provides a summary of changes in fair value of the Company’s Level 3 financial assets and liabilities for the three and nine months ended September 30, 2017 and 2016 . The transfers into and out of Level 3 were due to changes in the availability of market observable inputs. All transfers are reflected in the table at fair value as of the end of the reporting period. Balance as of June 30, 2017 Net income (loss) Other comprehensive (loss) income Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, trading $ 2,051 $ 22 $ — $ — $ — $ (373 ) $ 1,700 Equity securities, available-for-sale 21,348 566 (502 ) 38 (21,450 ) — — Fixed maturities, available-for-sale 41,512 (14 ) 208 1,954 (1,179 ) (8,373 ) 34,108 Fixed maturities, trading 312 1,992 — — (2,304 ) — — Life settlement contracts 396,782 33,617 — — (131,698 ) — 298,701 Life settlement contract profit commission (5,714 ) (213 ) — — — — (5,927 ) Contingent consideration (97,615 ) 3,348 — (1,853 ) 11,600 — (84,520 ) Total $ 358,676 $ 39,318 $ (294 ) $ 139 $ (145,031 ) $ (8,746 ) $ 244,062 Balance as of December 31, 2016 Net income (loss) Other comprehensive income (loss) Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, 2017 Equity securities, trading $ 3,133 $ (400 ) $ — $ 4,484 $ (2,134 ) $ (3,383 ) $ 1,700 Equity securities, available-for-sale 21,316 566 (164 ) 114 (38,198 ) 16,366 — Fixed maturities, available-for-sale 46,875 (14 ) (281 ) 9,459 (3,954 ) (17,977 ) 34,108 Fixed maturities, trading 312 1,992 — — (2,304 ) — — Life settlement contracts 356,856 82,233 — 16,473 (156,861 ) — 298,701 Life settlement contract profit commission (4,940 ) (987 ) — — — — (5,927 ) Contingent consideration (71,657 ) (442 ) — (29,032 ) 16,611 — (84,520 ) Total $ 351,895 $ 82,948 $ (445 ) $ 1,498 $ (186,840 ) $ (4,994 ) $ 244,062 Balance as of June 30, 2016 Net income (loss) Other comprehensive loss Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, available-for-sale $ 24,764 $ (16,983 ) $ 17,168 $ (2 ) $ (7,753 ) $ 15,985 $ 33,179 Commercial mortgage backed securities — — (194 ) — — 8,065 7,871 Collateralized loan / debt obligations — — (15 ) — — 21,748 21,733 Life settlement contracts 304,434 23,290 — 4,550 (189 ) — 332,085 Life settlement contract profit commission (9,054 ) (763 ) — — 5,000 — (4,817 ) Contingent consideration (as restated) (75,772 ) (2,226 ) — (5,443 ) 11,393 — (72,048 ) Total $ 244,372 $ 3,318 $ 16,959 $ (895 ) $ 8,451 $ 45,798 $ 318,003 Balance as of December 31, 2015 Net income (loss) Other comprehensive loss Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, available-for-sale $ 37,211 $ (16,983 ) $ 4,719 $ — $ (7,753 ) $ 15,985 $ 33,179 Commercial mortgage backed securities — — (194 ) — — 8,065 7,871 Collateralized loan / debt obligations — — (15 ) — — 21,748 21,733 Life settlement contracts 264,001 82,451 — 15,880 (30,247 ) — 332,085 Life settlement contract profit commission (15,406 ) (9,817 ) — — 20,406 — (4,817 ) Contingent consideration (as restated) (84,760 ) (8,224 ) — (13,903 ) 34,839 — (72,048 ) Total $ 201,046 $ 47,427 $ 4,510 $ 1,977 $ 17,245 $ 45,798 $ 318,003 A reconciliation of net income for life settlement contracts in the above table to gain (loss) on investment in life settlement contracts net of profit commission included in the Consolidated Statements of Income for the three and nine months ended September 30, 2017 and 2016 is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net income $ 33,617 $ 23,290 $ 82,233 $ 82,451 Premiums paid (9,960 ) (16,434 ) (48,694 ) (41,890 ) Profit commission (213 ) (763 ) (987 ) (9,817 ) Other expenses and loss on sale (24,368 ) (608 ) (26,127 ) (1,853 ) (Loss) gain on investment in life settlement contracts $ (924 ) $ 5,485 $ 6,425 $ 28,891 The Company uses the following methods and assumptions in estimating its fair value disclosures for financial instruments: • Equity and Fixed Maturity Investments: As of September 30, 2017 , the Company's Level 3 equity securities consisted primarily of privately placed warrants of companies that have publicly traded common stock. The fair value of these equity securities as of September 30, 2017 was derived from the quoted price of the underlying common stock adjusted for other inputs that are not market observable. • Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, and Short Term Investments: The carrying value of cash and cash equivalents, restricted cash and cash equivalents, and short term investments approximate their respective fair value and are classified as Level 1 in the fair value hierarchy. • Premiums Receivable, Accrued Interest, Reinsurance Recoverables: The carrying values reported in the accompanying balance sheets for these financial instruments approximate their fair values due to the short term nature of the asset and are classified as Level 1 in the financial hierarchy. • Equity Investment in Unconsolidated Subsidiaries - Related Party: In June 2017, the Company sold 10,586 common shares of NGHC. As a result of the sale, the Company ceased accounting for this investment under the equity method and has classified its remaining $32,667 investment in NGHC common stock as equity securities, available-for-sale. Refer to Notes 3 and 10 for more information. • Subordinated Debentures and Debt: The fair value of the Company's debt arrangements as of September 30, 2017 was as follows: Carrying Value Fair Value 6.125% Notes due 2023 $ 248,390 $ 249,255 2.75% Convertible senior notes due 2044 171,286 174,583 7.25% Subordinated Notes due 2055 145,296 154,200 7.50% Subordinated Notes due 2055 130,767 140,184 Revolving credit facility 130,000 130,000 Junior subordinated debentures due 2035-2037 122,094 110,070 Trust preferred securities due 2033-2037 92,786 85,906 Republic promissory note 52,343 53,163 Other 194,782 194,782 Total $ 1,287,744 $ 1,292,143 The 7.25% subordinated notes due 2055, the 7.50% subordinated notes due 2055, the 2.75% convertible senior notes due 2044, and the 6.125% notes due 2023 are publicly traded instruments and are classified as Level 1 in the fair value hierarchy. The fair value of the junior subordinated debentures due 2035-2037 and trust preferred securities due 2033-2037 were determined using the Black-Derman-Toy interest rate lattice model and are classified as Level 3 in the fair value hierarchy. In determining the fair value of its remaining debt, the Company uses estimates based on rates currently available to the Company for debt with similar terms and remaining maturities. Accordingly, the fair value of the Republic promissory note and other debt is classified as Level 2 within the valuation hierarchy. The Company considers its other debt's carrying value to approximate fair value as their interest rates approximate current borrowing rates. • Contingent consideration: The fair value of contingent consideration is based on a discounted cash flow methodology and is classified as Level 3 in the fair value hierarchy. The range of discount rates used for contingent consideration was primarily between 8% and 30% . • Life settlement contracts and life settlement contract profit commission: Life settlement contracts are described in Note 5. "Investments in Life Settlements" elsewhere in this report. The fair value of life settlement contracts as well as life settlement profit commission liability is based on information available to the Company at the end of the reporting period. These financial instruments are classified as Level 3 in the fair value hierarchy. The Company considers the following factors in its fair value estimates: cost at date of purchase, recent purchases and sales of similar investments (if available and applicable), financial standing of the issuer, changes in economic conditions affecting the issuer, maintenance cost, premiums, benefits, standard actuarially developed mortality tables and life expectancy reports prepared by nationally recognized and independent third party medical underwriters. The Company estimates the fair value of policies in the portfolio based on the expected cash flow to be generated by the policies (death benefit less premium payments), discounted to reflect the cost of funding, policy specific adjustments and reserves. In order to confirm the integrity of their calculation of fair value, the Company, quarterly, retains an independent third-party actuary to verify that the actuarial modeling used by the Company to determine fair value was performed correctly and that the valuation, as determined through the Company's actuarial modeling, is consistent with other methodologies. The Company considers this information in its assessment of the reasonableness of the life expectancy and discount rate inputs used in the valuation of these investments. The Company adjusts the standard mortality for each insured for the insured's life expectancy based on reviews of the insured's medical records and the independent life expectancy reports based thereon. The Company establishes policy specific reserves for the following uncertainties: improvements in mortality, the possibility that the high net worth individuals represented in its portfolio may have access to better health care, the volatility inherent in determining the life expectancy of insureds with significant reported health impairments, and the future expenses related to the administration of the portfolio, which incorporates current life expectancy assumptions, premium payments, the credit exposure to the insurance company that issued the life settlement contracts and the rate of return that a buyer would require on the contracts as no comparable market pricing is available. The application of the investment discount rate to the expected cash flow generated by the portfolio, net of the policy specific reserves, yields the fair value of the portfolio. The effective discount rate reflects the relationship between the fair value and the expected cash flow gross of these reserves. The following summarizes data utilized in estimating the fair value of the portfolio of life insurance policies as of September 30, 2017 and December 31, 2016 , and only includes data for policies to which the Company assigned value at those dates: September 30, December 31, Average age of insured (years) 84.3 82.8 Average life expectancy, months (1) 87 107 Average face amount per policy $ 7,088 $ 6,572 Effective discount rate (2) 12.4 % 12.4 % (1) Standard life expectancy as adjusted for specific circumstances. (2) Effective discount rate ("EDR") is the Company's estimated internal rate of return on its life settlement contract portfolio and is determined from the gross expected cash flows and valuation of the portfolio. The EDR is inclusive of the reserves and the gross expected cash flows of the portfolio. The Company anticipates that the EDR's range is between 10.0% and 15.0% and reflects the uncertainty that exists surrounding the information available as of the reporting date. As the accuracy and reliability of information improves (declines), the EDR will decrease (increase). The Company's assumptions are, by their nature, inherently uncertain and the effect of changes in estimates may be significant. The fair value measurements used in estimating the present value calculation are derived from valuation techniques generally used in the industry that include inputs for the asset that are not based on observable market data. The extent to which the fair value could reasonably vary in the near term has been quantified by evaluating the effect of changes in significant underlying assumptions used to estimate the fair value amount. If the life expectancies were increased or decreased by 4 months and the discount factors were increased or decreased by 1% while all other variables were held constant, the carrying value of the investment in life insurance policies would increase or (decrease) by the unaudited amounts summarized below as of September 30, 2017 and December 31, 2016 : Change in life expectancy Plus 4 Months Minus 4 Months Investment in life policies: September 30, 2017 $ (30,268 ) $ 28,432 December 31, 2016 $ (44,207 ) $ 43,492 Change in discount rate (1) Plus 1% Minus 1% Investment in life policies: September 30, 2017 $ (20,130 ) $ 22,121 December 31, 2016 $ (29,881 ) $ 33,155 (1) Discount rate is a present value calculation that considers legal risk, credit risk and liquidity risk and is a component of EDR.

Investment in Life Settlements

Investment in Life Settlements	9 Months Ended
	Sep. 30, 2017
Investments, All Other Investments [Abstract]
Investment in Life Settlements	Investment in Life Settlements The Company has a 50% ownership interest in each of two entities (collectively, the "LSC Entities") formed for the purpose of acquiring life settlement contracts, with a subsidiary of NGHC owning the remaining 50% . The LSC Entities are: Tiger Capital LLC (“Tiger”); and AMT Capital Holdings, S.A. (“AMTCH”). There were no capital contributions for the three months ended September 30, 2017 . Capital contributions of $27,000 were made to the LSC Entities during the nine months ended September 30, 2017 . Capital contributions of $29,366 and $40,366 were made to the LSC Entities during the three months and nine months ended September 30, 2016, respectively. The Company contributed 50% of these capital contributions. On August 16, 2017, the Company sold 114 life settlement contracts from the Tiger portfolio for consideration of $100,000 , which included a payment of $90,000 on the closing date. In addition, a payment of $5,000 is due on the next two anniversaries of the closing date. The LSC Entities paid a dividend of $90,000 during the three months ended September 30, 2017 . The Company received 50% of this dividend. The Company recorded a loss of $924 and a gain of $5,485 on investment in life settlement contracts, net of profit commission, for the three months ended September 30, 2017 and 2016, respectively, and a gain of $6,425 and $28,891 on investment in life settlement contracts, net of profit commission for the nine months ended September 30, 2017 and 2016, respectively. The following tables describe the Company’s investment in life settlements as of September 30, 2017 and December 31, 2016 : Expected Maturity Term in Years Number of Life Settlement Contracts (in whole numbers) Fair Value (1) Face Value Number of Life Settlement Contracts (in whole numbers) Fair Value (1) Face Value As of September 30, 2017 As of December 31, 2016 0-1 — $ — $ — — $ — $ — 1-2 6 41,011 58,000 2 8,873 12,500 2-3 3 22,994 32,422 7 39,495 63,000 3-4 13 45,357 101,000 10 37,436 75,422 4-5 13 25,426 60,400 10 34,003 82,900 Thereafter 107 163,913 744,880 225 237,049 1,405,414 Total 142 $ 298,701 $ 996,702 254 $ 356,856 $ 1,639,236 (1) As of September 30, 2017 and December 31, 2016 , the Company determined the fair value of 4 and 18 policies, respectively, to be negative and, therefore, assigned a fair value of zero to those policies. For these contracts, the table below details the amount of premiums paid and the death benefits received during the twelve months preceding September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of policies with a negative value from discounted cash flow model as of period end (in whole numbers) 4 18 Premiums paid for the preceding twelve month period for period ended $ 394 $ 2,640 Death benefit received $ — $ — Premiums to be paid by the LSC Entities for each of the five succeeding fiscal years to keep the life insurance policies in force as of September 30, 2017 , are as follows: Premiums Due on Life Settlement Contracts 2017 $ 35,423 2018 36,568 2019 35,922 2020 34,781 2021 32,544 Thereafter 215,213 Total $ 390,451 For additional information relating to the accounting for life settlement contracts, see Note 7 to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Loss and loss adjustment expens

Loss and loss adjustment expense reserves	9 Months Ended
	Sep. 30, 2017
Insurance [Abstract]
Loss and loss adjustment expense reserves	Loss and Loss Adjustment Expense Reserves The following table provides a reconciliation of the beginning and ending balances for loss and loss adjustment expense reserves ("Loss and LAE") for the three months ended September 30, 2017 , and 2016 , respectively: 2017 2016 Loss and LAE, gross of related reinsurance recoverables at beginning of period $ 11,149,511 $ 9,097,408 Less: Reinsurance recoverables at beginning of period 4,942,144 3,568,863 Net balance, beginning of period 6,207,367 5,528,545 Incurred related to: Current year 939,187 720,440 Prior year 326,931 90,608 Total incurred during the period 1,266,118 811,048 Paid related to: Current year (333,098 ) (262,738 ) Prior year (445,247 ) (387,735 ) Total paid during the period (778,345 ) (650,473 ) Retroactive reinsurance adjustment (326,931 ) — Effect of foreign exchange rates 50,882 61,202 Net balance, end of period 6,419,091 5,750,322 Plus reinsurance recoverables at end of period 5,667,553 3,677,448 Loss and LAE, gross of related reinsurance recoverables at end of period $ 12,086,644 $ 9,427,770 The following table provides a reconciliation of the beginning and ending balances for Loss and LAE for the nine months ended September 30, 2017 , and 2016 , respectively: 2017 2016 Loss and LAE, gross of related reinsurance recoverables at beginning of period $ 10,140,716 $ 7,208,367 Less: Reinsurance recoverables at beginning of period 3,873,786 2,665,187 Net balance, beginning of period 6,266,930 4,543,180 Incurred related to: Current year 2,712,079 2,117,774 Prior year 418,851 192,740 Total incurred during the period 3,130,930 2,310,514 Paid related to: Current year (699,340 ) (531,517 ) Prior year (1,593,524 ) (1,335,069 ) Total paid during the period (2,292,864 ) (1,866,586 ) Loss portfolio transfers — 312,049 Acquired loss and loss adjustment reserves 200,802 463,115 Retroactive reinsurance adjustment (1,025,000 ) — Effect of foreign exchange rates 138,293 (11,950 ) Net balance, end of period 6,419,091 5,750,322 Plus reinsurance recoverables at end of period 5,667,553 3,677,448 Loss and LAE, gross of related reinsurance recoverables at end of period $ 12,086,644 $ 9,427,770 In setting its reserves, the Company utilizes a combination of Company loss development factors and industry-wide loss development factors. In the event that the Company’s losses develop more favorably (adversely) than the industry, as a whole, the Company’s liabilities for unpaid losses and LAE may decrease (increase). The Company's management believes that its use of both its historical experience and industry-wide loss development factors provide a reasonable basis for estimating future losses. In either case, future events beyond the control of management, such as changes in law, judicial interpretations of law, and inflation may favorably or unfavorably impact the ultimate settlement of the Company’s Loss and LAE reserves. The anticipated effect of inflation is implicitly considered when estimating liabilities for losses and LAE. While the Company considers anticipated changes in claim costs due to inflation in estimating the ultimate claim costs, the increase in average severity of claims is caused by a number of factors that vary with the individual type of policy written. The Company projects future average severities based on historical trends adjusted for implemented changes in underwriting standards, policy provisions, and general economic trends. The Company monitors those anticipated trends based on actual development and makes modifications, if necessary. The Company's Loss and LAE, gross of related reinsurance recoverables, increased $937,133 and $330,362 , respectively, during the three months ended September 30, 2017 and 2016 , and $1,945,928 and $2,219,403 , respectively, during the nine months ended September 30, 2017 and 2016. The increase in 2017 primarily related to the acquisition of AHC Insurance Company ("AHC"), formerly known as AmeriHealth Casualty Insurance Company, and increased premium writings. The Company had adverse prior period reserve development of $326,931 and $418,851 , respectively, during the three and nine months ended September 30, 2017 . Consistent with prior quarters, the actuarial process was driven by updated and new incurred and paid loss data, continued review of actuarial diagnostics, which led to additional in-depth claims reviews or further development being recognized, and update of frequency and severity trends, which have continued to develop adversely. The adverse reserve development was primarily driven by unfavorable development related to emerging loss experience beyond the prior indications based on new and updated data, especially within the Company's Small Commercial workers' compensation book in accident years of 2014 through 2016, deterioration of claim severities within auto liability that continues to exceed previously revised expectations, and unfavorable development on Italian hospital liability business related to lower than expected benefits on claims savings strategies in the oldest few years. Additionally, Specialty Program segment adverse development was driven by development from long-tailed terminated programs, particularly general liability programs. The increase in 2016 related primarily to increased premium writings, and a loss portfolio transfer. The Company's liabilities for unpaid losses and LAE attributable to prior years increased $90,608 and $192,740 , respectively, for the three and nine months ended September 30, 2016 , primarily due to adverse loss experience in the Company's Specialty Program segment's general liability and auto liability portfolios, and the Company's Small Commercial Business segment's auto liability portfolio.

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt The Company’s outstanding debt consisted of the following at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 6.125% Notes due 2023 (the "2023 Notes") $ 248,390 $ 248,185 Secured loan agreements 175,345 75,762 2.75% Convertible senior notes due 2044 (the "2044 Notes") 171,286 166,387 7.25% Subordinated notes due 2055 (the "7.25% 2055 Notes") 145,296 145,202 7.50% Subordinated notes due 2055 (the "7.50% 2055 Notes") 130,767 130,684 Revolving credit facility 130,000 130,000 Junior subordinated debentures (the "2035-2037 Notes") 122,094 122,028 Trust preferred securities (the "2033-2037 TPS Notes") 92,786 92,786 Promissory notes 66,453 118,643 5.5% Convertible senior notes due 2021 (the "2021 Notes") 5,327 5,223 Total $ 1,287,744 $ 1,234,900 Additionally, the Company utilizes various letters of credit in its operations. The following is a summary of the Company's letters of credit as of September 30, 2017 : Limit Outstanding Available Revolving credit facility $ 175,000 $ 174,662 $ 338 Funds at Lloyd's facility 689,997 657,306 32,691 ING Bank N.V., BHF-BANK Aktiengesellschaft, and Deutsche Bank Netherlands N.V. facilities 90,615 73,180 17,435 Comerica Bank letters of credit 75,000 43,067 31,933 UniCredit Bank 100,000 100,000 — Other letters of credit, in aggregate 139,052 139,052 — Interest expense, including amortization of original issue discount and deferred origination costs, as well as applicable bank fees, related to the Company's outstanding debt and letters of credit for the three and nine months ended September 30, 2017 and 2016 was: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Revolving credit facility $ 1,571 $ 1,134 $ 4,610 $ 3,388 2021 Notes 118 116 352 345 2044 Notes 3,282 3,170 9,731 9,402 2023 Notes 3,897 3,897 11,690 11,690 2035-2037 Notes 1,445 1,548 4,333 4,609 2033-2037 TPS Notes 1,118 981 3,227 1,750 7.25% 2055 Notes 2,750 2,750 8,250 8,250 7.50% 2055 Notes 2,559 2,559 7,677 7,677 Secured loan agreements 1,701 756 4,528 1,768 Promissory notes 938 1,698 3,646 3,253 Funds at Lloyd's facility 1,342 1,065 4,057 3,387 Other, including interest income 2,152 2,450 8,602 391 Total $ 22,873 $ 22,124 $ 70,703 $ 55,910 Secured loan agreements On January 12, 2017, the Company, through three wholly-owned subsidiaries, entered into a ten -year secured loan agreement with Teachers Insurance and Annuity Association of America in the aggregate amount of £73,500 (or $98,475 as of September 30, 2017 ) to finance the purchase of a commercial office building in London, England. The loan bears interest at an annual rate of 3.45% and matures on January 15, 2027 . The loan requires quarterly interest payments for the term of the loan, with the principal and any accrued interest to be paid at maturity. On February 24, 2017, the Company, through a wholly-owned subsidiary, entered into a ten -year secured loan agreement with Citigroup Global Markets Realty Corp. in the aggregate amount of $11,350 to finance the purchase of a commercial office building in Alpharetta, Georgia. The loan bears interest at an annual rate of 4.67% and matures on March 6, 2027 . The loan requires monthly interest only payments through March 6, 2019, principal and interest payments of approximately $64 through February 6, 2027, with any remaining principal and accrued interest to be paid at maturity. Promissory Notes On April 18, 2016, in connection with the acquisition of Republic Companies, Inc. and its affiliates ("Republic"), the Company issued a $104,685 term promissory note to Delek Finance U.S. Inc. (subsequently assigned to Delek Group, Ltd.) as part of the consideration. The principal was to be paid in four equal installments on each of the first four anniversaries of the issuance date. The Company made the first principal payment of approximately $26,171 on March 30, 2017 and prepaid the second principal payment of approximately $25,910 (representing 99% of the principal payment due in April 2018) on June 29, 2017 . The parties agreed that the June 29, 2017 prepayment would satisfy in full the April 2018 principal payment. The remaining principal is payable in two equal installments on each of the third and fourth anniversaries of the issuance date.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table is a summary of the elements used in calculating basic and diluted earnings per share for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 As restated As restated Numerator: Net (loss) income attributable to AmTrust common stockholders $ (174,675 ) $ 80,650 $ (146,214 ) $ 291,784 Denominator: Weighted average common shares outstanding – basic 195,891 170,928 182,570 173,173 Plus: Dilutive effect of stock options, convertible debt, other (1) — 2,193 — 1,978 Weighted average common shares outstanding – dilutive 195,891 173,121 182,570 175,151 Net (loss) income per AmTrust common share - basic $ (0.89 ) $ 0.47 $ (0.80 ) $ 1.68 Net (loss) income per AmTrust common share – diluted $ (0.89 ) $ 0.47 $ (0.80 ) $ 1.67 (1) In accordance with ASC 260, Earnings Per Share , no potential common shares are included in the computation of diluted per share amounts when a loss from operations exists.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes As of September 30, 2017 , the Company has U.S. Net Operating Losses ("NOLs") of $23,476 that expire beginning in 2019 through 2037 . In addition, these NOLs are subject to certain limitations under Section 382 of the Internal Revenue Code due to changes in ownership of $9,084 per year. The Company also has foreign NOLs of $945,114 , the majority of which have no expiration. The Company’s management believes that as of September 30, 2017 , except for a portion of foreign NOLs, it will realize the benefits of its deferred tax assets. As a result, the Company recorded a valuation allowance of $164,814 and $142,462 as of September 30, 2017 and December 31, 2016 , respectively. The increase in the valuation allowance from December 31, 2016 to September 30, 2017 was primarily due to the increase of gross NOLs in Luxembourg, which required a full valuation allowance. For additional information relating to Income Taxes, see Note 20 to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company has various reinsurance and service agreements with Maiden Holdings, Ltd. ("Maiden") and ACP Re, Ltd. There have been no material changes to these agreements during the nine months ended September 30, 2017 . For more information related to these agreements, please see Note 17 to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016. Significant Transactions with National General Holding Corp. NGHC is a publicly-held specialty personal lines insurance holding company (Nasdaq: NGHC) that operates twenty-two insurance companies in the United States and provides a variety of insurance products, including personal and commercial automobile, homeowners and umbrella, and supplemental health. NGHC's two largest stockholders are the Michael Karfunkel Family 2005 Trust (the "Trust") and a grantor retained annuity trust controlled by Leah Karfunkel. Leah Karfunkel, who is co-trustee of the Trust along with Barry Zyskind, is a member of the Company’s board of directors, and the mother-in-law of Barry Zyskind, the Company’s Chairman, Chief Executive Officer and President. The ultimate beneficiaries of the Trust include Leah Karfunkel’s children, one of whom is married to Mr. Zyskind. In addition, Barry Karfunkel, the son of Leah Karfunkel and brother-in-law of Barry Zyskind, is the chief executive officer of NGHC and Barry Zyskind is NGHC’s non-executive chairman of the board. Sale of NGHC Common Stock On June 9, 2017 , the Company announced that it entered into agreements to sell 10,586 common shares of NGHC at a price of $20.00 per share (representing a discount of 8.3% to NGHC's common stock closing market price on the Nasdaq Stock Exchange on June 8, 2017 ). The sale was completed through separate, privately negotiated purchase agreements with unaffiliated third parties and resulted in a $68,425 realized gain, which is reflected in the Equity in earnings of unconsolidated subsidiaries - related parties caption on the Consolidated Statements of Income. As a result of the transaction, the Company's ownership interest in NGHC decreased from approximately 11.5% to approximately 1.6% . In accordance with ASC 323-10-15, Investments-Equity Method and Joint Ventures , the Company accounted for its investment in NGHC under the equity method through June 9, 2017 as it had the ability to exert significant influence on NGHC's operations. As a result of the aforementioned sale of NGHC common shares, the Company determined the fair value of its 1,709 remaining shares of NGHC common stock was not material to the Company's total assets or equity securities, available-for-sale, nor was the on-going income derived from the equity method accounting material to the Company's consolidated results of operations. Consequently, the Company ceased to account for its investment in NGHC under the equity method; rather, the Company classified the investment as a component of equity securities, available-for-sale on its consolidated balance sheets. The Company recorded $1,954 of income during the three months ended September 30, 2016, and $5,063 and $12,532 of income during the nine months ended September 30, 2017 and 2016, respectively, related to its investment in NGHC under the equity method of accounting. Sale of NPS and Termination of Master Service Agreement On September 13, 2017 , AmTrust North America, Inc. (“ANA”), one of the Company's wholly-owned subsidiaries, entered into an Asset Purchase and License Agreement (the “Agreement”) with NGHC, pursuant to which ANA sold to NGHC the personal lines policy management system that ANA had developed for NGHC (the “System”), the related intellectual property, as well as a non-exclusive perpetual license to certain software programs NGHC may use in connection with the System. NGHC will pay ANA consideration of $200,000 , which is payable in three equal installments, with the first payment made upon the execution of the Agreement, the second payment payable upon the six-month anniversary of the Agreement, and the third payment payable upon the completion of the full separation and transfer of the System to NGHC’s operating environment in accordance with the terms of the Agreement or eighteen months, whichever is later. The consideration also compensated ANA for System licensing fees of $9,267 through the date of sale. In addition, NGHC will be required to pay ANA costs for the implementation of the System in NGHC’s environment (up to $5,000 ) and certain other support costs consistent with past practice. NGHC offered employment to over 100 ANA employees who support the System. The Company has a perpetual license to use the System for its own internal purposes. The Company may not sell or sublicense the System to a third party and, for a period of three years, the Company may not build a personal lines policy system for any third party. NGHC has a perpetual license to use certain Company software applications in connection with the System, while the Company retains all ownership rights to these software applications. Except in certain limited circumstances, NGHC may not sell or sublicense the Company software to a third party. The Agreement terminated the Master Services Agreement, dated February 22, 2012, between ANA and a subsidiary of NGHC (the “MSA”) pursuant to which ANA provided (i) information technology services in connection with the development and licensing of the System at a cost of 1.25% of gross written premium of NGHC and its affiliates plus the Company’s costs for development services at a price of cost plus 20% and support services at cost; (ii) printing and mailing services at a per piece cost for policy and policy related materials, such as invoices, quotes, notices and endorsements, associated with the policies the Company processed for NGHC and its affiliates on the System; and (iii) lockbox services for policies processed on the System, and scanning of correspondence and supplemental materials. Under the MSA, NGHC was obligated to pay the licensing fee for use of the System until 2023 and actual cost for the other ancillary services. However, under the Agreement for a limited period of time until the parties agree upon a transition date, ANA will continue to provide NGHC and its affiliates printing, mailing and lockbox services and hosting of certain infrastructure, under the same terms as these services were provided under the MSA. As a result of the sale, the Company recognized a gain on sale of approximately $186,755 for the three and nine months ended September 30, 2017 . The Company recorded a financing receivable of $129,715 from NGHC for the remaining payments, which is shown in other assets on the consolidated balance sheets as of September 30, 2017 . $300,000 Private Placement As previously announced, the Company issued 24,096 shares of common stock at a price of $12.45 per share (the closing market price of the Company’s common stock on May 25, 2017 ), resulting in gross proceeds to the Company of $300,000 through a private placement ("Private Placement"). The Company contributed the proceeds from the Private Placement to the Company's insurance subsidiaries to support their financial strength, continued organic growth, and writing of business. Certain members of the families of each of George Karfunkel, a director of the company, Leah Karfunkel and Barry Zyskind were the sole purchasers in the Private Placement. The purchasers received unregistered common shares in AmTrust, as well as certain rights to register the shares at a future date. Additionally, the purchasers agreed not to transfer the common stock, subject to certain limited exceptions for bona fide estate planning purposes, for a period of one-year from the date of purchase and not to exercise their right to vote their shares of common stock until after the conclusion of the Company's 2018 annual meeting of shareholders.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions AmeriHealth Casualty Insurance Company On February 28, 2017, the Company completed its previously announced acquisition of AHC Insurance Company ("AHC"), formerly named AmeriHealth Casualty Insurance Company, a workers’ compensation insurance company operating primarily in Pennsylvania and New Jersey. The Company acquired 100% of the outstanding stock of AHC for approximately $92,786 in cash, which is subject to a reserve guarantee of $40,000 , subject to a 10% loss corridor retained by the Company and payable after five years, based on the development of AHC’s loss reserves as of June 30, 2016. As of September 30, 2017 , the Company had recorded $37,900 related to the reserve guarantee. A summary of the preliminary assets acquired and liabilities assumed for AHC are as follows: Assets Cash and investments $ 275,351 Premium receivable 45,288 Accrued interest and dividends 1,162 Reinsurance recoverable 14,512 Other assets 43,696 Goodwill and intangible assets 17,509 Total assets $ 397,518 Liabilities Loss and loss adjustment expense reserves $ 227,865 Unearned premiums 49,284 Accrued expenses and other liabilities 27,583 Total liabilities $ 304,732 Acquisition price $ 92,786 The goodwill and intangible assets, as well as AHC's results of operations, are included as a component of the Small Commercial Business segment. The goodwill is not expected to be deductible for income tax purposes. The intangible assets consist primarily of licenses and agent relationships. As a result of this acquisition, the Company recorded approximately $28,495 and $84,933 of gross written premium during the three and nine months ended September 30, 2017 , respectively. PDP Group, Inc. On May 1, 2017 , the Company acquired 100% of the outstanding common stock of PDP Group Inc. ("PDP"), a Maryland-based provider of tailored insurance solutions for auto dealers in North America. The purchase agreement required the Company to pay approximately $49,801 in cash on the acquisition date and contained an earn-out provision that is contingent on PDP meeting certain performance conditions over a three-year period. The Company valued the contingent consideration associated with the earn-out provision at $12,621 as of the acquisition date. A summary of the preliminary assets acquired and liabilities assumed for PDP are as follows: Assets Cash and cash equivalents $ 11,826 Premium receivable 29,188 Other assets 705 Property and equipment, net 776 Goodwill and intangible assets 55,586 Total assets $ 98,081 Liabilities Accrued expenses and other liabilities $ 35,659 Acquisition price $ 62,422 The goodwill and intangible assets, as well as PDP's results of operations, are included as a component of the Specialty Risk and Extended Warranty segment. The goodwill is not expected to be deductible for income tax purposes. As a result of this acquisition, the Company recorded approximately $11,468 and $19,120 in service and fee income related to PDP during the three and nine months ended September 30, 2017 , respectively. Other In addition, the Company completed other immaterial acquisitions during the nine months ended September 30, 2017 . No individual acquisition was significant and, therefore, the Company did not include any pro forma financial information related to those acquisitions in this report. Total purchase consideration paid for those immaterial acquisitions was approximately $36,936 in cash and $8,129 in contingent consideration. As of September 30, 2017 , the purchase price allocation accounting has not yet been finalized with respect to these immaterial acquisitions.

Shareholder Equity and Accumula

Shareholder Equity and Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Shareholder's Equity and Accumulated Other Comprehensive Income (Loss)	Stockholder's Equity and Accumulated Other Comprehensive Income (Loss) Stockholders' Equity The following table summarizes the ownership components of total stockholders' equity: Nine Months Ended September 30, 2017 2016 AmTrust Non-Controlling Interest Total AmTrust Non-Controlling Interest Total (As restated) (As restated) Balance, December 31, $ 3,269,103 $ 196,510 $ 3,465,613 $ 2,723,780 $ 176,455 $ 2,900,235 Net (loss) income (96,501 ) 16,127 (80,374 ) 323,727 12,222 335,949 Unrealized holding gain 94,889 — 94,889 214,519 — 214,519 Reclassification adjustment (54,130 ) — (54,130 ) (17,993 ) — (17,993 ) Foreign currency translation 127,235 — 127,235 (110,148 ) — (110,148 ) Unrealized gain on interest rate swap 145 — 145 540 — 540 Extinguishment of 2021 senior notes, equity component — — — (1 ) — (1 ) Share exercises, compensation and other 19,066 — 19,066 10,568 — 10,568 Common stock issuance 298,747 — 298,747 — — — Common share purchase, net — — — (152,047 ) — (152,047 ) Common stock dividends (95,681 ) — (95,681 ) (81,167 ) — (81,167 ) Preferred stock issuance, net of fees — — — 417,264 — 417,264 Preferred stock dividends (49,713 ) — (49,713 ) (31,943 ) — (31,943 ) Capital distributions, net — (31,336 ) (31,336 ) — (5,413 ) (5,413 ) Balance, September 30, $ 3,513,160 $ 181,301 $ 3,694,461 $ 3,297,099 $ 183,264 $ 3,480,363 During the nine months ended September 30, 2017 , net income attributable to non-controlling interest was $16,127 , and net income attributable to non-controlling interest and redeemable non-controlling interest of subsidiaries totaled $17,010 . During the nine months ended September 30, 2016 , net income attributable to non-controlling interest was $12,222 , and net income attributable to non-controlling interest and redeemable non-controlling interest of subsidiaries was $12,809 . Accumulated Other Comprehensive Income (Loss) The following table summarizes the activities and components of accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2017 and 2016: Foreign Currency Items Unrealized Gains (Losses) on Investments Interest Rate Swap Hedge Net Benefit Plan Assets and Obligations Recognized in Stockholders' Equity Accumulated Other Comprehensive Income (Loss) Balance, June 30, 2017 $ (111,677 ) $ 110,071 $ (52 ) $ (3,177 ) $ (4,835 ) Other comprehensive income (loss) before reclassification 50,709 17,175 64 — 67,948 Amounts reclassed out of accumulated other comprehensive (loss) income — (23,272 ) — — (23,272 ) Income tax benefit (expense) — 2,615 (39 ) — 2,576 Net current-period other comprehensive income (loss) 50,709 (3,482 ) 25 — 47,252 Balance, September 30, 2017 $ (60,968 ) $ 106,589 $ (27 ) $ (3,177 ) $ 42,417 Balance, June 30, 2016 (As restated) $ (178,077 ) $ 148,791 $ (413 ) $ (107 ) $ (29,806 ) Other comprehensive income (loss) before reclassification (30,145 ) 23,741 390 — (6,014 ) Amounts reclassed out of accumulated other comprehensive income (loss) — (3,399 ) — — (3,399 ) Income tax expense — (7,118 ) (137 ) — (7,255 ) Net current-period other comprehensive (loss) income (30,145 ) 13,224 253 — (16,668 ) Balance, September 30, 2016 (As restated) $ (208,222 ) $ 162,015 $ (160 ) $ (107 ) $ (46,474 ) Foreign Currency Items Unrealized Gains (Losses) on Investments Interest Rate Swap Hedge Net Benefit Plan Assets and Obligations Recognized in Stockholders' Equity Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2016 $ (188,203 ) $ 65,830 $ (172 ) $ (3,177 ) $ (125,722 ) Other comprehensive income before reclassification 127,235 115,235 212 — 242,682 Amounts reclassed out of accumulated other comprehensive (loss) income — (54,130 ) — — (54,130 ) Income tax expense — (20,346 ) (67 ) — (20,413 ) Net current-period other comprehensive income 127,235 40,759 145 — 168,139 Balance, September 30, 2017 $ (60,968 ) $ 106,589 $ (27 ) $ (3,177 ) $ 42,417 Balance, December 31, 2015 (As restated) $ (98,074 ) $ (34,511 ) $ (700 ) $ (107 ) $ (133,392 ) Other comprehensive (loss) income before reclassification (110,148 ) 328,409 831 — 219,092 Amounts reclassed out of accumulated other comprehensive (loss) income — (17,993 ) — — (17,993 ) Income tax expense — (113,890 ) (291 ) — (114,181 ) Net current-period other comprehensive (loss) income (110,148 ) 196,526 540 — 86,918 Balance, September 30, 2016 (As restated) $ (208,222 ) $ 162,015 $ (160 ) $ (107 ) $ (46,474 )

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation The Company’s insurance subsidiaries are named as defendants in various legal actions arising principally from claims made under insurance policies and contracts. Those actions are considered by the Company in estimating the loss and LAE reserves. The Company is also a party in various commercial and employment disputes, including claims both by and against the Company. The Company’s management believes the resolution of these actions will not have a material adverse effect on the Company’s financial position or results of operations. On April 7, 2015, one of the Company's stockholders, Cambridge Retirement System, filed a derivative action in the Court of Chancery of the State of Delaware against the Company, as nominal defendant, and against the Company's board of directors, Leah Karfunkel, and ACP Re, as defendants. Cambridge amended its complaint on November 3, 2015 to add NGHC as a defendant. The stockholder purports to bring the derivative action on the Company's behalf, alleging breaches of the duties of loyalty and care on the part of the Company's directors and majority shareholders related to the Company's transactions involving Tower Group International, Ltd. Cambridge's claim against NGHC and ACP Re is for unjust enrichment. The amended complaint seeks damages, disgorgement and reform of the Company's governance practices. On April 27, 2017, one of the Company's stockholders, David Shaev Profit Sharing Plan, filed a derivative action in the Supreme Court of the State of New York for the County of New York ( Shaev v. DeCarlo et al. ). Three derivative suits have also been filed in the United States District Court for the District of Delaware. On April 19, 2017, one of the Company's stockholders, Lily Ding, filed a derivative action in the District of Delaware against the Company, as nominal defendant, and against the Company's board of directors as defendants, but this stockholder subsequently voluntarily dismissed her suit ( Ding v. Zyskind et al .). On May 11, 2017, one of the Company's stockholders, West Palm Beach Police Pension Fund, filed suit ( West Palm Beach Police Pension Fund v. Zyskind et al .), and on June 28, 2017, two of the Company's stockholders, City of Lauderhill Police Officers Retirement Plan and Pompano Beach Police & Firefighters Retirement System, filed suit ( City of Lauderhill Police Officers Retirement Plan and Pompano Beach Police & Firefighters Retirement System et al. v. Zyskind et al .). These two Delaware derivative actions ( West Palm Beach Police Pension Fund and Lauderhill-Pompano Beach ) have been consolidated under the case name In re AmTrust Financial Services, Inc. Derivative Litigation . The stockholders purport to bring the derivative actions on the Company's behalf, and raise claims that primarily involve the Company's recent restatement of its financial statements and the identification of material weaknesses in its internal control over financial reporting. The In re AmTrust Derivative Litigation complaint alleges violations of Sections 10(b), 14(a), 20A, and 29(b) of the Exchange Act, breaches of fiduciary duties, unjust enrichment, and waste of corporate assets. The In re AmTrust Derivative Litigation complaint also seeks reform of the Company's governance practices, contribution and indemnification, and both sets of stockholders seek damages. The Company believes the allegations in these pending derivative actions to be unfounded and is vigorously pursuing its defenses. The Company and certain of its officers and directors are also defendants in three putative securities class action lawsuits filed in March and April of 2017 in the United States District Court for the Southern District of New York. Another putative class action, filed in February 2017 in the United States District Court for the Central District of California, was voluntarily dismissed ( Miller v. AmTrust, Zyskind, and Pipoly ). The three cases in the Southern District of New York have been consolidated under the case name In re AmTrust Financial Services, Inc. Securities Litigation. Plaintiffs in this proceeding filed a consolidated amended complaint on August 21, 2017 . Plaintiffs assert in the consolidated amended compliant claims under Sections 10(b) and 20(a) of the Exchange Act, and Rule 10b-5 promulgated thereunder and Sections 11, 12(a)(2) and 15 of the Securities Act of 1933, as amended. The consolidated amended complaint adds BDO USA LLP, Citigroup Global Markets Inc., Keefe, Bruyette & Woods, Inc., Morgan Stanley & Co. LLC, RBC Capital Markets, LLC, and UBS Securities LLC as defendants. Plaintiffs seek an unspecified amount in damages, attorneys’ fees, and other relief. The Company believes the allegations to be unfounded and is vigorously pursuing its defenses; however, the Company cannot reasonably estimate a potential range of loss, if any, due to the early stage of the proceedings. Additionally, in April, May, June and July, 2017, the Company received five demands for the inspection of books and records pursuant to Section 220 of the Delaware General Corporation Law, from stockholders Rikhard Dauber, Pompano Beach Police & Firefighters Retirement System, Nestor Shust, the City of Lauderhill Police Officers’ Retirement Plan and the Lislois Family Trust. Other than as discussed above, the Company is not involved presently in any material litigation nor, to the Company’s knowledge, is any material litigation threatened against the Company or its properties.

Segments

Segments	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segments	Segments The Company operates three business segments: Small Commercial Business; Specialty Risk and Extended Warranty; and Specialty Program. The Corporate and Other segment represents the activities of the holding company as well as a portion of service and fee income. Investment income and realized gains (losses) on investments are determined by calculating an overall annual return on cash and invested assets and applying that overall return to the cash and invested assets by segment. Ceding commission is allocated to each segment based on that segment’s proportionate share of the Company’s overall acquisition costs. Interest expense is allocated based on gross written premium by segment. Income taxes are allocated on a pro-rata basis based on the Company’s effective tax rate. Additionally, management reviews the performance of underwriting results in assessing the performance of and making decisions regarding the allocation of resources to the segments. Underwriting results excludes, primarily, service and fee income, investment income and other revenues, other expenses, interest expense and income taxes. Management believes that providing information in this manner is essential to providing the Company’s stockholders with an understanding of the Company’s business and operating performance. During the three and nine months ended September 30, 2017 , the Company did not have any segment derive over ten percent of its total revenue from one customer. During the three and nine months ended September 30, 2016 , the Company's Specialty Program segment derived over ten percent of its gross written premium from one customer. The following tables summarize the results of operations of the business segments for the three and nine months ended September 30, 2017 and 2016 : Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Three Months Ended September 30, 2017: Gross written premium $ 1,012,663 $ 756,714 $ 221,398 $ — $ 1,990,775 Revenues: Net written premium $ 498,514 $ 525,308 $ 151,935 $ — $ 1,175,757 Change in unearned premium 30,565 (42,490 ) 29,045 — 17,120 Net earned premium 529,079 482,818 180,980 — 1,192,877 Expenses: Loss and loss adjustment expense 546,219 458,379 261,520 — 1,266,118 Acquisition costs and other underwriting expenses 154,739 126,312 56,035 — 337,086 Total expenses 700,958 584,691 317,555 — 1,603,204 Underwriting loss (171,879 ) (101,873 ) (136,575 ) — (410,327 ) Other income (loss) Service and fee income 27,586 114,549 499 37,871 180,505 Investment income and realized gain on investments 32,936 33,527 19,160 — 85,623 Other expenses (45,239 ) (33,501 ) (9,935 ) (88,675 ) (177,350 ) Interest expense (11,661 ) (8,654 ) (2,558 ) — (22,873 ) Foreign currency loss — (62,819 ) — — (62,819 ) Loss on life settlement contracts (541 ) (241 ) (142 ) — (924 ) Gain on sale of policy management system — — — 186,755 186,755 Benefit (provision) for income taxes 65,012 (39,126 ) 75,564 (38,862 ) 62,588 Net (loss) income $ (103,786 ) $ (98,138 ) $ (53,987 ) $ 97,089 $ (158,822 ) Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Three Months Ended September 30, 2016 Gross written premium $ 998,071 $ 598,977 $ 437,050 $ — $ 2,034,098 Revenues: Net written premium $ 457,871 $ 448,845 $ 309,334 $ — $ 1,216,050 Change in unearned premium 59,127 (21,526 ) (57,415 ) — (19,814 ) Net earned premium 516,998 427,319 251,919 — 1,196,236 Expenses: Loss and loss adjustment expense 344,531 293,956 172,561 — 811,048 Acquisition costs and other underwriting expenses (As restated) 134,520 86,240 83,232 — 303,992 Total expenses 479,051 380,196 255,793 — 1,115,040 Underwriting income (loss) (As restated) 37,947 47,123 (3,874 ) — 81,196 Other income (loss) Service and fee income (As restated) 26,800 82,475 106 24,476 133,857 Investment income and realized gain on investments 29,218 24,519 14,412 — 68,149 Other expenses (As restated) (34,236 ) (20,503 ) (14,887 ) (69,625 ) (139,251 ) Interest expense (As restated) (10,988 ) (6,516 ) (4,620 ) — (22,124 ) Foreign currency loss (As restated) — (10,880 ) — — (10,880 ) Gain on life settlement contracts 2,521 1,614 1,350 — 5,485 (Provision) benefit for income taxes (As restated) (9,947 ) (22,070 ) 801 8,031 (23,185 ) Equity in earnings of unconsolidated subsidiary – related party — — — 1,954 1,954 Net income (loss) (As restated) $ 41,315 $ 95,762 $ (6,712 ) $ (35,164 ) $ 95,201 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Nine Months Ended September 30, 2017 Gross written premium $ 3,393,240 $ 2,285,088 $ 778,474 $ — $ 6,456,802 Revenues: Net written premium $ 1,796,255 $ 1,591,002 $ 504,468 $ — $ 3,891,725 Change in unearned premium (81,687 ) (95,691 ) 81,771 — (95,607 ) Net earned premium 1,714,568 1,495,311 586,239 — 3,796,118 Expenses: Loss and loss adjustment expense 1,390,557 1,141,823 598,550 — 3,130,930 Acquisition costs and other underwriting expenses 479,559 385,085 173,852 — 1,038,496 Total expenses 1,870,116 1,526,908 772,402 — 4,169,426 Underwriting loss (155,548 ) (31,597 ) (186,163 ) — (373,308 ) Other income (loss) Service and fee income 87,230 299,668 2,479 97,070 486,447 Investment income and realized gain on investments 95,145 87,374 47,725 — 230,244 Other expenses (141,909 ) (95,565 ) (32,557 ) (270,032 ) (540,063 ) Interest expense (37,157 ) (25,022 ) (8,524 ) — (70,703 ) Foreign currency loss — (139,735 ) — — (139,735 ) Gain on life settlement contracts 3,376 2,274 775 — 6,425 Gain on sale of policy management system — — — 186,755 186,755 Benefit (provision) for income taxes 64,611 (42,273 ) 76,504 (37,883 ) 60,959 Equity in earnings of unconsolidated subsidiary – related party — — — 73,488 73,488 Net (loss) income $ (84,252 ) $ 55,124 $ (99,761 ) $ 49,398 $ (79,491 ) Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Nine Months Ended September 30, 2016 Gross written premium $ 3,124,761 $ 1,779,984 $ 1,135,539 $ — $ 6,040,284 Revenues: Net written premium $ 1,684,037 $ 1,233,739 $ 787,389 $ — $ 3,705,165 Change in unearned premium (89,967 ) (126,695 ) (36,233 ) — (252,895 ) Net earned premium 1,594,070 1,107,044 751,156 — 3,452,270 Expenses: Loss and loss adjustment expense 1,060,165 736,220 514,129 — 2,310,514 Acquisition costs and other underwriting expenses (As restated) 418,201 237,864 214,872 — 870,937 Total expenses 1,478,366 974,084 729,001 — 3,181,451 Underwriting income (As restated) 115,704 132,960 22,155 — 270,819 Other income (loss) Service and fee income (As restated) 85,082 226,014 1,623 74,249 386,968 Investment income and realized gain on investments 84,265 63,195 43,923 — 191,383 Other expenses (As restated) (104,204 ) (59,359 ) (37,868 ) (201,431 ) (402,862 ) Interest expense (As restated) (28,923 ) (16,476 ) (10,511 ) — (55,910 ) Foreign currency loss (As restated) — (78,108 ) — — (78,108 ) Gain on life settlement contracts 14,946 8,514 5,431 — 28,891 Acquisition gain on purchase 455 48,320 — — 48,775 (Provision) benefit for income taxes (As restated) (27,418 ) (53,265 ) (4,056 ) 18,787 (65,952 ) Equity in earnings of unconsolidated subsidiary – related party — — — 12,532 12,532 Net income (loss) (As restated) $ 139,907 $ 271,795 $ 20,697 $ (95,863 ) $ 336,536 The following tables summarize net earned premium by major line of business, by segment, for the three and nine months ended September 30, 2017 and 2016 : Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Three Months Ended September 30, 2017: Workers' compensation $ 347,770 $ — $ 84,268 $ 432,038 Warranty — 238,910 7 238,917 Other liability — 35,752 48,652 84,404 Commercial auto and liability, physical damage 78,955 — 34,448 113,403 Medical malpractice — 60,982 — 60,982 Other 102,354 147,174 13,605 263,133 Total net earned premium $ 529,079 $ 482,818 $ 180,980 $ 1,192,877 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Three Months Ended September 30, 2016: Workers' compensation $ 349,030 $ — $ 149,246 $ 498,276 Warranty — 180,333 — 180,333 Other liability 11,292 26,169 47,332 84,793 Commercial auto and liability, physical damage 47,751 9,164 32,118 89,033 Medical malpractice — 59,186 — 59,186 Other 108,925 152,467 23,223 284,615 Total net earned premium $ 516,998 $ 427,319 $ 251,919 $ 1,196,236 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Nine Months Ended September 30, 2017: Workers' compensation $ 1,057,183 $ — $ 307,907 $ 1,365,090 Warranty — 709,231 26 709,257 Other liability — 125,259 155,322 280,581 Commercial auto and liability, physical damage 275,657 — 88,922 364,579 Medical malpractice — 167,635 — 167,635 Other 381,728 493,186 34,062 908,976 Total net earned premium $ 1,714,568 $ 1,495,311 $ 586,239 $ 3,796,118 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Nine Months Ended September 30, 2016: Workers' compensation $ 1,053,967 $ — $ 456,663 $ 1,510,630 Warranty — 527,835 — 527,835 Other liability 16,541 100,187 130,713 247,441 Commercial auto and liability, physical damage 245,647 26,340 97,863 369,850 Medical malpractice — 106,750 — 106,750 Other 277,915 345,932 65,917 689,764 Total net earned premium $ 1,594,070 $ 1,107,044 $ 751,156 $ 3,452,270

Reinsurance Agreement

Reinsurance Agreement	9 Months Ended
	Sep. 30, 2017
Insurance [Abstract]
Reinsurance Agreement	Reinsurance Agreement Effective June 30, 2017 , the Company entered into an adverse loss development cover agreement (the "agreement"), with Premia Reinsurance Ltd. ("Premia"). Under the agreement, Premia will pay the Company for ultimate net losses paid by the Company in excess of a retention of $5,963,000 , subject to an aggregate limit of $1,025,000 , which provides $400,000 of coverage in excess of the Company’s carried loss reserves as of March 31, 2017 in the amount of approximately $6,590,000 . The consideration for this agreement is a $675,000 payment, plus an annual claims monitoring fee, of which $50,000 represents a payment for the coverage above the carried loss reserves of approximately $6,590,000 . Premia deposited an incremental $100,000 of excess collateral at inception and will also deposit incremental collateral in accordance with a pre-agreed schedule. The Company was required to pay interest deposited into the collateral trust account at a rate of 3.75% per annum on any unpaid portion of the $675,000 consideration amount from July 1, 2017 to the date of payment, which must occur within 180 days following June 30, 2017 . Notwithstanding the foregoing, the parties agreed that no interest would accrue from August 6, 2017 until the date of the first $225,000 payment made by the Company, nor would any interest accrue from September 8, 2017 until the date of the second $225,000 payment by the Company. During the three months ended September 30, 2017, the Company paid consideration of $450,000 to Premia, which was placed into a collateral trust account as security for Premia's claim payment obligations to the Company. Ceded reserves are collateralized by the premium payment and paid consideration and all investment income inures to the benefit of the collateral trust account. The Company had $225,000 of consideration that remained unpaid as of September 30, 2017 , and incurred $4,531 of interest related to the unpaid portion during the three months ended September 30, 2017 , which was recorded as a reduction of the deferred gain, discussed further below. The agreement has been accounted for as retroactive reinsurance. During the three months ended June 30, 2017, the Company recognized a pre-tax loss of $58,949 , including the $50,000 payment mentioned above and $8,949 representing the net present value of the Company’s obligation to pay $1,000 annually in claims administration monitoring fees to Premia for up to 30 years. In addition, the Company recognized $73,069 of net adverse loss development, which exceeded the original pre-tax loss and resulted in a $14,120 deferred gain. For the three and nine month periods ended September 30, 2017 , the Company recorded $326,931 and $400,000 , respectively, of net adverse loss development covered under this agreement that resulted in a deferred gain of $337,054 as of September 30, 2017 . The deferred gain will be recognized in earnings over the estimated claim settlement period and is reported as "Deferred gain on retroactive reinsurance" on the Consolidated Balance Sheets. The Company retains sole authority to handle and resolve claims, and Premia has various access, association and consultation rights.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events On November 3, 2017, the Company and Mayfield Holdings LLC (“Mayfield”), entered into a Contribution and Stock Purchase Agreement (the “Acquisition Agreement”) with FeeCo Holdings LP (“Investor”), a newly-formed investment vehicle owned by affiliates of Madison Dearborn Partners, related to the Investor’s acquisition of a majority interest in the portion of the Company’s U.S. fee-based business that (a) acts as a managing general agent for the distribution, underwriting and procurement of property and casualty insurance on behalf of certain AFSI affiliates and other insurance carriers and (b) designs, develops, markets and acts as a third party administrator for programs for service contracts, limited warranties and replacement plans as further described in the Acquisition Agreement (the “Business”). Under the terms of the Acquisition Agreement, it is anticipated that (1) Investor will contribute to Mayfield $210,000 in cash in exchange for 51% of the common units of Mayfield (an entity formed to hold the Business), (2) the Company will, directly or indirectly, contribute into Mayfield a portion of the entities comprising the Business in exchange for 49% of the common units of Mayfield (with an implied value of approximately $200,000 ) and (3) one or more subsidiaries of Mayfield will acquire from the Company, directly or indirectly, the remaining portion of the entities comprising the Business in exchange for a base cash purchase price of approximately $950,000 (using proceeds from the cash contribution from Investor and the third-party indebtedness described below). The cash purchase price will be subject to customary purchase price adjustments based upon the amount of cash, indebtedness, transaction expenses and net working capital of Mayfield and its subsidiaries at the closing of the transactions relative to a target amount. In connection with the transaction, it is expected that one or more subsidiaries of Mayfield will incur new third-party indebtedness of approximately $750,000 . Following the closing of the transaction, the Company intends to cease consolidating the results of the Business within its financial statements and will report its ownership interest in Mayfield using the equity method of accounting. Closing of the transaction is expected to occur in the first half of 2018, and is subject to certain customary conditions, including: (i) receipt of consents, authorizations and approvals from governmental authorities, including antitrust and insurance regulatory authorities; (ii) completion of certain internal restructuring steps; (iii) certain third-party consents and (iv) certain other customary closing conditions.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Estimated Market Value and Gross Unrealized Appreciation and Depreciation of Available-for-sale Securities	The cost or amortized cost, gross unrealized gains and losses, and estimated fair value of fixed maturity and equity securities classified as available-for-sale as of September 30, 2017 and December 31, 2016 , are presented below: As of September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities: U.S. treasury securities $ 319,333 $ 1,080 $ (1,528 ) $ 318,885 U.S. government agencies 48,605 26 (481 ) 48,150 Municipal bonds 894,106 15,459 (3,772 ) 905,793 Foreign government 184,507 4,013 (1,404 ) 187,116 Corporate bonds: Finance 1,579,758 45,733 (2,413 ) 1,623,078 Industrial 2,184,009 60,640 (6,306 ) 2,238,343 Utilities 365,563 10,140 (964 ) 374,739 Commercial mortgage-backed securities 461,972 4,480 (5,461 ) 460,991 Residential mortgage-backed securities: Agency backed 801,586 13,362 (4,054 ) 810,894 Non-agency backed 5,677 3 (31 ) 5,649 Collateralized loan / debt obligation 617,392 9,323 (367 ) 626,348 Asset backed securities 21,464 114 (28 ) 21,550 Total fixed maturity securities $ 7,483,972 $ 164,373 $ (26,809 ) $ 7,621,536 Equity Securities: Common stock $ 87,416 $ 19,418 $ (2,294 ) $ 104,540 As of December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities: U.S. treasury securities $ 331,036 $ 1,235 $ (1,617 ) $ 330,654 U.S. government agencies 63,467 282 (17 ) 63,732 Municipal bonds 860,444 9,603 (15,877 ) 854,170 Foreign government 149,365 4,237 (726 ) 152,876 Corporate bonds: Finance 1,535,606 38,404 (7,722 ) 1,566,288 Industrial 2,222,843 62,133 (17,115 ) 2,267,861 Utilities 195,607 4,433 (1,210 ) 198,830 Commercial mortgage-backed securities 178,092 2,464 (2,562 ) 177,994 Residential mortgage-backed securities: Agency backed 1,210,229 13,685 (13,529 ) 1,210,385 Non-agency backed 61,646 586 (1,003 ) 61,229 Collateralized loan / debt obligations 476,767 8,389 (751 ) 484,405 Asset backed securities 29,939 31 (260 ) 29,710 Total fixed maturity securities $ 7,315,041 $ 145,482 $ (62,389 ) $ 7,398,134 Equity Securities: Preferred stock $ 4,044 $ — $ (59 ) $ 3,985 Common stock 122,626 12,899 (2,348 ) 133,177 Total equity securities $ 126,670 $ 12,899 $ (2,407 ) $ 137,162
Amortized Cost, Estimated Market Value and Gross Unrealized Appreciation and Depreciation of Trading Securities	The table below shows the portion of trading gains and losses for the period related to trading securities still held during the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net (losses) and gains recognized during the period on trading securities $ (2,241 ) $ 995 $ (17,481 ) $ 3,428 Less: Net (losses) and gains recognized during the period on trading securities sold during the period (1,584 ) 812 (933 ) 8,199 Unrealized (losses) and gains recognized during the reporting period on trading securities still held at the reporting date $ (657 ) $ 183 $ (16,548 ) $ (4,771 ) The amortized cost, estimated fair value and gross unrealized gains and losses of trading securities as of September 30, 2017 and December 31, 2016 are presented in the tables below: As of September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities U.S. Treasury securities $ 10,050 $ — $ (140 ) $ 9,910 Corporate bonds: Industrial 23,955 643 (2,699 ) 21,899 Utilities 295 70 — 365 Total Fixed Maturity Securities $ 34,300 $ 713 $ (2,839 ) $ 32,174 Common stock $ 88,746 $ 3,960 $ (11,594 ) $ 81,112 As of December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed Maturity Securities Corporate bonds: Industrial $ 24,151 $ 4,379 $ — $ 28,530 Utilities 4,930 322 — 5,252 Total Fixed Maturity Securities $ 29,081 $ 4,701 $ — $ 33,782 Common stock $ 76,163 $ 9,842 $ (4,045 ) $ 81,960
Summary of Available for Sale Fixed Securities by Contractual Maturity	A summary of the Company’s available-for-sale fixed maturity securities as of September 30, 2017 and December 31, 2016 , by contractual maturity, is shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. September 30, 2017 December 31, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 185,841 $ 186,532 $ 319,275 $ 319,882 Due after one through five years 1,748,551 1,788,962 2,956,429 2,998,711 Due after five through ten years 3,176,390 3,246,584 1,645,211 1,683,112 Due after ten years 465,099 474,026 437,452 432,702 Mortgage and asset backed securities 1,908,091 1,925,432 1,956,674 1,963,727 Total fixed maturity securities $ 7,483,972 $ 7,621,536 $ 7,315,041 $ 7,398,134
Net Investment Income	Net investment income for the three and nine months ended September 30, 2017 and 2016 was derived from the following sources: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Fixed maturity securities, available-for-sale $ 60,478 $ 59,712 $ 187,128 $ 152,140 Equity securities, available-for-sale 469 465 2,038 6,927 Fixed maturity securities, trading 473 — 1,505 — Equity securities, trading (141 ) (40 ) (121 ) (318 ) Cash and short term investments 5,695 410 8,977 2,182 Other invested assets (1) (664 ) — (15,665 ) — 66,310 60,547 183,862 160,931 Less: Investment expenses (5,207 ) (628 ) (10,208 ) (852 ) $ 61,103 $ 59,919 $ 173,654 $ 160,079 (1) Includes losses from equity method investments.
Summary of Gross Unrealized Losses of Fixed-maturities and Equity Securities	The tables below summarize the gross unrealized losses of our available-for-sale fixed maturity and equity securities by length of time the security has continuously been in an unrealized loss position as of September 30, 2017 and December 31, 2016 : Less Than 12 Months 12 Months or More Total As of September 30, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed Maturity Securities: U.S. treasury securities $ 257,511 $ (1,452 ) $ 6,263 $ (76 ) $ 263,774 $ (1,528 ) U.S. government agencies 43,352 (481 ) — — 43,352 (481 ) Municipal bonds 291,908 (2,778 ) 42,088 (994 ) 333,996 (3,772 ) Foreign government 75,485 (1,315 ) 9,258 (89 ) 84,743 (1,404 ) Corporate bonds: Finance 184,303 (1,589 ) 65,061 (824 ) 249,364 (2,413 ) Industrial 347,521 (4,169 ) 86,507 (2,137 ) 434,028 (6,306 ) Utilities 62,260 (494 ) 23,913 (470 ) 86,173 (964 ) Commercial mortgage-backed securities 252,831 (4,784 ) 9,674 (677 ) 262,505 (5,461 ) Residential mortgage-backed securities: Agency backed 253,181 (3,998 ) 2,264 (56 ) 255,445 (4,054 ) Non-agency backed 3,206 (9 ) 2,322 (22 ) 5,528 (31 ) Collateralized loan / debt obligations 69,034 (367 ) — — 69,034 (367 ) Asset backed securities 5,797 (6 ) 1,008 (22 ) 6,805 (28 ) Total fixed maturity securities $ 1,846,389 $ (21,442 ) $ 248,358 $ (5,367 ) $ 2,094,747 $ (26,809 ) Equity Securities: Common stock $ 16,245 $ (2,294 ) $ — $ — $ 16,245 $ (2,294 ) Less Than 12 Months 12 Months or More Total As of December 31, 2016 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed Maturity Securities: U.S. treasury securities $ 293,155 $ (1,613 ) $ 22,989 $ (4 ) $ 316,144 $ (1,617 ) U.S. government agencies 7,866 (17 ) — — 7,866 (17 ) Municipal bonds 519,578 (15,207 ) 15,742 (670 ) 535,320 (15,877 ) Foreign government 128,863 (688 ) 12,659 (38 ) 141,522 (726 ) Corporate bonds: Finance 1,071,982 (7,210 ) 16,840 (512 ) 1,088,822 (7,722 ) Industrial 1,200,129 (13,648 ) 114,035 (3,467 ) 1,314,164 (17,115 ) Utilities 119,488 (423 ) 10,391 (787 ) 129,879 (1,210 ) Commercial mortgage-backed securities 71,780 (1,654 ) 10,910 (908 ) 82,690 (2,562 ) Residential mortgage-backed securities: Agency backed 718,098 (13,469 ) 8,144 (60 ) 726,242 (13,529 ) Non-agency backed 24,372 (869 ) 4,462 (134 ) 28,834 (1,003 ) Collateralized loan / debt obligations 97,923 (433 ) 32,937 (318 ) 130,860 (751 ) Asset backed securities 9,220 (124 ) 4,926 (136 ) 14,146 (260 ) Total fixed maturity securities $ 4,262,454 $ (55,355 ) $ 254,035 $ (7,034 ) $ 4,516,489 $ (62,389 ) Equity Securities: Preferred stock $ 529 $ (30 ) $ — $ (29 ) $ 529 $ (59 ) Common stock 46,254 (1,394 ) 9,991 (954 ) 56,245 (2,348 ) Total equity securities $ 46,783 $ (1,424 ) $ 9,991 $ (983 ) $ 56,774 $ (2,407 )
Fair Values of Restricted Assets	The fair values of the Company's restricted assets as of September 30, 2017 and December 31, 2016 are as follows: September 30, 2017 December 31, 2016 Restricted cash and cash equivalents $ 879,478 $ 713,338 Restricted investments - fixed maturity securities at fair value 2,861,413 2,126,216 Total restricted cash, cash equivalents, and investments $ 3,740,891 $ 2,839,554
Realized Gain (Loss) on Investments	The tables below summarize the gross and net realized gains and (losses) for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2017 Gross Gains Gross Losses Net Gains (Losses) Gross Gains Gross Losses Net Gains (Losses) Fixed maturity securities, available-for-sale $ 15,577 $ (1,132 ) $ 14,445 $ 38,024 $ (3,188 ) $ 34,836 Equity securities, available-for-sale 9,122 (295 ) 8,827 21,633 (1,894 ) 19,739 Fixed maturity securities, trading 1,723 — 1,723 6,695 (9,548 ) (2,853 ) Equity securities, trading 6,204 (10,168 ) (3,964 ) 14,691 (29,319 ) (14,628 ) Other investments 3,489 — 3,489 19,516 (20 ) 19,496 $ 36,115 $ (11,595 ) $ 24,520 $ 100,559 $ (43,969 ) $ 56,590 Three Months Ended September 30, Nine Months Ended September 30, 2016 2016 Gross Gains Gross Losses Net Gains (Losses) Gross Gains Gross Losses Net Gains (Losses) Fixed maturity securities, available-for-sale $ 17,535 $ (2,582 ) $ 14,953 $ 57,346 $ (4,199 ) $ 53,147 Equity securities, available-for-sale 553 (1,126 ) (573 ) 1,821 (1,862 ) (41 ) Equity securities, trading 2,897 (1,902 ) 995 17,824 (14,396 ) 3,428 Other investments 3,449 (1,133 ) 2,316 1,189 (2 ) 1,187 Write-down of other invested assets — (6,440 ) (6,440 ) — (19,977 ) (19,977 ) Write-down of equity securities, available-for-sale — (3,021 ) (3,021 ) — (6,440 ) (6,440 ) $ 24,434 $ (16,204 ) $ 8,230 $ 78,180 $ (46,876 ) $ 31,304

Fair Value of Financial Instr25

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement of Financial Assets and Financial Liabilities on Recurring Basis	The following tables present the level within the fair value hierarchy at which the Company’s financial assets and financial liabilities are measured on a recurring basis as of September 30, 2017 and December 31, 2016 : As of September 30, 2017 Total Level 1 Level 2 Level 3 Financial Assets: U.S. treasury securities $ 328,795 $ 328,795 $ — $ — U.S. government agencies 48,150 — 48,150 — Municipal bonds 905,793 — 905,164 629 Foreign government 187,116 — 187,116 — Corporate bonds and other bonds: Finance 1,623,078 — 1,615,636 7,442 Industrial 2,260,242 — 2,258,428 1,814 Utilities 375,104 — 375,104 — Commercial mortgage-backed securities 460,991 — 437,559 23,432 Residential mortgage-backed securities: Agency backed 810,894 — 810,894 — Non-agency backed 5,649 — 5,649 — Collateralized loan / debt obligations 626,348 — 626,348 — Asset-backed securities 21,550 — 20,759 791 Equity securities, available-for-sale 104,540 104,540 — — Equity securities, trading 81,112 79,001 411 1,700 Life settlement contracts 298,701 — — 298,701 Total Financial Assets $ 8,138,063 $ 512,336 $ 7,291,218 $ 334,509 Financial Liabilities: Securities sold but not yet purchased, at fair value $ 56,181 $ 42,512 $ 13,669 $ — Life settlement contract profit commission 5,927 — — 5,927 Contingent consideration 84,520 — — 84,520 Total Financial Liabilities $ 146,628 $ 42,512 $ 13,669 $ 90,447 As of December 31, 2016 Total Level 1 Level 2 Level 3 Financial Assets: U.S. treasury securities $ 330,654 $ 330,654 $ — $ — U.S. government agencies 63,732 — 63,732 — Municipal bonds 854,170 — 854,170 — Foreign government 152,876 — 149,298 3,578 Corporate bonds and other bonds: Finance 1,566,288 — 1,559,800 6,488 Industrial 2,296,391 — 2,291,351 5,040 Utilities 204,082 — 199,503 4,579 Commercial mortgage-backed securities 177,994 — 177,994 — Residential mortgage-backed securities: Agency backed 1,210,385 — 1,186,315 24,070 Non-agency backed 61,229 — 58,109 3,120 Collateralized loan / debt obligations 484,405 — 484,405 — Asset-backed securities 29,710 — 29,710 — Equity securities, available-for-sale 137,162 66,228 49,618 21,316 Equity securities, trading 81,960 78,827 — 3,133 Life settlement contracts 356,856 — — 356,856 Total Financial Assets $ 8,007,894 $ 475,709 $ 7,104,005 $ 428,180 Financial Liabilities: Securities sold but not yet purchased, at fair value $ 36,394 $ 36,394 $ — $ — Fixed maturity securities sold but not yet purchased 160,270 — 160,270 — Life settlement contract profit commission 4,940 — — 4,940 Contingent consideration (as restated) 71,657 — — 71,657 Derivatives 243 — 243 — Total Financial Liabilities $ 273,504 $ 36,394 $ 160,513 $ 76,597
Changes in Fair Value of Level 3 Financial Assets And Liabilities	The following table provides a summary of changes in fair value of the Company’s Level 3 financial assets and liabilities for the three and nine months ended September 30, 2017 and 2016 . The transfers into and out of Level 3 were due to changes in the availability of market observable inputs. All transfers are reflected in the table at fair value as of the end of the reporting period. Balance as of June 30, 2017 Net income (loss) Other comprehensive (loss) income Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, trading $ 2,051 $ 22 $ — $ — $ — $ (373 ) $ 1,700 Equity securities, available-for-sale 21,348 566 (502 ) 38 (21,450 ) — — Fixed maturities, available-for-sale 41,512 (14 ) 208 1,954 (1,179 ) (8,373 ) 34,108 Fixed maturities, trading 312 1,992 — — (2,304 ) — — Life settlement contracts 396,782 33,617 — — (131,698 ) — 298,701 Life settlement contract profit commission (5,714 ) (213 ) — — — — (5,927 ) Contingent consideration (97,615 ) 3,348 — (1,853 ) 11,600 — (84,520 ) Total $ 358,676 $ 39,318 $ (294 ) $ 139 $ (145,031 ) $ (8,746 ) $ 244,062 Balance as of December 31, 2016 Net income (loss) Other comprehensive income (loss) Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, 2017 Equity securities, trading $ 3,133 $ (400 ) $ — $ 4,484 $ (2,134 ) $ (3,383 ) $ 1,700 Equity securities, available-for-sale 21,316 566 (164 ) 114 (38,198 ) 16,366 — Fixed maturities, available-for-sale 46,875 (14 ) (281 ) 9,459 (3,954 ) (17,977 ) 34,108 Fixed maturities, trading 312 1,992 — — (2,304 ) — — Life settlement contracts 356,856 82,233 — 16,473 (156,861 ) — 298,701 Life settlement contract profit commission (4,940 ) (987 ) — — — — (5,927 ) Contingent consideration (71,657 ) (442 ) — (29,032 ) 16,611 — (84,520 ) Total $ 351,895 $ 82,948 $ (445 ) $ 1,498 $ (186,840 ) $ (4,994 ) $ 244,062 Balance as of June 30, 2016 Net income (loss) Other comprehensive loss Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, available-for-sale $ 24,764 $ (16,983 ) $ 17,168 $ (2 ) $ (7,753 ) $ 15,985 $ 33,179 Commercial mortgage backed securities — — (194 ) — — 8,065 7,871 Collateralized loan / debt obligations — — (15 ) — — 21,748 21,733 Life settlement contracts 304,434 23,290 — 4,550 (189 ) — 332,085 Life settlement contract profit commission (9,054 ) (763 ) — — 5,000 — (4,817 ) Contingent consideration (as restated) (75,772 ) (2,226 ) — (5,443 ) 11,393 — (72,048 ) Total $ 244,372 $ 3,318 $ 16,959 $ (895 ) $ 8,451 $ 45,798 $ 318,003 Balance as of December 31, 2015 Net income (loss) Other comprehensive loss Purchases and issuances Sales and settlements Net transfers into (out of) Level 3 Balance as of September 30, Equity securities, available-for-sale $ 37,211 $ (16,983 ) $ 4,719 $ — $ (7,753 ) $ 15,985 $ 33,179 Commercial mortgage backed securities — — (194 ) — — 8,065 7,871 Collateralized loan / debt obligations — — (15 ) — — 21,748 21,733 Life settlement contracts 264,001 82,451 — 15,880 (30,247 ) — 332,085 Life settlement contract profit commission (15,406 ) (9,817 ) — — 20,406 — (4,817 ) Contingent consideration (as restated) (84,760 ) (8,224 ) — (13,903 ) 34,839 — (72,048 ) Total $ 201,046 $ 47,427 $ 4,510 $ 1,977 $ 17,245 $ 45,798 $ 318,003
Fair Value Measurements, Recurring and Nonrecurring	The fair value of the Company's debt arrangements as of September 30, 2017 was as follows: Carrying Value Fair Value 6.125% Notes due 2023 $ 248,390 $ 249,255 2.75% Convertible senior notes due 2044 171,286 174,583 7.25% Subordinated Notes due 2055 145,296 154,200 7.50% Subordinated Notes due 2055 130,767 140,184 Revolving credit facility 130,000 130,000 Junior subordinated debentures due 2035-2037 122,094 110,070 Trust preferred securities due 2033-2037 92,786 85,906 Republic promissory note 52,343 53,163 Other 194,782 194,782 Total $ 1,287,744 $ 1,292,143
Schedule of Reconciliation of Net Income	A reconciliation of net income for life settlement contracts in the above table to gain (loss) on investment in life settlement contracts net of profit commission included in the Consolidated Statements of Income for the three and nine months ended September 30, 2017 and 2016 is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Net income $ 33,617 $ 23,290 $ 82,233 $ 82,451 Premiums paid (9,960 ) (16,434 ) (48,694 ) (41,890 ) Profit commission (213 ) (763 ) (987 ) (9,817 ) Other expenses and loss on sale (24,368 ) (608 ) (26,127 ) (1,853 ) (Loss) gain on investment in life settlement contracts $ (924 ) $ 5,485 $ 6,425 $ 28,891
Premiums to be Paid for Each of Five Succeeding Fiscal Years to keep Life Insurance Policies in Force	The following summarizes data utilized in estimating the fair value of the portfolio of life insurance policies as of September 30, 2017 and December 31, 2016 , and only includes data for policies to which the Company assigned value at those dates: September 30, December 31, Average age of insured (years) 84.3 82.8 Average life expectancy, months (1) 87 107 Average face amount per policy $ 7,088 $ 6,572 Effective discount rate (2) 12.4 % 12.4 % (1) Standard life expectancy as adjusted for specific circumstances. (2) Effective discount rate ("EDR") is the Company's estimated internal rate of return on its life settlement contract portfolio and is determined from the gross expected cash flows and valuation of the portfolio. The EDR is inclusive of the reserves and the gross expected cash flows of the portfolio. The Company anticipates that the EDR's range is between 10.0% and 15.0% and reflects the uncertainty that exists surrounding the information available as of the reporting date. As the accuracy and reliability of information improves (declines), the EDR will decrease (increase).
Increase or (Decrease) in Carrying Value of Investment in Life Insurance Policies	The Company's assumptions are, by their nature, inherently uncertain and the effect of changes in estimates may be significant. The fair value measurements used in estimating the present value calculation are derived from valuation techniques generally used in the industry that include inputs for the asset that are not based on observable market data. The extent to which the fair value could reasonably vary in the near term has been quantified by evaluating the effect of changes in significant underlying assumptions used to estimate the fair value amount. If the life expectancies were increased or decreased by 4 months and the discount factors were increased or decreased by 1% while all other variables were held constant, the carrying value of the investment in life insurance policies would increase or (decrease) by the unaudited amounts summarized below as of September 30, 2017 and December 31, 2016 : Change in life expectancy Plus 4 Months Minus 4 Months Investment in life policies: September 30, 2017 $ (30,268 ) $ 28,432 December 31, 2016 $ (44,207 ) $ 43,492 Change in discount rate (1) Plus 1% Minus 1% Investment in life policies: September 30, 2017 $ (20,130 ) $ 22,121 December 31, 2016 $ (29,881 ) $ 33,155 (1) Discount rate is a present value calculation that considers legal risk, credit risk and liquidity risk and is a component of EDR.

Investment in Life Settlements

Investment in Life Settlements (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, All Other Investments [Abstract]
Investment in Life Settlements	The following tables describe the Company’s investment in life settlements as of September 30, 2017 and December 31, 2016 : Expected Maturity Term in Years Number of Life Settlement Contracts (in whole numbers) Fair Value (1) Face Value Number of Life Settlement Contracts (in whole numbers) Fair Value (1) Face Value As of September 30, 2017 As of December 31, 2016 0-1 — $ — $ — — $ — $ — 1-2 6 41,011 58,000 2 8,873 12,500 2-3 3 22,994 32,422 7 39,495 63,000 3-4 13 45,357 101,000 10 37,436 75,422 4-5 13 25,426 60,400 10 34,003 82,900 Thereafter 107 163,913 744,880 225 237,049 1,405,414 Total 142 $ 298,701 $ 996,702 254 $ 356,856 $ 1,639,236 (1) As of September 30, 2017 and December 31, 2016 , the Company determined the fair value of 4 and 18 policies, respectively, to be negative and, therefore, assigned a fair value of zero to those policies. For these contracts, the table below details the amount of premiums paid and the death benefits received during the twelve months preceding September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of policies with a negative value from discounted cash flow model as of period end (in whole numbers) 4 18 Premiums paid for the preceding twelve month period for period ended $ 394 $ 2,640 Death benefit received $ — $ —
Premiums to be Paid for Each of Five Succeeding Fiscal Years to keep Life Insurance Policies in Force	Premiums to be paid by the LSC Entities for each of the five succeeding fiscal years to keep the life insurance policies in force as of September 30, 2017 , are as follows: Premiums Due on Life Settlement Contracts 2017 $ 35,423 2018 36,568 2019 35,922 2020 34,781 2021 32,544 Thereafter 215,213 Total $ 390,451

Loss and loss adjustment expe27

Loss and loss adjustment expense reserves (Tables)	9 Months Ended
	Sep. 30, 2017
Insurance [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense	The following table provides a reconciliation of the beginning and ending balances for loss and loss adjustment expense reserves ("Loss and LAE") for the three months ended September 30, 2017 , and 2016 , respectively: 2017 2016 Loss and LAE, gross of related reinsurance recoverables at beginning of period $ 11,149,511 $ 9,097,408 Less: Reinsurance recoverables at beginning of period 4,942,144 3,568,863 Net balance, beginning of period 6,207,367 5,528,545 Incurred related to: Current year 939,187 720,440 Prior year 326,931 90,608 Total incurred during the period 1,266,118 811,048 Paid related to: Current year (333,098 ) (262,738 ) Prior year (445,247 ) (387,735 ) Total paid during the period (778,345 ) (650,473 ) Retroactive reinsurance adjustment (326,931 ) — Effect of foreign exchange rates 50,882 61,202 Net balance, end of period 6,419,091 5,750,322 Plus reinsurance recoverables at end of period 5,667,553 3,677,448 Loss and LAE, gross of related reinsurance recoverables at end of period $ 12,086,644 $ 9,427,770 The following table provides a reconciliation of the beginning and ending balances for Loss and LAE for the nine months ended September 30, 2017 , and 2016 , respectively: 2017 2016 Loss and LAE, gross of related reinsurance recoverables at beginning of period $ 10,140,716 $ 7,208,367 Less: Reinsurance recoverables at beginning of period 3,873,786 2,665,187 Net balance, beginning of period 6,266,930 4,543,180 Incurred related to: Current year 2,712,079 2,117,774 Prior year 418,851 192,740 Total incurred during the period 3,130,930 2,310,514 Paid related to: Current year (699,340 ) (531,517 ) Prior year (1,593,524 ) (1,335,069 ) Total paid during the period (2,292,864 ) (1,866,586 ) Loss portfolio transfers — 312,049 Acquired loss and loss adjustment reserves 200,802 463,115 Retroactive reinsurance adjustment (1,025,000 ) — Effect of foreign exchange rates 138,293 (11,950 ) Net balance, end of period 6,419,091 5,750,322 Plus reinsurance recoverables at end of period 5,667,553 3,677,448 Loss and LAE, gross of related reinsurance recoverables at end of period $ 12,086,644 $ 9,427,770

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Borrowings	The Company’s outstanding debt consisted of the following at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 6.125% Notes due 2023 (the "2023 Notes") $ 248,390 $ 248,185 Secured loan agreements 175,345 75,762 2.75% Convertible senior notes due 2044 (the "2044 Notes") 171,286 166,387 7.25% Subordinated notes due 2055 (the "7.25% 2055 Notes") 145,296 145,202 7.50% Subordinated notes due 2055 (the "7.50% 2055 Notes") 130,767 130,684 Revolving credit facility 130,000 130,000 Junior subordinated debentures (the "2035-2037 Notes") 122,094 122,028 Trust preferred securities (the "2033-2037 TPS Notes") 92,786 92,786 Promissory notes 66,453 118,643 5.5% Convertible senior notes due 2021 (the "2021 Notes") 5,327 5,223 Total $ 1,287,744 $ 1,234,900
Schedule of Line of Credit Facilities	Additionally, the Company utilizes various letters of credit in its operations. The following is a summary of the Company's letters of credit as of September 30, 2017 : Limit Outstanding Available Revolving credit facility $ 175,000 $ 174,662 $ 338 Funds at Lloyd's facility 689,997 657,306 32,691 ING Bank N.V., BHF-BANK Aktiengesellschaft, and Deutsche Bank Netherlands N.V. facilities 90,615 73,180 17,435 Comerica Bank letters of credit 75,000 43,067 31,933 UniCredit Bank 100,000 100,000 — Other letters of credit, in aggregate 139,052 139,052 —
Interest Income and Interest Expense Disclosure	Interest expense, including amortization of original issue discount and deferred origination costs, as well as applicable bank fees, related to the Company's outstanding debt and letters of credit for the three and nine months ended September 30, 2017 and 2016 was: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Revolving credit facility $ 1,571 $ 1,134 $ 4,610 $ 3,388 2021 Notes 118 116 352 345 2044 Notes 3,282 3,170 9,731 9,402 2023 Notes 3,897 3,897 11,690 11,690 2035-2037 Notes 1,445 1,548 4,333 4,609 2033-2037 TPS Notes 1,118 981 3,227 1,750 7.25% 2055 Notes 2,750 2,750 8,250 8,250 7.50% 2055 Notes 2,559 2,559 7,677 7,677 Secured loan agreements 1,701 756 4,528 1,768 Promissory notes 938 1,698 3,646 3,253 Funds at Lloyd's facility 1,342 1,065 4,057 3,387 Other, including interest income 2,152 2,450 8,602 391 Total $ 22,873 $ 22,124 $ 70,703 $ 55,910

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Summary of Elements Used in Calculating Basic and Diluted Earnings Per Share	The following table is a summary of the elements used in calculating basic and diluted earnings per share for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 As restated As restated Numerator: Net (loss) income attributable to AmTrust common stockholders $ (174,675 ) $ 80,650 $ (146,214 ) $ 291,784 Denominator: Weighted average common shares outstanding – basic 195,891 170,928 182,570 173,173 Plus: Dilutive effect of stock options, convertible debt, other (1) — 2,193 — 1,978 Weighted average common shares outstanding – dilutive 195,891 173,121 182,570 175,151 Net (loss) income per AmTrust common share - basic $ (0.89 ) $ 0.47 $ (0.80 ) $ 1.68 Net (loss) income per AmTrust common share – diluted $ (0.89 ) $ 0.47 $ (0.80 ) $ 1.67

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Schedule of Preliminary Assets Acquired and Liabilities Assumed	A summary of the preliminary assets acquired and liabilities assumed for PDP are as follows: Assets Cash and cash equivalents $ 11,826 Premium receivable 29,188 Other assets 705 Property and equipment, net 776 Goodwill and intangible assets 55,586 Total assets $ 98,081 Liabilities Accrued expenses and other liabilities $ 35,659 Acquisition price $ 62,422 A summary of the preliminary assets acquired and liabilities assumed for AHC are as follows: Assets Cash and investments $ 275,351 Premium receivable 45,288 Accrued interest and dividends 1,162 Reinsurance recoverable 14,512 Other assets 43,696 Goodwill and intangible assets 17,509 Total assets $ 397,518 Liabilities Loss and loss adjustment expense reserves $ 227,865 Unearned premiums 49,284 Accrued expenses and other liabilities 27,583 Total liabilities $ 304,732 Acquisition price $ 92,786

Shareholder Equity and Accumu31

Shareholder Equity and Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Ownership Components of Total Equity	The following table summarizes the ownership components of total stockholders' equity: Nine Months Ended September 30, 2017 2016 AmTrust Non-Controlling Interest Total AmTrust Non-Controlling Interest Total (As restated) (As restated) Balance, December 31, $ 3,269,103 $ 196,510 $ 3,465,613 $ 2,723,780 $ 176,455 $ 2,900,235 Net (loss) income (96,501 ) 16,127 (80,374 ) 323,727 12,222 335,949 Unrealized holding gain 94,889 — 94,889 214,519 — 214,519 Reclassification adjustment (54,130 ) — (54,130 ) (17,993 ) — (17,993 ) Foreign currency translation 127,235 — 127,235 (110,148 ) — (110,148 ) Unrealized gain on interest rate swap 145 — 145 540 — 540 Extinguishment of 2021 senior notes, equity component — — — (1 ) — (1 ) Share exercises, compensation and other 19,066 — 19,066 10,568 — 10,568 Common stock issuance 298,747 — 298,747 — — — Common share purchase, net — — — (152,047 ) — (152,047 ) Common stock dividends (95,681 ) — (95,681 ) (81,167 ) — (81,167 ) Preferred stock issuance, net of fees — — — 417,264 — 417,264 Preferred stock dividends (49,713 ) — (49,713 ) (31,943 ) — (31,943 ) Capital distributions, net — (31,336 ) (31,336 ) — (5,413 ) (5,413 ) Balance, September 30, $ 3,513,160 $ 181,301 $ 3,694,461 $ 3,297,099 $ 183,264 $ 3,480,363
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the activities and components of accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2017 and 2016: Foreign Currency Items Unrealized Gains (Losses) on Investments Interest Rate Swap Hedge Net Benefit Plan Assets and Obligations Recognized in Stockholders' Equity Accumulated Other Comprehensive Income (Loss) Balance, June 30, 2017 $ (111,677 ) $ 110,071 $ (52 ) $ (3,177 ) $ (4,835 ) Other comprehensive income (loss) before reclassification 50,709 17,175 64 — 67,948 Amounts reclassed out of accumulated other comprehensive (loss) income — (23,272 ) — — (23,272 ) Income tax benefit (expense) — 2,615 (39 ) — 2,576 Net current-period other comprehensive income (loss) 50,709 (3,482 ) 25 — 47,252 Balance, September 30, 2017 $ (60,968 ) $ 106,589 $ (27 ) $ (3,177 ) $ 42,417 Balance, June 30, 2016 (As restated) $ (178,077 ) $ 148,791 $ (413 ) $ (107 ) $ (29,806 ) Other comprehensive income (loss) before reclassification (30,145 ) 23,741 390 — (6,014 ) Amounts reclassed out of accumulated other comprehensive income (loss) — (3,399 ) — — (3,399 ) Income tax expense — (7,118 ) (137 ) — (7,255 ) Net current-period other comprehensive (loss) income (30,145 ) 13,224 253 — (16,668 ) Balance, September 30, 2016 (As restated) $ (208,222 ) $ 162,015 $ (160 ) $ (107 ) $ (46,474 ) Foreign Currency Items Unrealized Gains (Losses) on Investments Interest Rate Swap Hedge Net Benefit Plan Assets and Obligations Recognized in Stockholders' Equity Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2016 $ (188,203 ) $ 65,830 $ (172 ) $ (3,177 ) $ (125,722 ) Other comprehensive income before reclassification 127,235 115,235 212 — 242,682 Amounts reclassed out of accumulated other comprehensive (loss) income — (54,130 ) — — (54,130 ) Income tax expense — (20,346 ) (67 ) — (20,413 ) Net current-period other comprehensive income 127,235 40,759 145 — 168,139 Balance, September 30, 2017 $ (60,968 ) $ 106,589 $ (27 ) $ (3,177 ) $ 42,417 Balance, December 31, 2015 (As restated) $ (98,074 ) $ (34,511 ) $ (700 ) $ (107 ) $ (133,392 ) Other comprehensive (loss) income before reclassification (110,148 ) 328,409 831 — 219,092 Amounts reclassed out of accumulated other comprehensive (loss) income — (17,993 ) — — (17,993 ) Income tax expense — (113,890 ) (291 ) — (114,181 ) Net current-period other comprehensive (loss) income (110,148 ) 196,526 540 — 86,918 Balance, September 30, 2016 (As restated) $ (208,222 ) $ 162,015 $ (160 ) $ (107 ) $ (46,474 )

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Results of Operations of Business Segments	The following tables summarize the results of operations of the business segments for the three and nine months ended September 30, 2017 and 2016 : Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Three Months Ended September 30, 2017: Gross written premium $ 1,012,663 $ 756,714 $ 221,398 $ — $ 1,990,775 Revenues: Net written premium $ 498,514 $ 525,308 $ 151,935 $ — $ 1,175,757 Change in unearned premium 30,565 (42,490 ) 29,045 — 17,120 Net earned premium 529,079 482,818 180,980 — 1,192,877 Expenses: Loss and loss adjustment expense 546,219 458,379 261,520 — 1,266,118 Acquisition costs and other underwriting expenses 154,739 126,312 56,035 — 337,086 Total expenses 700,958 584,691 317,555 — 1,603,204 Underwriting loss (171,879 ) (101,873 ) (136,575 ) — (410,327 ) Other income (loss) Service and fee income 27,586 114,549 499 37,871 180,505 Investment income and realized gain on investments 32,936 33,527 19,160 — 85,623 Other expenses (45,239 ) (33,501 ) (9,935 ) (88,675 ) (177,350 ) Interest expense (11,661 ) (8,654 ) (2,558 ) — (22,873 ) Foreign currency loss — (62,819 ) — — (62,819 ) Loss on life settlement contracts (541 ) (241 ) (142 ) — (924 ) Gain on sale of policy management system — — — 186,755 186,755 Benefit (provision) for income taxes 65,012 (39,126 ) 75,564 (38,862 ) 62,588 Net (loss) income $ (103,786 ) $ (98,138 ) $ (53,987 ) $ 97,089 $ (158,822 ) Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Three Months Ended September 30, 2016 Gross written premium $ 998,071 $ 598,977 $ 437,050 $ — $ 2,034,098 Revenues: Net written premium $ 457,871 $ 448,845 $ 309,334 $ — $ 1,216,050 Change in unearned premium 59,127 (21,526 ) (57,415 ) — (19,814 ) Net earned premium 516,998 427,319 251,919 — 1,196,236 Expenses: Loss and loss adjustment expense 344,531 293,956 172,561 — 811,048 Acquisition costs and other underwriting expenses (As restated) 134,520 86,240 83,232 — 303,992 Total expenses 479,051 380,196 255,793 — 1,115,040 Underwriting income (loss) (As restated) 37,947 47,123 (3,874 ) — 81,196 Other income (loss) Service and fee income (As restated) 26,800 82,475 106 24,476 133,857 Investment income and realized gain on investments 29,218 24,519 14,412 — 68,149 Other expenses (As restated) (34,236 ) (20,503 ) (14,887 ) (69,625 ) (139,251 ) Interest expense (As restated) (10,988 ) (6,516 ) (4,620 ) — (22,124 ) Foreign currency loss (As restated) — (10,880 ) — — (10,880 ) Gain on life settlement contracts 2,521 1,614 1,350 — 5,485 (Provision) benefit for income taxes (As restated) (9,947 ) (22,070 ) 801 8,031 (23,185 ) Equity in earnings of unconsolidated subsidiary – related party — — — 1,954 1,954 Net income (loss) (As restated) $ 41,315 $ 95,762 $ (6,712 ) $ (35,164 ) $ 95,201 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Nine Months Ended September 30, 2017 Gross written premium $ 3,393,240 $ 2,285,088 $ 778,474 $ — $ 6,456,802 Revenues: Net written premium $ 1,796,255 $ 1,591,002 $ 504,468 $ — $ 3,891,725 Change in unearned premium (81,687 ) (95,691 ) 81,771 — (95,607 ) Net earned premium 1,714,568 1,495,311 586,239 — 3,796,118 Expenses: Loss and loss adjustment expense 1,390,557 1,141,823 598,550 — 3,130,930 Acquisition costs and other underwriting expenses 479,559 385,085 173,852 — 1,038,496 Total expenses 1,870,116 1,526,908 772,402 — 4,169,426 Underwriting loss (155,548 ) (31,597 ) (186,163 ) — (373,308 ) Other income (loss) Service and fee income 87,230 299,668 2,479 97,070 486,447 Investment income and realized gain on investments 95,145 87,374 47,725 — 230,244 Other expenses (141,909 ) (95,565 ) (32,557 ) (270,032 ) (540,063 ) Interest expense (37,157 ) (25,022 ) (8,524 ) — (70,703 ) Foreign currency loss — (139,735 ) — — (139,735 ) Gain on life settlement contracts 3,376 2,274 775 — 6,425 Gain on sale of policy management system — — — 186,755 186,755 Benefit (provision) for income taxes 64,611 (42,273 ) 76,504 (37,883 ) 60,959 Equity in earnings of unconsolidated subsidiary – related party — — — 73,488 73,488 Net (loss) income $ (84,252 ) $ 55,124 $ (99,761 ) $ 49,398 $ (79,491 ) Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Corporate and Other Total Nine Months Ended September 30, 2016 Gross written premium $ 3,124,761 $ 1,779,984 $ 1,135,539 $ — $ 6,040,284 Revenues: Net written premium $ 1,684,037 $ 1,233,739 $ 787,389 $ — $ 3,705,165 Change in unearned premium (89,967 ) (126,695 ) (36,233 ) — (252,895 ) Net earned premium 1,594,070 1,107,044 751,156 — 3,452,270 Expenses: Loss and loss adjustment expense 1,060,165 736,220 514,129 — 2,310,514 Acquisition costs and other underwriting expenses (As restated) 418,201 237,864 214,872 — 870,937 Total expenses 1,478,366 974,084 729,001 — 3,181,451 Underwriting income (As restated) 115,704 132,960 22,155 — 270,819 Other income (loss) Service and fee income (As restated) 85,082 226,014 1,623 74,249 386,968 Investment income and realized gain on investments 84,265 63,195 43,923 — 191,383 Other expenses (As restated) (104,204 ) (59,359 ) (37,868 ) (201,431 ) (402,862 ) Interest expense (As restated) (28,923 ) (16,476 ) (10,511 ) — (55,910 ) Foreign currency loss (As restated) — (78,108 ) — — (78,108 ) Gain on life settlement contracts 14,946 8,514 5,431 — 28,891 Acquisition gain on purchase 455 48,320 — — 48,775 (Provision) benefit for income taxes (As restated) (27,418 ) (53,265 ) (4,056 ) 18,787 (65,952 ) Equity in earnings of unconsolidated subsidiary – related party — — — 12,532 12,532 Net income (loss) (As restated) $ 139,907 $ 271,795 $ 20,697 $ (95,863 ) $ 336,536 The following tables summarize net earned premium by major line of business, by segment, for the three and nine months ended September 30, 2017 and 2016 : Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Three Months Ended September 30, 2017: Workers' compensation $ 347,770 $ — $ 84,268 $ 432,038 Warranty — 238,910 7 238,917 Other liability — 35,752 48,652 84,404 Commercial auto and liability, physical damage 78,955 — 34,448 113,403 Medical malpractice — 60,982 — 60,982 Other 102,354 147,174 13,605 263,133 Total net earned premium $ 529,079 $ 482,818 $ 180,980 $ 1,192,877 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Three Months Ended September 30, 2016: Workers' compensation $ 349,030 $ — $ 149,246 $ 498,276 Warranty — 180,333 — 180,333 Other liability 11,292 26,169 47,332 84,793 Commercial auto and liability, physical damage 47,751 9,164 32,118 89,033 Medical malpractice — 59,186 — 59,186 Other 108,925 152,467 23,223 284,615 Total net earned premium $ 516,998 $ 427,319 $ 251,919 $ 1,196,236 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Nine Months Ended September 30, 2017: Workers' compensation $ 1,057,183 $ — $ 307,907 $ 1,365,090 Warranty — 709,231 26 709,257 Other liability — 125,259 155,322 280,581 Commercial auto and liability, physical damage 275,657 — 88,922 364,579 Medical malpractice — 167,635 — 167,635 Other 381,728 493,186 34,062 908,976 Total net earned premium $ 1,714,568 $ 1,495,311 $ 586,239 $ 3,796,118 Small Commercial Business Specialty Risk and Extended Warranty Specialty Program Total Nine Months Ended September 30, 2016: Workers' compensation $ 1,053,967 $ — $ 456,663 $ 1,510,630 Warranty — 527,835 — 527,835 Other liability 16,541 100,187 130,713 247,441 Commercial auto and liability, physical damage 245,647 26,340 97,863 369,850 Medical malpractice — 106,750 — 106,750 Other 277,915 345,932 65,917 689,764 Total net earned premium $ 1,594,070 $ 1,107,044 $ 751,156 $ 3,452,270

Basis of Reporting (Narrative)

Basis of Reporting (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Service and fee income (related parties - three months $55,931; $19,367 and nine months $81,221; $61,137)	$ 180,505	$ 133,857	$ 486,447	$ 386,968
Net earned premium	(1,192,877)	(1,196,236)	(3,796,118)	(3,452,270)
Acquisition costs and other underwriting expenses	(337,086)	(303,992)	(1,038,496)	(870,937)
Other	177,350	$ 139,251	$ 540,063	$ 402,862
Overstatement of Net Earned Premium and Acquisitions Costs [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Service and fee income (related parties - three months $55,931; $19,367 and nine months $81,221; $61,137)	37,895
Net earned premium	39,170
Acquisition costs and other underwriting expenses	3,622
Other	$ 7,740

Investments - Amortized Cost, E

Investments - Amortized Cost, Estimated Market Value and Gross Unrealized Appreciation and Depreciation of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
U.S. treasury securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 319,333	$ 331,036
Gross Unrealized Gains	1,080	1,235
Gross Unrealized Losses	(1,528)	(1,617)
Fair Value	318,885	330,654
U.S. government agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	48,605	63,467
Gross Unrealized Gains	26	282
Gross Unrealized Losses	(481)	(17)
Fair Value	48,150	63,732
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	894,106	860,444
Gross Unrealized Gains	15,459	9,603
Gross Unrealized Losses	(3,772)	(15,877)
Fair Value	905,793	854,170
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	184,507	149,365
Gross Unrealized Gains	4,013	4,237
Gross Unrealized Losses	(1,404)	(726)
Fair Value	187,116	152,876
Finance | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,579,758	1,535,606
Gross Unrealized Gains	45,733	38,404
Gross Unrealized Losses	(2,413)	(7,722)
Fair Value	1,623,078	1,566,288
Industrial | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,184,009	2,222,843
Gross Unrealized Gains	60,640	62,133
Gross Unrealized Losses	(6,306)	(17,115)
Fair Value	2,238,343	2,267,861
Utilities | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	365,563	195,607
Gross Unrealized Gains	10,140	4,433
Gross Unrealized Losses	(964)	(1,210)
Fair Value	374,739	198,830
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	461,972	178,092
Gross Unrealized Gains	4,480	2,464
Gross Unrealized Losses	(5,461)	(2,562)
Fair Value	460,991	177,994
Agency backed | Residential mortgage-backed securities:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	801,586	1,210,229
Gross Unrealized Gains	13,362	13,685
Gross Unrealized Losses	(4,054)	(13,529)
Fair Value	810,894	1,210,385
Non-agency backed | Residential mortgage-backed securities:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,677	61,646
Gross Unrealized Gains	3	586
Gross Unrealized Losses	(31)	(1,003)
Fair Value	5,649	61,229
Collateralized loan / debt obligation
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	617,392	476,767
Gross Unrealized Gains	9,323	8,389
Gross Unrealized Losses	(367)	(751)
Fair Value	626,348	484,405
Asset backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,464	29,939
Gross Unrealized Gains	114	31
Gross Unrealized Losses	(28)	(260)
Fair Value	21,550	29,710
Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		4,044
Gross Unrealized Gains		0
Gross Unrealized Losses		(59)
Fair Value		3,985
Common stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	87,416	122,626
Gross Unrealized Gains	19,418	12,899
Gross Unrealized Losses	(2,294)	(2,348)
Fair Value	104,540	133,177
Fixed Maturity Securities:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,483,972	7,315,041
Gross Unrealized Gains	164,373	145,482
Gross Unrealized Losses	(26,809)	(62,389)
Fair Value	$ 7,621,536	7,398,134
Equity securities, available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		126,670
Gross Unrealized Gains		12,899
Gross Unrealized Losses		(2,407)
Fair Value		$ 137,162

Investments - Summary of Availa

Investments - Summary of Available for Sale Fixed Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Amortized Cost
Total fixed maturity securities	$ 7,484,353	$ 7,315,041
Fair Value
Total fixed maturity securities	7,621,536	7,398,134
Fixed maturity securities, available-for-sale
Amortized Cost
Due in one year or less	185,841	319,275
Due after one through five years	1,748,551	2,956,429
Due after five through ten years	3,176,390	1,645,211
Due after ten years	465,099	437,452
Mortgage and asset backed securities	1,908,091	1,956,674
Total fixed maturity securities	7,483,972	7,315,041
Fair Value
Due in one year or less	186,532	319,882
Due after one through five years	1,788,962	2,998,711
Due after five through ten years	3,246,584	1,683,112
Due after ten years	474,026	432,702
Mortgage and asset backed securities	1,925,432	1,963,727
Total fixed maturity securities	$ 7,621,536	$ 7,398,134

Investments - Summary of Gross

Investments - Summary of Gross Unrealized Losses of Fixed-maturities and Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
U.S. treasury securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 257,511	$ 293,155
Unrealized Losses	(1,452)	(1,613)
Fair Value	6,263	22,989
Unrealized Losses	(76)	(4)
Fair Value	263,774	316,144
Unrealized Losses	(1,528)	(1,617)
U.S. government agencies
Schedule of Available-for-sale Securities [Line Items]
Fair Value	43,352	7,866
Unrealized Losses	(481)	(17)
Fair Value	0	0
Unrealized Losses	0	0
Fair Value	43,352	7,866
Unrealized Losses	(481)	(17)
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Fair Value	291,908	519,578
Unrealized Losses	(2,778)	(15,207)
Fair Value	42,088	15,742
Unrealized Losses	(994)	(670)
Fair Value	333,996	535,320
Unrealized Losses	(3,772)	(15,877)
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Fair Value	75,485	128,863
Unrealized Losses	(1,315)	(688)
Fair Value	9,258	12,659
Unrealized Losses	(89)	(38)
Fair Value	84,743	141,522
Unrealized Losses	(1,404)	(726)
Finance | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	184,303	1,071,982
Unrealized Losses	(1,589)	(7,210)
Fair Value	65,061	16,840
Unrealized Losses	(824)	(512)
Fair Value	249,364	1,088,822
Unrealized Losses	(2,413)	(7,722)
Industrial | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	347,521	1,200,129
Unrealized Losses	(4,169)	(13,648)
Fair Value	86,507	114,035
Unrealized Losses	(2,137)	(3,467)
Fair Value	434,028	1,314,164
Unrealized Losses	(6,306)	(17,115)
Utilities | Corporate bonds:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	62,260	119,488
Unrealized Losses	(494)	(423)
Fair Value	23,913	10,391
Unrealized Losses	(470)	(787)
Fair Value	86,173	129,879
Unrealized Losses	(964)	(1,210)
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	252,831	71,780
Unrealized Losses	(4,784)	(1,654)
Fair Value	9,674	10,910
Unrealized Losses	(677)	(908)
Fair Value	262,505	82,690
Unrealized Losses	(5,461)	(2,562)
Agency backed
Schedule of Available-for-sale Securities [Line Items]
Fair Value		718,098
Unrealized Losses		(13,469)
Fair Value		8,144
Unrealized Losses		(60)
Fair Value		726,242
Unrealized Losses		(13,529)
Agency backed | Residential mortgage-backed securities:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	253,181
Unrealized Losses	(3,998)
Fair Value	2,264
Unrealized Losses	(56)
Fair Value	255,445
Unrealized Losses	(4,054)
Non-agency backed
Schedule of Available-for-sale Securities [Line Items]
Fair Value		24,372
Unrealized Losses		(869)
Fair Value		4,462
Unrealized Losses		(134)
Fair Value		28,834
Unrealized Losses		(1,003)
Non-agency backed | Residential mortgage-backed securities:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	3,206
Unrealized Losses	(9)
Fair Value	2,322
Unrealized Losses	(22)
Fair Value	5,528
Unrealized Losses	(31)
Collateralized loan / debt obligations
Schedule of Available-for-sale Securities [Line Items]
Fair Value	69,034	97,923
Unrealized Losses	(367)	(433)
Fair Value	0	32,937
Unrealized Losses	0	(318)
Fair Value	69,034	130,860
Unrealized Losses	(367)	(751)
Asset backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	5,797	9,220
Unrealized Losses	(6)	(124)
Fair Value	1,008	4,926
Unrealized Losses	(22)	(136)
Fair Value	6,805	14,146
Unrealized Losses	(28)	(260)
Fixed Maturity Securities:
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,846,389	4,262,454
Unrealized Losses	(21,442)	(55,355)
Fair Value	248,358	254,035
Unrealized Losses	(5,367)	(7,034)
Fair Value	2,094,747	4,516,489
Unrealized Losses	(26,809)	(62,389)
Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Fair Value		529
Unrealized Losses		(30)
Fair Value		0
Unrealized Losses		(29)
Fair Value		529
Unrealized Losses		(59)
Common stock
Schedule of Available-for-sale Securities [Line Items]
Fair Value	16,245	46,254
Unrealized Losses	(2,294)	(1,394)
Fair Value	0	9,991
Unrealized Losses	0	(954)
Fair Value	16,245	56,245
Unrealized Losses	$ (2,294)	(2,348)
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value		46,783
Unrealized Losses		(1,424)
Fair Value		9,991
Unrealized Losses		(983)
Fair Value		56,774
Unrealized Losses		$ (2,407)

Investments (Trading Securities

Investments (Trading Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, cost basis	$ 88,746		$ 88,746		$ 76,163
Fair Value	81,112		81,112		81,960
Proceeds from sale of trading securities	70,518	$ 47,177	379,933	$ 155,502
Net (losses) and gains recognized during the period on trading securities	(2,241)	995	(17,481)	3,428
Less: Net (losses) and gains recognized during the period on trading securities sold during the period	1,584	(812)	933	(8,199)
Unrealized (losses) and gains recognized during the reporting period on trading securities still held at the reporting date	(657)	$ 183	(16,548)	$ (4,771)
Common stock
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, cost basis	88,746		88,746		76,163
Gross Unrealized Gains	3,960		3,960		9,842
Gross Unrealized Losses	(11,594)		(11,594)		(4,045)
Fair Value	81,112		81,112		81,960
Fixed Maturity Securities:
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, cost basis	34,300		34,300		29,081
Gross Unrealized Gains	713		713		4,701
Gross Unrealized Losses	(2,839)		(2,839)		0
Fair Value	32,174		32,174		33,782
Industrial | Corporate bonds:
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, cost basis	23,955		23,955		24,151
Gross Unrealized Gains	643		643		4,379
Gross Unrealized Losses	(2,699)		(2,699)		0
Fair Value	21,899		21,899		28,530
Utilities | Corporate bonds:
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, cost basis	295		295		4,930
Gross Unrealized Gains	70		70		322
Gross Unrealized Losses	0		0		0
Fair Value	$ 365		$ 365		$ 5,252

Investments - Net Investment In

Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 66,310	$ 60,547	$ 183,862	$ 160,931
Investment expenses	(5,207)	(628)	(10,208)	(852)
Net investment income	61,103	59,919	173,654	160,079
Fixed maturity securities, available-for-sale
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	60,478	59,712	187,128	152,140
Equity securities, available-for-sale
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	469	465	2,038	6,927
Cash and short term investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	5,695	410	8,977	2,182
Other investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	(664)	0	(15,665)	0
Fixed Maturity Securities: | Equity securities, trading
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	473	0	1,505	0
Equity securities, trading | Equity securities, trading
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ (141)	$ (40)	$ (121)	$ (318)

Investments (Realized Gains and

Investments (Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	$ 36,115	$ 24,434	$ 100,559	$ 78,180
Write-down of equity securities, available-for-sale		(3,021)		(6,440)
Total of gross loss including write-downs	(11,595)	(16,204)	(43,969)	(46,876)
Net gain and losses, including write-down	24,520	8,230	56,590	31,304
Available-for-sale | Fixed maturity securities, available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	15,577	17,535	38,024	57,346
Gross Losses	(1,132)	(2,582)	(3,188)	(4,199)
Net Gains (Losses)	14,445	14,953	34,836	53,147
Write-down of equity securities, available-for-sale		(6,440)		(19,977)
Available-for-sale | Equity securities, available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	9,122	553	21,633	1,821
Gross Losses	(295)	(1,126)	(1,894)	(1,862)
Net Gains (Losses)	8,827	(573)	19,739	(41)
Trading Securities | Fixed maturity securities, available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	1,723		6,695
Gross Losses	0		(9,548)
Net Gains (Losses)	1,723		(2,853)
Trading Securities | Equity securities, available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	6,204	2,897	14,691	17,824
Gross Losses	(10,168)	(1,902)	(29,319)	(14,396)
Net Gains (Losses)	(3,964)	995	(14,628)	3,428
Other investments
Schedule of Available-for-sale Securities [Line Items]
Gross Gains	3,489	3,449	19,516	1,189
Gross Losses	0	(1,133)	(20)	(2)
Net Gains (Losses)	$ 3,489	$ 2,316	$ 19,496	$ 1,187

Investments - Fair Values of Re

Investments - Fair Values of Restricted Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Restricted cash and cash equivalents	$ 879,478	$ 713,338
Restricted investments - fixed maturity securities at fair value	2,861,413	2,126,216
Total restricted cash, cash equivalents, and investments	$ 3,740,891	$ 2,839,554

Investments - Additional Inform

Investments - Additional Information (Details) $ / shares in Units, $ in Thousands	Jun. 09, 2017USD ($)$ / sharesshares	Jun. 30, 2017shares	Sep. 30, 2017USD ($)Investment	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Investment	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Investmentagreement
Investment [Line Items]
Number of securities | Investment			1,499		1,499		2,125
Net realized investment gain			$ 24,520	$ 8,230	$ 56,590	$ 31,304
Proceeds from the sale of investments in available-for-sale securities			757,709	$ 647,928	1,897,690	$ 1,648,193
Securities sold but not yet purchased, at fair value			56,181		56,181		$ 36,394
Number of repurchase agreements | agreement							13
Equity and debt securities, at fair value							$ 160,270
Held-to-maturity securities pledged as collateral							175,700
Equity securities, available-for-sale
Investment [Line Items]
Securities sold but not yet purchased, at fair value			$ 56,181		$ 56,181		$ 36,394
Minimum
Investment [Line Items]
Stated interest rate (percentage)							0.75%
Maximum
Investment [Line Items]
Stated interest rate (percentage)							0.90%
NGHC
Investment [Line Items]
Sale of stock (in shares) | shares	10,586,000	10,586,000
Sale of Stock, price per share (usd per share) | $ / shares	$ 20
Sale of Stock, price per share, discount (in percent)	8.30%
Net realized investment gain	$ 68,425

Fair Value of Financial Instr42

Fair Value of Financial Instruments - Assets and Financial Liabilities on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	$ 8,138,063	$ 8,007,894
Fair Value of liabilities	146,628	273,504
Equity securities sold but not yet purchased, market
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		36,394
Equity securities sold but not yet purchased, market | Fixed maturities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		160,270
Equity securities sold but not yet purchased, market | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	56,181
Life settlement contract profit commission
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	5,927	4,940
Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	84,520	71,657
Derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		243
U.S. treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	328,795	330,654
U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	48,150	63,732
Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	905,793	854,170
Foreign government
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	187,116	152,876
Finance | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	1,623,078	1,566,288
Industrial | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	2,260,242	2,296,391
Utilities | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	375,104	204,082
Commercial mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	460,991	177,994
Agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	810,894	1,210,385
Non-agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	5,649	61,229
Collateralized loan / debt obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	626,348	484,405
Asset backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	21,550	29,710
Life settlement contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	298,701	356,856
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	512,336	475,709
Fair Value of liabilities	42,512	36,394
Level 1 | Equity securities sold but not yet purchased, market
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		36,394
Level 1 | Equity securities sold but not yet purchased, market | Fixed maturities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 1 | Equity securities sold but not yet purchased, market | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	42,512
Level 1 | Life settlement contract profit commission
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	0	0
Level 1 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	0	0
Level 1 | Derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 1 | U.S. treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	328,795	330,654
Level 1 | U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Foreign government
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Finance | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Industrial | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Utilities | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Commercial mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Non-agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Collateralized loan / debt obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Asset backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 1 | Life settlement contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	7,291,218	7,104,005
Fair Value of liabilities	13,669	160,513
Level 2 | Equity securities sold but not yet purchased, market
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 2 | Equity securities sold but not yet purchased, market | Fixed maturities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		160,270
Level 2 | Equity securities sold but not yet purchased, market | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	13,669
Level 2 | Life settlement contract profit commission
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	0	0
Level 2 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	0	0
Level 2 | Derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		243
Level 2 | U.S. treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 2 | U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	48,150	63,732
Level 2 | Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	905,164	854,170
Level 2 | Foreign government
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	187,116	149,298
Level 2 | Finance | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	1,615,636	1,559,800
Level 2 | Industrial | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	2,258,428	2,291,351
Level 2 | Utilities | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	375,104	199,503
Level 2 | Commercial mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	437,559	177,994
Level 2 | Agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	810,894	1,186,315
Level 2 | Non-agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	5,649	58,109
Level 2 | Collateralized loan / debt obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	626,348	484,405
Level 2 | Asset backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	20,759	29,710
Level 2 | Life settlement contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	334,509	428,180
Fair Value of liabilities	90,447	76,597
Level 3 | Equity securities sold but not yet purchased, market
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 3 | Equity securities sold but not yet purchased, market | Fixed maturities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 3 | Equity securities sold but not yet purchased, market | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	0
Level 3 | Life settlement contract profit commission
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	5,927	4,940
Level 3 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities	84,520	71,657
Level 3 | Derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of liabilities		0
Level 3 | U.S. treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 3 | U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 3 | Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	629	0
Level 3 | Foreign government
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	3,578
Level 3 | Finance | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	7,442	6,488
Level 3 | Industrial | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	1,814	5,040
Level 3 | Utilities | Corporate bonds:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	4,579
Level 3 | Commercial mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	23,432	0
Level 3 | Agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	24,070
Level 3 | Non-agency backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	3,120
Level 3 | Collateralized loan / debt obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	0
Level 3 | Asset backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	791	0
Level 3 | Life settlement contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	298,701	356,856
Available-for-sale | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	104,540	137,162
Available-for-sale | Level 1 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	104,540	66,228
Available-for-sale | Level 2 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	49,618
Available-for-sale | Level 3 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	0	21,316
Trading | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	81,112	81,960
Trading | Level 1 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	79,001	78,827
Trading | Level 2 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	411	0
Trading | Level 3 | Equity securities, available-for-sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets	$ 1,700	$ 3,133

Fair Value of Financial Instr43

Fair Value of Financial Instruments - Changes in Fair Value of Level 3 Financial Assets And Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	$ 358,676	$ 244,372	$ 351,895	$ 201,046
Net income	39,318	3,318	82,948	47,427
Other comprehensive income	(294)	16,959	(445)	4,510
Purchases and issuances	139	(895)	1,498	1,977
Sales and settlements	(145,031)	8,451	(186,840)	17,245
Net transfers into (out of) Level 3	(8,746)	45,798	(4,994)	45,798
Ending Balance	244,062	318,003	244,062	318,003
Trading Securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	2,051		3,133
Net income	22		(400)
Other comprehensive income	0		0
Purchases and issuances	0		4,484
Sales and settlements	0		(2,134)
Net transfers into (out of) Level 3	(373)		(3,383)
Ending Balance	1,700		1,700
Equity securities, available-for-sale
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	21,348	24,764	21,316	37,211
Net income	566	(16,983)	566	(16,983)
Other comprehensive income	(502)	17,168	(164)	4,719
Purchases and issuances	38	(2)	114	0
Sales and settlements	(21,450)	(7,753)	(38,198)	(7,753)
Net transfers into (out of) Level 3	0	15,985	16,366	15,985
Ending Balance	0	33,179	0	33,179
Life settlement contracts
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	396,782	304,434	356,856	264,001
Net income	33,617	23,290	82,233	82,451
Other comprehensive income	0	0	0	0
Purchases and issuances	0	4,550	16,473	15,880
Sales and settlements	(131,698)	(189)	(156,861)	(30,247)
Net transfers into (out of) Level 3	0		0
Ending Balance	298,701	332,085	298,701	332,085
Life settlement contract profit commission
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	(5,714)	(9,054)	(4,940)	(15,406)
Net income	(213)	(763)	(987)	(9,817)
Other comprehensive income	0	0	0	0
Purchases and issuances	0	0	0	0
Sales and settlements	0	5,000	0	20,406
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	(5,927)	(4,817)	(5,927)	(4,817)
Contingent consideration
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	(97,615)	(75,772)	(71,657)	(84,760)
Net income	3,348	(2,226)	(442)	(8,224)
Other comprehensive income	0	0	0	0
Purchases and issuances	(1,853)	(5,443)	(29,032)	(13,903)
Sales and settlements	11,600	11,393	16,611	34,839
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	(84,520)	(72,048)	(84,520)	(72,048)
Available-for-sale | Fixed maturity securities, available-for-sale
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	41,512		46,875
Net income	(14)		(14)
Other comprehensive income	208		(281)
Purchases and issuances	1,954		9,459
Sales and settlements	(1,179)		(3,954)
Net transfers into (out of) Level 3	(8,373)		(17,977)
Ending Balance	34,108		34,108
Trading Securities | Fixed maturity securities, available-for-sale
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	312		312
Net income	1,992		1,992
Other comprehensive income	0		0
Purchases and issuances	0		0
Sales and settlements	(2,304)		(2,304)
Net transfers into (out of) Level 3	0		0
Ending Balance	$ 0		$ 0
Commercial mortgage-backed securities | Fixed Maturity Securities:
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance		0		0
Net income		0		0
Other comprehensive income		(194)		(194)
Purchases and issuances		0		0
Sales and settlements		0		0
Net transfers into (out of) Level 3		8,065		8,065
Ending Balance		7,871		7,871
Collateralized loan / debt obligations | Fixed Maturity Securities:
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance		0		0
Net income		0		0
Other comprehensive income		(15)		(15)
Purchases and issuances		0		0
Sales and settlements		0		0
Net transfers into (out of) Level 3		21,748		21,748
Ending Balance		$ 21,733		$ 21,733

Fair Value of Financial Instr44

Fair Value of Financial Instruments - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net income	$ 39,318	$ 3,318	$ 82,948	$ 47,427
Gain on investment in life settlement contracts	(924)	5,485	6,425	28,891
Life settlement contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net income	33,617	23,290	82,233	82,451
Premiums paid	(9,960)	(16,434)	(48,694)	(41,890)
Other Expenses	(24,368)	(608)	(26,127)	(1,853)
Gain on investment in life settlement contracts	(924)	5,485	6,425	28,891
Life settlement contract profit commission
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net income	$ (213)	$ (763)	$ (987)	$ (9,817)

Fair Value of Financial Instr45

Fair Value of Financial Instruments -Fair Value of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
6.125% Notes due 2023 (the 2023 Notes)	$ 248,390	$ 248,185
Revolving credit facility	130,000	130,000
Other	194,782
Fair Value
Revolving credit facility	130,000
Other	194,782
7.25% Subordinated Notes due 2055
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Subordinated Debt	145,296	145,202
7.50% Subordinated Notes due 2055
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Subordinated Debt	130,767	130,684
2.75% Convertible senior notes due 2044 (the 2044 Notes)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior notes	171,286	166,387
Junior subordinated debentures (the 2035-2037 Notes)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Junior subordinated debentures	122,094	122,028
Trust preferred securities (the 2033-2037 TPS Notes)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Junior subordinated debentures	92,786	$ 92,786
Fair Value
Fair Value
6.125% Notes due 2023	249,255
Republic promissory note	53,163
Debt Instrument, Fair Value Disclosure	1,292,143
Fair Value | 7.25% Subordinated Notes due 2055
Fair Value
Subordinated Notes due 2055	154,200
Fair Value | 7.50% Subordinated Notes due 2055
Fair Value
Subordinated Notes due 2055	140,184
Fair Value | 2.75% Convertible senior notes due 2044 (the 2044 Notes)
Fair Value
Convertible senior notes due 2044	174,583
Fair Value | Junior subordinated debentures (the 2035-2037 Notes)
Fair Value
Junior subordinated debentures	110,070
Fair Value | Trust preferred securities (the 2033-2037 TPS Notes)
Fair Value
Junior subordinated debentures	85,906
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Republic promissory note	52,343
Fair Value
Debt Instrument, Fair Value Disclosure	$ 1,287,744

Fair Value of Financial Instr46

Fair Value of Financial Instruments - Fair Value of Portfolio of Life Insurance Policies (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Life Settlement Contracts, Fair Value Method [Abstract]
Average age of insured (in years)	84 years 3 months 1 day	82 years 9 months 1 day
Average life expectancy, months (in months)	87 months	107 months
Average face amount per policy	$ 7,088	$ 6,572
Implicit discount rate (in percentage)	12.40%	12.40%

Fair Value of Financial Instr47

Fair Value of Financial Instruments - Increase or (Decrease) in Carrying Value of Investment in Life Insurance Policies (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Life Settlement Contracts, Fair Value Method [Abstract]
Life expectancy Plus 4 Months	$ 30,268	$ 44,207
Life expectancy Minus 4 Months	28,432	43,492
Discount Plus 1%	20,130	29,881
Discount Minus 1%	$ 22,121	$ 33,155

Fair Value of Financial Instr48

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	Jun. 09, 2017	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2016	Feb. 24, 2017	Jan. 12, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer from Level 1 to Level 2			$ 35,818
Debt instrument, stated interest rate (in percentage)					4.67%	3.45%
Implicit discount rate (in percentage)			12.40%	12.40%
7.25% Subordinated Notes due 2055 | Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated interest rate (in percentage)			7.25%
7.50% Subordinated Notes due 2055
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated interest rate (in percentage)			7.50%
2.75% Convertible senior notes due 2044 (the 2044 Notes) | Convertible Notes Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated interest rate (in percentage)			2.75%
6.125% Notes due 2023 | Promissory Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated interest rate (in percentage)			6.125%
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Implicit discount rate (in percentage)			10.00%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Implicit discount rate (in percentage)			15.00%
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investment in NGHC			$ 32,667
Discounted Cash Flow Technique | Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment discount rate (in percentage)			8.00%
Discounted Cash Flow Technique | Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment discount rate (in percentage)			30.00%
NGHC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Sale of stock (in shares)	10,586,000	10,586,000
Fair value of investment in NGHC			$ 1,709

Investment in Life Settlement49

Investment in Life Settlements - Additional Information (Detail)	Aug. 16, 2017USD ($)Contract	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Contractpolicy	Sep. 30, 2017Entity	Sep. 30, 2017Contract	Sep. 30, 2017policy	Mar. 31, 2017
Schedule of Cost-method Investments [Line Items]
Capital contributions			$ 29,366,000	$ 27,000,000	$ 40,366,000
Percentage of ownership (in percentage)		50.00%		50.00%
Number of contracts | Contract						254		142
Contracts sold	$ 100,000
Proceeds from life settlement contract	90,000
Contract payment expected in the next two years	$ 5,000
(Loss) gain on investment in life settlement contracts net of profit commission		$ (924,000)	$ 5,485,000	$ 6,425,000	$ 28,891,000
Number of policies with a negative value from discounted cash flow model as of period end (in whole numbers)						18		4	4
Premiums paid for the preceding twelve month period for period ended				394,000		$ 2,640,000
Death benefit received				$ 0		$ 0
Tiger Capital LLC
Schedule of Cost-method Investments [Line Items]
Number of contracts | Contract	114
NGHC
Schedule of Cost-method Investments [Line Items]
Percentage of ownership (in percentage)		1.60%		1.60%						11.50%
LSC Entities
Schedule of Cost-method Investments [Line Items]
Percentage of ownership interest (in percentage)		50.00%		50.00%
Number of entities with ownership interest | Entity							2
Dividends		$ 90,000
NGHC | LSC Entities
Schedule of Cost-method Investments [Line Items]
Percentage of ownership interest (in percentage)		50.00%		50.00%
Life settlement contracts
Schedule of Cost-method Investments [Line Items]
Capital contributions		$ 11,000,000

Investment in Life Settlement50

Investment in Life Settlements - Expected Maturity Term in Years (Detail) $ in Thousands	Sep. 30, 2017USD ($)Contract	Dec. 31, 2016USD ($)Contract
Number of Life Settlement Contracts
0-1 | Contract	0	0
1-2 | Contract	6	2
2-3 | Contract	3	7
3-4 | Contract	13	10
4-5 | Contract	13	10
Thereafter | Contract	107	225
Total | Contract	142	254
Fair Value
0-1	$ 0	$ 0
1-2	41,011	8,873
2-3	22,994	39,495
3-4	45,357	37,436
4-5	25,426	34,003
Thereafter	163,913	237,049
Total	298,701	356,856
Face Value
0-1	0	0
1-2	58,000	12,500
2-3	32,422	63,000
3-4	101,000	75,422
4-5	60,400	82,900
Thereafter	744,880	1,405,414
Total	$ 996,702	$ 1,639,236

Investment in Life Settlement51

Investment in Life Settlements - Premiums to be Paid (Detail) - Premiums Due On Life Settlement Contracts $ in Thousands	Sep. 30, 2017USD ($)
Life Insurance Premiums and Related Investment Income [Line Items]
2,017	$ 35,423
2,018	36,568
2,019	35,922
2,020	34,781
2,021	32,544
Thereafter	215,213
Total	$ 390,451

Loss and loss adjustment expe52

Loss and loss adjustment expense reserves (Reconciliation of the beginning and ending balances for unpaid losses and LAE) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Loss and LAE, gross of related reinsurance recoverables at beginning of year	$ 11,149,511	$ 9,097,408	$ 10,140,716	$ 7,208,367
Less: Reinsurance recoverables at beginning of year	5,667,553	3,677,448	5,667,553	3,677,448	$ 4,942,144	$ 3,873,786	$ 3,568,863	$ 2,665,187
Net balance, beginning of year					6,207,367	6,266,930	5,528,545	4,543,180
Incurred related to:
Current year	939,187	720,440	2,712,079	2,117,774
Prior year	326,931	90,608	418,851	192,740
Total incurred during the year	1,266,118	811,048	3,130,930	2,310,514
Paid related to:
Current year	(333,098)	(262,738)	(699,340)	(531,517)
Prior year	(445,247)	(387,735)	(1,593,524)	(1,335,069)
Total paid during the year	(778,345)	(650,473)	(2,292,864)	(1,866,586)
Loss portfolio transfers			0	312,049
Acquired outstanding loss and loss adjustment reserves			200,802	463,115
Retroactive reinsurance adjustment	(326,931)	0	(1,025,000)	0
Effect of foreign exchange rates	(50,882)	(61,202)	(138,293)	11,950
Net balance, end of year	6,419,091	5,750,322	6,419,091	5,750,322
Plus reinsurance recoverables at end of year	5,667,553	3,677,448	5,667,553	3,677,448	$ 4,942,144	$ 3,873,786	$ 3,568,863	$ 2,665,187
Loss and LAE, gross of related reinsurance recoverables at end of period	12,086,644	9,427,770	12,086,644	9,427,770
Loss and LAE, gross of related reinsurance recoverables at end of period	$ 937,133	$ 330,362	$ 1,945,928	$ 2,219,403

Debt - Borrowings (Detail)

Debt - Borrowings (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
6.125% Notes due 2023 (the 2023 Notes)	$ 248,390	$ 248,185
Secured loan agreements	175,345	75,762
Revolving credit facility	130,000	130,000
Promissory notes	66,453	118,643
Total debt	1,287,744	1,234,900
2.75% Convertible senior notes due 2044 (the 2044 Notes)
Debt Instrument [Line Items]
Convertible senior notes	171,286	166,387
7.25% Subordinated Notes due 2055
Debt Instrument [Line Items]
Subordinate Notes due 2055	145,296	145,202
7.50% Subordinated Notes due 2055
Debt Instrument [Line Items]
Subordinate Notes due 2055	130,767	130,684
Junior subordinated debentures (the 2035-2037 Notes)
Debt Instrument [Line Items]
Junior subordinated debentures (the 2035-2037 Notes)	122,094	122,028
Trust preferred securities (the 2033-2037 TPS Notes)
Debt Instrument [Line Items]
Junior subordinated debentures (the 2035-2037 Notes)	92,786	92,786
5.5% Convertible senior notes due 2021 (the 2021 Notes)
Debt Instrument [Line Items]
Convertible senior notes	$ 5,327	$ 5,223

Debt - Credit Facilities (Detai

Debt - Credit Facilities (Details) - Line of Credit	Sep. 30, 2017USD ($)
Revolving credit facility
Line of Credit Facility [Line Items]
Limit	$ 175,000,000
Outstanding	174,662,000
Available	338,000
Lloyds | Letter of Credit
Line of Credit Facility [Line Items]
Limit	689,997,000
Outstanding	657,306,000
Available	32,691,000
ING Bank N.V., BHF-BANK Aktiengesellschaft, and Deutsche Bank Netherlands N.V. facilities | Letter of Credit
Line of Credit Facility [Line Items]
Limit	90,615,000
Outstanding	73,180,000
Available	17,435,000
Comerica Bank letters of credit | Letter of Credit
Line of Credit Facility [Line Items]
Limit	75,000,000
Outstanding	43,067,000
Available	31,933,000
UniCredit Bank | Letter of Credit
Line of Credit Facility [Line Items]
Limit	100,000,000
Outstanding	100,000,000
Available	0
Other letters of credit, in aggregate | Letter of Credit
Line of Credit Facility [Line Items]
Limit	139,052,000
Outstanding	139,052,000
Available	$ 0

Debt - Interest Expense (Detail

Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Interest expense (net of interest income)	$ 22,873	$ 22,124	$ 70,703	$ 55,910
Convertible Notes Payable
Debt Instrument [Line Items]
Interest expense (net of interest income)	3,282	3,170	9,731	9,402
Convertible Notes Payable | 2021 Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	118	116	352	345
Senior Notes | 2023 Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	3,897	3,897	11,690	11,690
Convertible Debt
Debt Instrument [Line Items]
Interest expense (net of interest income)			4,333	4,609
Convertible Debt | 2035-2037 Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	1,445	1,548
Junior Subordinated Debt | 2033-2037 TPS Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	1,118	981	3,227	1,750
Subordinated Debt | 7.25% 2055 Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	2,750	2,750	8,250	8,250
Subordinated Debt | 7.50% 2055 Notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	2,559	2,559	7,677	7,677
Secured loan agreements
Debt Instrument [Line Items]
Interest expense (net of interest income)	1,701	756	4,528	1,768
Promissory notes
Debt Instrument [Line Items]
Interest expense (net of interest income)	938	1,698	3,646	3,253
Other
Debt Instrument [Line Items]
Interest expense (net of interest income)	2,152	2,450	8,602	391
Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Interest expense (net of interest income)	1,571	1,134	4,610	3,388
Funds at Lloyd's facility | Line of Credit
Debt Instrument [Line Items]
Interest expense (net of interest income)	$ 1,342	$ 1,065	$ 4,057	$ 3,387

Debt - Secured Loan Agreement (

Debt - Secured Loan Agreement (Details)	Feb. 24, 2017USD ($)	Jan. 12, 2017subsidiary	Sep. 30, 2017USD ($)	Sep. 30, 2017EUR (€)
Debt Instrument [Line Items]
Number of Subsidiaries | subsidiary		3
Term of the debt instrument (in years)	10 years	10 years
Debt instrument, face amount	$ 11,350,000		$ 98,475,000	€ 73,500,000
Debt instrument, stated interest rate (in percentage)	4.67%	3.45%
Monthly interest expense | $			$ 64,000

Debt - Promissory Note (Details

Debt - Promissory Note (Details) $ in Thousands	Jun. 29, 2017USD ($)	Mar. 30, 2017USD ($)	Apr. 18, 2016USD ($)installment	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Promissory notes				$ 66,453	$ 118,643
Republic Companies
Debt Instrument [Line Items]
Promissory notes			$ 104,685
Number of installments | installment			4
Repayments of debt	$ 25,910	$ 26,171
Repayment of debt, percentage of principal	99.00%

Earnings Per Share - Summary of

Earnings Per Share - Summary of Elements Used in Calculating Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic earnings per share:
Net (loss) income attributable to AmTrust common stockholders	$ (174,675)	$ 80,650	$ (146,214)	$ 291,784
Weighted average common shares outstanding - basic (in shares)	195,891	170,928	182,570	173,173
Net income per AmTrust common share - basic (usd per share)	$ (0.89)	$ 0.47	$ (0.80)	$ 1.68
Diluted earnings per share:
Weighted average common shares outstanding - basic (in shares)	195,891	170,928	182,570	173,173
Plus: Dilutive effect of stock options, convertible debt, other (in shares)	0	2,193	0	1,978
Weighted average common shares outstanding - dilutive (in shares)	195,891	173,121	182,570	175,151
Net income per AmTrust common shares – diluted (usd per share)	$ (0.89)	$ 0.47	$ (0.80)	$ 1.67

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, limitation on use per year	$ 9,084,000
Operating loss carryforwards, valuation allowance	164,814,000	$ 142,462,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 23,476,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		$ 945,114,000

Related Party Transactions (NGH

Related Party Transactions (NGHC) (Details)		Sep. 13, 2017USD ($)installmentemployee	Jun. 09, 2017USD ($)$ / sharesshares	May 25, 2017USD ($)$ / sharesshares	Feb. 22, 2012	Jun. 30, 2017shares	Sep. 30, 2017USD ($)companyshareholder	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)companyshareholder	Sep. 30, 2016USD ($)	Mar. 31, 2017
Related Party Transaction [Line Items]
Number of insurance companies | company							22		22
Number of shareholder | shareholder							2		2
Net realized investment gain							$ 24,520,000	$ 8,230,000	$ 56,590,000	$ 31,304,000
Percentage of ownership in NGHC (in percentage)							50.00%		50.00%
Equity in earnings of unconsolidated subsidiaries – related parties	[1]								$ 73,488,000	12,532,000
NGHC
Related Party Transaction [Line Items]
Sale of stock (in shares) | shares			10,586,000			10,586,000
Sale of Stock, price per share (usd per share) | $ / shares			$ 20
Sale of Stock, price per share, discount (in percent)			8.30%
Net realized investment gain			$ 68,425,000
Percentage of ownership in NGHC (in percentage)							1.60%		1.60%		11.50%
Fair value of investment in NGHC							$ 1,709,000		$ 1,709,000
Equity in earnings of unconsolidated subsidiaries – related parties								$ 1,954,000	5,063,000	$ 12,532,000
Gross premium written (percentage)					1.25%
Cost plus (percentage)					20.00%
Private Placement | Director
Related Party Transaction [Line Items]
New shares issued | shares				24,096,384
Shares Issued, price per share (usd per share) | $ / shares				$ 12.45
Proceeds from sale of equity				$ 300,000,000
NGHC | Personal Lines Policy Management System | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | AmTrust North America
Related Party Transaction [Line Items]
Consideration for sale of assets		$ 200,000,000
Number of installments | installment		3
Licenses Revenue		$ 9,267,000
Implementation costs receivable		$ 5,000,000
Number of employees transfered to new company | employee		100
Gain on disposal									186,755,000
Financing receivable							$ 129,715		$ 129,715
[1]	2017 amounts relate to the sale of shares of National General Holding Corp. See Note 10 for more information.

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	May 01, 2017	Feb. 28, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Gross written premium			$ 1,990,775	$ 2,034,098	$ 6,456,802	$ 6,040,284
Service and fee income			180,505	$ 133,857	486,447	$ 386,968
AmeriHealth Casualty Insurance Company
Business Acquisition [Line Items]
Percentage of voting Interests acquired (in percentage)		100.00%
Acquisition price		$ 92,786
Reserve guarantee amount		$ 40,000	37,900		37,900
Reserve guarantee amount, subject to percentage loss corridor retained (percentage)		10.00%
Reserve guarantee (in years)		5 years
Gross written premium					84,933
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Acquisition price					36,936
Contingent consideration, liability			8,129		8,129
PDP Group, Inc
Business Acquisition [Line Items]
Percentage of voting Interests acquired (in percentage)	100.00%
Acquisition price	$ 62,422
Payments to acquire businesses	49,801
Service and fee income			$ 11,468		$ 19,120
Contingent consideration, liability	$ 12,621

Acquisitions - Purchase Price A

Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Thousands	May 01, 2017	Feb. 28, 2017
PDP Group, Inc
Business Acquisition [Line Items]
Cash and investments	$ 11,826
Premium receivables	29,188
Other assets	705
Property and equipment, net	776
Goodwill and intangible assets	55,586
Total assets	98,081
Accrued expenses and other liabilities	35,659
Acquisition price	$ 62,422
AmeriHealth Casualty Insurance Company
Business Acquisition [Line Items]
Cash and investments		$ 275,351
Premium receivables		45,288
Accrued interest and dividends		1,162
Reinsurance recoverable		14,512
Other assets		43,696
Goodwill and intangible assets		17,509
Total assets		397,518
Loss and loss expense reserves		227,865
Unearned premiums		49,284
Accrued expenses and other liabilities		27,583
Total liabilities		304,732
Acquisition price		$ 92,786

Shareholder's Equity and Accumu

Shareholder's Equity and Accumulated Other Comprehensive Income (Loss) - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Net (loss) income			$ (80,374)	$ 335,949
Net income (loss) attributable to non-controlling interest and redeemable non-controlling interest of subsidiaries	$ 718	$ (2,975)	(17,010)	(12,809)
Non-Controlling Interest
Class of Stock [Line Items]
Net (loss) income			$ 16,127	$ 12,222

Shareholder's Equity and Accu64

Shareholder's Equity and Accumulated Other Comprehensive Income (Loss) - Ownership Components of Total Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 3,465,613	$ 2,900,235	$ 2,900,235
Net (loss) income			(80,374)	335,949
Unrealized holding gain	$ 19,790	$ 16,623	94,889	214,519
Reclassification adjustment	(23,272)	(3,399)	(54,130)	(17,993)
Foreign currency translation			127,235	(110,148)
Unrealized gain on interest rate swap	25	253	145	540
Extinguishment of 2021 senior notes, equity component			0		1
Share exercises, compensation and other			19,066	10,568
Common share purchase, net			0	(152,047)
Common stock dividends			(95,681)	(81,167)
Preferred stock issuance, net of fees			298,747
Preferred stock dividends	(16,571)	(11,576)	(49,713)	(31,943)
Capital distributions, net			(31,336)	(5,413)
Ending Balance	3,694,461	3,480,363	3,694,461	3,480,363	3,465,613
Non-Controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			196,510	176,455	176,455
Net (loss) income			16,127	12,222
Capital distributions, net			(31,336)	(5,413)
Ending Balance	181,301	183,264	181,301	183,264	196,510
AmTrust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			3,269,103	2,723,780	2,723,780
Net (loss) income			(96,501)	323,727
Unrealized holding gain			94,889	214,519
Reclassification adjustment			(54,130)	(17,993)
Foreign currency translation			127,235	(110,148)
Unrealized gain on interest rate swap			145	540
Extinguishment of 2021 senior notes, equity component			0		(1)
Share exercises, compensation and other				0
Common share purchase, net				(152,047)
Common stock dividends				(31,943)
Preferred stock issuance, net of fees			19,066	10,568
Ending Balance	$ 3,513,160	$ 3,297,099	3,513,160	3,297,099	$ 3,269,103
Preferred stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock issuance, net of fees			$ 0	417,264
Preferred stock | AmTrust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock issuance, net of fees				417,264
Common stock | Non-Controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends				0
Common stock | AmTrust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends				$ (81,167)

Shareholder's Equity and Accu65

Shareholder's Equity and Accumulated Other Comprehensive Income (Loss) - AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			$ 3,465,613	$ 2,900,235
Other comprehensive income (loss) before reclassifications	$ 67,948	$ (6,014)	242,682	219,092
Amounts reclassed from accumulated other comprehensive loss	(23,272)	(3,399)	(54,130)	(17,993)
Income tax expense	2,576	(7,255)	(20,413)	(114,181)
Other comprehensive income (loss), net of tax	47,252	(16,668)	168,139	86,918
Ending Balance	3,694,461	3,480,363	3,694,461	3,480,363
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(4,835)	(29,806)	(125,722)	(133,392)
Ending Balance	42,417	(46,474)	42,417	(46,474)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(111,677)	(178,077)	(188,203)	(98,074)
Other comprehensive income (loss) before reclassifications	50,709	(30,145)	127,235	(110,148)
Amounts reclassed from accumulated other comprehensive loss	0	0	0	0
Income tax expense	0	0	0	0
Other comprehensive income (loss), net of tax	50,709	(30,145)	127,235	(110,148)
Ending Balance	(60,968)	(208,222)	(60,968)	(208,222)
Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	110,071	148,791	65,830	(34,511)
Other comprehensive income (loss) before reclassifications	17,175	23,741	115,235	328,409
Amounts reclassed from accumulated other comprehensive loss	(23,272)	(3,399)	(54,130)	(17,993)
Income tax expense	2,615	(7,118)	(20,346)	(113,890)
Other comprehensive income (loss), net of tax	(3,482)	13,224	40,759	196,526
Ending Balance	106,589	162,015	106,589	162,015
Interest Rate Swap Hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(52)	(413)	(172)	(700)
Other comprehensive income (loss) before reclassifications	64	390	212	831
Amounts reclassed from accumulated other comprehensive loss	0	0	0	0
Income tax expense	(39)	(137)	(67)	(291)
Other comprehensive income (loss), net of tax	25	253	145	540
Ending Balance	(27)	(160)	(27)	(160)
Net Benefit Plan Assets and Obligations Recognized in Stockholders' Equity
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(3,177)	(107)	(3,177)	(107)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassed from accumulated other comprehensive loss	0	0	0	0
Income tax expense	0	0	0	0
Other comprehensive income (loss), net of tax	0	0	0	0
Ending Balance	$ (3,177)	$ (107)	$ (3,177)	$ (107)

Segments - Results of Operation

Segments - Results of Operations of Business Segments (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)segment		Sep. 30, 2016USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			3
Gross written premium	$ 1,990,775	$ 2,034,098	$ 6,456,802		$ 6,040,284
Net written premium	1,175,757	1,216,050	3,891,725		3,705,165
Change in unearned premium	17,120	(19,814)	(95,607)		(252,895)
Net earned premium	1,192,877	1,196,236	3,796,118		3,452,270
Loss and loss adjustment expense	(1,266,118)	(811,048)	(3,130,930)		(2,310,514)
Acquisition costs and other underwriting expenses	(337,086)	(303,992)	(1,038,496)		(870,937)
Operating Expenses	1,603,204	1,115,040	4,169,426		3,181,451
Underwriting income (loss) (As restated)	(410,327)	81,196	(373,308)		270,819
Service and fee income	180,505	133,857	486,447		386,968
Investment income and realized gain on investments	85,623	68,149	230,244		191,383
Other expenses	(177,350)	(139,251)	(540,063)		(402,862)
Interest expense	(22,873)	(22,124)	(70,703)		(55,910)
Foreign currency loss	62,819	(10,880)	139,735		78,108
Gain (Loss) on investment in life settlement contracts, net	(924)	5,485	6,425		28,891
Gain on sale of policy management system	186,755	0	186,755	[1]	0	[1]
Gain on acquisition	0	0	0		48,775
Benefit (provision) for income taxes	62,588	(23,185)	60,959		(65,952)
Equity in earnings of unconsolidated subsidiary – related party	0	1,954	73,488		12,532
Net (loss) income	(158,822)	95,201	(79,491)		336,536
Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	1,192,877	1,196,236	3,796,118		3,452,270
Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Gross written premium	1,012,663	998,071	3,393,240		3,124,761
Net written premium	498,514	457,871	1,796,255		1,684,037
Change in unearned premium	30,565	59,127	(81,687)		(89,967)
Net earned premium	529,079	516,998	1,714,568		1,594,070
Loss and loss adjustment expense	(546,219)	(344,531)	(1,390,557)		(1,060,165)
Acquisition costs and other underwriting expenses	(154,739)	(134,520)	(479,559)		(418,201)
Operating Expenses	700,958	479,051	1,870,116		1,478,366
Underwriting income (loss) (As restated)	(171,879)	37,947	(155,548)		115,704
Service and fee income	27,586	26,800	87,230		85,082
Investment income and realized gain on investments	32,936	29,218	95,145		84,265
Other expenses	(45,239)	(34,236)	(141,909)		(104,204)
Interest expense	(11,661)	(10,988)	(37,157)		(28,923)
Foreign currency loss	0	0	0		0
Gain (Loss) on investment in life settlement contracts, net	(541)	2,521	3,376		14,946
Gain on sale of policy management system	0		0
Gain on acquisition					455
Benefit (provision) for income taxes	65,012	(9,947)	64,611		(27,418)
Equity in earnings of unconsolidated subsidiary – related party		0	0		0
Net (loss) income	(103,786)	41,315	(84,252)		139,907
Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Gross written premium	756,714	598,977	2,285,088		1,779,984
Net written premium	525,308	448,845	1,591,002		1,233,739
Change in unearned premium	(42,490)	(21,526)	(95,691)		(126,695)
Net earned premium	482,818	427,319	1,495,311		1,107,044
Loss and loss adjustment expense	(458,379)	(293,956)	(1,141,823)		(736,220)
Acquisition costs and other underwriting expenses	(126,312)	(86,240)	(385,085)		(237,864)
Operating Expenses	584,691	380,196	1,526,908		974,084
Underwriting income (loss) (As restated)	(101,873)	47,123	(31,597)		132,960
Service and fee income	114,549	82,475	299,668		226,014
Investment income and realized gain on investments	33,527	24,519	87,374		63,195
Other expenses	(33,501)	(20,503)	(95,565)		(59,359)
Interest expense	(8,654)	(6,516)	(25,022)		(16,476)
Foreign currency loss	62,819	(10,880)	139,735		78,108
Gain (Loss) on investment in life settlement contracts, net	(241)	1,614	2,274		8,514
Gain on sale of policy management system	0		0
Gain on acquisition					48,320
Benefit (provision) for income taxes	(39,126)	(22,070)	(42,273)		(53,265)
Equity in earnings of unconsolidated subsidiary – related party		0	0		0
Net (loss) income	(98,138)	95,762	55,124		271,795
Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Gross written premium	221,398	437,050	778,474		1,135,539
Net written premium	151,935	309,334	504,468		787,389
Change in unearned premium	29,045	(57,415)	81,771		(36,233)
Net earned premium	180,980	251,919	586,239		751,156
Loss and loss adjustment expense	(261,520)	(172,561)	(598,550)		(514,129)
Acquisition costs and other underwriting expenses	(56,035)	(83,232)	(173,852)		(214,872)
Operating Expenses	317,555	255,793	772,402		729,001
Underwriting income (loss) (As restated)	(136,575)	(3,874)	(186,163)		22,155
Service and fee income	499	106	2,479		1,623
Investment income and realized gain on investments	19,160	14,412	47,725		43,923
Other expenses	(9,935)	(14,887)	(32,557)		(37,868)
Interest expense	(2,558)	(4,620)	(8,524)		(10,511)
Foreign currency loss	0	0	0		0
Gain (Loss) on investment in life settlement contracts, net	(142)	1,350	775		5,431
Gain on sale of policy management system	0		0
Gain on acquisition					0
Benefit (provision) for income taxes	75,564	801	76,504		(4,056)
Equity in earnings of unconsolidated subsidiary – related party		0	0		0
Net (loss) income	(53,987)	(6,712)	(99,761)		20,697
Corporate and Other
Segment Reporting Information [Line Items]
Gross written premium	0	0	0		0
Net written premium	0	0	0		0
Change in unearned premium	0	0	0		0
Net earned premium	0	0	0		0
Loss and loss adjustment expense	0	0	0		0
Acquisition costs and other underwriting expenses	0	0	0		0
Operating Expenses	0	0	0		0
Underwriting income (loss) (As restated)	0	0	0		0
Service and fee income	37,871	24,476	97,070		74,249
Investment income and realized gain on investments	0	0	0		0
Other expenses	(88,675)	(69,625)	(270,032)		(201,431)
Interest expense	0	0	0		0
Foreign currency loss	0	0	0		0
Gain (Loss) on investment in life settlement contracts, net	0	0	0		0
Gain on sale of policy management system	186,755		186,755
Gain on acquisition					0
Benefit (provision) for income taxes	(38,862)	8,031	(37,883)		18,787
Equity in earnings of unconsolidated subsidiary – related party		1,954	73,488		12,532
Net (loss) income	97,089	(35,164)	49,398		(95,863)
Workers' compensation | Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	432,038	498,276	1,365,090		1,510,630
Workers' compensation | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	347,770	349,030	1,057,183		1,053,967
Workers' compensation | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	0	0	0		0
Workers' compensation | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	84,268	149,246	307,907		456,663
Warranty | Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	238,917	180,333	709,257		527,835
Warranty | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	0	0	0		0
Warranty | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	238,910	180,333	709,231		527,835
Warranty | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	7	0	26		0
Other liability | Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	84,404	84,793	280,581		247,441
Other liability | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	0	11,292	0		16,541
Other liability | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	35,752	26,169	125,259		100,187
Other liability | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	48,652	47,332	155,322		130,713
Commercial auto and liability, physical damage | Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	113,403	89,033	364,579		369,850
Commercial auto and liability, physical damage | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	78,955	47,751	275,657		245,647
Commercial auto and liability, physical damage | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	0	9,164	0		26,340
Commercial auto and liability, physical damage | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	34,448	32,118	88,922		97,863
Medical malpractice | Operating Segments
Segment Reporting Information [Line Items]
Net earned premium	60,982	59,186	167,635		106,750
Medical malpractice | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	0	0	0		0
Medical malpractice | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	60,982	59,186	167,635		106,750
Medical malpractice | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	0	0	0		0
Other | Operating Segments | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium			381,728		277,915
Other | Operating Segments | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium			493,186		345,932
Other | Operating Segments | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium			34,062		65,917
Other | Corporate and Other
Segment Reporting Information [Line Items]
Net earned premium	263,133	284,615	$ 908,976		$ 689,764
Other | Corporate and Other | Small Commercial Business
Segment Reporting Information [Line Items]
Net earned premium	102,354	108,925
Other | Corporate and Other | Specialty Risk and Extended Warranty
Segment Reporting Information [Line Items]
Net earned premium	147,174	152,467
Other | Corporate and Other | Specialty Program
Segment Reporting Information [Line Items]
Net earned premium	$ 13,605	$ 23,223
[1]	) 2017 amounts relate to the sale of the personal lines policy management system to National General Holdings Corp. See Note 10 for more information.

Segments - Long Lived Assets an

Segments - Long Lived Assets and Total Assets of Business Segments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total assets	$ 25,827,359	$ 22,614,668

Reinsurance Agreement (Details)

Reinsurance Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Jun. 30, 2017	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Reinsurance Retention Policy [Line Items]
Loss and loss adjustment expense reserves	$ 12,086,644	$ 11,149,511	$ 11,149,511	$ 12,086,644		$ 10,140,716	$ 9,427,770	$ 9,097,408	$ 7,208,367
Prepaid reinsurance premium	2,181,851			2,181,851		$ 1,994,092
Adverse Loss Development Cover Agreement
Reinsurance Retention Policy [Line Items]
Reinsurance excess of retention amount				400,000
Loss and loss adjustment expense reserves					$ 6,590,000
Payments for Reinsurance		450	675,000
Prepaid reinsurance premium		50,000	50,000
Loss on reinsurance agreement		58,949
Net present value of obligation from reinsurance agreement		8,949
Administration monitoring fees due		$ 1,000
Reinsurance agreement term		30 years
Net adverse loss development in excess of original pre-tax loss	326,931	$ 73,069		400,000
Deferred gain recognized in earnings from excess net adverse loss development	337,054	14,120
Incremental excess collateral deposited		$ 100,000	$ 100,000
Interest rate paid on unpaid portion of consideration			3.75%
Required payment period on interest			180 days
Reinsurance Payable	225,000			225,000
Interest Expense	$ 4,531
Adverse Loss Development Cover Agreement | Minimum
Reinsurance Retention Policy [Line Items]
Reinsurance retention amount				1,025,000
Adverse Loss Development Cover Agreement | Maximum
Reinsurance Retention Policy [Line Items]
Reinsurance retention amount				$ 5,963,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Forecast - Mayfield - Subsequent Event [Member] $ in Thousands	Nov. 03, 2017USD ($)
Subsequent Event [Line Items]
Percentage of voting Interests acquired (in percentage)	49.00%
Business Combination, Consideration Transferred, Other	$ 200,000
Acquisition price	$ 950,000
FeeCo Holding LP
Subsequent Event [Line Items]
Percentage of voting Interests acquired (in percentage)	51.00%
Payments to acquire businesses	$ 210,000
One or More Subsidiary
Subsequent Event [Line Items]
Liabilities incurred	$ 750,000