Jefferies Financial (JEF) 10-Q 1 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	JEFFERIES FINANCIAL GROUP INC.
Entity Central Index Key	96,223
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		323,072,855

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents		$ 4,895,788	$ 5,275,480
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations		913,456	578,014
Financial instruments owned, including securities pledged of $12,868,364 and $10,842,051:
Trading assets, at fair value		17,709,245	16,082,676
Debt securities, available for sale securities		1,868,420	628,075
Available for sale securities			716,561
Total financial instruments owned		19,577,665	16,799,237
Loans to and investments in associated companies		2,450,901	2,066,829
Securities borrowed		7,369,908	7,721,803
Securities purchased under agreements to resell		3,659,059	3,689,559
Receivables		5,864,815	5,419,015
Property, equipment and leasehold improvements, net		346,896	750,403
Intangible assets, net and goodwill		1,894,898	2,463,180
Deferred tax asset, net		468,297	743,811
Other assets		1,506,986	1,661,777
Total assets	[1]	48,948,669	47,169,108
LIABILITIES
Short-term borrowings		382,006	436,215
Trading liabilities, at fair value		9,479,213	8,454,965
Securities loaned		2,531,504	2,843,911
Securities sold under agreements to repurchase		9,864,483	8,660,511
Other secured financings		1,440,678	1,029,485
Payables, expense accruals and other liabilities		6,680,224	7,167,666
Long-term debt		7,777,425	7,885,783
Total liabilities	[1]	38,155,533	36,478,536
Commitments and contingencies
MEZZANINE EQUITY
Redeemable noncontrolling interests		21,385	426,593
Mandatorily redeemable convertible preferred shares		125,000	125,000
EQUITY
Common shares, par value $1 per share, authorized 600,000,000 shares; 331,415,732 and 356,227,038 shares issued and outstanding, after deducting 85,560,514 and 60,165,980 shares held in treasury		331,416	356,227
Additional paid-in capital		4,329,661	4,676,038
Accumulated other comprehensive income		287,745	372,724
Retained earnings		5,672,363	4,700,968
Total Jefferies Financial Group Inc. shareholders’ equity		10,621,185	10,105,957
Noncontrolling interests		25,566	33,022
Total equity		10,646,751	10,138,979
Total		$ 48,948,669	$ 47,169,108
[1]	Total assets include assets related to variable interest entities of $479.0 million and $382.9 million at September 30, 2018 and December 31, 2017, respectively, and Total liabilities include liabilities related to variable interest entities of $1,441.9 million and $1,031.0 million at September 30, 2018 and December 31, 2017, respectively. See Note 8 for additional information related to variable interest entities.

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
ASSETS
Securities pledged		$ 12,868,364	$ 10,842,051
Stockholders' Equity Attributable to Parent [Abstract]
Common shares, par value (USD per share)		$ 1	$ 1
Common shares, authorized (in shares)		600,000,000	600,000,000
Common shares, issued and outstanding after deducting shares held in treasury (in shares)		331,415,732	356,227,038
Treasury stock (in shares)		85,560,514	60,165,980
Assets	[1]	$ 48,948,669	$ 47,169,108
Liabilities	[1]	38,155,533	36,478,536
Variable interest entities
Assets		479,000	382,900
Liabilities		$ 1,441,900	$ 1,031,000
[1]	Total assets include assets related to variable interest entities of $479.0 million and $382.9 million at September 30, 2018 and December 31, 2017, respectively, and Total liabilities include liabilities related to variable interest entities of $1,441.9 million and $1,031.0 million at September 30, 2018 and December 31, 2017, respectively. See Note 8 for additional information related to variable interest entities.

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 1,458,977	$ 1,102,593	$ 3,863,914	$ 3,735,702
Interest expense	28,837	25,612	74,614	76,762
Net revenues	1,150,846	857,223	2,957,440	3,020,610
Expenses:
Compensation and benefits	461,265	493,471	1,429,439	1,468,373
Cost of sales	84,876	71,596	257,501	210,834
Floor brokerage and clearing fees	44,570	42,852	131,792	133,145
Depreciation and amortization	32,295	28,760	92,360	82,129
Selling, general and other expenses	245,178	199,441	708,084	552,155
Total expenses	897,021	861,732	2,693,790	2,523,398
Income (loss) from continuing operations before income taxes and income (loss) related to associated companies	253,825	(4,509)	263,650	497,212
Income (loss) related to associated companies	18,867	30,057	84,320	(84,413)
Income from continuing operations before income taxes	272,692	25,548	347,970	412,799
Income tax provision	90,391	9,770	51,560	127,198
Income from continuing operations	182,301	15,778	296,410	285,601
Income from discontinued operations, net of income tax provision of $0, $53,490, $47,045 and $90,856	0	120,989	130,063	219,151
Gain on disposal of discontinued operations, net of income tax provision of $0, $0, $229,553 and $0	0	0	643,921	0
Net income	182,301	136,767	1,070,394	504,752
Net (income) loss attributable to the noncontrolling interests	12,000	(28)	13,208	1,941
Net income attributable to the redeemable noncontrolling interests	(390)	(36,216)	(37,294)	(64,538)
Preferred stock dividends	(1,276)	(1,172)	(3,619)	(3,203)
Net income attributable to Jefferies Financial Group Inc. common shareholders	$ 192,635	$ 99,351	$ 1,042,689	$ 438,952
Basic earnings per common share attributable to Jefferies Financial Group Inc. common shareholders:
Income from continuing operations (in dollars per share)	$ 0.56	$ 0.04	$ 0.86	$ 0.77
Income from discontinued operations (in dollars per share)	0	0.23	0.26	0.42
Gain on disposal of discontinued operations (in dollars per share)	0	0	1.82	0
Net income (in dollars per share)	0.56	0.27	2.94	1.19
Diluted earnings per common share attributable to Jefferies Financial Group Inc. common shareholders:
Income from continuing operations (in dollars per share)	0.55	0.04	0.85	0.76
Income from discontinued operations (in dollars per share)	0	0.23	0.26	0.41
Gain on disposal of discontinued operations (in dollars per share)	0	0	1.80	0
Net income (in dollars per share)	0.55	0.27	2.91	1.17
Dividends per common share (in dollars per share)	$ 0.125	$ 0.10	$ 0.325	$ 0.225
Amounts attributable to Jefferies Financial Group Inc. common shareholders:
Income from continuing operations, net of taxes	$ 192,635	$ 14,992	$ 305,846	$ 284,889
Income from discontinued operations, net of taxes	0	84,359	92,922	154,063
Gain on disposal of discontinued operations, net of taxes	0	0	643,921	0
Net income attributable to Jefferies Financial Group Inc. common shareholders	192,635	99,351	1,042,689	438,952
Commissions and other fees
Revenues:
Total revenues	155,417	139,082	461,023	437,547
Principal transactions
Revenues:
Total revenues	116,204	84,143	315,622	725,780
Investment banking
Revenues:
Total revenues	460,043	475,702	1,400,331	1,235,586
Interest income
Revenues:
Total revenues	336,736	253,916	939,272	726,972
Manufacturing revenues
Revenues:
Total revenues	94,029	81,939	307,129	243,482
Other
Revenues:
Total revenues	296,548	67,811	440,537	366,335
Jefferies Group
Revenues:
Interest expense	$ 308,131	$ 245,370	$ 906,474	$ 715,092

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Income tax provision	$ 0	$ 53,490	$ 47,045	$ 90,856
Gain on disposal of discontinued operations, tax	$ 0	$ 0	$ 229,553	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 182,301	$ 136,767	$ 1,070,394	$ 504,752
Other comprehensive income (loss):
Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $(424), $(598), $(567) and $5,106	(1,198)	(1,030)	(1,606)	8,767
Less: reclassification adjustment for net (gains) losses included in net income, net of income tax provision (benefit) of $0, $(257), $37 and $14	(2)	443	(105)	(24)
Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $(424), $(341), $(604) and $5,092	(1,200)	(587)	(1,711)	8,743
Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $(3,367), $4,374, $(4,160) and $12,929	(27,660)	11,250	(59,067)	49,125
Less: reclassification adjustment for foreign exchange (gains) losses included in net income, net of income tax provision (benefit) of $0, $(11), $(16) and $1,086	0	20	(20,459)	5,310
Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $(3,367), $4,385, $(4,144) and $11,843	(27,660)	11,270	(79,526)	54,435
Net unrealized gains (losses) on instrument specific credit risk arising during the period, net of income tax provision (benefit) of $355, $2,149, $4,596 and $(5,270)	1,169	3,508	15,887	(8,870)
Less: reclassification adjustment for instrument specific credit risk (gains) losses included in net income, net of income tax provision (benefit) of $48, $0, $126 and $0	101	0	371	0
Net change in unrealized instrument specific credit risk gains (losses), net of income tax provision (benefit) of $307, $2,149, $4,470 and $(5,270)	1,068	3,508	15,516	(8,870)
Net change in unrealized cash flow hedges gains (losses), net of income tax provision (benefit) of $0, $0, $513 and $0	85	(1,585)	1,584	(1,585)
Reclassification adjustment for pension (gains) losses included in net income, net of income tax provision (benefit) of $(169), $(201), $(508) and $(1,835)	479	438	6,742	66
Other comprehensive income (loss), net of income taxes	(27,228)	13,044	(57,395)	52,789
Comprehensive income	155,073	149,811	1,012,999	557,541
Comprehensive (income) loss attributable to the noncontrolling interests	12,000	(28)	13,208	1,941
Comprehensive income attributable to the redeemable noncontrolling interests	(390)	(36,216)	(37,294)	(64,538)
Preferred stock dividends	(1,276)	(1,172)	(3,619)	(3,203)
Comprehensive income attributable to Jefferies Financial Group Inc. common shareholders	$ 165,407	$ 112,395	$ 985,294	$ 491,741

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit)	$ (424)	$ (598)	$ (567)	$ 5,106
Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit)	0	(257)	37	14
Net change in unrealized holding gains (losses) on investments, tax provision (benefit)	(424)	(341)	(604)	5,092
Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit)	(3,367)	4,374	(4,160)	12,929
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit)	0	(11)	(16)	1,086
Net change in unrealized foreign exchange gains (losses), tax provision (benefit)	(3,367)	4,385	(4,144)	11,843
Net unrealized gains (losses) on instrument specific credit risk arising during the period, tax provision (benefit)	355	2,149	4,596	(5,270)
Less: reclassification adjustment for instrument specific credit risk (gains) losses included in net income (loss), tax provision (benefit)	48	0	126	0
Net change in unrealized instrument specific credit risk gains (losses), tax provision (benefit)	307	2,149	4,470	(5,270)
Net change in unrealized cash flow hedges gains (losses), tax provision (benefit)	0	0	513	0
Less: reclassification adjustment for pension (gains) losses included in net income (loss), tax provision (benefit)	$ (169)	$ (201)	$ (508)	$ (1,835)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Net cash flows from operating activities:
Net income	$ 1,070,394	$ 504,752
Adjustments to reconcile net income to net cash provided by operations:
Pre-tax income from discontinued operations, including gain on disposal	(1,050,582)	(310,007)
Deferred income tax provision	275,307	185,994
Depreciation and amortization of property, equipment and leasehold improvements	80,647	69,480
Other amortization	(26,796)	(21,107)
Share-based compensation	37,975	31,494
Provision for doubtful accounts	26,529	26,764
Net securities (gains) losses	1,019	(21,278)
(Income) loss related to associated companies	(115,007)	19,090
Distributions from associated companies	98,426	100,033
Net losses related to property and equipment, and other assets	10,833	11,414
Gain on sale of subsidiaries and associated companies	(221,712)	(178,236)
Net change in:
Securities deposited with clearing and depository organizations	64,890	119
Trading assets	(1,670,376)	(639,464)
Securities borrowed	309,722	0
Securities purchased under agreements to resell	(53,020)	524,937
Receivables from brokers, dealers and clearing organizations	(261,534)	(602,761)
Receivables from customers of securities operations	(398,154)	(458,066)
Other receivables	(70,514)	(137,408)
Other assets	(23,910)	(44,494)
Trading liabilities	1,122,273	327,587
Securities loaned	(275,629)	(68,310)
Securities sold under agreements to repurchase	1,250,575	1,668,725
Payables to brokers, dealers and clearing organizations	(287,288)	(652,668)
Payables to customers of securities operations	523,611	162,387
Trade payables, expense accruals and other liabilities	(291,973)	134,125
Other	(90,448)	73,525
Net cash provided by operating activities - continuing operations	35,258	706,627
Net cash provided by operating activities - discontinued operations	164,650	354,289
Net cash provided by operating activities	199,908	1,060,916
Net cash flows from investing activities:
Acquisitions of property, equipment and leasehold improvements, and other assets	(282,397)	(90,168)
Proceeds from disposals of property and equipment, and other assets	11,994	25,213
Proceeds from sale of subsidiaries, net of expenses and cash of operations sold	100,000	289,767
Proceeds from sale of associated companies	379,130	0
Advances on notes, loans and other receivables	(10,000)	(46,532)
Collections on notes, loans and other receivables	17,404	268,920
Loans to and investments in associated companies	(1,936,496)	(3,043,800)
Capital distributions and loan repayments from associated companies	1,970,648	2,765,006
Purchases of investments (other than short-term)	(3,242,732)	(770,687)
Proceeds from maturities of investments	1,000,146	196,493
Proceeds from sales of investments	1,012,423	412,158
Other	130	1,341
Net cash provided by (used for) investing activities - continuing operations	(979,750)	7,711
Net cash provided by (used for) investing activities - discontinued operations	861,209	(36,465)
Net cash used for investing activities	(118,541)	(28,754)
Net cash flows from financing activities:
Issuance of debt, net of issuance costs	2,198,326	1,349,399
Other changes in short-term borrowings, net	0	4,282
Repayment of debt	(2,024,680)	(652,889)
Net change in other secured financings	409,780	(134,743)
Net change in bank overdrafts	2,369	(5,764)
Issuance of common shares	3,486	1,288
Distributions to noncontrolling interests	0	(9,617)
Contributions from noncontrolling interests	113	25,724
Purchase of common shares for treasury	(635,835)	(75,930)
Dividends paid	(111,776)	(81,445)
Other	456	(185)
Net cash provided by (used for) financing activities - continuing operations	(157,761)	420,120
Net cash provided by (used for) financing activities - discontinued operations	120,322	(202,137)
Net cash provided by (used for) financing activities	(37,439)	217,983
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	(16,469)	5,550
Change in cash classified as assets held for sale	0	(3,136)
Net increase in cash, cash equivalents and restricted cash	27,459	1,252,559
Cash, cash equivalents and restricted cash at January 1,	5,774,505	4,597,113
Cash, cash equivalents and restricted cash at September 30,	$ 5,801,964	$ 5,849,672

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 4,895,788	$ 5,016,932
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	878,616	803,970
Other assets	27,560	28,770
Total cash, cash equivalents and restricted cash	$ 5,801,964	$ 5,849,672

Consolidated Statements of Chan

Consolidated Statements of Changes In Equity - USD ($) $ in Thousands	Total	Common Shares $1 Par Value	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Subtotal	Noncontrolling Interests
Beginning Balance at Dec. 31, 2016	$ 10,303,649	$ 359,425	$ 4,812,587	$ 310,697	$ 4,645,391	$ 10,128,100	$ 175,549
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	437,011				438,952	438,952	(1,941)
Other comprehensive loss, net of taxes	52,789			52,789		52,789
Contributions from noncontrolling interests	25,724					0	25,724
Distributions to noncontrolling interests	(9,617)					0	(9,617)
Change in interest in consolidated subsidiary	0		48			48	(48)
Share-based compensation expense	31,494		31,494			31,494
Change in fair value of redeemable noncontrolling interests	(24,404)		(24,404)			(24,404)
Purchase of common shares for treasury	(96,882)	(3,883)	(92,999)			(96,882)
Dividends	(83,920)				(83,920)	(83,920)
Other	5,733	648	5,085			5,733
Ending Balance at Sep. 30, 2017	10,641,577	356,190	4,731,811	363,486	5,000,423	10,451,910	189,667
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of the adoption of accounting standards	17,812			(27,584)	45,396	17,812
Beginning Balance, Adjusted	10,156,791	356,227	4,676,038	345,140	4,746,364	10,123,769	33,022
Beginning Balance at Dec. 31, 2017	10,138,979	356,227	4,676,038	372,724	4,700,968	10,105,957	33,022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,029,481				1,042,689	1,042,689	(13,208)
Other comprehensive loss, net of taxes	(57,395)			(57,395)		(57,395)
Contributions from noncontrolling interests	113					0	113
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustments prior to deconsolidation	237,669		237,669			237,669
Change in interest in consolidated subsidiary	0		2,677			2,677	(2,677)
Share-based compensation expense	37,975		37,975			37,975
Change in fair value of redeemable noncontrolling interests	(28,136)		(28,136)			(28,136)
Consolidation of asset management entity	8,316					0	8,316
Exercise of options to purchase common shares	2,485	109	2,376			2,485
Purchase of common shares for treasury	(635,835)	(26,316)	(609,519)			(635,835)
Dividends	(116,690)				(116,690)	(116,690)
Other	11,977	1,396	10,581			11,977
Ending Balance at Sep. 30, 2018	$ 10,646,751	$ 331,416	$ 4,329,661	$ 287,745	$ 5,672,363	$ 10,621,185	$ 25,566

Consolidated Statements of Ch_2

Consolidated Statements of Changes In Equity (Parenthetical) - $ / shares	3 Months Ended				9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Dividends per common share (in dollars per share)	$ 0.125	$ 0.10	$ 0.10	$ 0.0625	$ 0.325	$ 0.225

Nature of Operations

Nature of Operations	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations Jefferies Financial Group Inc. ("Jefferies" or the "Company"), formerly known as Leucadia National Corporation, operates the largest independent full-service global investment banking firm headquartered in the U.S., together with an established merchant banking business. We engage in investment banking, sales and trading and asset management through Jefferies Group LLC ("Jefferies Group"). From time to time, we evaluate the retention and disposition of businesses and investments, and changes in the mix of these holdings should be expected. We own 31% of National Beef Packing Company. National Beef processes and markets fresh and chilled boxed beef, ground beef, beef by-products, consumer-ready beef and pork, and wet blue leather for domestic and international markets. On June 5, 2018, we completed the sale of 48% of National Beef to Marfrig Global Foods S.A. ("Marfrig") for $907.7 million in cash, reducing our ownership in National Beef from 79% to 31% . The pre-tax gain recognized as a result of this transaction was $873.5 million for the nine months ended September 30, 2018 . During 2018, prior to the closing, we received an additional $229.4 million in distributions of recent profits plus a true-up to the debt amount set in the enterprise valuation associated with the sale. Marfrig has also acquired a further 3% of National Beef from other equity owners and owns 51% of National Beef. We will continue to designate two board members and have a series of other rights in respect of our continuing equity interest, with a lockup period of five years and thereafter fair market value liquidity protections. As of the closing of the sale on June 5, 2018, we deconsolidated our investment in National Beef and account for our remaining 31% interest in National Beef under the equity method of accounting. We have classified the results of National Beef prior to June 5, 2018 as discontinued operations in the Consolidated Statements of Operations. See Note 24 for more information. During the third quarter of 2018, we sold 100% of our equity interests in Garcadia, our auto dealer group, and our associated real estate to our former partners, the Garff family, for $417.2 million in cash. The pre-tax gain recognized as a result of this transaction, $221.7 million for the three and nine months ended September 30, 2018 , is classified as Other revenue. Vitesse Energy, LLC ("Vitesse Energy Finance") is our consolidated subsidiary that acquires and invests in non-operated working and royalty oil and gas interests in the Bakken Shale oil field in North Dakota and Montana, as well as the Denver-Julesburg Basin in Wyoming. These non-operated interests represent Vitesse Energy Finance’s share of mineral rights associated with specified acreage. As operators convert undeveloped portions of this acreage into flowing horizontal wells, our interests in the mineral rights are essentially converted into interests in the cash flows associated with the wells. In April 2018, Vitesse Energy Finance acquired a package of non-operated Bakken assets from a private equity fund for $190 million in cash, of which approximately $144 million was funded as equity by Jefferies and the balance was drawn under Vitesse Energy Finance’s credit line. The assets purchased include interests in mineral rights associated with future oil and gas development, as well as interests in existing cash flows from producing wells through revenue sharing arrangements. Leucadia Asset Management ("LAM") supports and develops focused alternative asset management businesses led by distinct management teams. We are patiently developing this business over time, and changes in the platforms and structure should be expected. During the second quarter of 2018, we took steps to expand our asset management efforts including the formation of a strategic relationship with Weiss Multi-Strategy Advisers LLC and we invested $250.0 million in Weiss' strategy. We will receive a profit share in the first year, and a revenue share thereafter. In addition, we entered into an agreement with Schonfeld Strategic Advisors LLC to merge the business of Folger Hill Asset Management with Schonfeld's fundamental equities business, under the Schonfeld brand. In connection with the pending transaction, we have agreed to make a $250.0 million investment in the combined strategy and we will own a revenue share in the management company. On October 1, 2018, Jefferies transferred its membership interests in certain funds and separately managed accounts which are managed by Leucadia Asset Management, as well as its interest in Berkadia Commercial Mortgage LLC ("Berkadia"), to Jefferies Group (collectively, "the Transfer"). The Transfer was accomplished as a capital contribution to Jefferies Group of approximately $596 million and an internal transfer of cash from Jefferies Group of $78.3 million to the Jefferies parent company. On July 13, 2018, HRG Group, Inc. ("HRG") merged into its 62% owned subsidiary, Spectrum Brands Holdings, Inc. ("Spectrum Brands"). Our approximately 23% interest in HRG thereby converted into approximately 14% of the outstanding shares of Spectrum Brands, a NYSE company. On October 2, 2018, our Board of Directors and senior management approved a change of our fiscal year end from a calendar year basis to a fiscal year ending on November 30, consistent with the fiscal year of Jefferies Group. We will file a transition report on Form 10-K for the transition period from January 1, 2018 to November 30, 2018.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Our unaudited interim consolidated financial statements have been prepared in accordance with the instructions for Form 10-Q and, therefore, do not include all information and footnotes which are normally included in our Annual Report on Form 10-K. These financial statements reflect all adjustments (consisting of normal recurring items or items discussed herein) that management believes are necessary to fairly state results for the interim periods presented. Results of operations for interim periods are not necessarily indicative of annual results of operations. For a detailed discussion about the Company’s significant accounting policies, see Note 2, Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2017 ("2017 10-K"). The preparation of these financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP") requires us to make estimates and assumptions that affect the reported amounts in the financial statements and disclosures of contingent assets and liabilities. On an on-going basis, we evaluate all of these estimates and assumptions. The most important of these estimates and assumptions relate to fair value measurements, compensation and benefits, asset impairment, the ability to realize deferred tax assets, the recognition and measurement of uncertain tax positions and contingencies. Although these and other estimates and assumptions are based on the best available information, actual results could be different from these estimates. Jefferies Group has a November 30 year-end, which it retains for standalone reporting purposes. We reflect Jefferies Group in our consolidated financial statements utilizing a one month lag. We have reviewed Jefferies Group's business and internal operating results for the month of September 2018 for the purpose of evaluating whether financial statement disclosure or adjustments are required in this Quarterly Report on Form 10-Q, and we have concluded that no additional disclosures or adjustments are warranted. In connection with the planned change of our fiscal year-end to November 30, we also plan to eliminate the one month lag utilized to reflect Jefferies Group results in our consolidated financial statements, starting with a transition report on Form 10-K for the transition period from January 1, 2018 to November 30, 2018. During the nine months ended September 30, 2018 , other than the following, there were no significant updates made to the Company’s significant accounting policies. The accounting policy changes are attributable to the adoption of the Financial Accounting Standards Board ("FASB") guidance on Revenue from Contracts with Customers (the "new revenue standard"). These revenue recognition policy updates are applied prospectively in our financial statements from January 1, 2018 forward using the modified retrospective approach. Reported financial information for the historical comparable periods were not revised and continue to be reported under the accounting standards in effect during the historical periods. Revenue Recognition Policies Investment Banking Revenues: • Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed. • Expenses associated with investment banking advisory engagements are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related expenses, including expenses incurred related to restructuring advisory engagements, are expensed as incurred. • All investment banking expenses are recognized within their respective expense category in the Consolidated Statements of Operations and any expenses reimbursed by clients are recognized as Investment banking revenues. Asset Management Fees: • Performance fee revenue is generally recognized only at the end of the performance period to the extent that the benchmark return has been met. See Accounting Developments - Adopted Accounting Standards below and Note 17 for further information. Changes to the Consolidated Statements of Operations Manufacturing revenues, which were previously reported within Other revenues, are now reported separately in the Consolidated Statements of Operations. Manufacturing revenues are primarily from Idaho Timber, which manufactures and distributes an extensive range of quality wood products to markets across North America. Idaho Timber's primary business consists of the sale of lumber that is manufactured or remanufactured at one of its locations. Agreements with customers for these sales specify the type, quantity and price of products to be delivered as well as the delivery date and payment terms. The transaction price is fixed at the time of sale and revenue is generally recognized when the customer takes control of the product. We have reorganized the presentation of our gains and losses generated from our capital invested in asset management funds. This was previously presented as Other revenues and is now presented within Principal transactions revenues. For the three months ended September 30, 2017 , this resulted in a decrease to Principal transactions revenues of $11.3 million and an increase to Other revenues of $11.3 million . For the nine months ended September 30, 2017 , this resulted in a decrease to Principal transactions revenues of $12.2 million and an increase to Other revenues of $12.2 million . Receivables At September 30, 2018 and December 31, 2017 , Receivables include receivables from brokers, dealers and clearing organizations of $2,878.5 million and $2,635.2 million , respectively, and receivables from customers of securities operations of $1,951.8 million and $1,563.8 million , respectively. Payables, expense accruals and other liabilities At September 30, 2018 and December 31, 2017 , Payables, expense accruals and other liabilities include payables to brokers, dealers and clearing organizations of $1,913.3 million and $2,228.9 million , respectively, and payables to customers of securities operations of $3,187.6 million and $2,664.0 million , respectively. Supplemental Cash Flow Information For the Nine Months Ended September 30, 2018 2017 Cash paid during the year for: (In thousands) Interest $ 1,059,139 $ 837,020 Income tax payments (refunds), net $ 28,204 $ 9,183 During the nine months ended September 30, 2017 , we had $21.0 million in non-cash financing activities related to purchases of common shares for treasury which settled subsequent to quarter end. Accounting Developments - Adopted Accounting Standards Revenue Recognition. In May 2014, the FASB issued new guidance that defines how companies report revenues from contracts with customers, and also requires enhanced disclosures. The core principle of guidance is that an entity should recognize revenue to depict 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. We adopted the guidance as of January 1, 2018 and recognized an increase of $17.8 million after-tax to beginning retained earnings as the cumulative effect of adoption of accounting standards. The increase primarily relates to the recognition of $24.3 million of revenue previously deferred from the sale of real estate to HomeFed in 2014, offset by a decrease of $6.1 million related to Jefferies Group. For Jefferies Group, the impact of adoption primarily related to investment banking expenses that were deferred as of December 31, 2017 under the previously existing accounting guidance, which would have been expensed in prior periods under the new revenue standard and investment banking revenues that were previously recognized in prior periods, which would have been deferred as of December 31, 2017 under the new revenue standard. We elected to adopt the new guidance using a modified retrospective approach applied to contracts that were not completed as of January 1, 2018. Accordingly, the new revenue standard is applied prospectively in our financial statements from January 1, 2018 forward and reported financial information for historical comparable periods is not revised and continues to be reported under the accounting standards in effect during those historical periods. The new revenue standard does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, and as a result, did not have an impact on the elements of our Consolidated Statements of Operations most closely associated with financial instruments, including Principal transactions revenues, Interest income and Interest expense. The new revenue standard primarily impacts Jefferies Group's revenue recognition and presentation accounting policies as follows: • Investment Banking Revenues. Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed, as the performance obligation is to successfully broker a specific transaction. • Certain Capital Markets Revenues. Revenues associated with price stabilization activities as part of a securities underwriting were historically recognized as part of Investment banking revenues. Under the new revenue standard, revenues from these activities are recognized within Principal transactions revenues, as these revenues are not considered to be within the scope of the new standard. • Investment Banking Advisory Expenses. Historically, expenses associated with investment banking advisory assignments were deferred until reimbursed by the client, the related fee revenue is recognized or the engagement is otherwise concluded. Under the new revenue standard, expenses are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related expenses, including expenses incurred related to restructuring assignments, are expensed as incurred. • Investment Banking Underwriting and Advisory Expenses. Expenses have historically been recorded net of client reimbursements and/or netted against revenues. Under the new revenue standard, all investment banking expenses will be recognized within their respective expense category in the Consolidated Statements of Operations and any expense reimbursements will be recognized as Investment banking revenues (i.e., expenses are no longer recorded net of client reimbursements and are not netted against revenues). • Asset Management Fees. In certain asset management fee arrangements, Jefferies Group and LAM receive performance-based fees, which vary with performance or, in certain cases, are earned when the return on assets under management exceed certain benchmark returns or other performance targets. Historically, performance fees have been accrued (or reversed) quarterly based on measuring performance to date versus any relevant benchmark return hurdles stated in the investment management agreement. Under the new revenue standard, performance fees are considered variable as they are subject to fluctuation (e.g., based on market performance) and/or are contingent on a future event during the measurement period (e.g., exceeding a specified benchmark index) and are recognized only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty is resolved. Accordingly, performance fee revenue will generally be recognized only at the end of the performance period to the extent that the benchmark return has been met. There was no significant impact as a result of applying the new revenue standard to our consolidated financial statements for the three and nine months ended September 30, 2018 , except as it relates to the presentation of Jefferies Group's investment banking expenses. The table below presents the impact of applying the new revenue recognition standard to the Consolidated Statements of Operations for the three and nine months ended September 30, 2018 as a result of the change in presentation of investment banking expenses (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard Revenues: Commissions and other fees $ 155,417 $ — $ 155,417 $ 461,023 $ — $ 461,023 Principal transactions 116,204 — 116,204 315,622 — 315,622 Investment banking 460,043 36,319 423,724 1,400,331 101,146 1,299,185 Interest income 336,736 — 336,736 939,272 — 939,272 Manufacturing revenues 94,029 — 94,029 307,129 — 307,129 Other 296,548 — 296,548 440,537 — 440,537 Total revenues 1,458,977 36,319 1,422,658 3,863,914 101,146 3,762,768 Interest expense of Jefferies Group 308,131 — 308,131 906,474 — 906,474 Net revenues 1,150,846 36,319 1,114,527 2,957,440 101,146 2,856,294 Expenses: Compensation and benefits 461,265 — 461,265 1,429,439 — 1,429,439 Cost of sales 84,876 — 84,876 257,501 — 257,501 Floor brokerage and clearing fees 44,570 — 44,570 131,792 — 131,792 Interest expense 28,837 — 28,837 74,614 — 74,614 Depreciation and amortization 32,295 — 32,295 92,360 — 92,360 Selling, general and other expenses 245,178 36,319 208,859 708,084 101,146 606,938 Total expenses 897,021 36,319 860,702 2,693,790 101,146 2,592,644 Income from continuing operations before income taxes and income (loss) related to associated companies $ 253,825 $ — $ 253,825 $ 263,650 $ — $ 263,650 Financial Instruments. In January 2016, the FASB issued new guidance that affects the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. The guidance is effective for annual and interim periods beginning after December 15, 2017. We have adopted the new guidance as of January 1, 2018 with a cumulative effect increase to opening retained earnings of $27.6 million and a corresponding decrease to Accumulated other comprehensive income. The opening retained earnings adjustment is to recognize the unrealized gains we had for available for sale equity securities. Beginning in 2018, these available for sale equity securities are now reported as part of Trading assets, at fair value within the Consolidated Statements of Financial Condition. Early adoption was permitted for the accounting guidance on financial liabilities under the fair value option and we adopted this guidance in the first quarter of 2016. The adoption of the guidance on financial liabilities under the fair value option did not have a material impact on our consolidated financial statements. Retirement Benefits. In March 2017, the FASB issued new guidance for improving the presentation of net periodic pension costs in the statement of operations. The update also allows the service cost to be eligible for capitalization, when applicable. We adopted this guidance in the first quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. The adoption of this guidance resulted in the following adjustments to the Consolidated Statements of Operations for the three and nine months ended September 30, 2017 : a decrease of $0.9 million and $2.6 million , respectively, to Compensation and benefits expenses and an increase to Selling, general and other expenses of $0.9 million and $2.6 million , respectively. Cash Flow Classifications. In August 2016, the FASB issued new guidance to reduce the diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance adds or clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows. The guidance is effective for annual and interim periods beginning after December 15, 2017. In November 2016, the FASB issued new guidance on restricted cash. The guidance requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. We adopted this guidance in the first quarter of 2018. Prior periods were retrospectively adjusted to conform to the current period presentation. The adoption of the guidance did not have a material impact on our Consolidated Statements of Cash Flows. Upon adoption, we recorded an increase of $49.3 million in Net cash provided by operating activities and a decrease of $6.7 million in Net cash provided by investing activities for the nine months ended September 30, 2017 related to reclassifying the changes in our restricted cash balance from operating and investing activities to the cash and cash equivalent balances within the Consolidated Statements of Cash Flows. Compensation. In May 2017, the FASB issued new guidance providing clarity and reducing diversity in practice and cost and complexity when accounting for a change to the terms or conditions of a share-based payment award. We adopted this guidance in the first quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. Fair Value Measurement. In August 2018, the FASB issued new guidance to improve the effectiveness of disclosure requirements on fair value measurement by eliminating certain disclosure requirements for fair value measurements for all entities, requiring public entities to disclose certain new information and modifying some disclosure requirements. We early adopted this guidance in the third quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. Accounting Developments - Accounting Standards to be Adopted in Future Periods Leases. In February 2016, the FASB issued new guidance that affects the accounting and disclosure requirements for leases. The FASB requires the recognition of all leases that are longer than one year onto the balance sheet, which will result in the recognition of a right of use asset and a corresponding lease liability. The right of use asset and lease liability will be measured initially using the present value of the remaining rental payments. A significant portion of the population of contracts that will be subject to recognition on our Consolidated Statements of Financial Condition have been identified; however, their initial measurement still remains under evaluation. We are currently modifying our lease accounting systems to enable us to comply with the accounting requirements of this guidance. In July 2018, the FASB issued additional guidance on leases which allows an entity to recognize a cumulative-effect adjustment to the opening balance of retained earnings upon adoption. The guidance is effective for annual and interim periods beginning after December 15, 2018. We plan on adopting the lease standard in the first quarter of fiscal 2020 with a cumulative-effect adjustment to opening retained earnings in the period of adoption. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. Financial Instruments - Credit Losses. In June 2016, the FASB issued new guidance for estimating credit losses on certain types of financial instruments by introducing an approach based on expected losses. The guidance is effective in the first quarter of fiscal 2021. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. Goodwill. In January 2017, the FASB issued new guidance for simplifying goodwill impairment testing. The guidance is effective in the first quarter of fiscal 2021. We do not believe the new guidance will have a material impact on our consolidated financial statements. Derivatives and hedging. In August 2017, the FASB issued new guidance to improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. The guidance is effective in the first quarter of fiscal 2020 and early adoption is permitted. We do not believe the new guidance will have a material impact on our consolidated financial statements. Defined Benefit Plans. In August 2018, the FASB issued new guidance to improve the effectiveness of disclosure requirements on defined benefit pension plans and other post-retirement plans. The guidance is effective in the first quarter of fiscal 2021. We do not believe the new guidance will have a material impact on our consolidated financial statements. Internal-Use Software. In August 2018, the FASB issued new guidance which amends the definition of a hosting arrangement and requires that the customer in a hosting arrangement that is a service contract capitalize certain implementation costs as if the arrangement was an internal-use software project. The guidance is effective in the first quarter of fiscal 2021. We are currently evaluating the impact of the new guidance on our consolidated financial statements.

Fair Value Disclosures

Fair Value Disclosures	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Disclosures The following is a summary of our financial instruments, trading liabilities, short-term borrowings and long-term debt that are accounted for at fair value on a recurring basis, excluding Investments at fair value based on net asset value ("NAV") (within trading assets) of $399.0 million and $590.1 million at September 30, 2018 and December 31, 2017 , respectively, by level within the fair value hierarchy (in thousands): September 30, 2018 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 3,635,288 $ 72,569 $ 49,683 $ — $ 3,757,540 Corporate debt securities — 2,498,031 9,651 — 2,507,682 Collateralized debt obligations and collateralized loan obligations — 82,339 33,981 — 116,320 U.S. government and federal agency securities 3,000,805 45,889 — — 3,046,694 Municipal securities — 749,616 — — 749,616 Sovereign obligations 1,319,415 669,919 — — 1,989,334 Residential mortgage-backed securities — 1,894,533 4,954 — 1,899,487 Commercial mortgage-backed securities — 791,449 23,916 — 815,365 Other asset-backed securities — 263,967 69,305 — 333,272 Loans and other receivables — 1,455,496 48,985 — 1,504,481 Derivatives 13,117 3,507,491 3,137 (3,334,100 ) 189,645 Investments at fair value — — 326,977 — 326,977 FXCM term loan — — 73,800 — 73,800 Total trading assets, excluding investments at fair value based on NAV $ 7,968,625 $ 12,031,299 $ 644,389 $ (3,334,100 ) $ 17,310,213 Available for sale securities: U.S. government securities $ 1,607,725 $ — $ — $ — $ 1,607,725 Residential mortgage-backed securities — 146,678 — — 146,678 Commercial mortgage-backed securities — 15,719 — — 15,719 Other asset-backed securities — 98,298 — — 98,298 Total available for sale securities $ 1,607,725 $ 260,695 $ — $ — $ 1,868,420 Liabilities: Trading liabilities: Corporate equity securities $ 2,221,325 $ 1,507 $ 413 $ — $ 2,223,245 Corporate debt securities — 1,511,979 1,557 — 1,513,536 U.S. government and federal agency securities 1,398,222 — — — 1,398,222 Sovereign obligations 1,513,237 969,845 55 — 2,483,137 Commercial mortgage-backed securities — — 70 — 70 Loans — 1,136,579 8,661 — 1,145,240 Derivatives 8,487 4,149,630 12,134 (3,454,488 ) 715,763 Total trading liabilities $ 5,141,271 $ 7,769,540 $ 22,890 $ (3,454,488 ) $ 9,479,213 Long-term debt - structured notes $ — $ 545,927 $ 163,630 $ — $ 709,557 December 31, 2017 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 2,975,463 $ 60,300 $ 22,270 $ — $ 3,058,033 Corporate debt securities — 3,261,300 26,036 — 3,287,336 Collateralized debt obligations and collateralized loan obligations — 139,166 42,184 — 181,350 U.S. government and federal agency securities 1,269,230 39,443 — — 1,308,673 Municipal securities — 710,513 — — 710,513 Sovereign obligations 1,381,552 1,035,907 — — 2,417,459 Residential mortgage-backed securities — 1,453,294 26,077 — 1,479,371 Commercial mortgage-backed securities — 508,115 12,419 — 520,534 Other asset-backed securities — 217,111 61,129 — 278,240 Loans and other receivables — 1,620,581 47,304 — 1,667,885 Derivatives 165,396 3,323,278 9,295 (3,318,481 ) 179,488 Investments at fair value — 946 329,944 — 330,890 FXCM term loan — — 72,800 — 72,800 Total trading assets, excluding investments at fair value based on NAV $ 5,791,641 $ 12,369,954 $ 649,458 $ (3,318,481 ) $ 15,492,572 Available for sale securities: Corporate equity securities (2) $ 88,486 $ — $ — $ — $ 88,486 U.S. government securities 552,805 — — — 552,805 Residential mortgage-backed securities — 34,561 — — 34,561 Commercial mortgage-backed securities — 5,870 — — 5,870 Other asset-backed securities — 34,839 — — 34,839 Total available for sale securities $ 641,291 $ 75,270 $ — $ — $ 716,561 Liabilities: Trading liabilities: Corporate equity securities $ 1,721,267 $ 32,122 $ 48 $ — $ 1,753,437 Corporate debt securities — 1,688,825 522 — 1,689,347 U.S. government and federal agency securities 1,430,737 — — — 1,430,737 Sovereign obligations 1,216,643 956,992 — — 2,173,635 Commercial mortgage-backed securities — — 105 — 105 Loans — 1,148,824 3,486 — 1,152,310 Derivatives 249,361 3,480,506 16,041 (3,490,514 ) 255,394 Total trading liabilities $ 4,618,008 $ 7,307,269 $ 20,202 $ (3,490,514 ) $ 8,454,965 Short-term borrowings $ — $ 23,324 $ — $ — $ 23,324 Long-term debt - structured notes $ — $ 606,956 $ — $ — $ 606,956 (1) Represents counterparty and cash collateral netting across the levels of the fair value hierarchy for positions with the same counterparty. (2) As of January 1, 2018, the Company adopted the FASB's new guidance that affects the accounting for equity investments and the presentation and disclosure requirements for financial instruments. At September 30, 2018 , equity investments are primarily classified as Trading assets, at fair value and the change in fair value of equity securities is now recognized through the Consolidated Statements of Operations. See Note 2 for additional information. The following is a description of the valuation basis, including valuation techniques and inputs, used in measuring our financial assets and liabilities that are accounted for at fair value on a recurring basis: Corporate Equity Securities • Exchange Traded Equity Securities: Exchange traded equity securities are measured based on quoted closing exchange prices, which are generally obtained from external pricing services, and are categorized within Level 1 of the fair value hierarchy, otherwise they are categorized within Level 2 of the fair value hierarchy. To the extent these securities are actively traded, valuation adjustments are not applied. • Non-Exchange Traded Equity Securities : Non-exchange traded equity securities are measured primarily using broker quotations, pricing data from external pricing services and prices observed from recently executed market transactions and are categorized within Level 2 of the fair value hierarchy. Where such information is not available, non-exchange traded equity securities are categorized within Level 3 of the fair value hierarchy and measured using valuation techniques involving quoted prices of or market data for comparable companies, similar company ratios and multiples (e.g., price/Earnings before interest, taxes, depreciation and amortization ("EBITDA"), price/book value), discounted cash flow analyses and transaction prices observed from subsequent financing or capital issuance by Jefferies Group. When using pricing data of comparable companies, judgment must be applied to adjust the pricing data to account for differences between the measured security and the comparable security (e.g., issuer market capitalization, yield, dividend rate, geographical concentration). • Equity Warrants: Non-exchange traded equity warrants are measured primarily using pricing data from external pricing services, prices observed from recently executed market transactions and broker quotations and are categorized within Level 2 of the fair value hierarchy. Where such information is not available, non-exchange traded equity warrants are generally categorized within Level 3 of the fair value hierarchy and are measured using the Black-Scholes model with key inputs impacting the valuation including the underlying security price, implied volatility, dividend yield, interest rate curve, strike price and maturity date. Corporate Debt Securities • Corporate Bonds: Corporate bonds are measured primarily using pricing data from external pricing services and broker quotations, where available, prices observed from recently executed market transactions and bond spreads or credit default swap spreads of the issuer adjusted for basis differences between the swap curve and the bond curve. Corporate bonds measured using these valuation methods are categorized within Level 2 of the fair value hierarchy. If broker quotes, pricing data or spread data is not available, alternative valuation techniques are used including cash flow models incorporating interest rate curves, single name or index credit default swap curves for comparable issuers and recovery rate assumptions. Corporate bonds measured using alternative valuation techniques are categorized within Level 3 of the fair value hierarchy and are a limited portion of our corporate bonds. • High Yield Corporate and Convertible Bonds: A significant portion of our high yield corporate and convertible bonds are categorized within Level 2 of the fair value hierarchy and are measured primarily using broker quotations and pricing data from external pricing services, where available, and prices observed from recently executed market transactions of institutional size. Where pricing data is less observable, valuations are categorized within Level 3 of the fair value hierarchy and are based on pending transactions involving the issuer or comparable issuers, prices implied from an issuer’s subsequent financing or recapitalization, models incorporating financial ratios and projected cash flows of the issuer and market prices for comparable issuers. Collateralized Debt Obligations and Collateralized Loan Obligations Collateralized Debt Obligations ("CDOs") and Collateralized Loan Obligations ("CLOs") are measured based on prices observed from recently executed market transactions of the same or similar security or based on valuations received from third party brokers or data providers and are categorized within Level 2 or Level 3 of the fair value hierarchy depending on the observability and significance of the pricing inputs. Valuation that is based on recently executed market transactions of similar securities incorporates additional review and analysis of pricing inputs and comparability criteria, including, but not limited to, collateral type, tranche type, rating, origination year, prepayment rates, default rates and loss severity. U.S. Government and Federal Agency Securities • U.S. Treasury Securities: U.S. Treasury securities are measured based on quoted market prices and categorized within Level 1 of the fair value hierarchy. • U.S. Agency Debt Securities: Callable and non-callable U.S. agency debt securities are measured primarily based on quoted market prices obtained from external pricing services and are generally categorized within Level 1 or Level 2 of the fair value hierarchy. Municipal Securities Municipal securities are measured based on quoted prices obtained from external pricing services and are generally categorized within Level 2 of the fair value hierarchy. Sovereign Obligations Sovereign government obligations are measured based on quoted market prices obtained from external pricing services, where available, or recently executed independent transactions of comparable size. Sovereign government obligations are categorized within Level 1 or Level 2 of the fair value hierarchy, primarily based on the country of issuance. Sovereign government obligations are categorized within Level 2 or Level 3 of the fair value hierarchy depending on the observability of these input parameters. Residential Mortgage-Backed Securities • Agency Residential Mortgage-Backed Securities: Agency residential mortgage-backed securities include mortgage pass-through securities (fixed and adjustable rate), collateralized mortgage obligations and principal-only and interest-only (including inverse interest-only) securities. Agency residential mortgage-backed securities are generally measured using recent transactions, pricing data from external pricing services or expected future cash flow techniques that incorporate prepayment models and other prepayment assumptions to amortize the underlying mortgage loan collateral and are categorized within Level 2 of the fair value hierarchy. We use prices observed from recently executed transactions to develop market-clearing spread and yield curve assumptions. Valuation inputs with regard to the underlying collateral incorporate factors such as weighted average coupon, loan-to-value, credit scores, geographic location, maximum and average loan size, originator, servicer and weighted average loan age. • Non-Agency Residential Mortgage-Backed Securities: The fair value of non-agency residential mortgage-backed securities is determined primarily using discounted cash flow methodologies and securities are categorized within Level 2 or Level 3 of the fair value hierarchy based on the observability and significance of the pricing inputs used. Performance attributes of the underlying mortgage loans are evaluated to estimate pricing inputs, such as prepayment rates, default rates and the severity of credit losses. Attributes of the underlying mortgage loans that affect the pricing inputs include, but are not limited to, weighted average coupon; average and maximum loan size; loan-to-value; credit scores; documentation type; geographic location; weighted average loan age; originator; servicer; historical prepayment, default and loss severity experience of the mortgage loan pool; and delinquency rate. Yield curves used in the discounted cash flow models are based on observed market prices for comparable securities and published interest rate data to estimate market yields. In addition, broker quotes, where available, are also referenced to compare prices primarily on interest-only securities. Commercial Mortgage-Backed Securities • Agency Commercial Mortgage-Backed Securities: Government National Mortgage Association ("GNMA") project loan bonds are measured based on inputs corroborated from and benchmarked to observed prices of recent securitization transactions of similar securities with adjustments incorporating an evaluation of various factors, including prepayment speeds, default rates and cash flow structures, as well as the likelihood of pricing levels in the current market environment. Federal National Mortgage Association ("FNMA") Delegated Underwriting and Servicing ("DUS") mortgage-backed securities are generally measured by using prices observed from recently executed market transactions to estimate market-clearing spread levels for purposes of estimating fair value. GNMA project loan bonds and FNMA DUS mortgage-backed securities are categorized within Level 2 of the fair value hierarchy. • Non-Agency Commercial Mortgage-Backed Securities: Non-agency commercial mortgage-backed securities are measured using pricing data obtained from external pricing services, prices observed from recently executed market transactions or based on expected cash flow models that incorporate underlying loan collateral characteristics and performance. Non-agency commercial mortgage-backed securities are categorized within Level 2 and Level 3 of the fair value hierarchy depending on the observability of the underlying inputs. Other Asset-Backed Securities Other asset-backed securities include, but are not limited to, securities backed by auto loans, credit card receivables, student loans and other consumer loans and are categorized within Level 2 or Level 3 of the fair value hierarchy. Valuations are primarily determined using pricing data obtained from external pricing services, broker quotes and prices observed from recently executed market transactions. In addition, recent transaction data from comparable deals is deployed to develop market clearing yields and cumulative loss assumptions. The cumulative loss assumptions are based on the analysis of the underlying collateral and comparisons to earlier deals from the same issuer to gauge the relative performance of the deal. Loans and Other Receivables • Corporate Loans: Corporate loans categorized within Level 2 of the fair value hierarchy are measured based on market consensus pricing service quotations. Where available, market price quotations from external pricing services are reviewed to ensure they are supported by transaction data. Corporate loans categorized within Level 3 of the fair value hierarchy are measured based on price quotations that are considered to be less transparent, market prices for debt securities of the same creditor and estimates of future cash flows incorporating assumptions regarding creditor default and recovery rates and consideration of the issuer’s capital structure. • Participation Certificates in Agency Residential Loans: Valuations of participation certificates in agency residential loans are based on observed market prices of recently executed purchases and sales of similar loans and data provider pricing. The loan participation certificates are categorized within Level 2 of the fair value hierarchy given the observability and volume of recently executed transactions and availability of data provider pricing. • Project Loans and Participation Certificates in GNMA Project and Construction Loans: Valuations of participation certificates in GNMA project and construction loans are based on inputs corroborated from and benchmarked to observed prices of recent securitizations with similar underlying loan collateral to derive an implied spread. Securitization prices are adjusted to estimate the fair value of the loans to account for the arbitrage that is realized at the time of securitization. The measurements are categorized within Level 2 of the fair value hierarchy given the observability and volume of recently executed transactions. • Consumer Loans and Funding Facilities: Consumer and small business whole loans and related funding facilities are valued based on observed market transactions and incorporating valuation inputs including, but not limited to, delinquency and default rates, prepayment rates, borrower characteristics, loan risk grades and loan age. These assets are categorized within Level 2 or Level 3 of the fair value hierarchy. • Escrow and Trade Claim Receivables: Escrow and trade claim receivables are categorized within Level 3 of the fair value hierarchy where fair value is estimated based on reference to market prices and implied yields of debt securities of the same or similar issuers. Escrow and trade claim receivables are categorized within Level 2 of the fair value hierarchy where fair value is based on recent observations in the same receivable. Derivatives • Listed Derivative Contracts: Listed derivative contracts that are actively traded are measured based on quoted exchange prices, broker quotes or vanilla option valuation models, such as Black-Scholes, using observable valuation inputs from the principal market or consensus pricing services. Exchange quotes and/or valuation inputs are generally obtained from external vendors and pricing services. Broker quotes are validated directly through observable and tradeable quotes. Listed derivative contracts that use unadjusted exchange close prices are generally categorized within Level 1 of the fair value hierarchy. All other listed derivative contracts are generally categorized within Level 2 of the fair value hierarchy. • Over-the-Counter ("OTC") Derivative Contracts: OTC derivative contracts are generally valued using models, whose inputs reflect assumptions that we believe market participants would use in valuing the derivative in a current transaction. Inputs to valuation models are appropriately calibrated to market data. For many OTC derivative contracts, the valuation models do not involve material subjectivity as the methodologies do not entail significant judgment and the inputs to valuation models do not involve a high degree of subjectivity as the valuation model inputs are readily observable or can be derived from actively quoted markets. OTC derivative contracts are primarily categorized within Level 2 of the fair value hierarchy given the observability and significance of the inputs to the valuation models. Where significant inputs to the valuation are unobservable, derivative instruments are categorized within Level 3 of the fair value hierarchy. OTC options include OTC equity, foreign exchange, interest rate and commodity options measured using various valuation models, such as Black-Scholes, with key inputs including the underlying security price, foreign exchange spot rate, commodity price, implied volatility, dividend yield, interest rate curve, strike price and maturity date. Discounted cash flow models are utilized to measure certain OTC derivative contracts including the valuations of our interest rate swaps, which incorporate observable inputs related to interest rate curves, valuations of our foreign exchange forwards and swaps, which incorporate observable inputs related to foreign currency spot rates and forward curves and valuations of our commodity swaps and forwards, which incorporate observable inputs related to commodity spot prices and forward curves. Discounted cash flow models are also utilized to measure certain variable funding note swaps, which are backed by CLOs and incorporate constant prepayment rate, constant default rate and loss severity assumptions. Credit default swaps include both index and single-name credit default swaps. External prices are available as inputs in measuring index credit default swaps and single-name credit default swaps. For commodity and equity total return swaps, market prices are generally observable for the underlying asset and used as the basis for measuring the fair value of the derivative contracts. Total return swaps executed on other underlyings are measured based on valuations received from external pricing services. • Oil Futures Derivatives: Vitesse Energy Finance uses swaps and call and put options in order to reduce exposure to future oil price fluctuations. Vitesse Energy Finance accounts for the derivative instruments at fair value, which are classified as either Level 1 or Level 2 within the fair value hierarchy. Fair values classified as Level 1 are measured based on quoted closing exchange prices obtained from external pricing services and Level 2 are determined under the income valuation technique using an option-pricing model that is based on directly or indirectly observable inputs. Investments at Fair Value Investments at fair value based on NAV include investments in hedge funds, fund of funds and private equity funds, which are measured at the NAV of the funds, provided by the fund managers and are excluded from the fair value hierarchy. Investments at fair value also include direct equity investments in private companies, which are measured at fair value using valuation techniques involving quoted prices of or market data for comparable companies, similar company ratios and multiples (e.g., price/EBITDA, price/book value), discounted cash flow analyses and transaction prices observed for subsequent financing or capital issuance by the company. Direct equity investments in private companies are categorized within Level 2 or Level 3 of the fair value hierarchy. Additionally, investments at fair value include investments in insurance contracts relating to Jefferies Group's defined benefit plan in Germany. Fair value for the insurance contracts is determined using a third party and is categorized within Level 3 of the fair value hierarchy. The following tables present information about our investments in entities that have the characteristics of an investment company (in thousands). Fair Value (1) Unfunded Commitments Redemption Frequency (if currently eligible) September 30, 2018 Equity Long/Short Hedge Funds (2) $ 90,347 $ — (2) Fixed Income and High Yield Hedge Funds (3) 219 — — Fund of Funds (4) 175 — — Equity Funds (5) 36,702 20,209 — Commodity Funds (6) 10,228 — — Multi-asset Funds (7) 261,361 — — Total $ 399,032 $ 20,209 December 31, 2017 Equity Long/Short Hedge Funds (2) $ 407,895 $ — (2) Fixed Income and High Yield Hedge Funds (3) 417 — — Fund of Funds (4) 189 — — Equity Funds (5) 26,798 19,084 — Multi-asset Funds (7) 154,805 — — Total $ 590,104 $ 19,084 (1) Where fair value is calculated based on NAV, fair value has been derived from each of the funds' capital statements. (2) This category includes investments in hedge funds that invest, long and short, primarily in equity securities in domestic and international markets in both the public and private sectors. At December 31, 2017 , 73% of these investments were redeemable with 10 business days or less prior written notice; these investments were primarily liquidated during 2018. At September 30, 2018 and December 31, 2017 , 18% and 15% , respectively, of these investments are redeemable with 30 to 60 days prior written notice. (3) This category includes investments in funds that invest in loans secured by a first trust deed on property, domestic and international public high yield debt, private high yield investments, senior bank loans, public leveraged equities, distressed debt and private equity investments. There are no redemption provisions. (4) This category includes investments in fund of funds that invest in various private equity funds. The investments in this category are managed by us and have no redemption provisions. These investments are gradually being liquidated or we have requested redemption, however, we are unable to estimate when these funds will be received. (5) The investments in this category include investments in equity funds that invest in the equity of various U.S. and foreign private companies in the energy, technology, internet service and telecommunication service industries. These investments cannot be redeemed; instead distributions are received through the liquidation of the underlying assets of the funds, which are expected to be liquidated in one to ten years. (6) This category includes investments in hedge funds that invest, long and short, primarily in commodities. Investments in this category are redeemable with 60 days prior written notice. (7) This category includes investments in hedge funds that invest, long and short, primarily in multi-asset securities in domestic and international markets in both the public and private sectors. At September 30, 2018 and December 31, 2017 , investments representing approximately 17% and 12% , respectively, of the fair value of investments in this category are redeemable with 30 days prior written notice. Investment in FXCM FXCM Group, LLC ("FXCM") is a provider of online foreign exchange trading services. In January 2015, we entered into a credit agreement with FXCM, and provided FXCM a $300 million senior secured term loan due January 2017 (the term of which was subsequently extended to January 2019), with rights to a variable proportion of certain future distributions in connection with an FXCM sale of assets or certain other events, and to require a sale of FXCM beginning in January 2018. The loan had an initial interest rate of 10% per annum, increasing by 1.5% per annum each quarter, not to exceed 20.5% per annum. During the nine months ended September 30, 2018 , interest accrued at 20.5% per annum. During the nine months ended September 30, 2018 , we received $15.4 million of principal and interest from FXCM and $70.6 million of principal remained outstanding under the term loan as of September 30, 2018 . Through September 30, 2018 , we have received cumulatively $347.0 million of principal, interest and fees from our initial $279.0 million investment in FXCM. Our investment in the FXCM term loan is reported within Trading assets, at fair value in our Consolidated Statements of Financial Condition, and unrealized and realized changes in value, including the component related to interest income on the loan, is included within Principal transactions revenues in the Consolidated Statements of Operations. We recorded gains related to the term loan in Principal transactions revenues of $1.3 million and $16.4 million during the three and nine months ended September 30, 2018 , respectively, and $2.3 million and $17.6 million during the three and nine months ended September 30, 2017 , respectively. On September 1, 2016, we, Global Brokerage Inc. ("Global Brokerage") and Global Brokerage Holdings, LLC ("Global Brokerage Holdings") entered into an agreement that amended the terms of our loan and associated rights. On November 10, 2017, the terms of our loan and associated rights were amended further. Among other changes, the amendments extended the maturity of the term loan to January 2019; and exchanged our rights for a 50% voting interest in FXCM, and up to 75% of all distributions. Through these amendments, we also gained the right to appoint three of six board members for FXCM. We have the right, as does Global Brokerage Holdings, the owner of the remaining 50% of FXCM voting interest that is not held by Jefferies, to require a sale of FXCM beginning in January 2018. Distributions to Jefferies under the amended agreements are now: 100% until amounts due under the loan are repaid; 50% of the next $350 million ; then 90% of the next $600 million ; and 60% of all amounts thereafter. Through the amendments, we gained the ability to significantly influence FXCM through our seats on the board of directors. As a result, we classify our equity investment in FXCM in our September 30, 2018 and December 31, 2017 Consolidated Statements of Financial Condition as Loans to and investments in associated companies. We account for our equity interest on a one month lag. As the amendments only extended the maturity of the term loan, we continue to use the fair value option and classify our term loan within Trading assets, at fair value. FXCM is considered a variable interest entity ("VIE") and our term loan and equity ownership are variable interests. We have determined that we are not the primary beneficiary of FXCM because we do not have the power to direct the activities that most significantly impact FXCM's performance. Therefore, we do not consolidate FXCM and we account for our equity interest as an investment in an associated company. Our maximum exposure to loss as a result of our involvement with FXCM is limited to the carrying value of the term loan ( $73.8 million ) and the investment in associated company ( $139.0 million ), which totaled $212.8 million at September 30, 2018 . We estimate the fair value of our term loan by using a valuation model with inputs including management’s assumptions concerning the amount and timing of expected cash flows, the loan’s implied credit rating and effective yield. Because of these inputs and the degree of judgment involved, we have categorized our term loan within Level 3 of the fair value hierarchy. Nonrecurring Fair Value Measurements As described further in Note 9, in the third quarter of 2018 we engaged an independent valuation firm to assist management in estimating the fair value of our equity investment in Golden Queen. Our estimate of fair value was based on a discounted cash flow analysis and is categorized within Level 3 of the fair value hierarchy. The discounted cash flow valuation model used inputs including management's projections of future Golden Queen cash flows and a discount rate of 12% . The estimated fair value of our equity investment in Golden Queen was $62.3 million , which was $47.9 million lower than our prior carrying value at the end of the second quarter 2018. As a result, an impairment charge of $47.9 million was recorded in Income (loss) related to associated companies in the three and nine months ended September 30, 2018 . Additionally, in the first quarter of 2017 we engaged an independent valuation firm to assist management in estimating the fair value of our equity investment in FXCM. Our first quarter estimate of fair value was based on a discounted cash flow and comparable public company analysis and is categorized within Level 3 of the fair value hierarchy. The discounted cash flow valuation model used inputs including management's projections of future FXCM cash flows and a discount rate of approximately 15% . The comparable public company model used market data for comparable companies including a price to EBITDA multiple of 5.4 and a price to revenue multiple of 1.5 . The estimated fair value of our equity investment in FXCM was $186.7 million , which was $130.2 million lower than the carrying value at the end of the first quarter 2017. As a result, an impairment charge of $130.2 million was recorded in Income (loss) related to associated companies in the first quarter of 2017. Other Secured Financings Other secured financings that are accounted for at fair value include notes issued by consolidated VIEs, which are categorized within Level 2 or Level 3 of the fair value hierarchy. Fair value is based on recent transaction prices for similar assets. Short-term Borrowings/Long-term Debt Short-term borrowings tha

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Derivative Financial Instruments Derivative activities are recorded at fair value in the Consolidated Statements of Financial Condition in Trading assets and Trading liabilities, net of cash paid or received under credit support agreements and on a net counterparty basis when a legally enforceable right to offset exists under a master netting agreement. Predominantly, Jefferies Group and our Leucadia Asset Management businesses may enter into derivative transactions to satisfy the needs of its clients and to manage its own exposure to market and credit risks resulting from trading activities. In addition, Jefferies Group applies hedge accounting to an interest rate swap that has been designated as a fair value hedge of the changes in fair value due to the benchmark interest rate for certain fixed rate senior long-term debt. See Notes 3 and 20 for additional disclosures about derivative financial instruments. Derivatives are subject to various risks similar to other financial instruments, including market, credit and operational risk. The risks of derivatives should not be viewed in isolation, but rather should be considered on an aggregate basis along with our other trading-related activities. Jefferies Group manages the risks associated with derivatives on an aggregate basis along with the risks associated with proprietary trading as part of its firm wide risk management policies. In connection with Jefferies Group's derivative activities, Jefferies Group may enter into International Swaps and Derivatives Association, Inc. ("ISDA") master netting agreements or similar agreements with counterparties. See Note 10 for additional information regarding the offsetting of derivative contracts. The following table presents the fair value and related number of derivative contracts categorized by type of derivative contract as reflected in the Consolidated Statements of Financial Condition at September 30, 2018 and December 31, 2017 . The fair value of assets/liabilities represents our receivable/payable for derivative financial instruments, gross of counterparty netting and cash collateral received and pledged. The following tables also provide information regarding (1) the extent to which, under enforceable master netting arrangements, such balances are presented net in our Consolidated Statements of Financial Condition as appropriate under GAAP and (2) the extent to which other rights of setoff associated with these arrangements exist and could have an effect on our financial position (in thousands, except contract amounts): Assets Liabilities Fair Value Number of Contracts Fair Value Number of Contracts September 30, 2018 Derivatives designated as accounting hedges - interest rate contracts $ — — $ 30,018 1 Derivatives not designated as accounting hedges: Interest rate contracts $ 766,233 20,867 $ 892,562 38,331 Foreign exchange contracts 234,641 8,569 223,565 7,486 Equity contracts 2,491,005 1,892,926 2,987,654 1,836,128 Commodity contracts 4,599 6,331 16,312 3,585 Credit contracts 27,267 172 20,140 76 Total 3,523,745 4,140,233 Counterparty/cash-collateral netting (1) (3,334,100 ) (3,454,488 ) Total derivatives not designated as accounting hedges $ 189,645 $ 685,745 Total per Consolidated Statement of Financial Condition (2) $ 189,645 $ 715,763 December 31, 2017 Derivatives designated as accounting hedges - interest rate contracts $ — — $ 2,420 1 Derivatives not designated as accounting hedges: Interest rate contracts $ 1,717,058 38,941 $ 1,708,776 12,828 Foreign exchange contracts 366,541 6,463 349,512 4,612 Equity contracts 1,373,016 2,728,750 1,638,258 2,118,526 Commodity contracts 3,093 7,249 5,141 6,047 Credit contracts 38,261 130 41,801 191 Total 3,497,969 3,743,488 Counterparty/cash-collateral netting (1)(3) (3,318,481 ) (3,490,514 ) Total derivatives not designated as accounting hedges $ 179,488 $ 252,974 Total per Consolidated Statement of Financial Condition (2)(3) $ 179,488 $ 255,394 (1) Amounts netted include both netting by counterparty and for cash collateral paid or received. (2) We have not received or pledged additional collateral under master netting agreements and/or other credit support agreements that is eligible to be offset beyond what has been offset in the Consolidated Statements of Financial Condition. (3) Pursuant to a rule change by the London Clearing House in the first fiscal quarter of 2018, variation margin exchanged each day with this clearing organization on certain interest rate derivatives is characterized as settlement payments as opposed to cash posted as collateral. The impact of this rule change would have been a reduction in gross interest rate derivative assets and liabilities as of December 31, 2017 of approximately $800 million , and a corresponding decrease in counterparty and cash collateral netting, with no impact to our Consolidated Statement of Financial Condition . The following table provides information related to gains (losses) recognized in Interest expense of Jefferies Group in the Consolidated Statements of Operations on a fair value hedge (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate swaps $ (1,161 ) $ 6,217 $ (22,363 ) $ 13,960 Long-term debt 1,221 (4,680 ) 24,055 (9,570 ) Total $ 60 $ 1,537 $ 1,692 $ 4,390 The following table presents unrealized and realized gains (losses) on derivative contracts which are primarily recognized in Principal transactions revenues in Income (loss) from continuing operations in the Consolidated Statements of Operations, which are utilized in connection with our client activities and our economic risk management activities (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate contracts $ 13,951 $ (7,485 ) $ 36,053 $ 2,555 Foreign exchange contracts (4,781 ) 481 6,737 3,341 Equity contracts 1,019 (142,931 ) (249,546 ) (294,635 ) Commodity contracts (6,845 ) (1,422 ) (23,150 ) (3,260 ) Credit contracts 20 (7,947 ) 760 6,133 Total $ 3,364 $ (159,304 ) $ (229,146 ) $ (285,866 ) The net gains (losses) on derivative contracts in the table above are one of a number of activities comprising Jefferies Group's business activities and are before consideration of economic hedging transactions, which generally offset the net gains (losses) included above. Jefferies Group substantially mitigates its exposure to market risk on its cash instruments through derivative contracts, which generally provide offsetting revenues, and Jefferies Group manages the risk associated with these contracts in the context of its overall risk management framework. OTC Derivatives. The following tables set forth by remaining contract maturity the fair value of OTC derivative assets and liabilities as reflected in the Consolidated Statement of Financial Condition at September 30, 2018 (in thousands): OTC Derivative Assets (1) (2) (3) 0-12 Months 1-5 Years Greater Than 5 Years Cross- Maturity Netting (4) Total Commodity swaps, options and forwards $ 738 $ 512 $ — $ — $ 1,250 Equity swaps and options 10,226 8,071 2,195 — 20,492 Credit default swaps 82 21,802 — (11 ) 21,873 Total return swaps 46,036 29,910 — (4,334 ) 71,612 Foreign currency forwards, swaps and options 42,326 22,130 — (9,550 ) 54,906 Fixed income forwards 2,113 — — — 2,113 Interest rate swaps, options and forwards 13,104 96,631 95,973 (91,673 ) 114,035 Total $ 114,625 $ 179,056 $ 98,168 $ (105,568 ) 286,281 Cross product counterparty netting (34,971 ) Total OTC derivative assets included in Trading assets $ 251,310 (1) At September 30, 2018 , we held exchange traded derivative assets, other derivative assets and other credit agreements with a fair value of $96.6 million , which are not included in this table. (2) OTC derivative assets in the table above are gross of collateral received. OTC derivative assets are recorded net of collateral received in the Consolidated Statements of Financial Condition. At September 30, 2018 , cash collateral received was $158.2 million . (3) Derivative fair values include counterparty netting within product category. (4) Amounts represent the netting of receivable balances with payable balances for the same counterparty within product category across maturity categories. OTC Derivative Liabilities (1) (2) (3) 0-12 Months 1-5 Years Greater Than 5 Years Cross-Maturity Netting (4) Total Commodity swaps, options and forwards $ 12,234 $ 2,388 $ — $ — $ 14,622 Equity swaps and options 15,125 92,491 13,048 — 120,664 Credit default swaps 17 11,480 — (11 ) 11,486 Total return swaps 67,526 19,806 — (4,334 ) 82,998 Foreign currency forwards, swaps and options 36,183 17,496 — (9,550 ) 44,129 Fixed income forwards 685 — — — 685 Interest rate swaps, options and forwards 16,388 148,685 198,569 (91,673 ) 271,969 Total $ 148,158 $ 292,346 $ 211,617 $ (105,568 ) 546,553 Cross product counterparty netting (34,971 ) Total OTC derivative liabilities included in Trading liabilities $ 511,582 (1) At September 30, 2018 , we held exchange traded derivative liabilities, other derivative liabilities and other credit agreements with a fair value of $482.8 million , which are not included in this table. (2) OTC derivative liabilities in the table above are gross of collateral pledged. OTC derivative liabilities are recorded net of collateral pledged in the Consolidated Statements of Financial Condition. At September 30, 2018 , cash collateral pledged was $278.6 million . (3) Derivative fair values include counterparty netting within product category. (4) Amounts represent the netting of receivable balances with payable balances for the same counterparty within product category across maturity categories. At September 30, 2018 , the counterparty credit quality with respect to the fair value of our OTC derivative assets was as follows (in thousands): Counterparty credit quality (1): A- or higher $ 137,910 BBB- to BBB+ 20,490 BB+ or lower 74,097 Unrated 18,813 Total $ 251,310 (1) Jefferies Group utilizes internal credit ratings determined by Jefferies Group's Risk Management department. Credit ratings determined by Risk Management use methodologies that produce ratings generally consistent with those produced by external rating agencies. Credit Related Derivative Contracts The external credit ratings of the underlyings or referenced assets for our written credit related derivative contracts (in millions): External Credit Rating Investment Grade Non-investment grade Unrated Total Notional September 30, 2018 Credit protection sold: Index credit default swaps $ 3.0 $ 15.0 $ — $ 18.0 Single name credit default swaps $ 32.5 $ 39.9 $ 2.9 $ 75.3 December 31, 2017 Credit protection sold: Index credit default swaps $ 3.0 $ 126.0 $ — $ 129.0 Single name credit default swaps $ 129.1 $ 89.1 $ — $ 218.2 Contingent Features Certain of Jefferies Group's derivative instruments contain provisions that require their debt to maintain an investment grade credit rating from each of the major credit rating agencies. If Jefferies Group's debt were to fall below investment grade, it would be in violation of these provisions and the counterparties to the derivative instruments could request immediate payment or demand immediate and ongoing full overnight collateralization on Jefferies Group's derivative instruments in liability positions. The following table presents the aggregate fair value of all derivative instruments with such credit-risk-related contingent features that are in a liability position, the collateral amounts posted or received in the normal course of business and the potential collateral Jefferies Group would have been required to return and/or post additionally to its counterparties if the credit-risk-related contingent features underlying these agreements were triggered (in millions): September 30, 2018 December 31, 2017 Derivative instrument liabilities with credit-risk-related contingent features $ 106.3 $ 95.1 Collateral posted $ (59.3 ) $ (86.4 ) Collateral received $ 129.7 $ 5.6 Return of and additional collateral required in the event of a credit rating downgrade below investment grade (1) $ 176.6 $ 14.3 (1) These outflows include initial margin received from counterparties at the execution of the derivative contract. The initial margin will be returned if counterparties elect to terminate the contract after a downgrade. Other Derivatives Vitesse Energy Finance uses swaps and call and put options in order to reduce exposure to future oil price fluctuations. Vitesse Energy Finance accounts for the derivative instruments at fair value. The gains and losses associated with the change in fair value of the derivatives are recorded in Other revenues.

Collateralized Transactions

Collateralized Transactions	9 Months Ended
	Sep. 30, 2018
Collateralized Transactions [Abstract]
Collateralized Transactions	Collateralized Transactions Jefferies Group enters into secured borrowing and lending arrangements to obtain collateral necessary to effect settlement, finance inventory positions, meet customer needs or re-lend as part of dealer operations. Jefferies Group monitors the fair value of the securities loaned and borrowed on a daily basis as compared with the related payable or receivable, and requests additional collateral or return of excess collateral, as appropriate. Jefferies Group pledges financial instruments as collateral under repurchase agreements, securities lending agreements and other secured arrangements, including clearing arrangements. Jefferies Group's agreements with counterparties generally contain contractual provisions allowing the counterparty the right to sell or repledge the collateral. Pledged securities owned that can be sold or repledged by the counterparty are included in Financial instruments owned and noted parenthetically as Securities pledged in our Consolidated Statements of Financial Condition. The following tables set forth the carrying value of securities lending arrangements and repurchase agreements by class of collateral pledged and remaining contractual maturity (in thousands): Collateral Pledged Securities Lending Arrangements Repurchase Agreements Total September 30, 2018 Cash $ — $ 4,361 $ 4,361 Corporate equity securities 2,214,433 490,609 2,705,042 Corporate debt securities 315,718 1,496,127 1,811,845 Mortgage- and asset-backed securities — 2,667,439 2,667,439 U.S. government and federal agency securities 1,353 10,124,642 10,125,995 Municipal securities — 582,699 582,699 Sovereign obligations — 1,955,879 1,955,879 Loans and other receivables — 517,703 517,703 Total $ 2,531,504 $ 17,839,459 $ 20,370,963 December 31, 2017 Corporate equity securities $ 2,353,798 $ 214,413 $ 2,568,211 Corporate debt securities 470,908 2,336,702 2,807,610 Mortgage- and asset-backed securities — 2,562,268 2,562,268 U.S. government and federal agency securities 19,205 11,792,534 11,811,739 Municipal securities — 444,861 444,861 Sovereign obligations — 2,023,530 2,023,530 Loans and other receivables — 454,941 454,941 Total $ 2,843,911 $ 19,829,249 $ 22,673,160 Contractual Maturity Overnight and Continuous Up to 30 Days 30 to 90 Days Greater than 90 Days Total September 30, 2018 Securities lending arrangements $ 1,354,136 $ — $ 847,577 $ 329,791 $ 2,531,504 Repurchase agreements 8,122,962 2,733,400 4,342,923 2,640,174 17,839,459 Total $ 9,477,098 $ 2,733,400 $ 5,190,500 $ 2,969,965 $ 20,370,963 December 31, 2017 Securities lending arrangements $ 1,676,940 $ — $ 741,971 $ 425,000 $ 2,843,911 Repurchase agreements 10,780,474 4,058,228 3,211,464 1,779,083 19,829,249 Total $ 12,457,414 $ 4,058,228 $ 3,953,435 $ 2,204,083 $ 22,673,160 Jefferies Group receives securities as collateral under resale agreements, securities borrowing transactions and customer margin loans. Jefferies Group also receives securities as collateral in connection with securities-for-securities transactions in which it is the lender of securities. In many instances, Jefferies Group is permitted by contract to rehypothecate the securities received as collateral. These securities may be used to secure repurchase agreements, enter into securities lending transactions, satisfy margin requirements on derivative transactions or cover short positions. At September 30, 2018 and December 31, 2017 , the approximate fair value of securities received as collateral by Jefferies Group that may be sold or repledged was $25.2 billion and $27.1 billion , respectively. A substantial portion of these securities have been sold or repledged.

Securitization Activities

Securitization Activities	9 Months Ended
	Sep. 30, 2018
Securitization Activities [Abstract]
Securitization Activities	Securitization Activities Jefferies Group engages in securitization activities related to corporate loans, commercial mortgage loans, consumer loans and mortgage-backed and other asset-backed securities. In securitization transactions, Jefferies Group transfers assets to special purpose entities ("SPEs") and acts as the placement or structuring agent for the beneficial interests sold to investors by the SPE. A significant portion of the securitization transactions are the securitization of assets issued or guaranteed by U.S. government agencies. These SPEs generally meet the criteria of VIEs; however, the SPEs are generally not consolidated as Jefferies Group is not considered the primary beneficiary for these SPEs. Jefferies Group accounts for securitization transactions as sales, provided it has relinquished control over the transferred assets. Transferred assets are carried at fair value with unrealized gains and losses reflected in Principal transactions revenues in the Consolidated Statements of Operations prior to the identification and isolation for securitization. Subsequently, revenues recognized upon securitization are reflected as net underwriting revenues. Jefferies Group generally receives cash proceeds in connection with the transfer of assets to an SPE. Jefferies Group may, however, have continuing involvement with the transferred assets, which is limited to retaining one or more tranches of the securitization (primarily senior and subordinated debt securities in the form of mortgage- and other asset-backed securities or CLOs), which are included in Trading assets and are generally initially categorized as Level 2 within the fair value hierarchy. Jefferies Group applies fair value accounting to the securities. The following table presents activity related to Jefferies Group's securitizations that were accounted for as sales in which it had continuing involvement (in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Transferred assets $ 1,865.5 $ 1,009.1 $ 5,665.9 $ 2,677.7 Proceeds on new securitizations $ 1,866.2 $ 1,017.2 $ 5,668.6 $ 2,703.3 Cash flows received on retained interests $ 17.2 $ 8.7 $ 35.7 $ 22.7 Jefferies Group has no explicit or implicit arrangements to provide additional financial support to these SPEs, has no liabilities related to these SPEs and has no outstanding derivative contracts executed in connection with these securitization activities at September 30, 2018 and December 31, 2017 . The following table summarizes Jefferies Group's retained interests in SPEs where it transferred assets and has continuing involvement and received sale accounting treatment (in millions): September 30, 2018 December 31, 2017 Securitization Type Total Assets Retained Interests Total Assets Retained Interests U.S. government agency residential mortgage-backed securities $ 13,306.0 $ 192.7 $ 6,383.5 $ 28.2 U.S. government agency commercial mortgage-backed securities $ 2,101.5 $ 276.1 $ 2,075.7 $ 81.4 CLOs $ 3,442.3 $ 26.4 $ 3,957.8 $ 20.3 Consumer and other loans $ 648.9 $ 53.0 $ 247.6 $ 47.8 Total assets represent the unpaid principal amount of assets in the SPEs in which Jefferies Group has continuing involvement and are presented solely to provide information regarding the size of the transactions and the size of the underlying assets supporting its retained interests, and are not considered representative of the risk of potential loss. Assets retained in connection with a securitization transaction represent the fair value of the securities of one or more tranches issued by an SPE, including senior and subordinated tranches. Jefferies Group's risk of loss is limited to this fair value amount which is included in total Trading assets in our Consolidated Statements of Financial Condition. Although not obligated, in connection with secondary market-making activities Jefferies Group may make a market in the securities issued by these SPEs. In these market-making transactions, Jefferies Group buys these securities from and sells these securities to investors. Securities purchased through these market-making activities are not considered to be continuing involvement in these SPEs. To the extent Jefferies Group purchased securities through these market-making activities and Jefferies Group is not deemed to be the primary beneficiary of the VIE, these securities are included in agency and non-agency mortgage- and asset-backed securitizations in the nonconsolidated VIEs section presented in Note 8. Foursight Capital also utilizes SPEs to securitize automobile loans receivable. These SPEs are VIEs and our subsidiary is the primary beneficiary; the related assets and the secured borrowings are recognized in the Consolidated Statements of Financial Condition. These secured borrowings do not have recourse to our subsidiary’s general credit. See Note 8 for further information on securitization activities and VIEs.

Available for Sale Securities a

Available for Sale Securities and Other Investments	9 Months Ended
	Sep. 30, 2018
Investments [Abstract]
Available for Sale Securities and Other Investments	Available for Sale Securities and Other Investments The amortized cost, gross unrealized gains and losses and estimated fair value of investments classified as available for sale are as follows (in thousands): Amortized Gross Gross Estimated September 30, 2018 Bonds and notes: U.S. government securities $ 1,608,076 $ 2 $ 353 $ 1,607,725 Residential mortgage-backed securities 147,294 138 754 146,678 Commercial mortgage-backed securities 16,049 — 330 15,719 Other asset-backed securities 98,543 9 254 98,298 Total fixed maturities 1,869,962 149 1,691 1,868,420 Total Available for sale securities $ 1,869,962 $ 149 $ 1,691 $ 1,868,420 December 31, 2017 Bonds and notes: U.S. government securities $ 552,847 $ — $ 42 $ 552,805 Residential mortgage-backed securities 34,381 272 92 34,561 Commercial mortgage-backed securities 5,857 17 4 5,870 Other asset-backed securities 34,837 46 44 34,839 Total fixed maturities 627,922 335 182 628,075 Equity securities: Common stocks: Banks, trusts and insurance companies 35,071 17,500 — 52,571 Industrial, miscellaneous and all other 17,504 18,411 — 35,915 Total equity securities 52,575 35,911 — 88,486 Total Available for sale securities $ 680,497 $ 36,246 $ 182 $ 716,561 As of January 1, 2018, the Company adopted the FASB's new guidance that affects the accounting for equity investments and the presentation and disclosure requirements for financial instruments. At September 30, 2018 , equity investments are primarily classified as Trading assets, at fair value and the change in fair value of equity securities is now recognized through the Consolidated Statements of Operations. See Note 2 for additional information. At September 30, 2018 , the Company had other investments (classified as Other assets and Loans to and investments in associated companies) in which fair values are not readily determinable, aggregating $233.7 million . There were no unrealized gains, losses or impairments recognized on these investments during the three and nine months ended September 30, 2018 . The amortized cost and estimated fair value of investments classified as available for sale at September 30, 2018 , by contractual maturity, are shown below. Expected maturities are likely to differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Estimated Fair Value (In thousands) Due within one year $ 1,608,076 $ 1,607,725 1,608,076 1,607,725 Mortgage-backed and asset-backed securities 261,886 260,695 $ 1,869,962 $ 1,868,420 At September 30, 2018 , the unrealized losses on investments which have been in a continuous unrealized loss position 12 months or longer were not significant.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2018
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities VIEs are entities in which equity investors lack the characteristics of a controlling financial interest. VIEs are consolidated by the primary beneficiary. The primary beneficiary is the party who has both (1) the power to direct the activities of a VIE that most significantly impact the entity’s economic performance and (2) an obligation to absorb losses of the entity or a right to receive benefits from the entity that could potentially be significant to the entity. Our variable interests in VIEs include debt and equity interests, equity interests in associated companies, commitments, guarantees and certain fees. Our involvement with VIEs arises primarily from the following activities, but also includes other activities discussed below: • Purchases of securities in connection with our trading and secondary market-making activities; • Retained interests held as a result of securitization activities, including the resecuritization of mortgage- and other asset-backed securities and the securitization of commercial mortgage, corporate and consumer loans; • Acting as placement agent and/or underwriter in connection with client-sponsored securitizations; • Financing of agency and non-agency mortgage- and other asset-backed securities; • Warehouse funding arrangements for client-sponsored consumer loan vehicles and CLOs through participation certificates, forward sales agreements and revolving loan and note commitments; and • Loans to, investments in and fees from various investment vehicles. We determine whether we are the primary beneficiary of a VIE upon our initial involvement with the VIE and we reassess whether we are the primary beneficiary of a VIE on an ongoing basis. Our determination of whether we are the primary beneficiary of a VIE is based upon the facts and circumstances for each VIE and requires significant judgment. Our considerations in determining the VIE’s most significant activities and whether we have power to direct those activities include, but are not limited to, the VIE’s purpose and design and the risks passed through to investors, the voting interests of the VIE, management, service and/or other agreements of the VIE, involvement in the VIE’s initial design and the existence of explicit or implicit financial guarantees. In situations where we have determined that the power over the VIE’s significant activities is shared, we assess whether we are the party with the power over the most significant activities. If we are the party with the power over the most significant activities, we meet the "power" criteria of the primary beneficiary. If we do not have the power over the most significant activities or we determine that decisions require consent of each sharing party, we do not meet the "power" criteria of the primary beneficiary. We assess our variable interests in a VIE both individually and in aggregate to determine whether we have an obligation to absorb losses of or a right to receive benefits from the VIE that could potentially be significant to the VIE. The determination of whether our variable interest is significant to the VIE requires significant judgment. In determining the significance of our variable interest, we consider the terms, characteristics and size of the variable interests, the design and characteristics of the VIE, our involvement in the VIE and our market-making activities related to the variable interests. Consolidated VIEs The following table presents information about the assets and liabilities of our consolidated securitization vehicles VIEs, which are presented in our Consolidated Statements of Financial Condition in the respective asset and liability categories (in millions). The assets and liabilities in the table below are presented prior to consolidation and thus a portion of these assets and liabilities are eliminated in consolidation. September 30, 2018 December 31, 2017 Cash $ — $ 11.7 Financial instruments owned — 37.6 Securities purchased under agreement to resell (1) 1,043.4 729.3 Receivables 453.2 318.1 Other 25.8 15.5 Total assets $ 1,522.4 $ 1,112.2 Other secured financings (2) $ 1,478.3 $ 1,073.5 Other (3) 44.1 38.3 Total liabilities $ 1,522.4 $ 1,111.8 (1) Securities purchased under agreements to resell represent an amount due under a collateralized transaction on a related consolidated entity, which is eliminated in consolidation. (2) Approximately $37.7 million and $44.1 million of the secured financings represent an amount held by Jefferies Group in inventory and eliminated in consolidation at September 30, 2018 and December 31, 2017 , respectively. (3) Includes $31.1 million and $32.0 million at September 30, 2018 and December 31, 2017 , respectively, of intercompany payables that are eliminated in consolidation. Securitization Vehicles. Jefferies Group is the primary beneficiary of asset-backed financing vehicles to which Jefferies Group sells agency and non-agency residential and commercial mortgage loans, mortgage-backed securities and consumer loans pursuant to the terms of a master repurchase agreement. Jefferies Group manages the assets within these vehicles. Jefferies Group's variable interests in these vehicles consist of its collateral margin maintenance obligations under the master repurchase agreement and retained interests in securities issued. The assets of these VIEs consist of reverse repurchase agreements, which are available for the benefit of the vehicle’s debt holders. The creditors of these VIEs do not have recourse to Jefferies Group's general credit and each such VIE’s assets are not available to satisfy any other debt. Jefferies Group was previously the primary beneficiary of a securitization vehicle associated with their financing of small business loans. In the creation of the securitization vehicle, Jefferies Group was involved in the decisions made during the establishment and design of the entity and holds variable interests consisting of the securities retained that could potentially be significant. The assets of the VIE consisted of small business loans, which were available for the benefit of the vehicles' beneficial interest holders. The creditors of the VIE did not have recourse to Jefferies Group's general credit and the assets of the VIE were not available to satisfy any other debt. At September 30, 2018 and December 31, 2017 , Foursight Capital is the primary beneficiary of SPEs it utilized to securitize automobile loans receivable. Foursight Capital acts as the servicer for which it receives a fee, and owns an equity interest in the SPEs. The notes issued by the SPEs are secured solely by the assets of the SPEs and do not have recourse to Foursight Capital’s general credit and the assets of the VIEs are not available to satisfy any other debt. During the nine months ended September 30, 2018 , automobile loan receivables aggregating $290.9 million were securitized by Foursight Capital in connection with a secured borrowing offering. The majority of the proceeds from issuance of the secured borrowing were used to pay down Foursight Capital’s two credit facilities. Nonconsolidated VIEs The following tables present information about our variable interests in nonconsolidated VIEs (in millions): Financial Statement Carrying Amount Maximum Exposure to Loss VIE Assets Assets Liabilities September 30, 2018 CLOs $ 57.0 $ 0.7 $ 784.0 $ 3,348.0 Consumer loan vehicles 323.5 — 602.4 3,441.8 Related party private equity vehicles 34.1 — 52.0 107.2 Other private investment vehicles 160.4 — 170.8 5,324.2 Total $ 575.0 $ 0.7 $ 1,609.2 $ 12,221.2 December 31, 2017 CLOs $ 168.1 $ 8.9 $ 1,030.4 $ 5,364.3 Consumer loan vehicles 254.8 — 759.8 2,322.7 Related party private equity vehicles 23.7 — 45.4 75.0 Other private investment vehicles 133.0 — 142.0 4,624.9 Total $ 579.6 $ 8.9 $ 1,977.6 $ 12,386.9 Our maximum exposure to loss often differs from the carrying value of the variable interests. The maximum exposure to loss is dependent on the nature of the variable interests in the VIEs and is limited to the notional amounts of certain loan and equity commitments and guarantees. Our maximum exposure to loss does not include the offsetting benefit of any financial instruments that may be utilized to hedge the risks associated with its variable interests and is not reduced by the amount of collateral held as part of a transaction with a VIE. Collateralized Loan Obligations. Assets collateralizing the CLOs include bank loans, participation interests and sub-investment grade and senior secured U.S. loans. Jefferies Group underwrites securities issued in CLO transactions on behalf of sponsors and provides advisory services to the sponsors. Jefferies Group may also sell corporate loans to the CLOs. Jefferies Group's variable interests in connection with CLOs where it has been involved in providing underwriting and/or advisory services consist of the following: • Forward sale agreements whereby Jefferies Group commits to sell, at a fixed price, corporate loans and ownership interests in an entity holding such corporate loans to CLOs; • Warehouse funding arrangements in the form of participation interests in corporate loans held by CLOs and commitments to fund such participation interests; • Trading positions in securities issued in a CLO transaction; and • Investments in variable funding notes issued by CLOs. Consumer Loan Vehicles. Jefferies Group provides financing and lending related services to certain client-sponsored VIEs in the form of revolving funding note agreements, revolving credit facilities and forward purchase agreements. The underlying assets, which are collateralizing the vehicles, are primarily composed of unsecured consumer and small business loans. In addition, Jefferies Group may provide structuring and advisory services and act as an underwriter or placement agent for securities issued by the vehicles. Jefferies Group does not control the activities of these entities. Related Party Private Equity Vehicles. Jefferies Group committed to invest equity in private equity funds (the "JCP Funds") managed by Jefferies Capital Partners, LLC (the "JCP Manager"). Additionally, Jefferies Group committed to invest equity in the general partners of the JCP Funds (the "JCP General Partners") and the JCP Manager. Jefferies Group's variable interests in the JCP Funds, JCP General Partners and JCP Manager (collectively, the "JCP Entities") consist of equity interests that, in total, provide Jefferies Group with limited and general partner investment returns of the JCP Funds, a portion of the carried interest earned by the JCP General Partners and a portion of the management fees earned by the JCP Manager. At September 30, 2018 and December 31, 2017 , Jefferies Group's total equity commitment in the JCP Entities was $139.3 million and $148.1 million , respectively, of which $121.3 million and $126.3 million had been funded, respectively. The carrying value of Jefferies Group's equity investments in the JCP Entities was $34.1 million and $23.7 million at September 30, 2018 and December 31, 2017 , respectively. Jefferies Group's exposure to loss is limited to the total of its carrying value and unfunded equity commitment. The assets of the JCP Entities primarily consist of private equity and equity related investments. Other Private Investment Vehicles. The carrying amount of our equity investment was $160.4 million and $133.0 million at September 30, 2018 and December 31, 2017 , respectively. Our unfunded equity commitment related to these investments totaled $10.3 million and $9.1 million at September 30, 2018 and December 31, 2017 , respectively. Our exposure to loss is limited to the total of our carrying value and unfunded equity commitment. These private investment vehicles have assets primarily consisting of private and public equity investments, debt instruments and various oil and gas assets. Mortgage- and Other Asset-Backed Securitization Vehicles. In connection with Jefferies Group's secondary trading and market-making activities, Jefferies Group buys and sells agency and non-agency mortgage-backed securities and other asset-backed securities, which are issued by third-party securitization SPEs and are generally considered variable interests in VIEs. Securities issued by securitization SPEs are backed by residential mortgage loans, U.S. agency collateralized mortgage obligations, commercial mortgage loans, CDOs and CLOs and other consumer loans, such as installment receivables, auto loans and student loans. These securities are accounted for at fair value and included in Trading assets in our Consolidated Statements of Financial Condition. Jefferies Group has no other involvement with the related SPEs and therefore does not consolidate these entities. Jefferies Group also engages in underwriting, placement and structuring activities for third-party-sponsored securitization trusts generally through agency (FNMA ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac") or GNMA ("Ginnie Mae")) or non-agency-sponsored SPEs and may purchase loans or mortgage-backed securities from third parties that are subsequently transferred into the securitization trusts. The securitizations are backed by residential and commercial mortgage, home equity and auto loans. Jefferies Group does not consolidate agency-sponsored securitizations as it does not have the power to direct the activities of the SPEs that most significantly impact their economic performance. Further, Jefferies Group is not the servicer of non-agency-sponsored securitizations and therefore does not have power to direct the most significant activities of the SPEs and accordingly, does not consolidate these entities. Jefferies Group may retain unsold senior and/or subordinated interests at the time of securitization in the form of securities issued by the SPEs. Jefferies Group transfers existing securities, typically mortgage-backed securities, into resecuritization vehicles. These transactions in which debt securities are transferred to a VIE in exchange for new beneficial interests occur in connection with both agency and non-agency-sponsored VIEs. The consolidation analysis is largely dependent on Jefferies Group's role and interest in the resecuritization trusts. Most resecuritizations in which Jefferies Group is involved are in connection with investors seeking securities with specific risk and return characteristics. As such, Jefferies Group has concluded that the decision-making power is shared between Jefferies Group and the investor(s), considering the joint efforts involved in structuring the trust and selecting the underlying assets as well as the level of security interests the investor(s) hold in the SPE; therefore, Jefferies Group does not consolidate the resecuritization VIEs. At September 30, 2018 and December 31, 2017 , Jefferies Group held $2,622.2 million and $1,829.6 million of agency mortgage-backed securities, respectively, and $156.6 million and $253.2 million of non-agency mortgage- and other asset-backed securities, respectively, as a result of its secondary trading and market-making activities, underwriting, placement and structuring activities and resecuritization activities. Jefferies Group's maximum exposure to loss on these securities is limited to the carrying value of its investments in these securities. These mortgage- and other asset-backed securitization vehicles discussed are not included in the above table containing information about Jefferies Group's variable interests in nonconsolidated VIEs. We also have a variable interest in a nonconsolidated VIE consisting of our equity interest in an associated company, Golden Queen Mining Company, LLC ("Golden Queen"). In addition, we have a variable interest in a nonconsolidated VIE consisting of our senior secured term loan receivable and equity interest in FXCM. See Notes 3 and 9 for further discussion.

Loans to and Investments In Ass

Loans to and Investments In Associated Companies	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Loans to and Investments in Associated Companies	Loans to and Investments in Associated Companies A summary of Loans to and investments in associated companies accounted for under the equity method of accounting during the nine months ended September 30, 2018 and 2017 is as follows (in thousands): Loans to and investments in associated companies as of January 1, Income (losses) related to associated companies Income (losses) related to Jefferies Group's associated companies (1) Contributions to (distributions from) associated companies, net Other Loans to and investments in associated companies as of September 30, 2018 Jefferies Finance $ 655,467 $ — $ 36,497 $ 43,470 $ — $ 735,434 National Beef (2) — 83,287 — (48,656 ) 592,239 626,870 Berkadia 210,594 80,092 — (42,064 ) (1,054 ) 247,568 FXCM (3) 158,856 (19,322 ) — — (513 ) 139,021 Garcadia companies (4) 179,143 21,646 — (26,962 ) (173,827 ) — Linkem 192,136 (20,534 ) — 542 (3,601 ) 168,543 HomeFed 341,874 (3,338 ) — — — 338,536 Golden Queen (5) 105,005 (52,028 ) — 8,441 — 61,418 Other 223,754 (5,483 ) (5,810 ) (69,071 ) (9,879 ) 133,511 Total $ 2,066,829 $ 84,320 $ 30,687 $ (134,300 ) $ 403,365 $ 2,450,901 2017 Jefferies Finance $ 490,464 $ — $ 63,685 $ 109,899 $ — $ 664,048 Jefferies LoanCore 154,731 — 8,030 43,714 1,095 207,570 Berkadia 184,443 67,979 — (52,300 ) (174 ) 199,948 FXCM (3) 336,258 (166,360 ) — — 731 170,629 Garcadia companies 185,815 38,536 — (40,955 ) — 183,396 Linkem 154,000 (26,557 ) — 31,996 33,979 193,418 HomeFed 302,231 9,922 — 31,918 — 344,071 Golden Queen 111,302 (3,684 ) — (59 ) — 107,559 Other 205,854 (4,249 ) (6,392 ) 79,636 5,492 280,341 Total $ 2,125,098 $ (84,413 ) $ 65,323 $ 203,849 $ 41,123 $ 2,350,980 (1) Primarily classified in Investment banking revenues and Other revenues. (2) As discussed more fully in Notes 1 and 24, in June 2018, we completed the sale of 48% of National Beef to Marfrig, reducing our ownership in National Beef to 31% . As of the closing of the sale on June 5, 2018, we deconsolidated our investment in National Beef and account for our remaining interest under the equity method of accounting. The carrying value of our retained 31% interest was adjusted to a fair value of $592.3 million on the date of sale. (3) As further described in Note 3, our investment in FXCM includes both our equity method investment in FXCM and our term loan with FXCM. Our equity method investment is included as Loans to and investments in associated companies and our term loan is included as Trading assets, at fair value in our Consolidated Statements of Financial Condition. (4) As more fully discussed in Note 1, during the third quarter of 2018, we sold 100% of our equity interests in Garcadia and our associated real estate to our former partners, the Garff family. (5) At September 30, 2018 and December 31, 2017 , the balance reflects $15.1 million and $30.5 million , respectively, related to a noncontrolling interest. Income (losses) related to associated companies includes the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 National Beef $ 58,886 $ — $ 83,287 $ — Berkadia 28,350 34,839 80,092 67,979 FXCM (4,282 ) (4,345 ) (19,322 ) (166,360 ) Garcadia companies 691 12,565 21,646 38,536 Linkem (7,770 ) (9,533 ) (20,534 ) (26,557 ) HomeFed (7,783 ) 238 (3,338 ) 9,922 Golden Queen (48,732 ) (1,975 ) (52,028 ) (3,684 ) Other (493 ) (1,732 ) (5,483 ) (4,249 ) Total $ 18,867 $ 30,057 $ 84,320 $ (84,413 ) Income (losses) related to Jefferies Group's associated companies (primarily classified in Investment banking revenues and Other revenues) includes the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Jefferies Finance $ 5,931 $ 13,509 $ 36,497 $ 63,685 Jefferies LoanCore — 1,656 — 8,030 Other (78 ) (4,337 ) (5,810 ) (6,392 ) Total $ 5,853 $ 10,828 $ 30,687 $ 65,323 Jefferies Finance Through Jefferies Group, we own 50% of Jefferies Finance LLC ("Jefferies Finance"), our joint venture with Massachusetts Mutual Life Insurance Company ("MassMutual"). Jefferies Finance is a commercial finance company whose primary focus is the origination and syndication of senior secured debt to middle market and growth companies in the form of term and revolving loans. Loans are originated primarily through the investment banking efforts of Jefferies Group. Jefferies Finance may also originate other debt products such as second lien term, bridge and mezzanine loans, as well as related equity co-investments. Jefferies Finance also purchases syndicated loans in the secondary market and acts as an investment advisor for various loan funds. At September 30, 2018 , Jefferies Group and MassMutual each had equity commitments to Jefferies Finance of $750.0 million . At September 30, 2018 , $706.5 million of Jefferies Group's commitment was funded. The investment commitment is scheduled to expire on March 1, 2019 with automatic one year extensions absent a 60 -day termination notice by either party. Jefferies Finance has executed a Secured Revolving Credit Facility with Jefferies Group and MassMutual, to be funded equally, to support loan underwritings by Jefferies Finance, which bears interest based on the interest rates of the related Jefferies Finance underwritten loans and is secured by the underlying loans funded by the proceeds of the facility. The total Secured Revolving Credit Facility is a committed amount of $500.0 million at September 30, 2018 and December 31, 2017 . Advances are shared equally between Jefferies Group and MassMutual. The facility is scheduled to mature on March 1, 2019 with automatic one year extensions absent a 60 -day termination notice by either party. At September 30, 2018 and December 31, 2017 , none of Jefferies Group's $250.0 million commitment was funded. Jefferies Group recognized interest income and unfunded commitment fees related to the facility of $0.3 million and $0.5 million during the three months ended September 30, 2018 and 2017 , respectively, and $2.0 million and $3.3 million during the nine months ended September 30, 2018 and 2017 , respectively. Jefferies Group engages in debt capital markets transactions with Jefferies Finance related to the originations and syndications of loans by Jefferies Finance. In connection with such services, Jefferies Group earned fees of $71.1 million and $104.2 million during the three months ended September 30, 2018 and 2017 , respectively, and $282.1 million and $243.5 million during the nine months ended September 30, 2018 and 2017 , respectively, which are recognized in Investment banking revenues in the Consolidated Statements of Operations. In addition, Jefferies Group paid fees to Jefferies Finance in respect of certain loans originated by Jefferies Finance of $12.1 million and $0.0 million during the three months ended September 30, 2018 and 2017 , respectively, and $45.5 million and $2.5 million during the nine months ended September 30, 2018 and 2017 , respectively, which are recognized within Selling, general and other expenses in the Consolidated Statements of Operations. Jefferies Group acts as a placement agent for CLOs managed by Jefferies Finance, for which Jefferies Group recognized fees of $0.4 million and $0.8 million during the three months ended September 30, 2018 and 2017 , respectively, and $3.1 million and $4.7 million during the nine months ended September 30, 2018 and 2017 , respectively, which are included in Investment banking revenues in the Consolidated Statements of Operations. At September 30, 2018 and December 31, 2017 , Jefferies Group held securities issued by CLOs managed by Jefferies Finance, which are included in Trading assets. Additionally, Jefferies Group has entered into participation agreements and derivative contracts with Jefferies Finance based upon certain securities issued by the CLO. Gains (losses) related to the derivative contracts were not material. Under a service agreement, Jefferies Group charged Jefferies Finance $13.3 million and $7.9 million during the three months ended September 30, 2018 and 2017 , respectively, and $48.3 million and $37.4 million during the nine months ended September 30, 2018 and 2017 , respectively, for services provided. At September 30, 2018 , Jefferies Group had a receivable from Jefferies Finance, included in Other assets in the Consolidated Statement of Financial Condition, of $36.3 million and a payable to Jefferies Finance, included in Payables, expense accruals and other liabilities in the Consolidated Statement of Financial Condition of $14.1 million . At December 31, 2017 , Jefferies Group had a receivable from Jefferies Finance, included in Other assets in the Consolidated Statement of Financial Condition, of $34.6 million and a payable to Jefferies Finance, included in Payables, expense accruals and other liabilities in the Consolidated Statement of Financial Condition, of $14.1 million . Jefferies Group enters into OTC foreign exchange contracts with Jefferies Finance. In connection with these contracts Jefferies Group had $0.2 million recorded in Payables, expense accruals and other liabilities and $1.5 million included in Trading assets in our Consolidated Statements of Financial Condition at September 30, 2018 and December 31, 2017 , respectively. Jefferies LoanCore Jefferies LoanCore, a commercial real estate finance company and a joint venture with the Government of Singapore Investment Corporation, the Canada Pension Plan Investment Board and LoanCore, LLC, originates and purchases commercial real estate loans throughout the U.S. and Europe. On October 31, 2017, Jefferies Group sold all of its membership interests (which constituted a 48.5% voting interest) in Jefferies LoanCore for approximately $173.1 million , the estimated book value as of October 31, 2017. In addition, Jefferies Group may be entitled to additional cash consideration over the next five years in the event Jefferies LoanCore's yearly return on equity exceeds certain thresholds. National Beef National Beef processes and markets fresh and chilled boxed beef, ground beef, beef by-products, consumer-ready beef and pork, and wet blue leather for domestic and international markets. As discussed in Notes 1 and 24, on June 5, 2018, we completed the sale of 48% of National Beef to Marfrig, reducing our ownership in National Beef to 31% . As of the closing of the sale on June 5, 2018, we deconsolidated our investment in National Beef and account for our remaining interest under the equity method of accounting. As required as a result of the deconsolidation of National Beef, we adjusted the carrying value of our retained 31% interest in National Beef to fair value. The fair value of our retained 31% interest in National Beef of $592.3 million was based on the implied equity value of 100% of National Beef from the transaction with Marfrig. The transaction with Marfrig was based on a $1.9 billion equity valuation and a $2.3 billion enterprise valuation for 100% of National Beef. The fair value was allocated to the tangible and intangible assets of National Beef and a number of assets including customer relationships, tradenames, cattle supply contracts and property, plant and equipment had fair values higher than book values. As we recognize our share of National Beef's income going forward, the difference between the estimated fair value and the underlying book value of National Beef's customer relationships, tradenames, cattle supply contracts and property, plant and equipment will be amortized over their respective useful lives (weighted average life of 15 years). Berkadia Berkadia is a commercial mortgage banking and servicing joint venture formed in 2009 with Berkshire Hathaway Inc. We and Berkshire Hathaway each contributed $217.2 million of equity capital to the joint venture and each have a 50% equity interest in Berkadia. Berkadia originates commercial/multifamily real estate loans that are sold to U.S. government agencies, and originates and brokers commercial/multifamily mortgage loans which are not part of government agency programs. Berkadia is an investment sales advisor focused on the multifamily industry. Berkadia is a servicer of commercial real estate loans in the U.S., performing primary, master and special servicing functions for U.S. government agency programs, commercial mortgage-backed securities transactions, banks, insurance companies and other financial institutions. Berkadia uses all of the proceeds from the commercial paper sales of an affiliate of Berkadia to fund new mortgage loans, servicer advances, investments and other working capital requirements. Repayment of the commercial paper is supported by a $1.5 billion surety policy issued by a Berkshire Hathaway insurance subsidiary and corporate guaranty, and we have agreed to reimburse Berkshire Hathaway for one-half of any losses incurred thereunder. As of September 30, 2018 , the aggregate amount of commercial paper outstanding was $1.47 billion . As discussed further in Note 1, on October 1, 2018, the Company's interest in Berkadia was transferred to Jefferies Group. FXCM As discussed more fully in Note 3, at September 30, 2018 , Jefferies has a 50% voting interest in FXCM and a senior secured term loan to FXCM due January 2019. On September 1, 2016, we gained the ability to significantly influence FXCM through our seats on the board of directors. As a result, we classify our equity investment in FXCM in our Consolidated Statements of Financial Condition as Loans to and investments in associated companies. Our term loan remains classified within Trading assets, at fair value. We account for our equity interest in FXCM on a one month lag. We are amortizing our basis difference between the estimated fair value and the underlying book value of FXCM customer relationships, technology, tradename, leases and long-term debt over their respective useful lives. During February 2017, Global Brokerage Holdings and FXCM's U.S. subsidiary, Forex Capital Markets LLC ("FXCM U.S.") settled complaints filed by the National Futures Association and the Commodity Futures Trading Commission ("CFTC") against FXCM U.S. and certain of its principals relating to matters that occurred between 2010 and 2014. As part of the settlements, FXCM U.S. withdrew from business and sold FXCM U.S.'s customer accounts. Based on the above actions, we evaluated in the first quarter of 2017 whether our equity method investment was fully recoverable. We engaged an independent valuation firm to assist management in estimating the fair value of FXCM. Our estimate of fair value was based on a discounted cash flow and comparable public company analysis. The result of our analysis indicated that the estimated fair value of our equity interest in FXCM was lower than our carrying value by $130.2 million . We concluded based on the regulatory actions, FXCM's restructuring plan, investor perception and declines in the trading price of Global Brokerage's common shares and convertible debt, that the decline in fair value of our equity interest was other than temporary. As such, we impaired our equity investment in FXCM in the first quarter of 2017 by $130.2 million . FXCM is considered a VIE and our term loan and equity interest are variable interests. We have determined that we are not the primary beneficiary of FXCM because we do not have the power to direct the activities that most significantly impact FXCM's performance. Therefore, we do not consolidate FXCM. Garcadia Garcadia was a joint venture between us and Garff Enterprises, Inc. ("Garff") that owned and operated 28 automobile dealerships comprised of domestic and foreign automobile makers. The Garcadia joint venture agreement specified that we and Garff had equal board representation and equal votes on all matters affecting Garcadia, and that all operating cash flows from Garcadia would be allocated 65% to us and 35% to Garff, with the exception of one dealership from which we received 83% of all operating cash flows and four other dealerships from which we received 71% of all operating cash flows. Garcadia’s strategy was to acquire automobile dealerships in primary or secondary market locations meeting its specified return criteria. In the third quarter of 2018, we sold 100% of our equity interests in Garcadia and our associated real estate to our former partners, the Garff family, for $417.2 million in cash. The pre-tax gain recognized as a result of this transaction, $221.7 million for the three and nine months ended September 30, 2018 , is classified as Other revenue. Linkem We own approximately 42% of the common shares of Linkem, a fixed wireless broadband services provider in Italy. In addition, we own approximately 63% of the 5% convertible preferred stock, which is automatically convertible to common shares in 2022. If all of our convertible preferred stock was converted, it would increase our ownership to approximately 54% of Linkem’s common equity at September 30, 2018 . We have approximately 48% of the total voting securities of Linkem. HomeFed At September 30, 2018 , we own 10,852,123 shares of HomeFed’s common stock, representing approximately 70% of HomeFed’s outstanding common shares; however, we have contractually agreed to limit our voting rights such that we will not be able to vote more than 45% of HomeFed’s total voting securities voting on any matter, assuming all HomeFed shares not owned by us are voted. HomeFed develops and owns residential and mixed-use real estate properties. HomeFed is a public company traded on the NASD OTC Bulletin Board (Symbol: HOFD). As a result of a 1998 distribution to all of our shareholders, approximately 5% of HomeFed is beneficially owned by our Chairman at September 30, 2018 . Three of our executives serve on the board of directors of HomeFed, including our Chairman who serves as HomeFed’s Chairman, and our President. Since we do not control HomeFed, our investment in HomeFed is accounted for under the equity method as an investment in an associated company. Golden Queen Mining Company Since 2014, we invested $93.0 million , net in cash in a limited liability company (Gauss LLC) to partner with the Clay family and Golden Queen Mining Co. Ltd., to jointly fund, develop and operate the Soledad Mountain gold and silver mine project. Previously 100% owned by Golden Queen Mining Co. Ltd., the project is a fully-permitted, open pit, heap leach gold and silver project located in Kern County, California, which commenced gold and silver production in March 2016. In exchange for a noncontrolling ownership interest in Gauss LLC, the Clay family contributed $34.5 million , net in cash. Gauss LLC invested both our and the Clay family’s net contributions totaling $127.5 million to the joint venture, Golden Queen, in exchange for a 50% ownership interest. Golden Queen Mining Co. Ltd. contributed the Soledad Mountain project to the joint venture in exchange for the other 50% interest. As a result of our consolidating Gauss LLC, our Loans to and investments in associated companies reflects Gauss LLC’s net investment of $127.5 million in the joint venture, which includes both the amount we contributed and the amount contributed by the Clay family. The joint venture, Golden Queen, is considered a VIE and we have determined that we are not the primary beneficiary of the joint venture and are therefore not consolidating its results. Our maximum exposure to loss as a result of our involvement with the joint venture is limited to our investment. In the third quarter of 2018, Golden Queen completed an updated mine plan and financial projections reflecting lower grades of gold as well as a decrease in the market price of gold. As a result of lower projected cash flows, we engaged an independent valuation firm to assist management in estimating the fair value of our equity investment in Golden Queen. Our estimate of fair value was based on a discounted cash flow analysis. The result of our analysis indicated that the estimated fair value of our equity interest in Golden Queen was lower than our prior carrying value by $47.9 million . We concluded based on lower projected cash flows and a decline in the market price of gold that the decline in fair value of our equity interest was other than temporary. As such, an impairment charge of $47.9 million was recorded in Income (loss) related to associated companies in the three and nine months ended September 30, 2018 . Other The following table provides summarized data for certain associated companies (Jefferies Finance, National Beef for the period subsequent to the closing of the transaction with Marfrig on June 5, 2018 and Berkadia) (in thousands): For the Nine Months Ended September 30, 2018 2017 Revenues $ 3,341,369 $ 763,727 Income from continuing operations before extraordinary items $ 591,191 $ 267,796 Net income $ 591,191 $ 267,796

Financial Statement Offsetting

Financial Statement Offsetting	9 Months Ended
	Sep. 30, 2018
Offsetting [Abstract]
Financial Statement Offsetting	Financial Statement Offsetting In connection with Jefferies Group's derivative activities and securities financing activities, Jefferies Group may enter into master netting agreements and collateral arrangements with counterparties. Generally, transactions are executed under standard industry agreements, including, but not limited to: derivative transactions – ISDA master netting agreements; master securities lending agreements (securities lending transactions); and master repurchase agreements (repurchase transactions). A master agreement creates a single contract under which all transactions between two counterparties are executed allowing for trade aggregation and a single net payment obligation. Master agreements provide protection in bankruptcy in certain circumstances and, where legally enforceable, enable receivables and payables with the same counterparty to be settled or otherwise eliminated by applying amounts due to a counterparty against all or a portion of an amount due from the counterparty or a third party. Under Jefferies Group's derivative ISDA master netting agreements, Jefferies Group typically will also execute credit support annexes, which provide for collateral, either in the form of cash or securities, to be posted by or paid to a counterparty based on the fair value of the derivative receivable or payable based on the rates and parameters established in the credit support annex. In the event of the counterparty’s default, provisions of the master agreement permit acceleration and termination of all outstanding transactions covered by the agreement such that a single amount is owed by, or to, the non-defaulting party. In addition, any collateral posted can be applied to the net obligations, with any excess returned; and the collateralized party has a right to liquidate the collateral. Any residual claim after netting is treated along with other unsecured claims in bankruptcy court. The conditions supporting the legal right of offset may vary from one legal jurisdiction to another and the enforceability of master netting agreements and bankruptcy laws in certain countries or in certain industries is not free from doubt. The right of offset is dependent both on contract law under the governing arrangement and consistency with the bankruptcy laws of the jurisdiction where the counterparty is located. Industry legal opinions with respect to the enforceability of certain standard provisions in respective jurisdictions are relied upon as a part of managing credit risk. In cases where Jefferies Group has not determined an agreement to be enforceable, the related amounts are not offset. Master netting agreements are a critical component of Jefferies Group's risk management processes as part of reducing counterparty credit risk and managing liquidity risk. Jefferies Group is also a party to clearing agreements with various central clearing parties. Under these arrangements, the central clearing counterparty facilitates settlement between counterparties based on the net payable owed or receivable due and, with respect to daily settlement, cash is generally only required to be deposited to the extent of the net amount. In the event of default, a net termination amount is determined based on the market values of all outstanding positions and the clearing organization or clearing member provides for the liquidation and settlement of the net termination amount among all counterparties to the open contracts or transactions. The following table provides information regarding derivative contracts, repurchase agreements and securities borrowing and lending arrangements that are recognized in the Consolidated Statements of Financial Condition and (1) the extent to which, under enforceable master netting arrangements, such balances are presented net in the Consolidated Statements of Financial Condition as appropriate under GAAP and (2) the extent to which other rights of setoff associated with these arrangements exist and could have an effect on our consolidated financial position. (In thousands) Gross Amounts Netting in Consolidated Statements of Financial Condition Net Amounts in Consolidated Statements of Financial Condition Additional Amounts Available for Setoff (1) Available Collateral (2) Net Amount (3) Assets at September 30, 2018 Derivative contracts $ 3,523,745 $ (3,334,100 ) $ 189,645 $ — $ — $ 189,645 Securities borrowing arrangements $ 7,369,908 $ — $ 7,369,908 $ (529,662 ) $ (1,088,612 ) $ 5,751,634 Reverse repurchase agreements $ 11,634,035 $ (7,974,976 ) $ 3,659,059 $ (187,426 ) $ (3,441,009 ) $ 30,624 Liabilities at September 30, 2018 Derivative contracts $ 4,170,251 $ (3,454,488 ) $ 715,763 $ — $ — $ 715,763 Securities lending arrangements $ 2,531,504 $ — $ 2,531,504 $ (529,662 ) $ (1,977,558 ) $ 24,284 Repurchase agreements $ 17,839,459 $ (7,974,976 ) $ 9,864,483 $ (187,426 ) $ (8,632,482 ) $ 1,044,575 Assets at December 31, 2017 Derivative contracts $ 3,497,969 $ (3,318,481 ) $ 179,488 $ — $ — $ 179,488 Securities borrowing arrangements $ 7,721,803 $ — $ 7,721,803 $ (966,712 ) $ (1,032,629 ) $ 5,722,462 Reverse repurchase agreements $ 14,858,297 $ (11,168,738 ) $ 3,689,559 $ (463,973 ) $ (3,207,147 ) $ 18,439 Liabilities at December 31, 2017 Derivative contracts $ 3,745,908 $ (3,490,514 ) $ 255,394 $ — $ — $ 255,394 Securities lending arrangements $ 2,843,911 $ — $ 2,843,911 $ (966,712 ) $ (1,795,408 ) $ 81,791 Repurchase agreements $ 19,829,249 $ (11,168,738 ) $ 8,660,511 $ (463,973 ) $ (7,067,512 ) $ 1,129,026 (1) Under master netting agreements with our counterparties, we have the legal right of offset with a counterparty, which incorporates all of the counterparty’s outstanding rights and obligations under the arrangement. These balances reflect additional credit risk mitigation that is available by a counterparty in the event of a counterparty’s default, but which are not netted in the balance sheet because other netting provisions of GAAP are not met. Further, for derivative assets and liabilities, amounts netted include cash collateral paid or received. (2) Includes securities received or paid under collateral arrangements with counterparties that could be liquidated in the event of a counterparty default and thus offset against a counterparty’s rights and obligations under the respective repurchase agreements or securities borrowing or lending arrangements. (3) At September 30, 2018 , amounts include $5,717.1 million of securities borrowing arrangements, for which we have received securities collateral of $5,544.1 million , and $1,019.6 million of repurchase agreements, for which we have pledged securities collateral of $1,054.1 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable. At December 31, 2017 , amounts include $5,678.6 million of securities borrowing arrangements, for which we have received securities collateral of $5,516.7 million , and $1,084.4 million of repurchase agreements, for which we have pledged securities collateral of $1,115.9 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable.

Intangible Assets, Net and Good

Intangible Assets, Net and Goodwill	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net And Goodwill	Intangible Assets, Net and Goodwill A summary of Intangible assets, net and goodwill is as follows (in thousands): September 30, 2018 December 31, 2017 Indefinite-lived intangibles: Exchange and clearing organization membership interests and registrations $ 8,475 $ 8,551 Amortizable intangibles: Customer and other relationships, net of accumulated amortization of $100,591 and $230,074 70,071 347,767 Trademarks and tradenames, net of accumulated amortization of $20,211 and $95,627 108,406 293,851 Supply contracts, net of accumulated amortization of $0 and $57,440 — 86,160 Other, net of accumulated amortization of $4,132 and $3,885 4,818 4,701 Total intangible assets, net 191,770 741,030 Goodwill: National Beef — 14,991 Jefferies Group 1,699,269 1,703,300 Other operations 3,859 3,859 Total goodwill 1,703,128 1,722,150 Total intangible assets, net and goodwill $ 1,894,898 $ 2,463,180 Amortization expense on intangible assets included in Income (loss) from continuing operations was $3.3 million and $3.2 million for the three months ended September 30, 2018 and 2017 , respectively, and $9.9 million and $9.7 million for the nine months ended September 30, 2018 and 2017 , respectively. The estimated aggregate future amortization expense for the intangible assets for each of the next five years is as follows (in thousands): Remainder of current year $ 3,359 2019 $ 13,439 2020 $ 13,439 2021 $ 13,052 2022 $ 13,052 As further discussed in Note 1, on June 5, 2018, we sold 48% of National Beef to Marfrig. Upon closing of the transaction with Marfrig, we deconsolidated our investment in National Beef, including its Intangible assets, net and goodwill. Intangible assets, net and goodwill at December 31, 2017 included $539.6 million of intangibles and $15.0 million of goodwill related to National Beef. Goodwill and Intangible Impairment Testing We performed our annual impairment testing of Jefferies Group goodwill as of August 1, 2018. The quantitative goodwill impairment test is performed at our reporting unit level and consists of two steps. In the first step, the fair value of the reporting unit is compared with its carrying value, including goodwill and allocated intangible assets. If the fair value is in excess of the carrying value, the goodwill for the reporting unit is considered not to be impaired. If the fair value is less than the carrying value, then a second step is performed in order to measure the amount of the impairment loss, if any, which is based on comparing the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The estimated fair value of Jefferies Group is based on valuation techniques that we believe market participants would use, although the valuation process requires significant judgment and often involves the use of significant estimates and assumptions. The methodologies we utilize in estimating fair value include price-to-earnings and price-to-book multiples of comparable public companies and/or projected cash flows. In addition, as the fair values determined under the market approach represent a noncontrolling interest, we applied a control premium to arrive at the estimated fair value of our reporting units on a controlling basis. An independent valuation specialist was engaged to assist with the valuation process for Jefferies Group at August 1, 2018. The results of our annual goodwill impairment test for Jefferies Group did not indicate any goodwill impairment. Jefferies Group performed its annual impairment testing of intangible assets with an indefinite useful life, which consists of exchange and clearing organization membership interests and registrations, at August 1, 2018. Jefferies Group elected to perform a quantitative assessment of membership interests and registrations that have available quoted sales prices as well as certain other membership interests and registrations that have declined in utilization. A qualitative assessment was performed on the remainder of its indefinite-life intangible assets. With regard to its qualitative assessment of the remaining indefinite-life intangible assets, based on its assessment of market conditions, the utilization of the assets and the replacement costs associated with the assets, Jefferies Group has concluded that it is not more likely than not that the intangible assets are impaired. Jefferies Group recognized an immaterial impairment loss on certain exchange membership interests and registrations during the nine months ended September 30, 2018 .

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Short-Term Borrowings	Short-Term Borrowings Jefferies Group's short-term borrowings, which mature in one year or less, are as follows (in thousands): September 30, 2018 December 31, 2017 Bank loans (1) $ 324,021 $ 304,651 Floating rate puttable notes 57,985 108,240 Equity-linked notes — 23,324 Total short-term borrowings $ 382,006 $ 436,215 (1) Bank loans include loans entered into, pursuant to a Master Loan Agreement, between the Bank of New York and Jefferies Group. At September 30, 2018 and December 31, 2017 , the weighted average interest rate on short-term borrowings outstanding was 3.39% and 2.51% per annum, respectively. During the nine months ended September 30, 2018 , Jefferies Group issued equity-linked notes with a principal amount of $70.5 million , which matured on July 12, 2018. These notes were repaid with cash on hand on the maturity date. In addition, during the nine months ended September 30, 2018 , Jefferies Group's floating rate puttable notes with principal amounts of €41.0 million and Jefferies Group's equity-linked notes with a principal amount of $23.3 million matured. See Note 3 for further information. The Bank of New York Mellon has agreed to make revolving intraday credit advances ("Intraday Credit Facility") for an aggregate committed amount of $150.0 million . The Intraday Credit Facility contains financial covenants, which includes a minimum regulatory net capital requirement for Jefferies Group. Interest is based on the higher of the Federal funds effective rate plus 0.5% or the prime rate. During the nine months ended September 30, 2018 , Jefferies Group was in compliance with debt covenants under the Intraday Credit Facility.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Aggregate Indebtedness [Abstract]
Long-Term Debt	Long-Term Debt The principal amount (net of unamortized discounts, premiums and debt issuance costs), stated interest rate and maturity date of outstanding debt are as follows (dollars in thousands): September 30, 2018 December 31, 2017 Parent Company Debt: Senior Notes: 5.50% Senior Notes due October 18, 2023, $750,000 principal $ 743,203 $ 742,348 6.625% Senior Notes due October 23, 2043, $250,000 principal 246,710 246,673 Total long-term debt – Parent Company 989,913 989,021 Subsidiary Debt (non-recourse to Parent Company): Jefferies Group: 5.125% Senior Notes, due April 13, 2018, $0 and $678,300 principal (1) — 682,338 8.50% Senior Notes, due July 15, 2019, $680,800 principal 707,072 728,872 2.375% Euro Medium Term Notes, due May 20, 2020, $579,850 and $594,725 principal 578,896 593,334 6.875% Senior Notes, due April 15, 2021, $750,000 principal 795,967 808,157 2.25% Euro Medium Term Notes, due July 13, 2022, $4,639 and $4,758 principal 4,332 4,389 5.125% Senior Notes, due January 20, 2023, $600,000 principal 613,634 615,703 4.85% Senior Notes, due January 15, 2027, $750,000 principal (2) 712,667 736,357 6.45% Senior Debentures, due June 8, 2027, $350,000 principal 374,211 375,794 3.875% Convertible Senior Debentures, due November 1, 2029, $0 and $324,779 principal — 324,779 4.15% Senior Notes, due January 23, 2030, $1,000,000 and $0 principal 987,576 — 6.25% Senior Debentures, due January 15, 2036, $500,000 principal 511,758 512,040 6.50% Senior Notes, due January 20, 2043, $400,000 principal 420,718 420,990 Structured Notes (3) 709,557 614,091 Jefferies Group Revolving Credit Facility 158,478 — National Beef Reducing Revolver Loan — 120,000 National Beef Revolving Credit Facility — 76,809 Foursight Capital Credit Facilities 138,033 170,455 Other 74,613 112,654 Total long-term debt – subsidiaries 6,787,512 6,896,762 Long-term debt $ 7,777,425 $ 7,885,783 (1) On April 13, 2018, these 5.125% Senior Notes were redeemed by Jefferies Group with cash on hand. (2) Amount includes a gain of $24.1 million and a loss of $9.6 million during the nine months ended September 30, 2018 and 2017 , respectively, associated with an interest rate swap based on its designation as a fair value hedge. See Note 4 for further information. (3) Includes $709.6 million and $607.0 million at fair value at September 30, 2018 and December 31, 2017 , respectively. These structured notes contain various interest rate payment terms and are accounted for at fair value, with changes in fair value resulting from a change in the instrument specific credit risk presented in Accumulated other comprehensive income and changes in fair value resulting from non-credit components recognized in Principal transactions revenues. Subsidiary Debt : In November 2017, all of Jefferies Group's 3.875% Convertible Senior Debentures due 2029 were called for optional redemption, with a redemption date of January 5, 2018, at a redemption price equal to 100% of the principal amount of the convertible debentures redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. All of these remaining convertible debentures were redeemed in January 2018. In addition, Jefferies Group's 5.125% senior notes with a principal of $668.3 million were redeemed in April 2018. In January 2018, Jefferies Group issued 4.15% senior notes with a principal amount of $1.0 billion , due 2030. Additionally, structured notes with a total principal amount of approximately $162.6 million , net of retirements were issued during the nine months ended September 30, 2018 . On May 16, 2018, Jefferies Group entered into a senior secured revolving credit facility ("Jefferies Group Revolving Credit Facility") with a group of commercial banks for an aggregate principal amount of $160.0 million . Jefferies Group Revolving Credit Facility contains certain financial covenants, including, but not limited to, restrictions on future indebtedness of certain of its subsidiaries and its minimum tangible net worth, liquidity requirements and minimum capital requirements. Interest is based on an annual alternative base rate or an adjusted London Interbank Offered Rate ("LIBOR"), as defined in Jefferies Group Revolving Credit Facility agreement. The obligations of certain of Jefferies Group's subsidiaries under Jefferies Group Revolving Credit Facility are secured by substantially all its assets. At September 30, 2018 , Jefferies Group was in compliance with debt covenants under Jefferies Group Revolving Credit Facility. As further discussed in Note 1, on June 5, 2018, we sold 48% of National Beef to Marfrig. Upon closing of the transaction with Marfrig, we deconsolidated our investment in National Beef, including its long-term debt. Long-term debt at December 31, 2017 included $199.2 million related to National Beef. At September 30, 2018 , Foursight Capital's credit facilities consisted of two warehouse credit commitments aggregating $225.0 million , which mature in March 2020 and July 2020. The March 2020 credit facility bears interest based on the three-month LIBOR plus a credit spread fixed through its maturity and the July 2020 credit facility bears interest based on the one-month LIBOR plus a credit spread fixed through its maturity. As a condition of the March 2020 credit facility, Foursight Capital is obligated to maintain cash reserves in an amount equal to the quoted price of an interest rate cap sufficient to meet the hedging requirements of the credit commitment. The credit facilities are secured by first priority liens on auto loan receivables owed to Foursight Capital of approximately $167.9 million at September 30, 2018 .

Mezzanine Equity

Mezzanine Equity	9 Months Ended
	Sep. 30, 2018
Temporary Equity Disclosure [Abstract]
Mezzanine Equity	Mezzanine Equity Redeemable Noncontrolling Interests At December 31, 2017 , the redeemable noncontrolling interests primarily relate to National Beef and were held by its minority owners, USPB, NBPCo Holdings and the chief executive officer of National Beef. The holders of these interests shared in the profits and losses of National Beef on a pro rata basis with us. As discussed in Note 1, we deconsolidated National Beef as a result of the 48% sale to Marfrig on June 5, 2018. Immediately prior to the deconsolidation, the cumulative increase in fair value of $237.7 million recorded to the redeemable noncontrolling interest since the initial acquisition of National Beef was reversed through Additional paid-in capital in the Consolidated Statement of Financial Condition. Redeemable noncontrolling interests in National Beef are reflected in the Consolidated Statements of Financial Condition at fair value. The following table rolls forward National Beef’s redeemable noncontrolling interests activity (in thousands): For the Nine Months Ended September 30, 2018 2017 As of January 1, $ 412,128 $ 321,962 Income allocated to redeemable noncontrolling interests 37,141 65,088 Distributions to redeemable noncontrolling interests (70,681 ) (37,029 ) Increase in fair value of redeemable noncontrolling interests 21,404 24,404 Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation (237,669 ) — Deconsolidation of National Beef (162,323 ) — Balance, September 30, $ — $ 374,425 At September 30, 2018 and December 31, 2017 , redeemable noncontrolling interests also include other redeemable noncontrolling interests of $21.4 million and $14.5 million , respectively, primarily related to our oil and gas exploration and development businesses. The majority of the increase in redeemable noncontrolling interests is due to an increase in fair value associated with Vitesse Energy Finance. We estimated the fair value of Vitesse Energy Finance based on a discounted cash flow analysis, market comparable method and market transaction method. Mandatorily Redeemable Convertible Preferred Shares In connection with our acquisition of Jefferies Group in March 2013, we issued a new series of 3.25% Cumulative Convertible Preferred Shares ("Preferred Shares") ( $125.0 million at mandatory redemption value) in exchange for Jefferies Group's outstanding 3.25% Series A-1 Cumulative Convertible Preferred Stock. The Preferred Shares have a 3.25% annual, cumulative cash dividend and are currently convertible into 4,162,200 common shares, an effective conversion price of $30.03 per share. The holders of the Preferred Shares are also entitled to an additional quarterly payment in the event we declare and pay a dividend on our common stock in an amount greater than $0.0625 per common share per quarter. The additional quarterly payment would be paid to the holders of Preferred Shares on an as converted basis and on a per share basis would equal the quarterly dividend declared and paid to a holder of a share of common stock in excess of $0.0625 per share. In the third quarter of 2017, we increased our quarterly dividend from $0.0625 to $0.10 per common share. In the third quarter of 2018, we increased our quarterly dividend from $0.10 to $0.125 per common share. These increased the preferred stock dividend from $3.2 million for the nine months ended September 30, 2017 to $3.6 million for the nine months ended September 30, 2018 . The Preferred Shares are callable beginning in 2023 at a price of $1,000 per share plus accrued interest and are mandatorily redeemable in 2038.

Compensation Plans

Compensation Plans	9 Months Ended
	Sep. 30, 2018
Share-based Compensation [Abstract]
Compensation Plans	Compensation Plans Restricted Stock and Restricted Stock Units. Restricted stock and restricted stock units ("RSUs") may be granted to new employees as "sign-on" awards, to existing employees as "retention" awards and to certain executive officers as awards for multiple years. Sign-on and retention awards are generally subject to annual ratable vesting over a four -year service period and are amortized as compensation expense on a straight-line basis over the related four years. Restricted stock and RSUs are granted to certain senior executives with market, performance and service conditions. Market conditions are incorporated into the grant-date fair value of senior executive awards using a Monte Carlo valuation model. Compensation expense for awards with market conditions is recognized over the service period and is not reversed if the market condition is not met. Awards with performance conditions are amortized over the service period if it is determined that it is probable that the performance condition will be achieved. Senior Executive Compensation Plan. The Compensation Committee of the Jefferies Board of Directors approved an executive compensation plan effective January 1, 2018 that extends Jefferies prior compensation plans for our CEO and our President (together, our "Senior Executives") for compensation years 2018, 2019 and 2020. For each Senior Executive, the Compensation Committee has targeted long-term compensation of $25.0 million per year under the plan with a target of $16.0 million in long-term equity in the form of RSUs and a target of $9.0 million in long-term cash, subject to performance targets over the three -year measurement period for each compensation year. To receive targeted long-term equity, our Senior Executives will have to achieve 8% growth on an annual and multi-year compounded basis in Jefferies Total Shareholder Return ("TSR") and to receive targeted long-term cash, our Senior Executives will have to achieve 8% growth on an annual and multi-year compounded basis in Jefferies Return on Tangible Deployable Equity ("ROTDE"). If TSR and ROTDE are less than 5% , our Senior Executives will receive no long-term compensation. If TSR and ROTDE growth rates are greater than 8% , our Senior Executives are eligible to receive up to 50% additional incentive compensation on a pro rata basis up to 12% growth rates. TSR is based on annualized rate of return reflecting price appreciation plus reinvestment of dividends and distributions to shareholders. ROTDE is net income adjusted for amortization of intangible assets divided by tangible book value at the beginning of year adjusted for intangible assets and deferred tax assets. Stock-Based Compensation Expense. Compensation and benefits expense included $12.8 million and $11.1 million for the three months ended September 30, 2018 and 2017 , respectively, and $38.0 million and $31.5 million for the nine months ended September 30, 2018 and 2017 , respectively, for share-based compensation expense relating to grants made under our share-based compensation plans. Total compensation cost includes the amortization of sign-on, retention and senior executive awards, less forfeitures and clawbacks. The total tax benefit recognized in results of operations related to share-based compensation expenses was $4.0 million and $4.0 million for the three months ended September 30, 2018 and 2017 , respectively, and $10.0 million and $11.2 million for the nine months ended September 30, 2018 and 2017 , respectively. As of September 30, 2018 , total unrecognized compensation cost related to nonvested share-based compensation plans was $131.5 million ; this cost is expected to be recognized over a weighted average period of 2.4 years. At September 30, 2018 , there were 1,862,000 shares of restricted stock outstanding with future service required, 9,424,000 RSUs outstanding with future service required (including target RSUs issuable under the senior executive compensation plan), 10,262,000 RSUs outstanding with no future service required and 871,000 shares issuable under other plans. Excluding shares issuable pursuant to outstanding stock options, the maximum potential increase to common shares outstanding resulting from these outstanding awards is 20,557,000 . Restricted Cash Awards. Jefferies Group provides compensation to certain new and existing employees in the form of loans and/or other cash awards which are subject to ratable vesting terms with service requirements. The restricted cash awards are amortized to compensation expense over the relevant service period. At September 30, 2018 , the remaining unamortized amount of the restricted cash awards was $446.9 million ; this cost is expected to be recognized over a weighted average period of two years.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Activity in accumulated other comprehensive income is reflected in the Consolidated Statements of Comprehensive Income (Loss) and Consolidated Statements of Changes in Equity but not in the Consolidated Statements of Operations. A summary of accumulated other comprehensive income, net of taxes is as follows (in thousands): September 30, 2018 December 31, 2017 Net unrealized gains on available for sale securities $ 542,790 $ 572,085 Net unrealized foreign exchange losses (180,926 ) (101,400 ) Net unrealized losses on instrument specific credit risk (18,916 ) (34,432 ) Net unrealized gains (losses) on cash flow hedges 446 (1,138 ) Net minimum pension liability (55,649 ) (62,391 ) $ 287,745 $ 372,724 For the nine months ended September 30, 2018 and 2017 , significant amounts reclassified out of accumulated other comprehensive income to net income are as follows (in thousands): Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Consolidated Statements of Operations 2018 2017 Net unrealized gains on available for sale securities, net of income tax provision of $37 and $14 $ 105 $ 24 Other revenues Net unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $(16) and $1,086 20,459 (5,310 ) Other income and other expenses Net unrealized gains on instrument specific credit risk, net of income tax provision of $126 and $0 371 — Principal transactions Amortization of defined benefit pension plan actuarial losses, net of income tax benefit of $(508) and $(604) (1,398 ) (1,297 ) Selling, general and other expenses, which includes pension expense Other pension, net of income tax benefit of $0 and $(1,231) (5,344 ) 1,231 Compensation and benefits expense and Income tax provision (benefit) Total reclassifications for the period, net of tax $ 14,193 $ (5,352 ) In connection with the acquisition of Jefferies Bache from Prudential on July 1, 2011, Jefferies Group acquired a defined benefit pension plan located in Germany (the "German Pension Plan") for the benefit of eligible employees of Jefferies Bache in that territory. On December 28, 2017, a Liquidation Insurance Contract was entered into between Jefferies Bache Limited and Generali Lebensversicherung AG ("Generali") to transfer the defined benefit pension obligations and insurance contracts to Generali, for approximately €6.5 million , which was paid in January 2018 and released Jefferies Group from any and all obligations under the German Pension Plan. This transaction was completed in the first quarter of 2018. In connection with the transfer of the German Pension Plan, $5.3 million was reclassified to Compensation and benefits expense in the Consolidated Statements of Operations from Accumulated other comprehensive income during the nine months ended September 30, 2018 .

Revenues from Contracts with Cu

Revenues from Contracts with Customers	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenues from Contracts with Customers	Revenues from Contracts with Customers The following table presents our total revenues separated for our revenues from contracts with customers and our other sources of revenues (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 Revenues from contracts with customers: Commissions and other fees $ 155,417 $ 461,023 Investment banking 460,043 1,400,331 Manufacturing revenues 94,029 307,129 Other 70,590 174,565 Total revenue from contracts with customers 780,079 2,343,048 Other sources of revenue: Principal transactions 116,204 315,622 Interest income 336,736 939,272 Other 225,958 265,972 Total revenue from other sources 678,898 1,520,866 Total revenues $ 1,458,977 $ 3,863,914 Revenue from contracts with customers is recognized when, or as, we satisfy our performance obligations by transferring the promised goods or services to the customers. A good or service is transferred to a customer when, or as, the customer obtains control of that good or service. A performance obligation may be satisfied over time or at a point in time. Revenue from a performance obligation satisfied over time is recognized by measuring our progress in satisfying the performance obligation in a manner that depicts the transfer of the goods or services to the customer. Revenue from a performance obligation satisfied at a point in time is recognized at the point in time that we determine the customer obtains control over the promised good or service. The amount of revenue recognized reflects the consideration we expect to be entitled to in exchange for those promised goods or services (the "transaction price"). In determining the transaction price, we consider multiple factors, including the effects of variable consideration. Variable consideration is included in the transaction price only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainties with respect to the amount are resolved. In determining when to include variable consideration in the transaction price, we consider the range of possible outcomes, the predictive value of our past experiences, the time period of when uncertainties expect to be resolved and the amount of consideration that is susceptible to factors outside of our influence, such as market volatility or the judgment and actions of third parties. The following provides detailed information on the recognition of our revenues from contracts with customers: Commissions and Other Fees. Jefferies Group earns commission revenue by executing, settling and clearing transactions for clients primarily in equity, equity-related and futures products. Trade execution and clearing services, when provided together, represent a single performance obligation as the services are not separately identifiable in the context of the contract. Commission revenues associated with combined trade execution and clearing services, as well as trade execution services on a standalone basis, are recognized at a point in time on trade-date. Commissions revenues are generally paid on settlement date and Jefferies Group records a receivable between trade-date and payment on settlement date. Jefferies Group permits institutional customers to allocate a portion of their gross commissions to pay for research products and other services provided by third parties. The amounts allocated for those purposes are commonly referred to as soft dollar arrangements. Jefferies Group acts as an agent in the soft dollar arrangements as the customer controls the use of the soft dollars and directs Jefferies Group's payments to third-party service providers on its behalf. Accordingly, amounts allocated to soft dollar arrangements are netted against commission revenues in our Consolidated Statements of Operations. Jefferies Group earns account advisory and distribution fees in connection with wealth management services. Account advisory fees are recognized over time using the time-elapsed method as Jefferies Group determined that the customer simultaneously receives and consumes the benefits of investment advisory services as they are provided. Account advisory fees may be paid in advance of a specified service period or in arrears at the end of the specified service period (e.g., quarterly). Account advisory fees paid in advance are initially deferred within Payables, expense accruals and other liabilities in the Consolidated Statements of Financial Condition. Distribution fees are variable and recognized when uncertainties with respect to the amounts are resolved. Investment Banking Fees. Jefferies Group provides its clients with a full range of capital markets and financial advisory services. Capital markets services include underwriting and placement agent services in both the equity and debt capital markets, including private equity placements, initial public offerings, follow-on offerings and equity-linked convertible securities transactions and structuring, underwriting and distributing public and private debt, including investment grade debt, high yield bonds, leveraged loans, municipal bonds and mortgage- and asset-backed securities. Underwriting and placement agent revenues are recognized at a point in time on trade-date, as the client obtains the control and benefit of the capital markets offering at that point. Costs associated with capital markets transactions are deferred until the related revenue is recognized or the engagement is otherwise concluded, and are recorded on a gross basis within Selling, general and other expenses in the Consolidated Statements of Operations as Jefferies Group is acting as a principal in the arrangement. Any expenses reimbursed by its clients are recognized as Investment banking revenues. Revenues from financial advisory services primarily consist of fees generated in connection with merger, acquisition and restructuring transactions. Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed, as the performance obligation is to successfully broker a specific transaction. Fees received prior to the completion of the transaction are deferred within Payables, expense accruals and other liabilities in the Consolidated Statements of Financial Condition. Advisory fees from restructuring engagements are recognized over time using a time elapsed measure of progress as Jefferies Group's clients simultaneously receive and consume the benefits of those services as they are provided. A significant portion of the fees Jefferies Group receives for its advisory services are considered variable as they are contingent upon a future event (e.g., completion of a transaction or third-party emergence from bankruptcy) and are excluded from the transaction price until the uncertainty associated with the variable consideration is subsequently resolved, which is expected to occur upon achievement of the specified milestone. Payment for advisory services are generally due promptly upon completion of a specified milestone or, for retainer fees, periodically over the course of the engagement. Jefferies Group recognizes a receivable between the date of completion of the milestone and payment by the customer. Expenses associated with investment banking advisory engagements are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related expenses, including expenses incurred related to restructuring assignments, are expensed as incurred. All investment banking advisory expenses are recognized within their respective expense category in the Consolidated Statements of Operations and any expenses reimbursed by Jefferies Group's clients are recognized as Investment banking revenues. Asset Management Fees. Jefferies Group and LAM earn management and performance fees, recorded in Other revenues, in connection with investment advisory services provided to various funds and accounts, which are satisfied over time and measured using a time elapsed measure of progress as the customer receives the benefits of the services evenly throughout the term of the contract. Management and performance fees are considered variable as they are subject to fluctuation (e.g., changes in assets under management, market performance) and/ or are contingent on a future event during the measurement period (e.g., meeting a specified benchmark) and are recognized only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty is resolved. Management fees are generally based on month-end assets under management or an agreed upon notional amount and are included in the transaction price at the end of each month when the assets under management or notional amount is known. Performance fees are received when the return on assets under management for a specified performance period exceed certain benchmark returns, "high-water marks" or other performance targets. The performance period related to performance fees is annual, semi-annual or quarterly. Accordingly, performance fee revenue will generally be recognized only at the end of the performance period to the extent that the benchmark return has been met. Manufacturing Revenues. Idaho Timber's primary business consists of the sale of lumber that is manufactured or remanufactured at one of its locations. Agreements with customers for these sales specify the type, quantity and price of products to be delivered as well as the delivery date and payment terms. The transaction price is fixed at the time of sale and revenue is generally recognized when the customer takes control of the product. Disaggregation of Revenue The following presents our revenues from contracts with customers disaggregated by major business activity and primary geographic regions for the three and nine months ended September 30, 2018 (in thousands): Three months ended September 30, 2018 Reportable Segments Jefferies Group Corporate All Other Total Major Business Activity: Jefferies Group: Equities (1) $ 159,571 $ — $ — $ 159,571 Fixed Income (1) 3,007 — — 3,007 Investment Banking 460,043 — — 460,043 Asset Management 5,184 — — 5,184 Manufacturing revenues — — 94,029 94,029 Oil and gas revenues — — 46,506 46,506 Other revenues — — 11,739 11,739 Total revenues from contracts with customers $ 627,805 $ — $ 152,274 $ 780,079 Primary Geographic Region: Americas $ 545,998 $ — $ 151,687 $ 697,685 Europe, Middle East and Africa 62,914 — 514 63,428 Asia 18,893 — 73 18,966 Total revenues from contracts with customers $ 627,805 $ — $ 152,274 $ 780,079 Nine months ended September 30, 2018 Reportable Segments Jefferies Group Corporate All Other Total Major Business Activity: Jefferies Group: Equities (1) $ 471,161 $ — $ — $ 471,161 Fixed Income (1) 10,511 — — 10,511 Investment Banking 1,400,331 — — 1,400,331 Asset Management 16,130 — — 16,130 Manufacturing revenues — — 307,129 307,129 Oil and gas revenues — — 106,741 106,741 Other revenues — — 31,045 31,045 Total revenues from contracts with customers $ 1,898,133 $ — $ 444,915 $ 2,343,048 Primary Geographic Region: Americas $ 1,638,828 $ — $ 443,718 $ 2,082,546 Europe, Middle East and Africa 203,103 — 976 204,079 Asia 56,202 — 221 56,423 Total revenues from contracts with customers $ 1,898,133 $ — $ 444,915 $ 2,343,048 (1) Revenues from contracts with customers associated with the equities and fixed income businesses primarily represent commissions and other fee revenue. Information on Remaining Performance Obligations and Revenue Recognized from Past Performance We do not disclose information about remaining performance obligations pertaining to contracts that have an original expected duration of one year or less. The transaction price allocated to remaining unsatisfied or partially unsatisfied performance obligations with an original expected duration exceeding one year was not material at September 30, 2018 . Investment banking advisory fees that are contingent upon completion of a specific milestone and fees associated with certain distribution services are also excluded as the fees are considered variable and not included in the transaction price at September 30, 2018 . During the three and nine months ended September 30, 2018 , Jefferies Group recognized $4.4 million and $18.3 million , respectively, of revenue related to performance obligations satisfied (or partially satisfied) in previous periods, mainly due to resolving uncertainties in consideration that was constrained in prior periods. In addition, Jefferies Group recognized $4.6 million and $13.5 million , respectively, of revenues primarily associated with distribution services during the three and nine months ended September 30, 2018 , a portion of which relates to prior periods. Contract Balances The timing of revenue recognition may differ from the timing of payment by customers. We record a receivable when revenue is recognized prior to payment and it has an unconditional right to payment. Alternatively, when payment precedes the provision of the related services, we record deferred revenue until the performance obligations are satisfied. Jefferies Group deferred revenue primarily relates to retainer and milestone fees received in investment banking advisory engagements where the performance obligation has not yet been satisfied. We had receivables related to revenues from contracts with customers of $259.1 million and $469.3 million at September 30, 2018 and December 31, 2017 , respectively. As further discussed in Note 1, on June 5, 2018, we sold 48% of National Beef to Marfrig. Upon closing of the transaction with Marfrig, we deconsolidated our investment in National Beef, including its receivables related to revenues from contracts with customers. Receivables related to revenues from contracts with customers at December 31, 2017 included $183.4 million related to National Beef. We had no significant impairments related to these receivables during the three and nine months ended September 30, 2018 . Our deferred revenue, which primarily relates to Jefferies Group, was $16.3 million and $15.5 million at September 30, 2018 and December 31, 2017 , respectively, which are recorded as Payables, expense accruals and other liabilities in the Consolidated Statements of Financial Condition. During the three months ended September 30, 2018 , we recognized $6.3 million of deferred revenue from the balance at June 30, 2018 . During the nine months ended September 30, 2018 , we recognized $20.8 million of deferred revenue from the balance at December 31, 2017 . Contract Costs Jefferies Group capitalizes costs to fulfill contracts associated with investment banking advisory engagements where the revenue is recognized at a point in time and the costs are determined to be recoverable. Capitalized costs to fulfill a contract are recognized at the point in time that the related revenue is recognized. At September 30, 2018 , Jefferies Group's capitalized costs to fulfill a contract were $4.8 million , which are recorded in Receivables in the Consolidated Statement of Financial Condition. For the three and nine months ended September 30, 2018 , Jefferies Group recognized $1.5 million and $1.5 million , respectively, of expenses related to costs to fulfill a contract that were capitalized as of the beginning of the period. There were no significant impairment charges recognized in relation to these capitalized costs during the three and nine months ended September 30, 2018 . At September 30, 2018 , capitalized costs related to our other subsidiaries were not material.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The aggregate amount of gross unrecognized tax benefits related to uncertain tax positions at September 30, 2018 was $237.8 million (including $63.0 million for interest), of which $184.0 million related to Jefferies Group. The aggregate amount of gross unrecognized tax benefits related to uncertain tax positions at December 31, 2017 was $226.4 million (including $57.4 million for interest), of which $177.8 million related to Jefferies Group. If recognized, such amounts would lower our effective tax rate. Accrued interest is included in Payables, expense accruals and other liabilities in the Consolidated Statements of Financial Condition. No material penalties were accrued for the nine months ended September 30, 2018 and the year ended December 31, 2017. The statute of limitations with respect to our federal income tax returns has expired for all years through 2013. We have settled our 2013 Internal Revenue Service examination with the settlement having an immaterial impact on our effective tax rate. Our New York State and New York City income tax returns are currently being audited for the 2012 to 2014 period and 2011 to 2014 period, respectively. Prior to becoming a wholly-owned subsidiary, Jefferies Group filed a consolidated U.S. federal income tax return with its qualifying subsidiaries and was subject to income tax in various states, municipalities and foreign jurisdictions. Jefferies Group is currently under examination by various major tax jurisdictions. We do not expect that resolution of these examinations will have a significant effect on our Consolidated Statements of Financial Condition, but could have a significant impact on the Consolidated Statements of Operations for the period in which resolution occurs. Our provision for income taxes for continuing operations for the nine months ended September 30, 2018 was reduced by a $43.9 million benefit resulting from a reversal of our valuation allowance with respect to certain federal and state net operating loss carryforwards ("NOLs") which we now believe are more likely than not to be utilized before they expire. Our provision for income taxes from continuing operations for the nine months ended September 30, 2017 was reduced by a $31.9 million benefit resulting from the repatriation of Jefferies Group's earnings from certain of its foreign subsidiaries, along with their associated foreign tax credits. On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 ("SAB 118"), which provides guidance on accounting for the tax effects of the Tax Cuts and Jobs Act (the "Tax Act"). SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under Accounting Standards Codification 740, Income Taxes ("ASC 740"). While the initial estimated impact of the Tax Act was calculated using all available information, we anticipate modifications based on the procedures set forth under SAB 118. This process is applied at each reporting period to account for and qualitatively disclose: (1) the effects of the change in tax law for which accounting is complete; (2) provisional amounts (or adjustments to provisional amounts) for the effects of the tax law where accounting is not complete, but that a reasonable estimate has been determined; and (3) where a reasonable estimate cannot yet be made, taxes are reflected in accordance with the law prior to the enactment of the Tax Act. Due to the complex nature of the Tax Act, we have not completed our accounting for the income tax effects of certain elements of the Tax Act. If we were able to make reasonable estimates of the effects of certain elements for which our analysis is not yet complete, we recorded a provisional estimate in the financial statements. If we were not yet able to make reasonable estimates of the impact of certain elements, we have not recorded any adjustments related to those elements and have continued accounting for them in accordance with ASC 740 on the basis of the tax laws in effect before the Tax Act. The ultimate impact of the Tax Act may differ from this estimate, possibly materially, due to refinement of our calculations based on updated information, changes in interpretations and assumptions, and guidance that may be issued and actions we may take in response to the Tax Act. We note that the Tax Act is complex and we continue to assess the impact that various provisions will have on our business. Since the Tax Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation are expected, we consider the accounting for the deferred tax asset remeasurements, the transition tax, and other items to be incomplete due to the forthcoming guidance and our ongoing analysis of final year-end data and tax positions. During the nine months ended September 30, 2018 , we revised our prior estimate and recorded a $3.8 million increase in our tax expense related to the Tax Act.

Common Share and Earnings (Loss

Common Share and Earnings (Loss) Per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Common Share and Earnings (Loss) Per Common Share	Common Share and Earnings (Loss) Per Common Share Basic and diluted earnings (loss) per share amounts were calculated by dividing net income (loss) by the weighted average number of common shares outstanding. The numerators and denominators used to calculate basic and diluted earnings (loss) per share are as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Numerator for earnings per share: Net income attributable to Jefferies Financial Group Inc. common shareholders $ 192,635 $ 99,351 $ 1,042,689 $ 438,952 Allocation of earnings to participating securities (1) (1,054 ) (368 ) (5,049 ) (1,692 ) Net income attributable to Jefferies Financial Group Inc. common shareholders for basic earnings per share 191,581 98,983 1,037,640 437,260 Adjustment to allocation of earnings to participating securities related to diluted shares (1) 3 (2 ) 34 3 Mandatorily redeemable convertible preferred share dividends 1,276 — — 3,203 Net income attributable to Jefferies Financial Group Inc. common shareholders for diluted earnings per share $ 192,860 $ 98,981 $ 1,037,674 $ 440,466 Denominator for earnings per share: Weighted average common shares outstanding 332,191 358,039 343,829 359,031 Weighted average shares of restricted stock outstanding with future service required (1,879 ) (1,320 ) (1,681 ) (1,377 ) Weighted average RSUs outstanding with no future service required 11,122 11,109 11,152 11,082 Denominator for basic earnings per share – weighted average shares 341,434 367,828 353,300 368,736 Stock options 5 23 13 22 Senior executive compensation plan awards 4,706 2,347 3,856 2,313 Mandatorily redeemable convertible preferred shares 4,162 — — 4,162 Denominator for diluted earnings per share 350,307 370,198 357,169 375,233 (1) Represents dividends declared during the period on participating securities plus an allocation of undistributed earnings to participating securities. Net losses are not allocated to participating securities. Participating securities represent restricted stock and RSUs for which requisite service has not yet been rendered and amounted to weighted average shares of 1,888,700 and 1,366,700 for the three months ended September 30, 2018 and 2017 , respectively, and 1,700,700 and 1,433,500 for the nine months ended September 30, 2018 and 2017 , respectively. Dividends declared on participating securities were not material during three and nine months ended September 30, 2018 and 2017 . Undistributed earnings are allocated to participating securities based upon their right to share in earnings if all earnings for the period had been distributed. For the nine months ended September 30, 2018 and the three and nine months ended September 30, 2017 , shares related to the 3.875% Convertible Senior Debentures were not included in the computation of diluted per share amounts as the conversion price exceeded the average market price. All of these convertible debentures were redeemed in January 2018. For the nine months ended September 30, 2018 and the three months ended September 30, 2017 , shares related to the mandatorily redeemable convertible preferred shares were not included in the computation of diluted per share amounts as the effect was antidilutive. The Board of Directors from time to time has authorized the repurchase of our common shares. In April 2018, the Board of Directors approved an increase to our share repurchase program to 25,000,000 common shares from the 12,500,000 million remaining under its prior authorization. In July 2018, the Board of Directors approved an increase to our share repurchase program by an additional 25,000,000 common shares. During the nine months ended September 30, 2018 , we purchased a total of 26,119,483 of our common shares under these authorizations. As of September 30, 2018 , 23,880,517 common shares remained authorized for repurchase.

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies And Guarantees	Commitments, Contingencies and Guarantees Commitments The following table summarizes commitments associated with certain business activities (in millions): Expected Maturity Date 2018 2019 2020 and 2021 2022 and 2023 2024 and Later Maximum Payout Equity commitments (1) $ 280.0 $ 56.9 $ 31.7 $ — $ 9.8 $ 378.4 Loan commitments (1) — 250.0 54.4 32.5 — 336.9 Underwriting commitments 411.0 — — — — 411.0 Forward starting reverse repos (2) 3,159.4 — — — — 3,159.4 Forward starting repos (2) 2,057.8 — — — — 2,057.8 Other unfunded commitments (1) 60.0 148.7 42.3 — 4.9 255.9 $ 5,968.2 $ 455.6 $ 128.4 $ 32.5 $ 14.7 $ 6,599.4 (1) Equity commitments, loan commitments and other unfunded commitments are presented by contractual maturity date. The amounts are however mostly available on demand. (2) At September 30, 2018 , $3,141.9 million of the forward starting securities purchased under agreements to resell and all of the securities sold under agreements to repurchase settled within three business days. Equity Commitments. Equity commitments include commitments to invest in Jefferies Group's joint venture, Jefferies Finance, and commitments to invest in private equity funds and in Jefferies Capital Partners, LLC, the manager of the private equity funds, which consist of a team led by Brian P. Friedman, our President and a Director. At September 30, 2018 , Jefferies Group's outstanding commitments relating to Jefferies Capital Partners, LLC and its private equity funds were $18.1 million . See Note 9 for additional information regarding Jefferies Group's investment in Jefferies Finance. Additionally, as of September 30, 2018 , we had other outstanding equity commitments to invest up to $316.7 million in various other investments, which include $280.0 million as part of the further development of our alternative asset management platforms. Loan Commitments. From time to time Jefferies Group makes commitments to extend credit to investment banking and other clients in loan syndication, acquisition finance and securities transactions and to SPE sponsors in connection with the funding of CLO and other asset-backed transactions. These commitments and any related drawdowns of these facilities typically have fixed maturity dates and are contingent on certain representations, warranties and contractual conditions applicable to the borrower. At September 30, 2018 , Jefferies Group had $86.3 million of outstanding loan commitments to clients. Loan commitments outstanding at September 30, 2018 , also include Jefferies Group's portion of the outstanding secured revolving credit facility provided to Jefferies Finance to support loan underwritings by Jefferies Finance. At September 30, 2018 , none of Jefferies Group's $250.0 million commitment was funded. Underwriting Commitments . In connection with investment banking activities, Jefferies Group may from time to time provide underwriting commitments to its clients in connection with capital raising transactions. Forward Starting Reverse Repos and Repos. Jefferies Group enters into commitments to take possession of securities with agreements to resell on a forward starting basis and to sell securities with agreements to repurchase on a forward starting basis that are primarily secured by U.S. government and agency securities. Other Unfunded Commitments. Other unfunded commitments include obligations in the form of revolving notes to provide financing to asset-backed and CLO vehicles. Upon advancing funds, drawn amounts are collateralized by the assets of an entity. Contingencies We and our subsidiaries are parties to legal and regulatory proceedings that are considered to be either ordinary, routine litigation incidental to their business or not significant to our consolidated financial position. We and our subsidiaries are also involved, from time to time, in other exams, investigations and similar reviews (both formal and informal) by governmental and self-regulatory agencies regarding our businesses, certain of which may result in judgments, settlements, fines, penalties or other injunctions. We do not believe that any of these actions will have a significant adverse effect on our consolidated financial position or liquidity, but any amounts paid could be significant to results of operations for the period. Guarantees Derivative Contracts. Jefferies Group dealer activities cause it to make markets and trade in a variety of derivative instruments. Certain derivative contracts that Jefferies Group has entered into meet the accounting definition of a guarantee under GAAP, including credit default swaps, written foreign currency options and written equity put options. On certain of these contracts, such as written interest rate caps and foreign currency options, the maximum payout cannot be quantified since the increase in interest or foreign exchange rates are not contractually limited by the terms of the contract. As such, we have disclosed notional values as a measure of Jefferies Group's maximum potential payout under these contracts. The following table summarizes the notional amounts associated with Jefferies Group derivative contracts meeting the definition of a guarantee under GAAP as of September 30, 2018 (in millions): Expected Maturity Date Guarantee Type 2018 2019 2020 and 2021 2022 and 2023 2024 and Later Notional/ Maximum Payout Derivative contracts – non-credit related $ 10,898.5 $ 5,978.6 $ 2,948.5 $ 1,015.0 $ 454.6 $ 21,295.2 Written derivative contracts – credit related — — 36.4 33.8 — 70.2 Total derivative contracts $ 10,898.5 $ 5,978.6 $ 2,984.9 $ 1,048.8 $ 454.6 $ 21,365.4 The derivative contracts deemed to meet the definition of a guarantee under GAAP are before consideration of hedging transactions and only reflect a partial or "one-sided" component of any risk exposure. Written equity options and written credit default swaps are often executed in a strategy that is in tandem with long cash instruments (e.g., equity and debt securities). Jefferies Group substantially mitigates its exposure to market risk on these contracts through hedges, such as other derivative contracts and/or cash instruments and Jefferies Group manages the risk associated with these contracts in the context of its overall risk management framework. Jefferies Group believes notional amounts overstate its expected payout and that fair value of these contracts is a more relevant measure of its obligations. The fair value of derivative contracts meeting the definition of a guarantee is approximately $216.9 million at September 30, 2018 . Berkadia. We have agreed to reimburse Berkshire Hathaway for up to one-half of any losses incurred under a $1.5 billion surety policy securing outstanding commercial paper issued by an affiliate of Berkadia. At September 30, 2018 , the aggregate amount of commercial paper outstanding was $1.47 billion . Other Guarantees. Jefferies Group is a member of various exchanges and clearing houses. In the normal course of business, Jefferies Group provides guarantees to securities clearing houses and exchanges. These guarantees generally are required under the standard membership agreements, such that members are required to guarantee the performance of other members. Additionally, if a member becomes unable to satisfy its obligations to the clearing house, other members would be required to meet these shortfalls. To mitigate these performance risks, the exchanges and clearing houses often require members to post collateral. Jefferies Group's obligations under such guarantees could exceed the collateral amounts posted. Jefferies Group's maximum potential liability under these arrangements cannot be quantified; however, the potential for Jefferies Group to be required to make payments under such guarantees is deemed remote. Accordingly, no liability has been recognized for these arrangements. Standby Letters of Credit. At September 30, 2018 , Jefferies Group provided guarantees to certain counterparties in the form of standby letters of credit in the amount of $51.8 million . Standby letters of credit commit Jefferies Group to make payment to the beneficiary if the guaranteed party fails to fulfill its obligation under a contractual arrangement with that beneficiary. Since commitments associated with these collateral instruments may expire unused, the amount shown does not necessarily reflect the actual future cash funding requirement. Other subsidiaries of ours have outstanding letters of credit aggregating $1.1 million at September 30, 2018 . Primarily all letters of credit expire within one year.

Net Capital Requirements

Net Capital Requirements	9 Months Ended
	Sep. 30, 2018
Net Capital Requirements [Abstract]
Net Capital Requirements	Net Capital Requirements Jefferies Group operates as a broker-dealer registered with the SEC and member firms of the Financial Industry Regulatory Authority ("FINRA"). Jefferies LLC is subject to the Securities and Exchange Commission Uniform Net Capital Rule ("Rule 15c3-1"), which requires the maintenance of minimum net capital and has elected to calculate minimum capital requirements using the alternative method permitted by Rule 15c3-1 in calculating net capital. Jefferies LLC, as a dually-registered U.S. broker-dealer and futures commission merchant ("FCM"), is also subject to Rule 1.17 of the CFTC, which sets forth minimum financial requirements. The minimum net capital requirement in determining excess net capital for a dually-registered U.S. broker-dealer and FCM is equal to the greater of the requirement under Rule 15c3-1 or CFTC Rule 1.17. Jefferies LLC’s net capital and excess net capital at September 30, 2018 were $1,917.6 million and $1,806.2 million , respectively. FINRA is the designated examining authority for Jefferies Group's U.S. broker-dealer and the National Futures Association is the designated self-regulatory organization for Jefferies LLC as an FCM. Certain other U.S. and non-U.S. subsidiaries of Jefferies Group are subject to capital adequacy requirements as prescribed by the regulatory authorities in their respective jurisdictions, including Jefferies International Limited which is authorized and regulated by the Financial Conduct Authority in the United Kingdom. The regulatory capital requirements referred to above may restrict our ability to withdraw capital from Jefferies Group's regulated subsidiaries. Some of our other consolidated subsidiaries also have credit agreements which may restrict the payment of cash dividends, or the ability to make loans or advances to the parent company.

Other Fair Value Information

Other Fair Value Information	9 Months Ended
	Sep. 30, 2018
Other Fair Value Information [Abstract]
Other Fair Value Information	Other Fair Value Information The carrying amounts and estimated fair values of our principal financial instruments that are not recognized at fair value on a recurring basis are as follows (in thousands): September 30, 2018 December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value Receivables: Notes and loans receivable (1) $ 663,508 $ 644,184 $ 579,071 $ 565,285 Financial Liabilities: Short-term borrowings (2) $ 382,006 $ 382,006 $ 412,891 $ 412,891 Long-term debt (3) $ 7,067,868 $ 7,113,515 $ 7,278,827 $ 7,678,210 (1) Notes and loans receivable: The fair values are estimated principally based on a discounted future cash flows model using market interest rates for similar instruments. If measured at fair value in the financial statements, these financial instruments would be classified as Level 3 in the fair value hierarchy. (2) Short-term borrowings: The fair values of short-term borrowings are estimated to be the carrying amount due to their short maturities. If measured at fair value in the financial statements, these financial instruments would be classified as Level 3 in the fair value hierarchy. (3) Long-term debt: The fair values are estimated using quoted prices, pricing information obtained from external data providers and, for certain variable rate debt, is estimated to be the carrying amount. If measured at fair value in the financial statements, these financial instruments would be classified as Level 2 and Level 3 in the fair value hierarchy.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Jefferies Capital Partners Related Funds. Jefferies Group has equity investments in the JCP Manager and in private equity funds, which are managed by a team led by Brian P. Friedman, our President and a Director ("Private Equity Related Funds"). Reflected in our Consolidated Statements of Financial Condition at September 30, 2018 and December 31, 2017 are Jefferies Group's equity investments in Private Equity Related Funds of $34.1 million and $23.7 million , respectively. Net gains (losses) aggregating $0.2 million and $(0.4) million for the three months ended September 30, 2018 and 2017 , respectively, and $10.2 million and $(9.8) million for the nine months ended September 30, 2018 and 2017 , respectively, were recorded in Other revenues related to the Private Equity Related Funds. For further information regarding our commitments and funded amounts to the Private Equity Related Funds, see Notes 8 and 20 . Berkadia Commercial Mortgage, LLC. At September 30, 2018 and December 31, 2017 , Jefferies Group has commitments to purchase $748.8 million and $864.1 million , respectively, in agency commercial mortgage-backed securities from Berkadia. HRG. Jefferies Group recognized investment banking revenues of $3.0 million for the three and nine months ended September 30, 2018 in connection with the merger of HRG into Spectrum Brands, which is partially owned by Jefferies. FXCM . Jefferies Group entered into OTC foreign exchange contracts with FXCM. In connection with these contracts, Jefferies Group had $12.3 million and $17.0 million at September 30, 2018 and December 31, 2017 , respectively, included in Payables, expense accruals and other liabilities in our Consolidated Statements of Financial Condition. Officers, Directors and Employees. We have $51.2 million and $45.6 million of loans outstanding to certain officers and employees (none of whom are an executive officer or director of the Company) at September 30, 2018 and December 31, 2017 , respectively. Receivables from and payables to customers include balances arising from officers, directors and employees' individual security transactions. These transactions are subject to the same regulations as all customer transactions and are provided on substantially the same terms. See Note 9 for information on transactions with Jefferies Finance and HomeFed.

Discontinued Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On June 5, 2018, we sold 48% of National Beef to Marfrig for $907.7 million in cash, reducing our ownership in National Beef to 31% . Marfrig has also acquired an additional 3% of National Beef from other equity owners and now owns 51% of National Beef. Jefferies will continue to designate two board members and have a series of other rights in respect of our continuing equity interest, with a lockup period of five years and thereafter fair market value liquidity protections. As of the closing of the sale on June 5, 2018, we deconsolidated our investment in National Beef and account for our remaining interest under the equity method of accounting. The sale of National Beef meets the GAAP criteria to be classified as a discontinued operation as the sale represents a strategic shift that has a major effect in our operations and financial results. As such, we have classified the results of National Beef prior to June 5, 2018 as a discontinued operation and reported those results in Income from discontinued operations, net of income tax provision in the Consolidated Statements of Operations. A summary of the results of discontinued operations for National Beef is as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2018 (1) 2017 Revenues: Beef processing services $ 2,038,821 $ 3,137,611 $ 5,472,339 Interest income 58 131 230 Other 420 4,329 3,705 Total revenues 2,039,299 3,142,071 5,476,274 Expenses: Compensation and benefits 10,505 17,414 29,649 Cost of sales 1,816,480 2,884,983 5,030,887 Interest expense 1,713 4,316 5,781 Depreciation and amortization 26,664 43,959 73,522 Selling, general and other expenses 9,458 14,291 26,428 Total expenses 1,864,820 2,964,963 5,166,267 Income from discontinued operations before income taxes 174,479 177,108 310,007 Income tax provision 53,490 47,045 90,856 Income from discontinued operations, net of income tax provision $ 120,989 $ 130,063 $ 219,151 (1) Discontinued operations for the nine months ended September 30, 2018 include National Beef results through the June 5, 2018 transaction with Marfrig. Net income attributable to the redeemable noncontrolling interests in the Consolidated Statements of Operations includes $36.6 million for the three months ended September 30, 2017 and $37.1 million and $65.1 million for the nine months ended September 30, 2018 and 2017 , respectively, related to National Beef's noncontrolling interests. Pre-tax income from discontinued operations attributable to Jefferies Financial Group Inc. common shareholders was $137.8 million for the three months ended September 30, 2017 and $140.0 million and $244.9 million for the nine months ended September 30, 2018 and 2017 , respectively. As discussed above, we account for our retained 31% ownership of National Beef subsequent to the sale to Marfrig under the equity method. From June 5, 2018 through September 30, 2018 , we recorded $83.3 million in Income (loss) related to associated companies from our 31% ownership in National Beef and we received distributions from National Beef of $48.7 million . The pre-tax income of 100% National Beef from June 5, 2018 through September 30, 2018 was $276.5 million . During the nine months ended September 30, 2018 , we also recorded a pre-tax gain on the National Beef transaction of $873.5 million ( $643.9 million after-tax) which is reported in Gain on disposal of discontinued operations, net of income tax provision in the Consolidated Statements of Operations. Included in the $873.5 million pre-tax gain on the sale of National Beef was approximately $352.4 million related to the remeasurement of our retained 31% interest in National Beef to fair value. The $592.3 million fair value of our retained 31% interest in National Beef was based on the implied equity value of 100% of National Beef from the transaction with Marfrig and is considered a Level 3 input. The transaction with Marfrig was based on a $1.9 billion equity valuation and a $2.3 billion enterprise valuation.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information Our operating segments consist of our consolidated businesses, which offer different products and services and are managed separately. Our reportable segments, based on qualitative and quantitative requirements, are Jefferies Group and Corporate. Jefferies Group is a global full-service, integrated securities and investment banking firm. Corporate assets primarily consist of financial instruments owned, the deferred tax asset (exclusive of Jefferies Group's deferred tax asset), cash and cash equivalents. Corporate revenues primarily include interest income. We do not allocate Corporate revenues or overhead expenses to the operating units. All other consists of our other financial services businesses and investments and our merchant banking businesses and investments. Our other financial services businesses and investments include the Leucadia Asset Management platform, Foursight Capital, and our investments in Berkadia, HomeFed and FXCM. Our merchant banking businesses and investments primarily include Vitesse Energy Finance, JETX Energy, Idaho Timber and our investments in Spectrum Brands, National Beef, Garcadia, Linkem and Golden Queen. As a result of the announced transactions and our current operating strategy, we have made changes to the corporate segment to reflect the way we currently manage our business, and have reclassified the prior periods to conform to current presentation. As discussed further in Notes 1 and 24, on June 5, 2018, we sold 48% of National Beef to Marfrig and deconsolidated our investment in National Beef. Results prior to June 5, 2018 are classified in discontinued operations and are not included in the table below. Our retained 31% interest in National Beef is accounted for under the equity method and results subsequent to the June 5, 2018 closing are included in All other in the table below. Certain information concerning our segments is presented in the following table. Consolidated subsidiaries are reflected as of the date a majority controlling interest was acquired. As discussed above, Jefferies Group is reflected in our consolidated financial statements utilizing a one month lag. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Net revenues: Reportable Segments: Jefferies Group $ 774,749 $ 802,909 $ 2,419,410 $ 2,381,967 Corporate 8,692 1,915 14,753 4,257 Total net revenues related to reportable segments 783,441 804,824 2,434,163 2,386,224 All other (1) 367,405 52,399 523,277 634,386 Total consolidated net revenues $ 1,150,846 $ 857,223 $ 2,957,440 $ 3,020,610 Income (loss) from continuing operations before income taxes: Reportable Segments: Jefferies Group $ 86,154 $ 128,112 $ 336,922 $ 383,094 Corporate (14,563 ) (16,311 ) (55,708 ) (56,816 ) Income from continuing operations before income taxes related to reportable segments 71,591 111,801 281,214 326,278 All other (1) 215,856 (71,516 ) 111,007 130,722 Parent Company interest (14,755 ) (14,737 ) (44,251 ) (44,201 ) Total consolidated income from continuing operations before income taxes $ 272,692 $ 25,548 $ 347,970 $ 412,799 Depreciation and amortization expenses: Reportable Segments: Jefferies Group $ 17,175 $ 15,928 $ 50,829 $ 46,877 Corporate 852 865 2,599 2,599 Total depreciation and amortization expenses related to reportable segments 18,027 16,793 53,428 49,476 All other 14,268 11,967 38,932 32,653 Total consolidated depreciation and amortization expenses $ 32,295 $ 28,760 $ 92,360 $ 82,129 (1) All other Net revenues and Income from continuing operations before income taxes include realized and unrealized gains (losses) relating to our investment in FXCM of $1.3 million and $(2.9) million , respectively, for the three months ended September 30, 2018 ; $16.4 million and $(2.9) million , respectively, for the nine months ended September 30, 2018 ; $2.3 million and $(2.0) million , respectively, for the three months ended September 30, 2017 ; and $17.6 million and $(148.7) million , respectively, for the nine months ended September 30, 2017 . Interest expense classified as a component of Net revenues relates to Jefferies Group. For the three months ended September 30, 2018 and 2017 , interest expense classified as a component of Expenses was primarily comprised of parent company interest ( $14.8 million and $14.7 million , respectively) and all other ( $14.0 million and $10.9 million , respectively). For the nine months ended September 30, 2018 and 2017 , interest expense classified as a component of Expenses was primarily comprised of parent company interest ( $44.3 million and $44.2 million , respectively) and all other ( $30.3 million and $32.6 million , respectively). As discussed above, during the third quarter of 2018, we sold 100% of our equity interests in Garcadia and our associated real estate to our former partners, the Garff family and recognized a pre-tax gain of $221.7 million for the three and nine months ended September 30, 2018 in Other revenues. The gain on the sale is included within All other above. Conwed Plastics ("Conwed") was our consolidated subsidiary that manufactured and marketed lightweight plastic netting. In January 2017, we sold 100% of Conwed to Schweitzer-Mauduit International, Inc., (NYSE: SWM) for $295 million in cash plus potential earn-out payments in 2019, 2020 and 2021 totaling up to $40 million in cash to the extent the results of Conwed’s subsidiary, Filtrexx International, exceed certain performance thresholds. We recognized a $178.2 million pre-tax gain on the sale of Conwed in Other revenues primarily during the nine months ended September 30, 2017 . The gain on the sale of Conwed is included within All other above.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Revenue Recognition Policies	Revenue Recognition Policies Investment Banking Revenues: • Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed. • Expenses associated with investment banking advisory engagements are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related expenses, including expenses incurred related to restructuring advisory engagements, are expensed as incurred. • All investment banking expenses are recognized within their respective expense category in the Consolidated Statements of Operations and any expenses reimbursed by clients are recognized as Investment banking revenues. Asset Management Fees: • Performance fee revenue is generally recognized only at the end of the performance period to the extent that the benchmark return has been met.
Receivables	Receivables At September 30, 2018 and December 31, 2017 , Receivables include receivables from brokers, dealers and clearing organizations of $2,878.5 million and $2,635.2 million , respectively, and receivables from customers of securities operations of $1,951.8 million and $1,563.8 million , respectively.
Payables, expense accruals and other liabilities	Payables, expense accruals and other liabilities At September 30, 2018 and December 31, 2017 , Payables, expense accruals and other liabilities include payables to brokers, dealers and clearing organizations of $1,913.3 million and $2,228.9 million , respectively, and payables to customers of securities operations of $3,187.6 million and $2,664.0 million , respectively.
Accounting Developments	Accounting Developments - Adopted Accounting Standards Revenue Recognition. In May 2014, the FASB issued new guidance that defines how companies report revenues from contracts with customers, and also requires enhanced disclosures. The core principle of guidance is that an entity should recognize revenue to depict 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. We adopted the guidance as of January 1, 2018 and recognized an increase of $17.8 million after-tax to beginning retained earnings as the cumulative effect of adoption of accounting standards. The increase primarily relates to the recognition of $24.3 million of revenue previously deferred from the sale of real estate to HomeFed in 2014, offset by a decrease of $6.1 million related to Jefferies Group. For Jefferies Group, the impact of adoption primarily related to investment banking expenses that were deferred as of December 31, 2017 under the previously existing accounting guidance, which would have been expensed in prior periods under the new revenue standard and investment banking revenues that were previously recognized in prior periods, which would have been deferred as of December 31, 2017 under the new revenue standard. We elected to adopt the new guidance using a modified retrospective approach applied to contracts that were not completed as of January 1, 2018. Accordingly, the new revenue standard is applied prospectively in our financial statements from January 1, 2018 forward and reported financial information for historical comparable periods is not revised and continues to be reported under the accounting standards in effect during those historical periods. The new revenue standard does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, and as a result, did not have an impact on the elements of our Consolidated Statements of Operations most closely associated with financial instruments, including Principal transactions revenues, Interest income and Interest expense. The new revenue standard primarily impacts Jefferies Group's revenue recognition and presentation accounting policies as follows: • Investment Banking Revenues. Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed, as the performance obligation is to successfully broker a specific transaction. • Certain Capital Markets Revenues. Revenues associated with price stabilization activities as part of a securities underwriting were historically recognized as part of Investment banking revenues. Under the new revenue standard, revenues from these activities are recognized within Principal transactions revenues, as these revenues are not considered to be within the scope of the new standard. • Investment Banking Advisory Expenses. Historically, expenses associated with investment banking advisory assignments were deferred until reimbursed by the client, the related fee revenue is recognized or the engagement is otherwise concluded. Under the new revenue standard, expenses are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related expenses, including expenses incurred related to restructuring assignments, are expensed as incurred. • Investment Banking Underwriting and Advisory Expenses. Expenses have historically been recorded net of client reimbursements and/or netted against revenues. Under the new revenue standard, all investment banking expenses will be recognized within their respective expense category in the Consolidated Statements of Operations and any expense reimbursements will be recognized as Investment banking revenues (i.e., expenses are no longer recorded net of client reimbursements and are not netted against revenues). • Asset Management Fees. In certain asset management fee arrangements, Jefferies Group and LAM receive performance-based fees, which vary with performance or, in certain cases, are earned when the return on assets under management exceed certain benchmark returns or other performance targets. Historically, performance fees have been accrued (or reversed) quarterly based on measuring performance to date versus any relevant benchmark return hurdles stated in the investment management agreement. Under the new revenue standard, performance fees are considered variable as they are subject to fluctuation (e.g., based on market performance) and/or are contingent on a future event during the measurement period (e.g., exceeding a specified benchmark index) and are recognized only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty is resolved. Accordingly, performance fee revenue will generally be recognized only at the end of the performance period to the extent that the benchmark return has been met. There was no significant impact as a result of applying the new revenue standard to our consolidated financial statements for the three and nine months ended September 30, 2018 , except as it relates to the presentation of Jefferies Group's investment banking expenses. The table below presents the impact of applying the new revenue recognition standard to the Consolidated Statements of Operations for the three and nine months ended September 30, 2018 as a result of the change in presentation of investment banking expenses (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard Revenues: Commissions and other fees $ 155,417 $ — $ 155,417 $ 461,023 $ — $ 461,023 Principal transactions 116,204 — 116,204 315,622 — 315,622 Investment banking 460,043 36,319 423,724 1,400,331 101,146 1,299,185 Interest income 336,736 — 336,736 939,272 — 939,272 Manufacturing revenues 94,029 — 94,029 307,129 — 307,129 Other 296,548 — 296,548 440,537 — 440,537 Total revenues 1,458,977 36,319 1,422,658 3,863,914 101,146 3,762,768 Interest expense of Jefferies Group 308,131 — 308,131 906,474 — 906,474 Net revenues 1,150,846 36,319 1,114,527 2,957,440 101,146 2,856,294 Expenses: Compensation and benefits 461,265 — 461,265 1,429,439 — 1,429,439 Cost of sales 84,876 — 84,876 257,501 — 257,501 Floor brokerage and clearing fees 44,570 — 44,570 131,792 — 131,792 Interest expense 28,837 — 28,837 74,614 — 74,614 Depreciation and amortization 32,295 — 32,295 92,360 — 92,360 Selling, general and other expenses 245,178 36,319 208,859 708,084 101,146 606,938 Total expenses 897,021 36,319 860,702 2,693,790 101,146 2,592,644 Income from continuing operations before income taxes and income (loss) related to associated companies $ 253,825 $ — $ 253,825 $ 263,650 $ — $ 263,650 Financial Instruments. In January 2016, the FASB issued new guidance that affects the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. The guidance is effective for annual and interim periods beginning after December 15, 2017. We have adopted the new guidance as of January 1, 2018 with a cumulative effect increase to opening retained earnings of $27.6 million and a corresponding decrease to Accumulated other comprehensive income. The opening retained earnings adjustment is to recognize the unrealized gains we had for available for sale equity securities. Beginning in 2018, these available for sale equity securities are now reported as part of Trading assets, at fair value within the Consolidated Statements of Financial Condition. Early adoption was permitted for the accounting guidance on financial liabilities under the fair value option and we adopted this guidance in the first quarter of 2016. The adoption of the guidance on financial liabilities under the fair value option did not have a material impact on our consolidated financial statements. Retirement Benefits. In March 2017, the FASB issued new guidance for improving the presentation of net periodic pension costs in the statement of operations. The update also allows the service cost to be eligible for capitalization, when applicable. We adopted this guidance in the first quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. The adoption of this guidance resulted in the following adjustments to the Consolidated Statements of Operations for the three and nine months ended September 30, 2017 : a decrease of $0.9 million and $2.6 million , respectively, to Compensation and benefits expenses and an increase to Selling, general and other expenses of $0.9 million and $2.6 million , respectively. Cash Flow Classifications. In August 2016, the FASB issued new guidance to reduce the diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance adds or clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows. The guidance is effective for annual and interim periods beginning after December 15, 2017. In November 2016, the FASB issued new guidance on restricted cash. The guidance requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. We adopted this guidance in the first quarter of 2018. Prior periods were retrospectively adjusted to conform to the current period presentation. The adoption of the guidance did not have a material impact on our Consolidated Statements of Cash Flows. Upon adoption, we recorded an increase of $49.3 million in Net cash provided by operating activities and a decrease of $6.7 million in Net cash provided by investing activities for the nine months ended September 30, 2017 related to reclassifying the changes in our restricted cash balance from operating and investing activities to the cash and cash equivalent balances within the Consolidated Statements of Cash Flows. Compensation. In May 2017, the FASB issued new guidance providing clarity and reducing diversity in practice and cost and complexity when accounting for a change to the terms or conditions of a share-based payment award. We adopted this guidance in the first quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. Fair Value Measurement. In August 2018, the FASB issued new guidance to improve the effectiveness of disclosure requirements on fair value measurement by eliminating certain disclosure requirements for fair value measurements for all entities, requiring public entities to disclose certain new information and modifying some disclosure requirements. We early adopted this guidance in the third quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements. Accounting Developments - Accounting Standards to be Adopted in Future Periods Leases. In February 2016, the FASB issued new guidance that affects the accounting and disclosure requirements for leases. The FASB requires the recognition of all leases that are longer than one year onto the balance sheet, which will result in the recognition of a right of use asset and a corresponding lease liability. The right of use asset and lease liability will be measured initially using the present value of the remaining rental payments. A significant portion of the population of contracts that will be subject to recognition on our Consolidated Statements of Financial Condition have been identified; however, their initial measurement still remains under evaluation. We are currently modifying our lease accounting systems to enable us to comply with the accounting requirements of this guidance. In July 2018, the FASB issued additional guidance on leases which allows an entity to recognize a cumulative-effect adjustment to the opening balance of retained earnings upon adoption. The guidance is effective for annual and interim periods beginning after December 15, 2018. We plan on adopting the lease standard in the first quarter of fiscal 2020 with a cumulative-effect adjustment to opening retained earnings in the period of adoption. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. Financial Instruments - Credit Losses. In June 2016, the FASB issued new guidance for estimating credit losses on certain types of financial instruments by introducing an approach based on expected losses. The guidance is effective in the first quarter of fiscal 2021. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. Goodwill. In January 2017, the FASB issued new guidance for simplifying goodwill impairment testing. The guidance is effective in the first quarter of fiscal 2021. We do not believe the new guidance will have a material impact on our consolidated financial statements. Derivatives and hedging. In August 2017, the FASB issued new guidance to improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. The guidance is effective in the first quarter of fiscal 2020 and early adoption is permitted. We do not believe the new guidance will have a material impact on our consolidated financial statements. Defined Benefit Plans. In August 2018, the FASB issued new guidance to improve the effectiveness of disclosure requirements on defined benefit pension plans and other post-retirement plans. The guidance is effective in the first quarter of fiscal 2021. We do not believe the new guidance will have a material impact on our consolidated financial statements. Internal-Use Software. In August 2018, the FASB issued new guidance which amends the definition of a hosting arrangement and requires that the customer in a hosting arrangement that is a service contract capitalize certain implementation costs as if the arrangement was an internal-use software project. The guidance is effective in the first quarter of fiscal 2021. We are currently evaluating the impact of the new guidance on our consolidated financial statements.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Supplemental cash flow information	Supplemental Cash Flow Information For the Nine Months Ended September 30, 2018 2017 Cash paid during the year for: (In thousands) Interest $ 1,059,139 $ 837,020 Income tax payments (refunds), net $ 28,204 $ 9,183
Schedule of Impact of Applying New Revenue Recognition Standard	The table below presents the impact of applying the new revenue recognition standard to the Consolidated Statements of Operations for the three and nine months ended September 30, 2018 as a result of the change in presentation of investment banking expenses (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard As Reported Impact of Adoption of Revenue Recognition Standard Financial Results Prior to Adoption of Revenue Recognition Standard Revenues: Commissions and other fees $ 155,417 $ — $ 155,417 $ 461,023 $ — $ 461,023 Principal transactions 116,204 — 116,204 315,622 — 315,622 Investment banking 460,043 36,319 423,724 1,400,331 101,146 1,299,185 Interest income 336,736 — 336,736 939,272 — 939,272 Manufacturing revenues 94,029 — 94,029 307,129 — 307,129 Other 296,548 — 296,548 440,537 — 440,537 Total revenues 1,458,977 36,319 1,422,658 3,863,914 101,146 3,762,768 Interest expense of Jefferies Group 308,131 — 308,131 906,474 — 906,474 Net revenues 1,150,846 36,319 1,114,527 2,957,440 101,146 2,856,294 Expenses: Compensation and benefits 461,265 — 461,265 1,429,439 — 1,429,439 Cost of sales 84,876 — 84,876 257,501 — 257,501 Floor brokerage and clearing fees 44,570 — 44,570 131,792 — 131,792 Interest expense 28,837 — 28,837 74,614 — 74,614 Depreciation and amortization 32,295 — 32,295 92,360 — 92,360 Selling, general and other expenses 245,178 36,319 208,859 708,084 101,146 606,938 Total expenses 897,021 36,319 860,702 2,693,790 101,146 2,592,644 Income from continuing operations before income taxes and income (loss) related to associated companies $ 253,825 $ — $ 253,825 $ 263,650 $ — $ 263,650

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule Of Assets And Liabilities Measured On Recurring Basis At Fair Value	The following is a summary of our financial instruments, trading liabilities, short-term borrowings and long-term debt that are accounted for at fair value on a recurring basis, excluding Investments at fair value based on net asset value ("NAV") (within trading assets) of $399.0 million and $590.1 million at September 30, 2018 and December 31, 2017 , respectively, by level within the fair value hierarchy (in thousands): September 30, 2018 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 3,635,288 $ 72,569 $ 49,683 $ — $ 3,757,540 Corporate debt securities — 2,498,031 9,651 — 2,507,682 Collateralized debt obligations and collateralized loan obligations — 82,339 33,981 — 116,320 U.S. government and federal agency securities 3,000,805 45,889 — — 3,046,694 Municipal securities — 749,616 — — 749,616 Sovereign obligations 1,319,415 669,919 — — 1,989,334 Residential mortgage-backed securities — 1,894,533 4,954 — 1,899,487 Commercial mortgage-backed securities — 791,449 23,916 — 815,365 Other asset-backed securities — 263,967 69,305 — 333,272 Loans and other receivables — 1,455,496 48,985 — 1,504,481 Derivatives 13,117 3,507,491 3,137 (3,334,100 ) 189,645 Investments at fair value — — 326,977 — 326,977 FXCM term loan — — 73,800 — 73,800 Total trading assets, excluding investments at fair value based on NAV $ 7,968,625 $ 12,031,299 $ 644,389 $ (3,334,100 ) $ 17,310,213 Available for sale securities: U.S. government securities $ 1,607,725 $ — $ — $ — $ 1,607,725 Residential mortgage-backed securities — 146,678 — — 146,678 Commercial mortgage-backed securities — 15,719 — — 15,719 Other asset-backed securities — 98,298 — — 98,298 Total available for sale securities $ 1,607,725 $ 260,695 $ — $ — $ 1,868,420 Liabilities: Trading liabilities: Corporate equity securities $ 2,221,325 $ 1,507 $ 413 $ — $ 2,223,245 Corporate debt securities — 1,511,979 1,557 — 1,513,536 U.S. government and federal agency securities 1,398,222 — — — 1,398,222 Sovereign obligations 1,513,237 969,845 55 — 2,483,137 Commercial mortgage-backed securities — — 70 — 70 Loans — 1,136,579 8,661 — 1,145,240 Derivatives 8,487 4,149,630 12,134 (3,454,488 ) 715,763 Total trading liabilities $ 5,141,271 $ 7,769,540 $ 22,890 $ (3,454,488 ) $ 9,479,213 Long-term debt - structured notes $ — $ 545,927 $ 163,630 $ — $ 709,557 December 31, 2017 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 2,975,463 $ 60,300 $ 22,270 $ — $ 3,058,033 Corporate debt securities — 3,261,300 26,036 — 3,287,336 Collateralized debt obligations and collateralized loan obligations — 139,166 42,184 — 181,350 U.S. government and federal agency securities 1,269,230 39,443 — — 1,308,673 Municipal securities — 710,513 — — 710,513 Sovereign obligations 1,381,552 1,035,907 — — 2,417,459 Residential mortgage-backed securities — 1,453,294 26,077 — 1,479,371 Commercial mortgage-backed securities — 508,115 12,419 — 520,534 Other asset-backed securities — 217,111 61,129 — 278,240 Loans and other receivables — 1,620,581 47,304 — 1,667,885 Derivatives 165,396 3,323,278 9,295 (3,318,481 ) 179,488 Investments at fair value — 946 329,944 — 330,890 FXCM term loan — — 72,800 — 72,800 Total trading assets, excluding investments at fair value based on NAV $ 5,791,641 $ 12,369,954 $ 649,458 $ (3,318,481 ) $ 15,492,572 Available for sale securities: Corporate equity securities (2) $ 88,486 $ — $ — $ — $ 88,486 U.S. government securities 552,805 — — — 552,805 Residential mortgage-backed securities — 34,561 — — 34,561 Commercial mortgage-backed securities — 5,870 — — 5,870 Other asset-backed securities — 34,839 — — 34,839 Total available for sale securities $ 641,291 $ 75,270 $ — $ — $ 716,561 Liabilities: Trading liabilities: Corporate equity securities $ 1,721,267 $ 32,122 $ 48 $ — $ 1,753,437 Corporate debt securities — 1,688,825 522 — 1,689,347 U.S. government and federal agency securities 1,430,737 — — — 1,430,737 Sovereign obligations 1,216,643 956,992 — — 2,173,635 Commercial mortgage-backed securities — — 105 — 105 Loans — 1,148,824 3,486 — 1,152,310 Derivatives 249,361 3,480,506 16,041 (3,490,514 ) 255,394 Total trading liabilities $ 4,618,008 $ 7,307,269 $ 20,202 $ (3,490,514 ) $ 8,454,965 Short-term borrowings $ — $ 23,324 $ — $ — $ 23,324 Long-term debt - structured notes $ — $ 606,956 $ — $ — $ 606,956 (1) Represents counterparty and cash collateral netting across the levels of the fair value hierarchy for positions with the same counterparty. (2) As of January 1, 2018, the Company adopted the FASB's new guidance that affects the accounting for equity investments and the presentation and disclosure requirements for financial instruments. At September 30, 2018 , equity investments are primarily classified as Trading assets, at fair value and the change in fair value of equity securities is now recognized through the Consolidated Statements of Operations. See Note 2 for additional information.
Investments Measured At Fair Value Based On Net Asset Value	The following tables present information about our investments in entities that have the characteristics of an investment company (in thousands). Fair Value (1) Unfunded Commitments Redemption Frequency (if currently eligible) September 30, 2018 Equity Long/Short Hedge Funds (2) $ 90,347 $ — (2) Fixed Income and High Yield Hedge Funds (3) 219 — — Fund of Funds (4) 175 — — Equity Funds (5) 36,702 20,209 — Commodity Funds (6) 10,228 — — Multi-asset Funds (7) 261,361 — — Total $ 399,032 $ 20,209 December 31, 2017 Equity Long/Short Hedge Funds (2) $ 407,895 $ — (2) Fixed Income and High Yield Hedge Funds (3) 417 — — Fund of Funds (4) 189 — — Equity Funds (5) 26,798 19,084 — Multi-asset Funds (7) 154,805 — — Total $ 590,104 $ 19,084 (1) Where fair value is calculated based on NAV, fair value has been derived from each of the funds' capital statements. (2) This category includes investments in hedge funds that invest, long and short, primarily in equity securities in domestic and international markets in both the public and private sectors. At December 31, 2017 , 73% of these investments were redeemable with 10 business days or less prior written notice; these investments were primarily liquidated during 2018. At September 30, 2018 and December 31, 2017 , 18% and 15% , respectively, of these investments are redeemable with 30 to 60 days prior written notice. (3) This category includes investments in funds that invest in loans secured by a first trust deed on property, domestic and international public high yield debt, private high yield investments, senior bank loans, public leveraged equities, distressed debt and private equity investments. There are no redemption provisions. (4) This category includes investments in fund of funds that invest in various private equity funds. The investments in this category are managed by us and have no redemption provisions. These investments are gradually being liquidated or we have requested redemption, however, we are unable to estimate when these funds will be received. (5) The investments in this category include investments in equity funds that invest in the equity of various U.S. and foreign private companies in the energy, technology, internet service and telecommunication service industries. These investments cannot be redeemed; instead distributions are received through the liquidation of the underlying assets of the funds, which are expected to be liquidated in one to ten years. (6) This category includes investments in hedge funds that invest, long and short, primarily in commodities. Investments in this category are redeemable with 60 days prior written notice. (7) This category includes investments in hedge funds that invest, long and short, primarily in multi-asset securities in domestic and international markets in both the public and private sectors. At September 30, 2018 and December 31, 2017 , investments representing approximately 17% and 12% , respectively, of the fair value of investments in this category are redeemable with 30 days prior written notice.
Summary Of Changes In Fair Value Of Financial Assets And Liabilities Classified As Level 3	The following is a summary of changes in fair value of our financial assets and liabilities that have been categorized within Level 3 of the fair value hierarchy for the nine months ended September 30, 2018 (in thousands): Nine Months Ended September 30, 2018 Balance, December 31, 2017 Total gains/ losses (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance at September 30, 2018 Changes in unrealized gains/losses included in earnings relating to instruments still held at September 30, 2018 (1) Assets: Trading assets: Corporate equity securities $ 22,270 $ 31,475 $ 35,993 $ (39,008 ) $ (2,082 ) $ — $ 1,035 $ 49,683 $ 26,852 Corporate debt securities 26,036 1,090 22,204 (38,553 ) (2,066 ) — 940 9,651 (1,738 ) CDOs and CLOs 42,184 (4,123 ) 242,864 (249,691 ) (5,859 ) — 8,606 33,981 (7,333 ) Residential mortgage-backed securities 26,077 (7,334 ) 2,018 (12,621 ) (6 ) — (3,180 ) 4,954 316 Commercial mortgage-backed securities 12,419 (1,236 ) 1,720 (548 ) (5,415 ) — 16,976 23,916 (2,272 ) Other asset-backed securities 61,129 (7,528 ) 523,045 (495,055 ) (12,281 ) — (5 ) 69,305 (3,307 ) Loans and other receivables 47,304 (2,812 ) 104,009 (98,733 ) (14,610 ) — 13,827 48,985 (3,769 ) Investments at fair value 329,944 3,865 9,791 (17,569 ) — — 946 326,977 3,271 FXCM term loan 72,800 16,432 — — (15,432 ) — — 73,800 5,539 Liabilities: Trading liabilities: Corporate equity securities $ 48 $ 365 $ — $ — $ — $ — $ — $ 413 $ (365 ) Corporate debt securities 522 39 — — 996 — — 1,557 (39 ) Sovereign obligations — 3 (598 ) 629 — — 21 55 (124 ) Commercial mortgage-backed securities 105 (35 ) — — — — — 70 (70 ) Loans 3,486 (1,059 ) (15,702 ) 19,409 — — 2,527 8,661 1,059 Net derivatives (2) 6,746 (1,034 ) (6 ) — 2,984 296 11 8,997 (2,660 ) Long-term debt (1) — (25,078 ) — — — 81,284 107,424 163,630 13,235 (1) Realized and unrealized gains (losses) are primarily reported in Principal transactions revenues in the Consolidated Statements of Operations. Changes in instrument-specific credit risk related to structured notes are included in our Consolidated Statements of Comprehensive Income (Loss), net of tax. Changes in unrealized gains (losses) included in other comprehensive income (loss) for instruments still held at September 30, 2018 were gains of $11.8 million . (2) Net derivatives represent Trading assets - Derivatives and Trading liabilities - Derivatives. The following is a summary of changes in fair value of our financial assets and liabilities that have been categorized within Level 3 of the fair value hierarchy for the three months ended September 30, 2017 (in thousands): Three Months Ended September 30, 2017 Balance, June 30, 2017 Total gains/ losses (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance, September 30, 2017 Changes in unrealized gains/ losses relating to instruments still held at September 30, 2017 (1) Assets: Trading assets: Corporate equity securities $ 20,548 $ 4,344 $ 4 $ (645 ) $ (55 ) $ — $ (2,022 ) $ 22,174 $ 4,319 Corporate debt securities 24,727 (2,350 ) 5,901 (5,551 ) (31 ) — 2,319 25,015 (2,224 ) CDOs and CLOs 48,208 (15,205 ) 52,918 (36,564 ) 245 — 468 50,070 (12,638 ) Residential mortgage-backed securities 33,032 (263 ) 494 (732 ) (291 ) — (11,591 ) 20,649 188 Commercial mortgage-backed securities 16,263 (125 ) — (676 ) (637 ) — 2,811 17,636 (161 ) Other asset-backed securities 43,349 (6,454 ) 5,798 (3,789 ) (2,924 ) — 32,966 68,946 (3,570 ) Loans and other receivables 49,365 15,261 9,265 (5,854 ) (8,249 ) — 2,868 62,656 14,005 Investments at fair value 315,297 3,964 10,000 — (292 ) — — 328,969 3,964 FXCM term loan 129,050 2,330 — — (60,580 ) — — 70,800 (2,401 ) Liabilities: Trading liabilities: Corporate equity securities $ 354 $ 107 $ (369 ) $ 27 $ — $ — $ — $ 119 $ (92 ) Corporate debt securities 522 — — — — — — 522 — Commercial mortgage-backed securities 70 (35 ) — — — — — 35 (35 ) Loans 4,967 (3,071 ) — 333 — — 1,056 3,285 3,018 Net derivatives (2) 3,022 (2,980 ) — — 5,040 — — 5,082 (2,474 ) (1) Realized and unrealized gains (losses) are reported in Principal transactions revenues in the Consolidated Statements of Operations. (2) Net derivatives represent Trading assets - Derivatives and Trading liabilities - Derivatives. The following is a summary of changes in fair value of our financial assets and liabilities that have been categorized within Level 3 of the fair value hierarchy for the three months ended September 30, 2018 (in thousands): Three months ended September 30, 2018 Balance, June 30, 2018 Total gains/ losses (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance at September 30, 2018 Changes in unrealized gains/losses included in earnings relating to instruments still held at September 30, 2018 (1) Assets: Trading assets: Corporate equity securities $ 44,871 $ 11,796 $ 17,652 $ (23,010 ) $ (302 ) $ — $ (1,324 ) $ 49,683 $ 9,136 Corporate debt securities 28,066 1,057 507 (21,403 ) (59 ) — 1,483 9,651 (165 ) CDOs and CLOs 42,517 (967 ) 238,281 (240,002 ) (2,127 ) — (3,721 ) 33,981 (3,872 ) Residential mortgage-backed securities 3,655 (66 ) 72 (1,597 ) (1 ) — 2,891 4,954 90 Commercial mortgage-backed securities 27,239 (222 ) 8 — (1,156 ) — (1,953 ) 23,916 (288 ) Other asset-backed securities 55,535 (2,269 ) 307,358 (290,838 ) (4,356 ) — 3,875 69,305 (1,124 ) Loans and other receivables 64,036 (1,353 ) 14,932 (23,700 ) (3,453 ) — (1,477 ) 48,985 1,007 Investments at fair value 318,543 2,383 6,051 — — — — 326,977 2,383 FXCM term loan 76,100 1,347 — — (3,647 ) — — 73,800 (2,300 ) Liabilities: Trading liabilities: Corporate equity securities $ 87 $ 326 $ — $ — $ — $ — $ — $ 413 $ (326 ) Corporate debt securities 522 39 — — 996 — — 1,557 (39 ) Sovereign obligations — 3 (598 ) 629 — — 21 55 (124 ) Commercial mortgage-backed securities — 70 — — — — — 70 (70 ) Loans 12,881 (148 ) (4,871 ) 1,787 — — (988 ) 8,661 149 Net derivatives (2) 5,874 1,107 — — 1,990 — 26 8,997 (2,090 ) Long-term debt (1) 160,626 3,004 — — — — — 163,630 (2,953 ) (1) Realized and unrealized gains (losses) are primarily reported in Principal transactions revenues in the Consolidated Statements of Operations. Changes in instrument-specific credit risk related to structured notes are included in our Consolidated Statements of Comprehensive Income (Loss), net of tax. Changes in unrealized gains (losses) included in other comprehensive income (loss) for instruments still held at September 30, 2018 were losses of $0.1 million . (2) Net derivatives represent Trading assets - Derivatives and Trading liabilities - Derivatives. The following is a summary of changes in fair value of our financial assets and liabilities that have been categorized within Level 3 of the fair value hierarchy for the nine months ended September 30, 2017 (in thousands): Nine Months Ended September 30, 2017 Balance, December 31, 2016 Total gains/ losses (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance, September 30, 2017 Changes in unrealized gains/ losses relating to instruments still held at September 30, 2017 (1) Assets: Trading assets: Corporate equity securities $ 21,739 $ 3,416 $ 945 $ (1,502 ) $ (356 ) $ — $ (2,068 ) $ 22,174 $ 2,689 Corporate debt securities 25,005 (3,280 ) 19,610 (18,364 ) (1,724 ) — 3,768 25,015 (3,424 ) CDOs and CLOs 54,354 (21,595 ) 65,523 (62,441 ) 239 — 13,990 50,070 (21,998 ) Municipal securities 27,257 (1,547 ) — (25,710 ) — — — — — Residential mortgage-backed securities 38,772 (1,446 ) 113,391 (125,731 ) (572 ) — (3,765 ) 20,649 (2,005 ) Commercial mortgage-backed securities 20,580 (1,180 ) 2,033 (5,199 ) (985 ) — 2,387 17,636 (952 ) Other asset-backed securities 40,911 (15,338 ) 67,611 (4,121 ) (16,891 ) — (3,226 ) 68,946 (8,872 ) Loans and other receivables 81,872 27,709 84,342 (83,791 ) (23,241 ) — (24,235 ) 62,656 16,294 Investments at fair value 314,359 12,760 12,800 (10,119 ) (831 ) — — 328,969 14,783 FXCM term loan 164,500 17,638 — — (111,338 ) — — 70,800 (930 ) Liabilities: Trading liabilities: Corporate equity securities $ 313 $ 134 $ (355 ) $ 27 $ — $ — $ — $ 119 $ (92 ) Corporate debt securities 523 (1 ) — — — — — 522 1 Commercial mortgage-backed securities — 35 — — — — — 35 (35 ) Loans 378 1,604 (364 ) 333 — — 1,334 3,285 (1,583 ) Net derivatives (2) 3,441 (2,854 ) — — 5,162 404 (1,071 ) 5,082 (2,333 ) Other secured financings 418 (418 ) — — — — — — — (1) Realized and unrealized gains (losses) are reported in Principal transactions revenues in the Consolidated Statements of Operations. (2) Net derivatives represent Trading assets - Derivatives and Trading liabilities - Derivatives.
Quantitative Information About Significant Unobservable Inputs Used In Level 3 Fair Value Measurements	September 30, 2018 Financial Instruments Owned Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Corporate equity securities $ 41,038 Non-exchange traded securities Market approach Price $3 to $75 $25.0 Underlying stock price $1 to $11 $9.0 Corporate debt securities $ 9,651 Market approach Discount rate/yield 19% — Estimated recovery percentage 46% — Price $10 — Comparable asset price $101 — CDOs and CLOs $ 33,981 Discounted cash flows Constant prepayment rate 20% — Constant default rate 1% to 2% 2 % Loss severity 30% — Discount rate/yield 5% to 41% 16 % Scenario analysis Estimated recovery percentage 2% to 41% 23 % Residential mortgage-backed securities $ 4,954 Discounted cash flows Cumulative loss rate 23% — Duration (years) 15 years — Discount rate/yield 9% — Market approach Price $100 — Commercial mortgage-backed securities $ 23,916 Discounted cash flows Cumulative loss rate 8% to 84% 33 % Duration (years) 0 year to 3 years 1 year Discount rate/yield 3% to 38% 12 % Scenario analysis Estimated recovery percentage 26% — Price $49 — Other asset-backed securities $ 69,305 Discounted cash flows Cumulative loss rate 0% to 29% 18 % Duration (years) 1 year to 5 years 2 years Discount rate/yield 5% to 12% 7 % Market approach Price $100 — Loans and other receivables $ 48,985 Market approach Estimated recovery percentage 0% — Price $50 to $100 $95.0 Scenario analysis Estimated recovery percentage 57% to 107% 88 % Derivatives $ 3,137 Total return swaps Market approach Price $100 — Investments at fair value $ 111,899 Private equity securities Market approach Price $3 to $250 $105.0 Discount rate 20% — Investment in FXCM $ 73,800 Term loan Discounted cash flows Term based on the pay off (years) 0 months to 0.3 years 0.3 years Trading Liabilities Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Corporate debt securities $ 1,557 Market approach Estimated recovery percentage 53% — Loans $ 8,661 Market approach Estimated recovery percentage 0% — Price $50 — Derivatives $ 12,134 Equity options Option model/default rate Default probability 0% — Unfunded commitments Market approach Price $99 — Total return swaps Market approach Price $95 to $100 $97.0 Variable funding note swaps Discounted cash flows Constant prepayment rate 20% — Constant default rate 2% — Loss severity 30% — Discount rate/yield 41% — Long-term debt $ 163,630 Structured notes Market approach Price $70 to $100 $80.0 Price €80 to €112 €96.0 December 31, 2017 Financial Instruments Owned Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Corporate equity securities $ 18,109 Non-exchange traded securities Market approach Price $3 to $75 $33.0 Underlying stock price $6 — Comparable pricing Comparable asset price $7 — Corporate debt securities $ 26,036 Convertible bond model Discount rate/yield 8% — Volatility 40% — Market approach Estimated recovery percentage 17% — Price $10 — CDOs and CLOs $ 38,845 Discounted cash flows Constant prepayment rate 20% — Constant default rate 2% — Loss severity 25% to 30% 26 % Discount rate/yield 3% to 26% 12 % Scenario analysis Estimated recovery percentage 8% to 45% 26 % Residential mortgage-backed securities $ 26,077 Discounted cash flows Cumulative loss rate 3% to 19% 10 % Duration (years) 2 years to 4 years 3 years Discount rate/yield 6% to 10% 8 % Commercial mortgage-backed securities $ 12,419 Discounted cash flows Discount rate/yield 2% to 26% 12 % Cumulative loss rate 8% to 65% 44 % Duration (years) 1 year to 3 years 2 years Scenario analysis Estimated recovery percentage 26% to 32% 28 % Price $52 to $56 $54.0 Other asset-backed securities $ 61,129 Discounted cash flows Cumulative loss rate 0% to 33% 23 % Duration (years) 1 year to 6 years 2 years Discount rate/yield 5% to 39% 9 % Market approach Price $100 — Scenario analysis Estimated recovery percentage 14% — Loans and other receivables $ 46,121 Market approach Estimated recovery percentage 76% — Price $54 to $100 $95.0 Scenario analysis Estimated recovery percentage 13% to 107% 78 % Derivatives $ 9,295 Total return swaps Market approach Price $101 to $106 $103.0 Interest rate swaps Market approach Credit spread 800 bps — Investments at fair value $ 110,010 Private equity securities Market approach Transaction level $3 to $250 $172.0 Price $7 — Discount rate 20% — Investment in FXCM $ 72,800 Term loan Discounted cash flows Term based on the pay off (years) 0 months to 1 year 0.2 years Trading Liabilities Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Derivatives $ 16,041 Equity options Option model/default rate Default probability 0% — Unfunded commitments Market approach Price $99 — Total return swaps Market approach Price $101 to $106 $103.0 Variable funding note swaps Discounted cash flows Constant prepayment rate 20% — Constant default rate 2% — Loss severity 25% — Discount rate/yield 26% —
Summary Of Gains (Losses) Due To Changes In Instrument Specific Credit Risk For Loans and Other Receivables And Loan Commitments Measured At Fair Value Under Fair Value Option	The following is a summary of Jefferies Group's gains (losses) due to changes in instrument specific credit risk on loans, other receivables and debt instruments and gains (losses) due to other changes in fair value on long-term debt and short-term borrowings measured at fair value under the fair value option (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Financial Instruments Owned: Loans and other receivables $ 14,002 $ 24,846 $ 7,495 $ 27,715 Financial Instruments Sold: Loans $ (2,708 ) $ 3,436 $ (2,467 ) $ (7,286 ) Loan commitments $ (1,695 ) $ 82 $ (1,964 ) $ 229 Long-term Debt: Changes in instrument specific credit risk (1) $ 1,401 $ 5,638 $ 19,986 $ (14,141 ) Other changes in fair value (2) $ (6,842 ) $ (1,854 ) $ 33,626 $ 2,786 Short-term Borrowings: Changes in instrument specific credit risk (1) $ — $ 19 $ — $ 1 Other changes in fair value (2) $ — $ (2,570 ) $ — $ (37 ) (1) Changes in instrument specific credit risk related to structured notes are included in the Consolidated Statements of Comprehensive Income (Loss), net of tax. (2) Other changes in fair value are included in Principal transactions revenues in the Consolidated Statements of Operations.
Summary Of Amount By Which Contractual Principal Exceeds Fair Value For Loans And Other Receivables Measured At Fair Value Under Fair Value Option	The following is a summary of the amount by which contractual principal exceeds fair value for loans and other receivables, long-term debt and short-term borrowings measured at fair value under the fair value option (in thousands): September 30, 2018 December 31, 2017 Financial Instruments Owned: Loans and other receivables (1) $ 896,470 $ 752,076 Loans and other receivables on nonaccrual status and/or 90 days or greater past due (1) (2) $ 167,355 $ 159,462 Long-term debt and short-term borrowings $ 89,345 $ 32,839 (1) Interest income is recognized separately from other changes in fair value and is included in Interest income in the Consolidated Statements of Operations. (2) Amounts include all loans and other receivables 90 days or greater past due by which contractual principal exceeds fair value of $33.7 million and $38.7 million at September 30, 2018 and December 31, 2017 , respectively.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value And Related Number Of Derivative Contracts Categorized By Predominant Risk Exposure	The following table presents the fair value and related number of derivative contracts categorized by type of derivative contract as reflected in the Consolidated Statements of Financial Condition at September 30, 2018 and December 31, 2017 . The fair value of assets/liabilities represents our receivable/payable for derivative financial instruments, gross of counterparty netting and cash collateral received and pledged. The following tables also provide information regarding (1) the extent to which, under enforceable master netting arrangements, such balances are presented net in our Consolidated Statements of Financial Condition as appropriate under GAAP and (2) the extent to which other rights of setoff associated with these arrangements exist and could have an effect on our financial position (in thousands, except contract amounts): Assets Liabilities Fair Value Number of Contracts Fair Value Number of Contracts September 30, 2018 Derivatives designated as accounting hedges - interest rate contracts $ — — $ 30,018 1 Derivatives not designated as accounting hedges: Interest rate contracts $ 766,233 20,867 $ 892,562 38,331 Foreign exchange contracts 234,641 8,569 223,565 7,486 Equity contracts 2,491,005 1,892,926 2,987,654 1,836,128 Commodity contracts 4,599 6,331 16,312 3,585 Credit contracts 27,267 172 20,140 76 Total 3,523,745 4,140,233 Counterparty/cash-collateral netting (1) (3,334,100 ) (3,454,488 ) Total derivatives not designated as accounting hedges $ 189,645 $ 685,745 Total per Consolidated Statement of Financial Condition (2) $ 189,645 $ 715,763 December 31, 2017 Derivatives designated as accounting hedges - interest rate contracts $ — — $ 2,420 1 Derivatives not designated as accounting hedges: Interest rate contracts $ 1,717,058 38,941 $ 1,708,776 12,828 Foreign exchange contracts 366,541 6,463 349,512 4,612 Equity contracts 1,373,016 2,728,750 1,638,258 2,118,526 Commodity contracts 3,093 7,249 5,141 6,047 Credit contracts 38,261 130 41,801 191 Total 3,497,969 3,743,488 Counterparty/cash-collateral netting (1)(3) (3,318,481 ) (3,490,514 ) Total derivatives not designated as accounting hedges $ 179,488 $ 252,974 Total per Consolidated Statement of Financial Condition (2)(3) $ 179,488 $ 255,394 (1) Amounts netted include both netting by counterparty and for cash collateral paid or received. (2) We have not received or pledged additional collateral under master netting agreements and/or other credit support agreements that is eligible to be offset beyond what has been offset in the Consolidated Statements of Financial Condition. (3) Pursuant to a rule change by the London Clearing House in the first fiscal quarter of 2018, variation margin exchanged each day with this clearing organization on certain interest rate derivatives is characterized as settlement payments as opposed to cash posted as collateral. The impact of this rule change would have been a reduction in gross interest rate derivative assets and liabilities as of December 31, 2017 of approximately $800 million , and a corresponding decrease in counterparty and cash collateral netting, with no impact to our Consolidated Statement of Financial Condition .
Unrealized And Realized Gains (Losses) On Derivative Contracts	The following table provides information related to gains (losses) recognized in Interest expense of Jefferies Group in the Consolidated Statements of Operations on a fair value hedge (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate swaps $ (1,161 ) $ 6,217 $ (22,363 ) $ 13,960 Long-term debt 1,221 (4,680 ) 24,055 (9,570 ) Total $ 60 $ 1,537 $ 1,692 $ 4,390 The following table presents unrealized and realized gains (losses) on derivative contracts which are primarily recognized in Principal transactions revenues in Income (loss) from continuing operations in the Consolidated Statements of Operations, which are utilized in connection with our client activities and our economic risk management activities (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate contracts $ 13,951 $ (7,485 ) $ 36,053 $ 2,555 Foreign exchange contracts (4,781 ) 481 6,737 3,341 Equity contracts 1,019 (142,931 ) (249,546 ) (294,635 ) Commodity contracts (6,845 ) (1,422 ) (23,150 ) (3,260 ) Credit contracts 20 (7,947 ) 760 6,133 Total $ 3,364 $ (159,304 ) $ (229,146 ) $ (285,866 )
Remaining Contract Maturity Of Fair Value Of OTC Derivative Assets And Liabilities	The following tables set forth by remaining contract maturity the fair value of OTC derivative assets and liabilities as reflected in the Consolidated Statement of Financial Condition at September 30, 2018 (in thousands): OTC Derivative Assets (1) (2) (3) 0-12 Months 1-5 Years Greater Than 5 Years Cross- Maturity Netting (4) Total Commodity swaps, options and forwards $ 738 $ 512 $ — $ — $ 1,250 Equity swaps and options 10,226 8,071 2,195 — 20,492 Credit default swaps 82 21,802 — (11 ) 21,873 Total return swaps 46,036 29,910 — (4,334 ) 71,612 Foreign currency forwards, swaps and options 42,326 22,130 — (9,550 ) 54,906 Fixed income forwards 2,113 — — — 2,113 Interest rate swaps, options and forwards 13,104 96,631 95,973 (91,673 ) 114,035 Total $ 114,625 $ 179,056 $ 98,168 $ (105,568 ) 286,281 Cross product counterparty netting (34,971 ) Total OTC derivative assets included in Trading assets $ 251,310 (1) At September 30, 2018 , we held exchange traded derivative assets, other derivative assets and other credit agreements with a fair value of $96.6 million , which are not included in this table. (2) OTC derivative assets in the table above are gross of collateral received. OTC derivative assets are recorded net of collateral received in the Consolidated Statements of Financial Condition. At September 30, 2018 , cash collateral received was $158.2 million . (3) Derivative fair values include counterparty netting within product category. (4) Amounts represent the netting of receivable balances with payable balances for the same counterparty within product category across maturity categories. OTC Derivative Liabilities (1) (2) (3) 0-12 Months 1-5 Years Greater Than 5 Years Cross-Maturity Netting (4) Total Commodity swaps, options and forwards $ 12,234 $ 2,388 $ — $ — $ 14,622 Equity swaps and options 15,125 92,491 13,048 — 120,664 Credit default swaps 17 11,480 — (11 ) 11,486 Total return swaps 67,526 19,806 — (4,334 ) 82,998 Foreign currency forwards, swaps and options 36,183 17,496 — (9,550 ) 44,129 Fixed income forwards 685 — — — 685 Interest rate swaps, options and forwards 16,388 148,685 198,569 (91,673 ) 271,969 Total $ 148,158 $ 292,346 $ 211,617 $ (105,568 ) 546,553 Cross product counterparty netting (34,971 ) Total OTC derivative liabilities included in Trading liabilities $ 511,582 (1) At September 30, 2018 , we held exchange traded derivative liabilities, other derivative liabilities and other credit agreements with a fair value of $482.8 million , which are not included in this table. (2) OTC derivative liabilities in the table above are gross of collateral pledged. OTC derivative liabilities are recorded net of collateral pledged in the Consolidated Statements of Financial Condition. At September 30, 2018 , cash collateral pledged was $278.6 million . (3) Derivative fair values include counterparty netting within product category. (4) Amounts represent the netting of receivable balances with payable balances for the same counterparty within product category across maturity categories.
Counterparty Credit Quality With Respect To Fair Value Of OTC Derivatives Assets	At September 30, 2018 , the counterparty credit quality with respect to the fair value of our OTC derivative assets was as follows (in thousands): Counterparty credit quality (1): A- or higher $ 137,910 BBB- to BBB+ 20,490 BB+ or lower 74,097 Unrated 18,813 Total $ 251,310 (1) Jefferies Group utilizes internal credit ratings determined by Jefferies Group's Risk Management department. Credit ratings determined by Risk Management use methodologies that produce ratings generally consistent with those produced by external rating agencies.
Credit Related Derivative Contracts	The external credit ratings of the underlyings or referenced assets for our written credit related derivative contracts (in millions): External Credit Rating Investment Grade Non-investment grade Unrated Total Notional September 30, 2018 Credit protection sold: Index credit default swaps $ 3.0 $ 15.0 $ — $ 18.0 Single name credit default swaps $ 32.5 $ 39.9 $ 2.9 $ 75.3 December 31, 2017 Credit protection sold: Index credit default swaps $ 3.0 $ 126.0 $ — $ 129.0 Single name credit default swaps $ 129.1 $ 89.1 $ — $ 218.2
Derivative Instruments With Contingent Features	The following table presents the aggregate fair value of all derivative instruments with such credit-risk-related contingent features that are in a liability position, the collateral amounts posted or received in the normal course of business and the potential collateral Jefferies Group would have been required to return and/or post additionally to its counterparties if the credit-risk-related contingent features underlying these agreements were triggered (in millions): September 30, 2018 December 31, 2017 Derivative instrument liabilities with credit-risk-related contingent features $ 106.3 $ 95.1 Collateral posted $ (59.3 ) $ (86.4 ) Collateral received $ 129.7 $ 5.6 Return of and additional collateral required in the event of a credit rating downgrade below investment grade (1) $ 176.6 $ 14.3 (1) These outflows include initial margin received from counterparties at the execution of the derivative contract. The initial margin will be returned if counterparties elect to terminate the contract after a downgrade.

Collateralized Transactions (Ta

Collateralized Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
Collateralized Transactions [Abstract]
Schedule of Collateralized Financing Transactions	The following tables set forth the carrying value of securities lending arrangements and repurchase agreements by class of collateral pledged and remaining contractual maturity (in thousands): Collateral Pledged Securities Lending Arrangements Repurchase Agreements Total September 30, 2018 Cash $ — $ 4,361 $ 4,361 Corporate equity securities 2,214,433 490,609 2,705,042 Corporate debt securities 315,718 1,496,127 1,811,845 Mortgage- and asset-backed securities — 2,667,439 2,667,439 U.S. government and federal agency securities 1,353 10,124,642 10,125,995 Municipal securities — 582,699 582,699 Sovereign obligations — 1,955,879 1,955,879 Loans and other receivables — 517,703 517,703 Total $ 2,531,504 $ 17,839,459 $ 20,370,963 December 31, 2017 Corporate equity securities $ 2,353,798 $ 214,413 $ 2,568,211 Corporate debt securities 470,908 2,336,702 2,807,610 Mortgage- and asset-backed securities — 2,562,268 2,562,268 U.S. government and federal agency securities 19,205 11,792,534 11,811,739 Municipal securities — 444,861 444,861 Sovereign obligations — 2,023,530 2,023,530 Loans and other receivables — 454,941 454,941 Total $ 2,843,911 $ 19,829,249 $ 22,673,160 Contractual Maturity Overnight and Continuous Up to 30 Days 30 to 90 Days Greater than 90 Days Total September 30, 2018 Securities lending arrangements $ 1,354,136 $ — $ 847,577 $ 329,791 $ 2,531,504 Repurchase agreements 8,122,962 2,733,400 4,342,923 2,640,174 17,839,459 Total $ 9,477,098 $ 2,733,400 $ 5,190,500 $ 2,969,965 $ 20,370,963 December 31, 2017 Securities lending arrangements $ 1,676,940 $ — $ 741,971 $ 425,000 $ 2,843,911 Repurchase agreements 10,780,474 4,058,228 3,211,464 1,779,083 19,829,249 Total $ 12,457,414 $ 4,058,228 $ 3,953,435 $ 2,204,083 $ 22,673,160

Securitization Activities (Tabl

Securitization Activities (Tables)	9 Months Ended
	Sep. 30, 2018
Securitization Activities [Abstract]
Activity Related To Securitizations Accounted For As Sales	The following table presents activity related to Jefferies Group's securitizations that were accounted for as sales in which it had continuing involvement (in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Transferred assets $ 1,865.5 $ 1,009.1 $ 5,665.9 $ 2,677.7 Proceeds on new securitizations $ 1,866.2 $ 1,017.2 $ 5,668.6 $ 2,703.3 Cash flows received on retained interests $ 17.2 $ 8.7 $ 35.7 $ 22.7
Summary Of Retained Interests In SPEs	The following table summarizes Jefferies Group's retained interests in SPEs where it transferred assets and has continuing involvement and received sale accounting treatment (in millions): September 30, 2018 December 31, 2017 Securitization Type Total Assets Retained Interests Total Assets Retained Interests U.S. government agency residential mortgage-backed securities $ 13,306.0 $ 192.7 $ 6,383.5 $ 28.2 U.S. government agency commercial mortgage-backed securities $ 2,101.5 $ 276.1 $ 2,075.7 $ 81.4 CLOs $ 3,442.3 $ 26.4 $ 3,957.8 $ 20.3 Consumer and other loans $ 648.9 $ 53.0 $ 247.6 $ 47.8

Available for Sale Securities_2

Available for Sale Securities and Other Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Investments [Abstract]
Schedule of Available for Sale Securities	The amortized cost and estimated fair value of investments classified as available for sale at September 30, 2018 , by contractual maturity, are shown below. Expected maturities are likely to differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Estimated Fair Value (In thousands) Due within one year $ 1,608,076 $ 1,607,725 1,608,076 1,607,725 Mortgage-backed and asset-backed securities 261,886 260,695 $ 1,869,962 $ 1,868,420 The amortized cost, gross unrealized gains and losses and estimated fair value of investments classified as available for sale are as follows (in thousands): Amortized Gross Gross Estimated September 30, 2018 Bonds and notes: U.S. government securities $ 1,608,076 $ 2 $ 353 $ 1,607,725 Residential mortgage-backed securities 147,294 138 754 146,678 Commercial mortgage-backed securities 16,049 — 330 15,719 Other asset-backed securities 98,543 9 254 98,298 Total fixed maturities 1,869,962 149 1,691 1,868,420 Total Available for sale securities $ 1,869,962 $ 149 $ 1,691 $ 1,868,420 December 31, 2017 Bonds and notes: U.S. government securities $ 552,847 $ — $ 42 $ 552,805 Residential mortgage-backed securities 34,381 272 92 34,561 Commercial mortgage-backed securities 5,857 17 4 5,870 Other asset-backed securities 34,837 46 44 34,839 Total fixed maturities 627,922 335 182 628,075 Equity securities: Common stocks: Banks, trusts and insurance companies 35,071 17,500 — 52,571 Industrial, miscellaneous and all other 17,504 18,411 — 35,915 Total equity securities 52,575 35,911 — 88,486 Total Available for sale securities $ 680,497 $ 36,246 $ 182 $ 716,561

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2018
Variable Interest Entities [Abstract]
Assets And Liabilities Of Consolidated VIEs	The following table presents information about the assets and liabilities of our consolidated securitization vehicles VIEs, which are presented in our Consolidated Statements of Financial Condition in the respective asset and liability categories (in millions). The assets and liabilities in the table below are presented prior to consolidation and thus a portion of these assets and liabilities are eliminated in consolidation. September 30, 2018 December 31, 2017 Cash $ — $ 11.7 Financial instruments owned — 37.6 Securities purchased under agreement to resell (1) 1,043.4 729.3 Receivables 453.2 318.1 Other 25.8 15.5 Total assets $ 1,522.4 $ 1,112.2 Other secured financings (2) $ 1,478.3 $ 1,073.5 Other (3) 44.1 38.3 Total liabilities $ 1,522.4 $ 1,111.8 (1) Securities purchased under agreements to resell represent an amount due under a collateralized transaction on a related consolidated entity, which is eliminated in consolidation. (2) Approximately $37.7 million and $44.1 million of the secured financings represent an amount held by Jefferies Group in inventory and eliminated in consolidation at September 30, 2018 and December 31, 2017 , respectively. (3) Includes $31.1 million and $32.0 million at September 30, 2018 and December 31, 2017 , respectively, of intercompany payables that are eliminated in consolidation.
Non-Consolidated Variable Interest Entities	The following tables present information about our variable interests in nonconsolidated VIEs (in millions): Financial Statement Carrying Amount Maximum Exposure to Loss VIE Assets Assets Liabilities September 30, 2018 CLOs $ 57.0 $ 0.7 $ 784.0 $ 3,348.0 Consumer loan vehicles 323.5 — 602.4 3,441.8 Related party private equity vehicles 34.1 — 52.0 107.2 Other private investment vehicles 160.4 — 170.8 5,324.2 Total $ 575.0 $ 0.7 $ 1,609.2 $ 12,221.2 December 31, 2017 CLOs $ 168.1 $ 8.9 $ 1,030.4 $ 5,364.3 Consumer loan vehicles 254.8 — 759.8 2,322.7 Related party private equity vehicles 23.7 — 45.4 75.0 Other private investment vehicles 133.0 — 142.0 4,624.9 Total $ 579.6 $ 8.9 $ 1,977.6 $ 12,386.9

Loans to and Investments In A_2

Loans to and Investments In Associated Companies (Tables)	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Loans to and Investments in Associated Companies	A summary of Loans to and investments in associated companies accounted for under the equity method of accounting during the nine months ended September 30, 2018 and 2017 is as follows (in thousands): Loans to and investments in associated companies as of January 1, Income (losses) related to associated companies Income (losses) related to Jefferies Group's associated companies (1) Contributions to (distributions from) associated companies, net Other Loans to and investments in associated companies as of September 30, 2018 Jefferies Finance $ 655,467 $ — $ 36,497 $ 43,470 $ — $ 735,434 National Beef (2) — 83,287 — (48,656 ) 592,239 626,870 Berkadia 210,594 80,092 — (42,064 ) (1,054 ) 247,568 FXCM (3) 158,856 (19,322 ) — — (513 ) 139,021 Garcadia companies (4) 179,143 21,646 — (26,962 ) (173,827 ) — Linkem 192,136 (20,534 ) — 542 (3,601 ) 168,543 HomeFed 341,874 (3,338 ) — — — 338,536 Golden Queen (5) 105,005 (52,028 ) — 8,441 — 61,418 Other 223,754 (5,483 ) (5,810 ) (69,071 ) (9,879 ) 133,511 Total $ 2,066,829 $ 84,320 $ 30,687 $ (134,300 ) $ 403,365 $ 2,450,901 2017 Jefferies Finance $ 490,464 $ — $ 63,685 $ 109,899 $ — $ 664,048 Jefferies LoanCore 154,731 — 8,030 43,714 1,095 207,570 Berkadia 184,443 67,979 — (52,300 ) (174 ) 199,948 FXCM (3) 336,258 (166,360 ) — — 731 170,629 Garcadia companies 185,815 38,536 — (40,955 ) — 183,396 Linkem 154,000 (26,557 ) — 31,996 33,979 193,418 HomeFed 302,231 9,922 — 31,918 — 344,071 Golden Queen 111,302 (3,684 ) — (59 ) — 107,559 Other 205,854 (4,249 ) (6,392 ) 79,636 5,492 280,341 Total $ 2,125,098 $ (84,413 ) $ 65,323 $ 203,849 $ 41,123 $ 2,350,980 (1) Primarily classified in Investment banking revenues and Other revenues. (2) As discussed more fully in Notes 1 and 24, in June 2018, we completed the sale of 48% of National Beef to Marfrig, reducing our ownership in National Beef to 31% . As of the closing of the sale on June 5, 2018, we deconsolidated our investment in National Beef and account for our remaining interest under the equity method of accounting. The carrying value of our retained 31% interest was adjusted to a fair value of $592.3 million on the date of sale. (3) As further described in Note 3, our investment in FXCM includes both our equity method investment in FXCM and our term loan with FXCM. Our equity method investment is included as Loans to and investments in associated companies and our term loan is included as Trading assets, at fair value in our Consolidated Statements of Financial Condition. (4) As more fully discussed in Note 1, during the third quarter of 2018, we sold 100% of our equity interests in Garcadia and our associated real estate to our former partners, the Garff family. (5) At September 30, 2018 and December 31, 2017 , the balance reflects $15.1 million and $30.5 million , respectively, related to a noncontrolling interest. Income (losses) related to associated companies includes the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 National Beef $ 58,886 $ — $ 83,287 $ — Berkadia 28,350 34,839 80,092 67,979 FXCM (4,282 ) (4,345 ) (19,322 ) (166,360 ) Garcadia companies 691 12,565 21,646 38,536 Linkem (7,770 ) (9,533 ) (20,534 ) (26,557 ) HomeFed (7,783 ) 238 (3,338 ) 9,922 Golden Queen (48,732 ) (1,975 ) (52,028 ) (3,684 ) Other (493 ) (1,732 ) (5,483 ) (4,249 ) Total $ 18,867 $ 30,057 $ 84,320 $ (84,413 ) Income (losses) related to Jefferies Group's associated companies (primarily classified in Investment banking revenues and Other revenues) includes the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Jefferies Finance $ 5,931 $ 13,509 $ 36,497 $ 63,685 Jefferies LoanCore — 1,656 — 8,030 Other (78 ) (4,337 ) (5,810 ) (6,392 ) Total $ 5,853 $ 10,828 $ 30,687 $ 65,323
Schedule of Equity Method Investments	The following table provides summarized data for certain associated companies (Jefferies Finance, National Beef for the period subsequent to the closing of the transaction with Marfrig on June 5, 2018 and Berkadia) (in thousands): For the Nine Months Ended September 30, 2018 2017 Revenues $ 3,341,369 $ 763,727 Income from continuing operations before extraordinary items $ 591,191 $ 267,796 Net income $ 591,191 $ 267,796

Financial Statement Offsetting

Financial Statement Offsetting (Tables)	9 Months Ended
	Sep. 30, 2018
Offsetting [Abstract]
Summary of Offsetting Assets	The following table provides information regarding derivative contracts, repurchase agreements and securities borrowing and lending arrangements that are recognized in the Consolidated Statements of Financial Condition and (1) the extent to which, under enforceable master netting arrangements, such balances are presented net in the Consolidated Statements of Financial Condition as appropriate under GAAP and (2) the extent to which other rights of setoff associated with these arrangements exist and could have an effect on our consolidated financial position. (In thousands) Gross Amounts Netting in Consolidated Statements of Financial Condition Net Amounts in Consolidated Statements of Financial Condition Additional Amounts Available for Setoff (1) Available Collateral (2) Net Amount (3) Assets at September 30, 2018 Derivative contracts $ 3,523,745 $ (3,334,100 ) $ 189,645 $ — $ — $ 189,645 Securities borrowing arrangements $ 7,369,908 $ — $ 7,369,908 $ (529,662 ) $ (1,088,612 ) $ 5,751,634 Reverse repurchase agreements $ 11,634,035 $ (7,974,976 ) $ 3,659,059 $ (187,426 ) $ (3,441,009 ) $ 30,624 Liabilities at September 30, 2018 Derivative contracts $ 4,170,251 $ (3,454,488 ) $ 715,763 $ — $ — $ 715,763 Securities lending arrangements $ 2,531,504 $ — $ 2,531,504 $ (529,662 ) $ (1,977,558 ) $ 24,284 Repurchase agreements $ 17,839,459 $ (7,974,976 ) $ 9,864,483 $ (187,426 ) $ (8,632,482 ) $ 1,044,575 Assets at December 31, 2017 Derivative contracts $ 3,497,969 $ (3,318,481 ) $ 179,488 $ — $ — $ 179,488 Securities borrowing arrangements $ 7,721,803 $ — $ 7,721,803 $ (966,712 ) $ (1,032,629 ) $ 5,722,462 Reverse repurchase agreements $ 14,858,297 $ (11,168,738 ) $ 3,689,559 $ (463,973 ) $ (3,207,147 ) $ 18,439 Liabilities at December 31, 2017 Derivative contracts $ 3,745,908 $ (3,490,514 ) $ 255,394 $ — $ — $ 255,394 Securities lending arrangements $ 2,843,911 $ — $ 2,843,911 $ (966,712 ) $ (1,795,408 ) $ 81,791 Repurchase agreements $ 19,829,249 $ (11,168,738 ) $ 8,660,511 $ (463,973 ) $ (7,067,512 ) $ 1,129,026 (1) Under master netting agreements with our counterparties, we have the legal right of offset with a counterparty, which incorporates all of the counterparty’s outstanding rights and obligations under the arrangement. These balances reflect additional credit risk mitigation that is available by a counterparty in the event of a counterparty’s default, but which are not netted in the balance sheet because other netting provisions of GAAP are not met. Further, for derivative assets and liabilities, amounts netted include cash collateral paid or received. (2) Includes securities received or paid under collateral arrangements with counterparties that could be liquidated in the event of a counterparty default and thus offset against a counterparty’s rights and obligations under the respective repurchase agreements or securities borrowing or lending arrangements. (3) At September 30, 2018 , amounts include $5,717.1 million of securities borrowing arrangements, for which we have received securities collateral of $5,544.1 million , and $1,019.6 million of repurchase agreements, for which we have pledged securities collateral of $1,054.1 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable. At December 31, 2017 , amounts include $5,678.6 million of securities borrowing arrangements, for which we have received securities collateral of $5,516.7 million , and $1,084.4 million of repurchase agreements, for which we have pledged securities collateral of $1,115.9 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable.
Summary of Offsetting Liabilities	The following table provides information regarding derivative contracts, repurchase agreements and securities borrowing and lending arrangements that are recognized in the Consolidated Statements of Financial Condition and (1) the extent to which, under enforceable master netting arrangements, such balances are presented net in the Consolidated Statements of Financial Condition as appropriate under GAAP and (2) the extent to which other rights of setoff associated with these arrangements exist and could have an effect on our consolidated financial position. (In thousands) Gross Amounts Netting in Consolidated Statements of Financial Condition Net Amounts in Consolidated Statements of Financial Condition Additional Amounts Available for Setoff (1) Available Collateral (2) Net Amount (3) Assets at September 30, 2018 Derivative contracts $ 3,523,745 $ (3,334,100 ) $ 189,645 $ — $ — $ 189,645 Securities borrowing arrangements $ 7,369,908 $ — $ 7,369,908 $ (529,662 ) $ (1,088,612 ) $ 5,751,634 Reverse repurchase agreements $ 11,634,035 $ (7,974,976 ) $ 3,659,059 $ (187,426 ) $ (3,441,009 ) $ 30,624 Liabilities at September 30, 2018 Derivative contracts $ 4,170,251 $ (3,454,488 ) $ 715,763 $ — $ — $ 715,763 Securities lending arrangements $ 2,531,504 $ — $ 2,531,504 $ (529,662 ) $ (1,977,558 ) $ 24,284 Repurchase agreements $ 17,839,459 $ (7,974,976 ) $ 9,864,483 $ (187,426 ) $ (8,632,482 ) $ 1,044,575 Assets at December 31, 2017 Derivative contracts $ 3,497,969 $ (3,318,481 ) $ 179,488 $ — $ — $ 179,488 Securities borrowing arrangements $ 7,721,803 $ — $ 7,721,803 $ (966,712 ) $ (1,032,629 ) $ 5,722,462 Reverse repurchase agreements $ 14,858,297 $ (11,168,738 ) $ 3,689,559 $ (463,973 ) $ (3,207,147 ) $ 18,439 Liabilities at December 31, 2017 Derivative contracts $ 3,745,908 $ (3,490,514 ) $ 255,394 $ — $ — $ 255,394 Securities lending arrangements $ 2,843,911 $ — $ 2,843,911 $ (966,712 ) $ (1,795,408 ) $ 81,791 Repurchase agreements $ 19,829,249 $ (11,168,738 ) $ 8,660,511 $ (463,973 ) $ (7,067,512 ) $ 1,129,026 (1) Under master netting agreements with our counterparties, we have the legal right of offset with a counterparty, which incorporates all of the counterparty’s outstanding rights and obligations under the arrangement. These balances reflect additional credit risk mitigation that is available by a counterparty in the event of a counterparty’s default, but which are not netted in the balance sheet because other netting provisions of GAAP are not met. Further, for derivative assets and liabilities, amounts netted include cash collateral paid or received. (2) Includes securities received or paid under collateral arrangements with counterparties that could be liquidated in the event of a counterparty default and thus offset against a counterparty’s rights and obligations under the respective repurchase agreements or securities borrowing or lending arrangements. (3) At September 30, 2018 , amounts include $5,717.1 million of securities borrowing arrangements, for which we have received securities collateral of $5,544.1 million , and $1,019.6 million of repurchase agreements, for which we have pledged securities collateral of $1,054.1 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable. At December 31, 2017 , amounts include $5,678.6 million of securities borrowing arrangements, for which we have received securities collateral of $5,516.7 million , and $1,084.4 million of repurchase agreements, for which we have pledged securities collateral of $1,115.9 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable.

Intangible Assets, Net and Go_2

Intangible Assets, Net and Goodwill (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Intangible Assets, Net And Goodwill	A summary of Intangible assets, net and goodwill is as follows (in thousands): September 30, 2018 December 31, 2017 Indefinite-lived intangibles: Exchange and clearing organization membership interests and registrations $ 8,475 $ 8,551 Amortizable intangibles: Customer and other relationships, net of accumulated amortization of $100,591 and $230,074 70,071 347,767 Trademarks and tradenames, net of accumulated amortization of $20,211 and $95,627 108,406 293,851 Supply contracts, net of accumulated amortization of $0 and $57,440 — 86,160 Other, net of accumulated amortization of $4,132 and $3,885 4,818 4,701 Total intangible assets, net 191,770 741,030 Goodwill: National Beef — 14,991 Jefferies Group 1,699,269 1,703,300 Other operations 3,859 3,859 Total goodwill 1,703,128 1,722,150 Total intangible assets, net and goodwill $ 1,894,898 $ 2,463,180
Schedule of Estimated Aggregate Future Amortization Expense	The estimated aggregate future amortization expense for the intangible assets for each of the next five years is as follows (in thousands): Remainder of current year $ 3,359 2019 $ 13,439 2020 $ 13,439 2021 $ 13,052 2022 $ 13,052

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Short-term Borrowings	Jefferies Group's short-term borrowings, which mature in one year or less, are as follows (in thousands): September 30, 2018 December 31, 2017 Bank loans (1) $ 324,021 $ 304,651 Floating rate puttable notes 57,985 108,240 Equity-linked notes — 23,324 Total short-term borrowings $ 382,006 $ 436,215 (1) Bank loans include loans entered into, pursuant to a Master Loan Agreement, between the Bank of New York and Jefferies Group.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Aggregate Indebtedness [Abstract]
Schedule Of Indebtedness	The principal amount (net of unamortized discounts, premiums and debt issuance costs), stated interest rate and maturity date of outstanding debt are as follows (dollars in thousands): September 30, 2018 December 31, 2017 Parent Company Debt: Senior Notes: 5.50% Senior Notes due October 18, 2023, $750,000 principal $ 743,203 $ 742,348 6.625% Senior Notes due October 23, 2043, $250,000 principal 246,710 246,673 Total long-term debt – Parent Company 989,913 989,021 Subsidiary Debt (non-recourse to Parent Company): Jefferies Group: 5.125% Senior Notes, due April 13, 2018, $0 and $678,300 principal (1) — 682,338 8.50% Senior Notes, due July 15, 2019, $680,800 principal 707,072 728,872 2.375% Euro Medium Term Notes, due May 20, 2020, $579,850 and $594,725 principal 578,896 593,334 6.875% Senior Notes, due April 15, 2021, $750,000 principal 795,967 808,157 2.25% Euro Medium Term Notes, due July 13, 2022, $4,639 and $4,758 principal 4,332 4,389 5.125% Senior Notes, due January 20, 2023, $600,000 principal 613,634 615,703 4.85% Senior Notes, due January 15, 2027, $750,000 principal (2) 712,667 736,357 6.45% Senior Debentures, due June 8, 2027, $350,000 principal 374,211 375,794 3.875% Convertible Senior Debentures, due November 1, 2029, $0 and $324,779 principal — 324,779 4.15% Senior Notes, due January 23, 2030, $1,000,000 and $0 principal 987,576 — 6.25% Senior Debentures, due January 15, 2036, $500,000 principal 511,758 512,040 6.50% Senior Notes, due January 20, 2043, $400,000 principal 420,718 420,990 Structured Notes (3) 709,557 614,091 Jefferies Group Revolving Credit Facility 158,478 — National Beef Reducing Revolver Loan — 120,000 National Beef Revolving Credit Facility — 76,809 Foursight Capital Credit Facilities 138,033 170,455 Other 74,613 112,654 Total long-term debt – subsidiaries 6,787,512 6,896,762 Long-term debt $ 7,777,425 $ 7,885,783 (1) On April 13, 2018, these 5.125% Senior Notes were redeemed by Jefferies Group with cash on hand. (2) Amount includes a gain of $24.1 million and a loss of $9.6 million during the nine months ended September 30, 2018 and 2017 , respectively, associated with an interest rate swap based on its designation as a fair value hedge. See Note 4 for further information. (3) Includes $709.6 million and $607.0 million at fair value at September 30, 2018 and December 31, 2017 , respectively. These structured notes contain various interest rate payment terms and are accounted for at fair value, with changes in fair value resulting from a change in the instrument specific credit risk presented in Accumulated other comprehensive income and changes in fair value resulting from non-credit components recognized in Principal transactions revenues.

Mezzanine Equity (Tables)

Mezzanine Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Temporary Equity Disclosure [Abstract]
Schedule Of Redeemable Noncontrolling Interests	The following table rolls forward National Beef’s redeemable noncontrolling interests activity (in thousands): For the Nine Months Ended September 30, 2018 2017 As of January 1, $ 412,128 $ 321,962 Income allocated to redeemable noncontrolling interests 37,141 65,088 Distributions to redeemable noncontrolling interests (70,681 ) (37,029 ) Increase in fair value of redeemable noncontrolling interests 21,404 24,404 Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation (237,669 ) — Deconsolidation of National Beef (162,323 ) — Balance, September 30, $ — $ 374,425

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Summary Of Accumulated Other Comprehensive Income, Net Of Taxes	A summary of accumulated other comprehensive income, net of taxes is as follows (in thousands): September 30, 2018 December 31, 2017 Net unrealized gains on available for sale securities $ 542,790 $ 572,085 Net unrealized foreign exchange losses (180,926 ) (101,400 ) Net unrealized losses on instrument specific credit risk (18,916 ) (34,432 ) Net unrealized gains (losses) on cash flow hedges 446 (1,138 ) Net minimum pension liability (55,649 ) (62,391 ) $ 287,745 $ 372,724
Schedule Of Accumulated Other Comprehensive Income Reclassifications	For the nine months ended September 30, 2018 and 2017 , significant amounts reclassified out of accumulated other comprehensive income to net income are as follows (in thousands): Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Consolidated Statements of Operations 2018 2017 Net unrealized gains on available for sale securities, net of income tax provision of $37 and $14 $ 105 $ 24 Other revenues Net unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $(16) and $1,086 20,459 (5,310 ) Other income and other expenses Net unrealized gains on instrument specific credit risk, net of income tax provision of $126 and $0 371 — Principal transactions Amortization of defined benefit pension plan actuarial losses, net of income tax benefit of $(508) and $(604) (1,398 ) (1,297 ) Selling, general and other expenses, which includes pension expense Other pension, net of income tax benefit of $0 and $(1,231) (5,344 ) 1,231 Compensation and benefits expense and Income tax provision (benefit) Total reclassifications for the period, net of tax $ 14,193 $ (5,352 )

Revenues from Contracts with _2

Revenues from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents our total revenues separated for our revenues from contracts with customers and our other sources of revenues (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 Revenues from contracts with customers: Commissions and other fees $ 155,417 $ 461,023 Investment banking 460,043 1,400,331 Manufacturing revenues 94,029 307,129 Other 70,590 174,565 Total revenue from contracts with customers 780,079 2,343,048 Other sources of revenue: Principal transactions 116,204 315,622 Interest income 336,736 939,272 Other 225,958 265,972 Total revenue from other sources 678,898 1,520,866 Total revenues $ 1,458,977 $ 3,863,914 The following presents our revenues from contracts with customers disaggregated by major business activity and primary geographic regions for the three and nine months ended September 30, 2018 (in thousands): Three months ended September 30, 2018 Reportable Segments Jefferies Group Corporate All Other Total Major Business Activity: Jefferies Group: Equities (1) $ 159,571 $ — $ — $ 159,571 Fixed Income (1) 3,007 — — 3,007 Investment Banking 460,043 — — 460,043 Asset Management 5,184 — — 5,184 Manufacturing revenues — — 94,029 94,029 Oil and gas revenues — — 46,506 46,506 Other revenues — — 11,739 11,739 Total revenues from contracts with customers $ 627,805 $ — $ 152,274 $ 780,079 Primary Geographic Region: Americas $ 545,998 $ — $ 151,687 $ 697,685 Europe, Middle East and Africa 62,914 — 514 63,428 Asia 18,893 — 73 18,966 Total revenues from contracts with customers $ 627,805 $ — $ 152,274 $ 780,079 Nine months ended September 30, 2018 Reportable Segments Jefferies Group Corporate All Other Total Major Business Activity: Jefferies Group: Equities (1) $ 471,161 $ — $ — $ 471,161 Fixed Income (1) 10,511 — — 10,511 Investment Banking 1,400,331 — — 1,400,331 Asset Management 16,130 — — 16,130 Manufacturing revenues — — 307,129 307,129 Oil and gas revenues — — 106,741 106,741 Other revenues — — 31,045 31,045 Total revenues from contracts with customers $ 1,898,133 $ — $ 444,915 $ 2,343,048 Primary Geographic Region: Americas $ 1,638,828 $ — $ 443,718 $ 2,082,546 Europe, Middle East and Africa 203,103 — 976 204,079 Asia 56,202 — 221 56,423 Total revenues from contracts with customers $ 1,898,133 $ — $ 444,915 $ 2,343,048 (1) Revenues from contracts with customers associated with the equities and fixed income businesses primarily represent commissions and other fee revenue.

Common Share and Earnings (Lo_2

Common Share and Earnings (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share Computation	The numerators and denominators used to calculate basic and diluted earnings (loss) per share are as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Numerator for earnings per share: Net income attributable to Jefferies Financial Group Inc. common shareholders $ 192,635 $ 99,351 $ 1,042,689 $ 438,952 Allocation of earnings to participating securities (1) (1,054 ) (368 ) (5,049 ) (1,692 ) Net income attributable to Jefferies Financial Group Inc. common shareholders for basic earnings per share 191,581 98,983 1,037,640 437,260 Adjustment to allocation of earnings to participating securities related to diluted shares (1) 3 (2 ) 34 3 Mandatorily redeemable convertible preferred share dividends 1,276 — — 3,203 Net income attributable to Jefferies Financial Group Inc. common shareholders for diluted earnings per share $ 192,860 $ 98,981 $ 1,037,674 $ 440,466 Denominator for earnings per share: Weighted average common shares outstanding 332,191 358,039 343,829 359,031 Weighted average shares of restricted stock outstanding with future service required (1,879 ) (1,320 ) (1,681 ) (1,377 ) Weighted average RSUs outstanding with no future service required 11,122 11,109 11,152 11,082 Denominator for basic earnings per share – weighted average shares 341,434 367,828 353,300 368,736 Stock options 5 23 13 22 Senior executive compensation plan awards 4,706 2,347 3,856 2,313 Mandatorily redeemable convertible preferred shares 4,162 — — 4,162 Denominator for diluted earnings per share 350,307 370,198 357,169 375,233 (1) Represents dividends declared during the period on participating securities plus an allocation of undistributed earnings to participating securities. Net losses are not allocated to participating securities. Participating securities represent restricted stock and RSUs for which requisite service has not yet been rendered and amounted to weighted average shares of 1,888,700 and 1,366,700 for the three months ended September 30, 2018 and 2017 , respectively, and 1,700,700 and 1,433,500 for the nine months ended September 30, 2018 and 2017 , respectively. Dividends declared on participating securities were not material during three and nine months ended September 30, 2018 and 2017 . Undistributed earnings are allocated to participating securities based upon their right to share in earnings if all earnings for the period had been distributed.

Commitments, Contingencies an_2

Commitments, Contingencies and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	The following table summarizes commitments associated with certain business activities (in millions): Expected Maturity Date 2018 2019 2020 and 2021 2022 and 2023 2024 and Later Maximum Payout Equity commitments (1) $ 280.0 $ 56.9 $ 31.7 $ — $ 9.8 $ 378.4 Loan commitments (1) — 250.0 54.4 32.5 — 336.9 Underwriting commitments 411.0 — — — — 411.0 Forward starting reverse repos (2) 3,159.4 — — — — 3,159.4 Forward starting repos (2) 2,057.8 — — — — 2,057.8 Other unfunded commitments (1) 60.0 148.7 42.3 — 4.9 255.9 $ 5,968.2 $ 455.6 $ 128.4 $ 32.5 $ 14.7 $ 6,599.4 (1) Equity commitments, loan commitments and other unfunded commitments are presented by contractual maturity date. The amounts are however mostly available on demand. (2) At September 30, 2018 , $3,141.9 million of the forward starting securities purchased under agreements to resell and all of the securities sold under agreements to repurchase settled within three business days.
Guarantees	The following table summarizes the notional amounts associated with Jefferies Group derivative contracts meeting the definition of a guarantee under GAAP as of September 30, 2018 (in millions): Expected Maturity Date Guarantee Type 2018 2019 2020 and 2021 2022 and 2023 2024 and Later Notional/ Maximum Payout Derivative contracts – non-credit related $ 10,898.5 $ 5,978.6 $ 2,948.5 $ 1,015.0 $ 454.6 $ 21,295.2 Written derivative contracts – credit related — — 36.4 33.8 — 70.2 Total derivative contracts $ 10,898.5 $ 5,978.6 $ 2,984.9 $ 1,048.8 $ 454.6 $ 21,365.4

Other Fair Value Information (T

Other Fair Value Information (Tables)	9 Months Ended
	Sep. 30, 2018
Other Fair Value Information [Abstract]
Methods And Assumptions Used To Estimate The Fair Values	The carrying amounts and estimated fair values of our principal financial instruments that are not recognized at fair value on a recurring basis are as follows (in thousands): September 30, 2018 December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value Receivables: Notes and loans receivable (1) $ 663,508 $ 644,184 $ 579,071 $ 565,285 Financial Liabilities: Short-term borrowings (2) $ 382,006 $ 382,006 $ 412,891 $ 412,891 Long-term debt (3) $ 7,067,868 $ 7,113,515 $ 7,278,827 $ 7,678,210 (1) Notes and loans receivable: The fair values are estimated principally based on a discounted future cash flows model using market interest rates for similar instruments. If measured at fair value in the financial statements, these financial instruments would be classified as Level 3 in the fair value hierarchy. (2) Short-term borrowings: The fair values of short-term borrowings are estimated to be the carrying amount due to their short maturities. If measured at fair value in the financial statements, these financial instruments would be classified as Level 3 in the fair value hierarchy. (3) Long-term debt: The fair values are estimated using quoted prices, pricing information obtained from external data providers and, for certain variable rate debt, is estimated to be the carrying amount. If measured at fair value in the financial statements, these financial instruments would be classified as Level 2 and Level 3 in the fair value hierarchy.

Discontinued Operations (Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Summary of results of discontinued operations	A summary of the results of discontinued operations for National Beef is as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2018 (1) 2017 Revenues: Beef processing services $ 2,038,821 $ 3,137,611 $ 5,472,339 Interest income 58 131 230 Other 420 4,329 3,705 Total revenues 2,039,299 3,142,071 5,476,274 Expenses: Compensation and benefits 10,505 17,414 29,649 Cost of sales 1,816,480 2,884,983 5,030,887 Interest expense 1,713 4,316 5,781 Depreciation and amortization 26,664 43,959 73,522 Selling, general and other expenses 9,458 14,291 26,428 Total expenses 1,864,820 2,964,963 5,166,267 Income from discontinued operations before income taxes 174,479 177,108 310,007 Income tax provision 53,490 47,045 90,856 Income from discontinued operations, net of income tax provision $ 120,989 $ 130,063 $ 219,151 (1) Discontinued operations for the nine months ended September 30, 2018 include National Beef results through the June 5, 2018 transaction with Marfrig.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule Of Segment Reporting Information, By Segment	Certain information concerning our segments is presented in the following table. Consolidated subsidiaries are reflected as of the date a majority controlling interest was acquired. As discussed above, Jefferies Group is reflected in our consolidated financial statements utilizing a one month lag. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Net revenues: Reportable Segments: Jefferies Group $ 774,749 $ 802,909 $ 2,419,410 $ 2,381,967 Corporate 8,692 1,915 14,753 4,257 Total net revenues related to reportable segments 783,441 804,824 2,434,163 2,386,224 All other (1) 367,405 52,399 523,277 634,386 Total consolidated net revenues $ 1,150,846 $ 857,223 $ 2,957,440 $ 3,020,610 Income (loss) from continuing operations before income taxes: Reportable Segments: Jefferies Group $ 86,154 $ 128,112 $ 336,922 $ 383,094 Corporate (14,563 ) (16,311 ) (55,708 ) (56,816 ) Income from continuing operations before income taxes related to reportable segments 71,591 111,801 281,214 326,278 All other (1) 215,856 (71,516 ) 111,007 130,722 Parent Company interest (14,755 ) (14,737 ) (44,251 ) (44,201 ) Total consolidated income from continuing operations before income taxes $ 272,692 $ 25,548 $ 347,970 $ 412,799 Depreciation and amortization expenses: Reportable Segments: Jefferies Group $ 17,175 $ 15,928 $ 50,829 $ 46,877 Corporate 852 865 2,599 2,599 Total depreciation and amortization expenses related to reportable segments 18,027 16,793 53,428 49,476 All other 14,268 11,967 38,932 32,653 Total consolidated depreciation and amortization expenses $ 32,295 $ 28,760 $ 92,360 $ 82,129 (1) All other Net revenues and Income from continuing operations before income taxes include realized and unrealized gains (losses) relating to our investment in FXCM of $1.3 million and $(2.9) million , respectively, for the three months ended September 30, 2018 ; $16.4 million and $(2.9) million , respectively, for the nine months ended September 30, 2018 ; $2.3 million and $(2.0) million , respectively, for the three months ended September 30, 2017 ; and $17.6 million and $(148.7) million , respectively, for the nine months ended September 30, 2017 .

Nature of Operations (Details)

Nature of Operations (Details) $ in Millions	Oct. 01, 2018USD ($)	Jun. 05, 2018USD ($)	Apr. 30, 2018USD ($)	Sep. 30, 2018USD ($)directorDealership	Jun. 30, 2018USD ($)	Jun. 04, 2018USD ($)	Sep. 30, 2018USD ($)directorDealership	Jul. 13, 2018	Jul. 12, 2018	Dec. 31, 2017
National Beef
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary				100.00%			100.00%
Number of seats on investment committee retained by Company | director				2			2
Lockup period related to divestiture of businesses							5 years
Marfrig Global Foods S.A.
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary				51.00%			51.00%
Ownership percentage to be acquired further from other equity owners		3.00%
Garcadia
Nature Of Operations [Line Items]
Number of automobile dealerships | Dealership				28			28
Vitesse Energy, LLC
Nature Of Operations [Line Items]
Payments to acquire productive assets, funded as equity			$ 144
Discontinued operations, disposed of by sale | National Beef
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		48.00%
Cash from sale of subsidiary		$ 907.7
Pre-tax gain on disposal of discontinued operations							$ 873.5
Held-for-sale, not discontinued operations | Garcadia
Nature Of Operations [Line Items]
Percentage of equity method investment for sale				100.00%
Proceeds from sale of equity method investments and associated real estate				$ 417.2
Pre-tax gain on sale of equity method investments and associated real estate				$ 221.7			$ 221.7
Package of Non-Operated Bakken Assets | Vitesse Energy, LLC
Nature Of Operations [Line Items]
Payments to acquire Bakken assets			$ 190
HRG
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary									23.00%	23.00%
National Beef
Nature Of Operations [Line Items]
Equity method investment, ownership percentage		31.00%		31.00%			31.00%
Percentage interest owned in subsidiary						79.00%
Weiss Multi-Strategy Advisors LLC
Nature Of Operations [Line Items]
Amount invested in asset management strategy					$ 250
Combined Strategy
Nature Of Operations [Line Items]
Equity commitments				$ 250			$ 250
Spectrum Brands
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary				14.00%			14.00%	14.00%
Spectrum Brands | HRG
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary								62.00%
National Beef
Nature Of Operations [Line Items]
Additional proceeds expected from divestiture of businesses						$ 229.4
Subsequent Event [Member]
Nature Of Operations [Line Items]
Capital contributed	$ 596
Jefferies Group | Affiliated Entity | Subsequent Event [Member]
Nature Of Operations [Line Items]
Proceeds from related party transfer	$ 78.3

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Receivables from brokers, dealers and clearing organizations	$ 2,878,500		$ 2,878,500			$ 2,635,200
Receivables from customers of securities operations	1,951,800		1,951,800			1,563,800
Payables to brokers, dealers and clearing organizations	1,913,300		1,913,300			2,228,900
Payables to customers of securities operations	3,187,600		3,187,600			2,664,000
Cash paid during the year for:
Interest			1,059,139	$ 837,020
Income tax payments (refunds), net			28,204	9,183
Purchase of common shares for treasury settled subsequent to quarter end				21,000
Retained earnings	5,672,363		5,672,363			4,700,968
Decrease to accumulated other comprehensive income	(287,745)		(287,745)			$ (372,724)
Decrease to compensation and benefits expenses	(461,265)	$ (493,471)	(1,429,439)	(1,468,373)
Increase to selling, general and other expenses	$ 245,178	199,441	708,084	552,155
Decrease in net cash used for operating activities			199,908	1,060,916
Increase in net cash provided by (used for) investing activities			$ (118,541)	(28,754)
Accounting Standards Update 2014-09
Cash paid during the year for:
Retained earnings					$ 17,800
Accounting Standards Update 2016-13
Cash paid during the year for:
Retained earnings					27,600
Decrease to accumulated other comprehensive income					27,600
Accounting Standards Update 2016-18
Cash paid during the year for:
Decrease in net cash used for operating activities				49,300
Increase in net cash provided by (used for) investing activities				6,700
Accounting Standards Update 2017-07
Cash paid during the year for:
Decrease to compensation and benefits expenses		900		2,600
Increase to selling, general and other expenses		900		2,600
Changes to Presentation of Gains and Losses Generated from Capital Invested in Assets Management Funds
Summary Of Significant Accounting Policies [Line Items]
Decrease of principal transactions revenue, Net		11,300		12,200
Increase of other revenues		$ 11,300		$ 12,200
HomeFed | Accounting Standards Update 2014-09
Cash paid during the year for:
Retained earnings					24,300
Jefferies Group | Accounting Standards Update 2014-09
Cash paid during the year for:
Retained earnings					$ (6,100)

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies (Schedule of Impact of Applying New Revenue Recognition Standard) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenues	$ 1,458,977	$ 1,102,593	$ 3,863,914	$ 3,735,702
Interest expense	28,837	25,612	74,614	76,762
Net revenues	1,150,846	857,223	2,957,440	3,020,610
Expenses:
Compensation and benefits	461,265	493,471	1,429,439	1,468,373
Cost of sales	84,876	71,596	257,501	210,834
Floor brokerage and clearing fees	44,570	42,852	131,792	133,145
Depreciation and amortization	32,295	28,760	92,360	82,129
Selling, general and other expenses	245,178	199,441	708,084	552,155
Total expenses	897,021	861,732	2,693,790	2,523,398
Income (loss) from continuing operations before income taxes and income (loss) related to associated companies	253,825	(4,509)	263,650	497,212
Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	36,319		101,146
Interest expense	0		0
Net revenues	36,319		101,146
Expenses:
Compensation and benefits	0		0
Cost of sales	0		0
Floor brokerage and clearing fees	0		0
Depreciation and amortization	0		0
Selling, general and other expenses	36,319		101,146
Total expenses	36,319		101,146
Income (loss) from continuing operations before income taxes and income (loss) related to associated companies	0		0
Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	1,422,658		3,762,768
Interest expense	28,837		74,614
Net revenues	1,114,527		2,856,294
Expenses:
Compensation and benefits	461,265		1,429,439
Cost of sales	84,876		257,501
Floor brokerage and clearing fees	44,570		131,792
Depreciation and amortization	32,295		92,360
Selling, general and other expenses	208,859		606,938
Total expenses	860,702		2,592,644
Income (loss) from continuing operations before income taxes and income (loss) related to associated companies	253,825		263,650
Commissions and other fees
Revenues:
Revenues	155,417	139,082	461,023	437,547
Commissions and other fees | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	0		0
Commissions and other fees | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	155,417		461,023
Principal transactions
Revenues:
Revenues	116,204	84,143	315,622	725,780
Principal transactions | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	0		0
Principal transactions | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	116,204		315,622
Investment banking
Revenues:
Revenues	460,043	475,702	1,400,331	1,235,586
Investment banking | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	36,319		101,146
Investment banking | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	423,724		1,299,185
Interest income
Revenues:
Revenues	336,736	253,916	939,272	726,972
Interest income | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	0		0
Interest income | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	336,736		939,272
Manufacturing revenues
Revenues:
Revenues	94,029	81,939	307,129	243,482
Manufacturing revenues | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	0		0
Manufacturing revenues | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	94,029		307,129
Other
Revenues:
Revenues	296,548	67,811	440,537	366,335
Other | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Revenues	0		0
Other | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Revenues	296,548		440,537
Jefferies Group
Revenues:
Interest expense	308,131	$ 245,370	906,474	$ 715,092
Jefferies Group | Impact of Adoption of Revenue Recognition Standard | Accounting Standards Update 2014-09
Revenues:
Interest expense	0		0
Jefferies Group | Financial Results Prior to Adoption of Revenue Recognition Standard
Revenues:
Interest expense	$ 308,131		$ 906,474

Fair Value Disclosures (Schedul

Fair Value Disclosures (Schedule Of Assets And Liabilities Measured On Recurring Basis At Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets:
Trading assets, at fair value	$ 17,310,213	$ 15,492,572
Derivative assets	189,645	179,488
Counterparty and Cash Collateral Netting, assets	(3,334,100)	(3,318,481)
Available for sale securities, equity securities		88,486
Debt securities, available for sale securities	1,868,420	628,075
Available-for-sale Securities		716,561
Liabilities:
Trading liabilities, at fair value	9,479,213	8,454,965
Counterparty and Cash Collateral Netting, liabilities	(3,454,488)	(3,490,514)
Short-term borrowings		23,324
Long-term debt - structured notes	709,557	606,956
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	913,456	578,014
Level 1
Assets:
Trading assets, at fair value	7,968,625	5,791,641
Derivative assets	13,117	165,396
Available for sale securities, equity securities		88,486
Debt securities, available for sale securities	1,607,725
Available-for-sale Securities		641,291
Liabilities:
Trading liabilities, at fair value	5,141,271	4,618,008
Short-term borrowings		0
Long-term debt - structured notes	0	0
Level 2
Assets:
Trading assets, at fair value	12,031,299	12,369,954
Derivative assets	3,507,491	3,323,278
Available for sale securities, equity securities		0
Debt securities, available for sale securities	260,695
Available-for-sale Securities		75,270
Liabilities:
Trading liabilities, at fair value	7,769,540	7,307,269
Short-term borrowings		23,324
Long-term debt - structured notes	545,927	606,956
Level 3
Assets:
Trading assets, at fair value	644,389	649,458
Derivative assets	3,137	9,295
Available for sale securities, equity securities		0
Debt securities, available for sale securities	0
Available-for-sale Securities		0
Liabilities:
Trading liabilities, at fair value	22,890	20,202
Short-term borrowings		0
Long-term debt - structured notes	163,630	0
Fair Value Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Alternative investments	399,032	590,104
Corporate equity securities
Assets:
Trading assets, at fair value	3,757,540	3,058,033
Liabilities:
Trading liabilities, at fair value	2,223,245	1,753,437
Corporate equity securities | Level 1
Assets:
Trading assets, at fair value	3,635,288	2,975,463
Liabilities:
Trading liabilities, at fair value	2,221,325	1,721,267
Corporate equity securities | Level 2
Assets:
Trading assets, at fair value	72,569	60,300
Liabilities:
Trading liabilities, at fair value	1,507	32,122
Corporate equity securities | Level 3
Assets:
Trading assets, at fair value	49,683	22,270
Liabilities:
Trading liabilities, at fair value	413	48
Corporate debt securities
Assets:
Trading assets, at fair value	2,507,682	3,287,336
Liabilities:
Trading liabilities, at fair value	1,513,536	1,689,347
Corporate debt securities | Level 1
Assets:
Trading assets, at fair value	0	0
Liabilities:
Trading liabilities, at fair value	0	0
Corporate debt securities | Level 2
Assets:
Trading assets, at fair value	2,498,031	3,261,300
Liabilities:
Trading liabilities, at fair value	1,511,979	1,688,825
Corporate debt securities | Level 3
Assets:
Trading assets, at fair value	9,651	26,036
Liabilities:
Trading liabilities, at fair value	1,557	522
Collateralized debt obligations and collateralized loan obligations
Assets:
Trading assets, at fair value	116,320	181,350
Collateralized debt obligations and collateralized loan obligations | Level 1
Assets:
Trading assets, at fair value	0	0
Collateralized debt obligations and collateralized loan obligations | Level 2
Assets:
Trading assets, at fair value	82,339	139,166
Collateralized debt obligations and collateralized loan obligations | Level 3
Assets:
Trading assets, at fair value	33,981	42,184
U.S. government securities
Assets:
Trading assets, at fair value	3,046,694	1,308,673
Debt securities, available for sale securities	1,607,725	552,805
Liabilities:
Trading liabilities, at fair value	1,398,222	1,430,737
U.S. government securities | Level 1
Assets:
Trading assets, at fair value	3,000,805	1,269,230
Liabilities:
Trading liabilities, at fair value	1,398,222	1,430,737
U.S. government securities | Level 2
Assets:
Trading assets, at fair value	45,889	39,443
Liabilities:
Trading liabilities, at fair value	0	0
U.S. government securities | Level 3
Assets:
Trading assets, at fair value	0	0
Liabilities:
Trading liabilities, at fair value	0	0
Municipal securities
Assets:
Trading assets, at fair value	749,616	710,513
Municipal securities | Level 1
Assets:
Trading assets, at fair value	0	0
Municipal securities | Level 2
Assets:
Trading assets, at fair value	749,616	710,513
Municipal securities | Level 3
Assets:
Trading assets, at fair value	0	0
Sovereign obligations
Assets:
Trading assets, at fair value	1,989,334	2,417,459
Liabilities:
Trading liabilities, at fair value	2,483,137	2,173,635
Sovereign obligations | Level 1
Assets:
Trading assets, at fair value	1,319,415	1,381,552
Liabilities:
Trading liabilities, at fair value	1,513,237	1,216,643
Sovereign obligations | Level 2
Assets:
Trading assets, at fair value	669,919	1,035,907
Liabilities:
Trading liabilities, at fair value	969,845	956,992
Sovereign obligations | Level 3
Assets:
Trading assets, at fair value	0	0
Liabilities:
Trading liabilities, at fair value	55	0
Residential mortgage-backed securities
Assets:
Trading assets, at fair value	1,899,487	1,479,371
Debt securities, available for sale securities	146,678	34,561
Residential mortgage-backed securities | Level 1
Assets:
Trading assets, at fair value	0	0
Debt securities, available for sale securities	0	0
Residential mortgage-backed securities | Level 2
Assets:
Trading assets, at fair value	1,894,533	1,453,294
Debt securities, available for sale securities	146,678	34,561
Residential mortgage-backed securities | Level 3
Assets:
Trading assets, at fair value	4,954	26,077
Debt securities, available for sale securities	0	0
Commercial mortgage-backed securities
Assets:
Trading assets, at fair value	815,365	520,534
Debt securities, available for sale securities	15,719	5,870
Liabilities:
Trading liabilities, at fair value	70	105
Commercial mortgage-backed securities | Level 1
Assets:
Trading assets, at fair value	0	0
Debt securities, available for sale securities	0	0
Liabilities:
Trading liabilities, at fair value	0	0
Commercial mortgage-backed securities | Level 2
Assets:
Trading assets, at fair value	791,449	508,115
Debt securities, available for sale securities	15,719	5,870
Liabilities:
Trading liabilities, at fair value	0	0
Commercial mortgage-backed securities | Level 3
Assets:
Trading assets, at fair value	23,916	12,419
Debt securities, available for sale securities	0	0
Liabilities:
Trading liabilities, at fair value	70	105
Other asset-backed securities
Assets:
Trading assets, at fair value	333,272	278,240
Debt securities, available for sale securities	98,298	34,839
Other asset-backed securities | Level 1
Assets:
Trading assets, at fair value	0	0
Debt securities, available for sale securities	0	0
Other asset-backed securities | Level 2
Assets:
Trading assets, at fair value	263,967	217,111
Debt securities, available for sale securities	98,298	34,839
Other asset-backed securities | Level 3
Assets:
Trading assets, at fair value	69,305	61,129
Debt securities, available for sale securities	0	0
Loans and other receivables
Assets:
Trading assets, at fair value	1,504,481	1,667,885
Loans and other receivables | Level 1
Assets:
Trading assets, at fair value	0	0
Loans and other receivables | Level 2
Assets:
Trading assets, at fair value	1,455,496	1,620,581
Loans and other receivables | Level 3
Assets:
Trading assets, at fair value	48,985	47,304
Investments at fair value
Assets:
Trading assets, at fair value	326,977	330,890
Investments at fair value | Level 1
Assets:
Trading assets, at fair value	0	0
Investments at fair value | Level 2
Assets:
Trading assets, at fair value	0	946
Investments at fair value | Level 3
Assets:
Trading assets, at fair value	326,977	329,944
FXCM term loan
Assets:
Trading assets, at fair value	73,800	72,800
FXCM term loan | Level 1
Assets:
Trading assets, at fair value	0	0
FXCM term loan | Level 2
Assets:
Trading assets, at fair value	0	0
FXCM term loan | Level 3
Assets:
Trading assets, at fair value	73,800	72,800
Loans
Liabilities:
Trading liabilities, at fair value	1,145,240	1,152,310
Loans | Level 1
Liabilities:
Trading liabilities, at fair value	0	0
Loans | Level 2
Liabilities:
Trading liabilities, at fair value	1,136,579	1,148,824
Loans | Level 3
Liabilities:
Trading liabilities, at fair value	8,661	3,486
US Treasury securities
Assets:
Debt securities, available for sale securities	1,607,725	552,805
US Treasury securities | Level 1
Assets:
Debt securities, available for sale securities	1,607,725	552,805
Liabilities:
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	34,800	99,700
US Treasury securities | Level 2
Assets:
Debt securities, available for sale securities	0	0
US Treasury securities | Level 3
Assets:
Debt securities, available for sale securities	0	0
Derivatives
Liabilities:
Trading liabilities, at fair value	715,763	255,394
Counterparty and Cash Collateral Netting, liabilities	(3,454,488)	(3,490,514)
Derivatives | Level 1
Liabilities:
Trading liabilities, at fair value	8,487	249,361
Derivatives | Level 2
Liabilities:
Trading liabilities, at fair value	4,149,630	3,480,506
Derivatives | Level 3
Assets:
Derivative assets	3,137	9,295
Liabilities:
Trading liabilities, at fair value	$ 12,134	$ 16,041

Fair Value Disclosures (Investm

Fair Value Disclosures (Investments Measured At Fair Value Based On Net Asset Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 20,209	$ 19,084	$ 20,209	$ 19,084
Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 0	$ 0	$ 0	$ 0
Equity Long/Short Hedge Funds | Minimum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investments prior written notice period	30 days	30 days
Equity Long/Short Hedge Funds | Maximum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investments prior written notice period	60 days	60 days
Equity Long/Short Hedge Funds | 10 business days or less prior written notice
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investments prior written notice period		10 days
Percentage of investments redeemable		73.00%		73.00%
Equity Long/Short Hedge Funds | 30 to 60 days prior written notice
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of investments redeemable	18.00%	15.00%	18.00%	15.00%
Fixed Income and High Yield Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 0	$ 0	$ 0	$ 0
Fund of Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	0	0	0	0
Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	20,209	19,084	$ 20,209	$ 19,084
Equity Funds | Minimum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Estimated period for the liquidation of the underlying assets			1 year	1 year
Equity Funds | Maximum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Estimated period for the liquidation of the underlying assets			10 years	10 years
Commodity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	0		$ 0
Notice period redemption of investments prior written notice period			60 days
Multi-asset Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 0	$ 0	$ 0	$ 0
Notice period redemption of investments prior written notice period		30 days	30 days
Percentage of investments redeemable	17.00%	12.00%	17.00%	12.00%
Fair Value Measured at NAV
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 399,032	$ 590,104	$ 399,032	$ 590,104
Fair Value Measured at NAV | Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	90,347	407,895	90,347	407,895
Fair Value Measured at NAV | Fixed Income and High Yield Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	219	417	219	417
Fair Value Measured at NAV | Fund of Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	175	189	175	189
Fair Value Measured at NAV | Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	36,702	26,798	36,702	26,798
Fair Value Measured at NAV | Commodity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	10,228		10,228
Fair Value Measured at NAV | Multi-asset Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 261,361	$ 154,805	$ 261,361	$ 154,805

Fair Value Disclosures (Inves_2

Fair Value Disclosures (Investment in FXCM Narrative) (Details)	3 Months Ended		9 Months Ended		45 Months Ended
	Sep. 30, 2018USD ($)director	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)director	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)director	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 31, 2015USD ($)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Investment in associated company	$ 2,450,901,000	$ 2,350,980,000	$ 2,450,901,000	$ 2,350,980,000	$ 2,450,901,000	$ 2,066,829,000	$ 2,125,098,000
FXCM
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Senior secured term loan receivable	70,600,000		$ 70,600,000		70,600,000			$ 300,000,000
Loan receivable interest rate percentage								10.00%
Increase in Interest rate per annum each quarter								1.50%
Accrued interest rate			20.50%
Principal and interest payments received			$ 15,400,000
Principal, interest and fees received					347,000,000
Initial investment amount								$ 279,000,000
Unrealized and realized gains (losses), interest income and fees	1,300,000	$ 2,300,000	16,400,000	$ 17,600,000
FXCM term loan	73,800,000		73,800,000		73,800,000
Investment in associated company	139,000,000		139,000,000		139,000,000
Investment in FXCM	$ 212,800,000		$ 212,800,000		$ 212,800,000
Maximum | FXCM
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Loan receivable interest rate percentage								20.50%
Investment in FXCM
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Equity method investment, ownership percentage	50.00%		50.00%		50.00%
Maximum percentage of all distributions	75.00%		75.00%		75.00%
Number of directors appointed by Company | director	3		3		3
Number of directors appointed | director	6		6		6
Percentage of distributions from sale of assets or certain other events until loan repayment	100.00%		100.00%		100.00%
Percentage of distributions from sale of assets or certain other events until next milestone amount	50.00%		50.00%		50.00%
Distributions milestone after loan repayment	$ 350,000,000		$ 350,000,000		$ 350,000,000
Percentage of distributions from sale of assets or certain other events until milestone two	90.00%		90.00%		90.00%
Distributions milestone two after loan repayment	$ 600,000,000		$ 600,000,000		$ 600,000,000
Percentage of distributions from sale of assets or certain other events thereafter	60.00%		60.00%		60.00%
Investment in FXCM | Global Brokerage Holdings
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Percentage of ownership owned	50.00%		50.00%		50.00%

Fair Value Disclosures (Nonrecu

Fair Value Disclosures (Nonrecurring Fair Value Measurements Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Mar. 31, 2017USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)
Investment in FXCM
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment impairment		$ 130.2
Investment in FXCM | Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments, fair value		$ 186.7
Investment In Golden Queen
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment impairment	$ 47.9		$ 47.9
Investment In Golden Queen | Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments, fair value				$ 62.3
Measurement Input, Discount Rate | Investment in FXCM | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment, measurement input		0.15
Measurement Input, Discount Rate | Investment In Golden Queen | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment, measurement input				0.12
Measurement Input, EBITDA Multiple | Investment in FXCM | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment, measurement input		5.4
Measurement Input, Revenue Multiple | Investment in FXCM | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment, measurement input		1.5

Fair Value Disclosures (Level 3

Fair Value Disclosures (Level 3 Rollforwards) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Assets:
Total gains (losses) (realized and unrealized)	$ 11,700	$ 1,500	$ 29,800	$ 17,100
Liabilities:
Total gains (losses) (realized and unrealized)	(4,400)	6,000	26,800	1,500
Fair value, Liabilities, change in unrealized gains/(losses) included in other comprehensive income relating to instruments still held	(100)		11,800
Corporate equity securities
Assets:
Beginning Balance	44,871	20,548	22,270	21,739
Total gains (losses) (realized and unrealized)	11,796	4,344	31,475	3,416
Purchases	17,652	4	35,993	945
Sales	(23,010)	(645)	(39,008)	(1,502)
Settlements	(302)	(55)	(2,082)	(356)
Net transfers into (out of) Level 3	(1,324)	(2,022)	1,035	(2,068)
Ending Balance	49,683	22,174	49,683	22,174
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	9,136	4,319	26,852	2,689
Liabilities:
Beginning Balance	87	354	48	313
Total gains (losses) (realized and unrealized)	326	107	365	134
Purchases	0	(369)	0	(355)
Sales	0	27	0	27
Settlements	0	0	0	0
Issuances	0	0	0	0
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	413	119	413	119
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	(326)	(92)	(365)	(92)
Corporate debt securities
Assets:
Beginning Balance	28,066	24,727	26,036	25,005
Total gains (losses) (realized and unrealized)	1,057	(2,350)	1,090	(3,280)
Purchases	507	5,901	22,204	19,610
Sales	(21,403)	(5,551)	(38,553)	(18,364)
Settlements	(59)	(31)	(2,066)	(1,724)
Net transfers into (out of) Level 3	1,483	2,319	940	3,768
Ending Balance	9,651	25,015	9,651	25,015
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	(165)	(2,224)	(1,738)	(3,424)
Liabilities:
Beginning Balance	522	522	522	523
Total gains (losses) (realized and unrealized)	39	0	39	(1)
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	996	0	996	0
Issuances	0	0	0	0
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	1,557	522	1,557	522
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	(39)	0	(39)	1
Sovereign obligations
Liabilities:
Beginning Balance	0		0
Total gains (losses) (realized and unrealized)	3		3
Purchases	(598)		(598)
Sales	629		629
Settlements	0		0
Issuances	0		0
Net transfers into (out of) Level 3	21		21
Ending Balance	55		55
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	(124)		(124)
CDOs and CLOs
Assets:
Beginning Balance	42,517	48,208	42,184	54,354
Total gains (losses) (realized and unrealized)	(967)	(15,205)	(4,123)	(21,595)
Purchases	238,281	52,918	242,864	65,523
Sales	(240,002)	(36,564)	(249,691)	(62,441)
Settlements	(2,127)	245	(5,859)	239
Net transfers into (out of) Level 3	(3,721)	468	8,606	13,990
Ending Balance	33,981	50,070	33,981	50,070
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	(3,872)	(12,638)	(7,333)	(21,998)
Municipal securities
Assets:
Beginning Balance				27,257
Total gains (losses) (realized and unrealized)				(1,547)
Purchases				0
Sales				(25,710)
Settlements				0
Net transfers into (out of) Level 3				0
Ending Balance		0		0
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held				0
Residential mortgage-backed securities
Assets:
Beginning Balance	3,655	33,032	26,077	38,772
Total gains (losses) (realized and unrealized)	(66)	(263)	(7,334)	(1,446)
Purchases	72	494	2,018	113,391
Sales	(1,597)	(732)	(12,621)	(125,731)
Settlements	(1)	(291)	(6)	(572)
Net transfers into (out of) Level 3	2,891	(11,591)	(3,180)	(3,765)
Ending Balance	4,954	20,649	4,954	20,649
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	90	188	316	(2,005)
Commercial mortgage-backed securities
Assets:
Beginning Balance	27,239	16,263	12,419	20,580
Total gains (losses) (realized and unrealized)	(222)	(125)	(1,236)	(1,180)
Purchases	8	0	1,720	2,033
Sales	0	(676)	(548)	(5,199)
Settlements	(1,156)	(637)	(5,415)	(985)
Net transfers into (out of) Level 3	(1,953)	2,811	16,976	2,387
Ending Balance	23,916	17,636	23,916	17,636
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	(288)	(161)	(2,272)	(952)
Liabilities:
Beginning Balance	0	70	105	0
Total gains (losses) (realized and unrealized)	70	(35)	(35)	35
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Issuances	0	0	0	0
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	70	35	70	35
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	(70)	(35)	(70)	(35)
Other asset-backed securities
Assets:
Beginning Balance	55,535	43,349	61,129	40,911
Total gains (losses) (realized and unrealized)	(2,269)	(6,454)	(7,528)	(15,338)
Purchases	307,358	5,798	523,045	67,611
Sales	(290,838)	(3,789)	(495,055)	(4,121)
Settlements	(4,356)	(2,924)	(12,281)	(16,891)
Net transfers into (out of) Level 3	3,875	32,966	(5)	(3,226)
Ending Balance	69,305	68,946	69,305	68,946
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	(1,124)	(3,570)	(3,307)	(8,872)
Loans and other receivables
Assets:
Beginning Balance	64,036	49,365	47,304	81,872
Total gains (losses) (realized and unrealized)	(1,353)	15,261	(2,812)	27,709
Purchases	14,932	9,265	104,009	84,342
Sales	(23,700)	(5,854)	(98,733)	(83,791)
Settlements	(3,453)	(8,249)	(14,610)	(23,241)
Net transfers into (out of) Level 3	(1,477)	2,868	13,827	(24,235)
Ending Balance	48,985	62,656	48,985	62,656
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	1,007	14,005	(3,769)	16,294
Investments at fair value
Assets:
Beginning Balance	318,543	315,297	329,944	314,359
Total gains (losses) (realized and unrealized)	2,383	3,964	3,865	12,760
Purchases	6,051	10,000	9,791	12,800
Sales	0	0	(17,569)	(10,119)
Settlements	0	(292)	0	(831)
Net transfers into (out of) Level 3	0	0	946	0
Ending Balance	326,977	328,969	326,977	328,969
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	2,383	3,964	3,271	14,783
FXCM term loan
Assets:
Beginning Balance	76,100	129,050	72,800	164,500
Total gains (losses) (realized and unrealized)	1,347	2,330	16,432	17,638
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	(3,647)	(60,580)	(15,432)	(111,338)
Net transfers into (out of) Level 3	0	0	0	0
Ending Balance	73,800	70,800	73,800	70,800
Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held	(2,300)	(2,401)	5,539	(930)
Loans
Liabilities:
Beginning Balance	12,881	4,967	3,486	378
Total gains (losses) (realized and unrealized)	(148)	(3,071)	(1,059)	1,604
Purchases	(4,871)	0	(15,702)	(364)
Sales	1,787	333	19,409	333
Settlements	0	0	0	0
Issuances	0	0	0	0
Net transfers into (out of) Level 3	(988)	1,056	2,527	1,334
Ending Balance	8,661	3,285	8,661	3,285
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	149	3,018	1,059	(1,583)
Derivatives
Liabilities:
Beginning Balance	5,874	3,022	6,746	3,441
Total gains (losses) (realized and unrealized)	1,107	(2,980)	(1,034)	(2,854)
Purchases	0	0	(6)	0
Sales	0	0	0	0
Settlements	1,990	5,040	2,984	5,162
Issuances	0	0	296	404
Net transfers into (out of) Level 3	26	0	11	(1,071)
Ending Balance	8,997	5,082	8,997	5,082
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	(2,090)	(2,474)	(2,660)	(2,333)
Long-term debt
Liabilities:
Beginning Balance	160,626		0
Total gains (losses) (realized and unrealized)	3,004		(25,078)
Purchases	0		0
Sales	0		0
Settlements	0		0
Issuances	0		81,284
Net transfers into (out of) Level 3	0		107,424
Ending Balance	163,630		163,630
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held	$ (2,953)		$ 13,235
Other secured financings
Liabilities:
Beginning Balance				418
Total gains (losses) (realized and unrealized)				(418)
Purchases				0
Sales				0
Settlements				0
Issuances				0
Net transfers into (out of) Level 3				0
Ending Balance		$ 0		0
Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held				$ 0

Fair Value Disclosures (Analysi

Fair Value Disclosures (Analysis of Level 3 Assets and Liabilities Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	$ 13,600	$ 63,500	$ 49,100	$ 30,900
Transfers of assets from Level 3 to Level 2	13,800	35,700	10,000	44,000
Net gains (losses) on Level 3 assets (realized and unrealized)	11,700	1,500	29,800	17,100
Net gains (losses) on Level 3 liabilities (realized and unrealized)	(4,400)	6,000	26,800	1,500
Excluded assets from unobservable quantitative information	223,700		223,700		$ 228,600
Excluded liabilities from unobservable quantitative information	500		500		$ 4,200
Commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	2,600		17,000
Transfers of assets from Level 3 to Level 2	4,600
Net gains (losses) on Level 3 assets (realized and unrealized)	(222)	(125)	(1,236)	(1,180)
Net gains (losses) on Level 3 liabilities (realized and unrealized)	70	(35)	(35)	35
Other asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	3,900	46,400
Transfers of assets from Level 3 to Level 2		13,500
Net gains (losses) on Level 3 assets (realized and unrealized)	(2,269)	(6,454)	(7,528)	(15,338)
Residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	2,900
Transfers of assets from Level 3 to Level 2		14,600	4,600
Net gains (losses) on Level 3 assets (realized and unrealized)	(66)	(263)	(7,334)	(1,446)
Municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Net gains (losses) on Level 3 assets (realized and unrealized)				(1,547)
Loans and other receivables
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3			15,300
Transfers of assets from Level 3 to Level 2				28,300
Net gains (losses) on Level 3 assets (realized and unrealized)	(1,353)	15,261	(2,812)	27,709
Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3				8,100
Net gains (losses) on Level 3 assets (realized and unrealized)	1,057	(2,350)	1,090	(3,280)
Net gains (losses) on Level 3 liabilities (realized and unrealized)	39	0	39	(1)
CDOs and CLOs
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3			8,700	14,000
Transfers of assets from Level 3 to Level 2	3,700
Net gains (losses) on Level 3 assets (realized and unrealized)	(967)	(15,205)	(4,123)	(21,595)
Corporate equity securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 3 to Level 2	2,600		2,500
Net gains (losses) on Level 3 assets (realized and unrealized)	11,796	4,344	31,475	3,416
Net gains (losses) on Level 3 liabilities (realized and unrealized)	326	107	365	134
Investments at fair value
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Net gains (losses) on Level 3 assets (realized and unrealized)	2,383	$ 3,964	3,865	$ 12,760
Long-term debt
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 2 to Level 3			107,400
Net gains (losses) on Level 3 liabilities (realized and unrealized)	$ 3,004		$ (25,078)

Fair Value Disclosures (Quantit

Fair Value Disclosures (Quantitative Information About Significant Unobservable Inputs Used In Level 3 Fair Value Measurements) (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)$ / shares$ / Bond$ / Asset	Sep. 30, 2018	Sep. 30, 2018$ / shares	Sep. 30, 2018€ / Bond	Sep. 30, 2018$ / Bond
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative assets | $	$ 189,645,000	$ 179,488,000
Derivative liability | $	715,763,000	255,394,000
Long-term debt, fair value | $	709,557,000	606,956,000
Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative assets | $	3,137,000	9,295,000
Long-term debt, fair value | $	163,630,000	0
Level 3 | Price | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Long-term debt, measurement input					80	70
Level 3 | Price | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Long-term debt, measurement input					112	100
Level 3 | Price | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Long-term debt, measurement input					96	80
Level 3 | Non-exchange traded securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	41,038,000	$ 18,109,000
Level 3 | Non-exchange traded securities | Price | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				3
Level 3 | Non-exchange traded securities | Price | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				75
Level 3 | Non-exchange traded securities | Price | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				25
Level 3 | Non-exchange traded securities | Price | Market approach | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		3
Level 3 | Non-exchange traded securities | Price | Market approach | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		75
Level 3 | Non-exchange traded securities | Price | Market approach | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		33
Level 3 | Non-exchange traded securities | Underlying stock price | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				1
Level 3 | Non-exchange traded securities | Underlying stock price | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				11
Level 3 | Non-exchange traded securities | Underlying stock price | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				9
Level 3 | Non-exchange traded securities | Underlying stock price | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		6
Level 3 | Non-exchange traded securities | Comparable asset price | Comparable pricing
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / Asset		7
Level 3 | Private equity securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	111,899,000	$ 110,010,000
Level 3 | Private equity securities | Price | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				3
Level 3 | Private equity securities | Price | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				250
Level 3 | Private equity securities | Underlying stock price
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		7
Level 3 | Private equity securities | Underlying stock price | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares				105
Level 3 | Private equity securities | Discount rate/yield
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.20	0.20
Level 3 | Private equity securities | Transaction level | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		3
Level 3 | Private equity securities | Transaction level | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $ / shares		250
Level 3 | Private equity securities | Transaction level | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input | $		172
Level 3 | Corporate debt securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	9,651,000	$ 26,036,000
Debt instrument, fair value | $	1,557,000
Level 3 | Corporate debt securities | Price
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input						10
Level 3 | Corporate debt securities | Price | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		10
Level 3 | Corporate debt securities | Comparable asset price
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input						101
Level 3 | Corporate debt securities | Discount rate/yield
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.19
Level 3 | Corporate debt securities | Discount rate/yield | Convertible bond model
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.08
Level 3 | Corporate debt securities | Estimated recovery percentage
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.46
Debt instrument, measurement input			0.53
Level 3 | Corporate debt securities | Estimated recovery percentage | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.17
Level 3 | Corporate debt securities | Volatility | Convertible bond model
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.40
Level 3 | CDOs and CLOs
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	33,981,000	$ 38,845,000
Level 3 | CDOs and CLOs | Discount rate/yield | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.03	0.05
Level 3 | CDOs and CLOs | Discount rate/yield | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.26	0.41
Level 3 | CDOs and CLOs | Discount rate/yield | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.12	0.16
Level 3 | CDOs and CLOs | Estimated recovery percentage | Scenario analysis | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.08	0.02
Level 3 | CDOs and CLOs | Estimated recovery percentage | Scenario analysis | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.45	0.41
Level 3 | CDOs and CLOs | Estimated recovery percentage | Scenario analysis | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.26	0.23
Level 3 | CDOs and CLOs | Constant prepayment rate | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.20	0.20
Level 3 | CDOs and CLOs | Constant default rate | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.02
Level 3 | CDOs and CLOs | Constant default rate | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.01
Level 3 | CDOs and CLOs | Constant default rate | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.02
Level 3 | CDOs and CLOs | Constant default rate | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.02
Level 3 | CDOs and CLOs | Loss severity | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.30
Level 3 | CDOs and CLOs | Loss severity | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.25
Level 3 | CDOs and CLOs | Loss severity | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.30
Level 3 | CDOs and CLOs | Loss severity | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.26
Level 3 | Residential mortgage-backed securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	$ 4,954,000	$ 26,077,000
Level 3 | Residential mortgage-backed securities | Price | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input						100
Level 3 | Residential mortgage-backed securities | Discount rate/yield | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.06
Level 3 | Residential mortgage-backed securities | Discount rate/yield | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.10
Level 3 | Residential mortgage-backed securities | Discount rate/yield | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.08
Level 3 | Residential mortgage-backed securities | Discount rate/yield | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.09
Level 3 | Residential mortgage-backed securities | Cumulative loss rate | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.03
Level 3 | Residential mortgage-backed securities | Cumulative loss rate | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.19
Level 3 | Residential mortgage-backed securities | Cumulative loss rate | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.10
Level 3 | Residential mortgage-backed securities | Cumulative loss rate | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.23
Level 3 | Residential mortgage-backed securities | Duration (years) | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term		2 years
Level 3 | Residential mortgage-backed securities | Duration (years) | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term		4 years
Level 3 | Residential mortgage-backed securities | Duration (years) | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term		3 years
Level 3 | Residential mortgage-backed securities | Duration (years) | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	15 years
Level 3 | Commercial mortgage-backed securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	$ 23,916,000	$ 12,419,000
Level 3 | Commercial mortgage-backed securities | Price | Scenario analysis
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input						49
Level 3 | Commercial mortgage-backed securities | Price | Scenario analysis | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		52
Level 3 | Commercial mortgage-backed securities | Price | Scenario analysis | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		56
Level 3 | Commercial mortgage-backed securities | Price | Scenario analysis | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		54
Level 3 | Commercial mortgage-backed securities | Discount rate/yield | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.02	0.03
Level 3 | Commercial mortgage-backed securities | Discount rate/yield | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.26	0.38
Level 3 | Commercial mortgage-backed securities | Discount rate/yield | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.12	0.12
Level 3 | Commercial mortgage-backed securities | Estimated recovery percentage | Scenario analysis
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input			0.26
Level 3 | Commercial mortgage-backed securities | Estimated recovery percentage | Scenario analysis | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.26
Level 3 | Commercial mortgage-backed securities | Estimated recovery percentage | Scenario analysis | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.32
Level 3 | Commercial mortgage-backed securities | Estimated recovery percentage | Scenario analysis | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.28
Level 3 | Commercial mortgage-backed securities | Cumulative loss rate | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.08	0.08
Level 3 | Commercial mortgage-backed securities | Cumulative loss rate | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.65	0.84
Level 3 | Commercial mortgage-backed securities | Cumulative loss rate | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.44	0.33
Level 3 | Commercial mortgage-backed securities | Duration (years) | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	0 years	1 year
Level 3 | Commercial mortgage-backed securities | Duration (years) | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	3 years	3 years
Level 3 | Commercial mortgage-backed securities | Duration (years) | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	1 year	2 years
Level 3 | Other asset-backed securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	$ 69,305,000	$ 61,129,000
Level 3 | Other asset-backed securities | Price | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		100				100
Level 3 | Other asset-backed securities | Discount rate/yield | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.05	0.05
Level 3 | Other asset-backed securities | Discount rate/yield | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.39	0.12
Level 3 | Other asset-backed securities | Discount rate/yield | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.09	0.07
Level 3 | Other asset-backed securities | Estimated recovery percentage | Scenario analysis
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.14
Level 3 | Other asset-backed securities | Cumulative loss rate | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0	0
Level 3 | Other asset-backed securities | Cumulative loss rate | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.33	0.29
Level 3 | Other asset-backed securities | Cumulative loss rate | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.23	0.18
Level 3 | Other asset-backed securities | Duration (years) | Discounted cash flows | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	1 year	1 year
Level 3 | Other asset-backed securities | Duration (years) | Discounted cash flows | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	5 years	6 years
Level 3 | Other asset-backed securities | Duration (years) | Discounted cash flows | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	2 years	2 years
Level 3 | Loans and other receivables
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	$ 48,985,000	$ 46,121,000
Level 3 | Loans and other receivables | Price | Market approach | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		54				50
Level 3 | Loans and other receivables | Price | Market approach | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		100				100
Level 3 | Loans and other receivables | Price | Market approach | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		95				95
Level 3 | Loans and other receivables | Estimated recovery percentage | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.76	0
Level 3 | Loans and other receivables | Estimated recovery percentage | Scenario analysis | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.13	0.57
Level 3 | Loans and other receivables | Estimated recovery percentage | Scenario analysis | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		1.07	1.07
Level 3 | Loans and other receivables | Estimated recovery percentage | Scenario analysis | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input		0.78	0.88
Level 3 | Derivatives
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative assets | $	3,137,000	$ 9,295,000
Derivative liability | $	12,134,000	$ 16,041,000
Level 3 | Derivatives | Price | Total return swaps
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative asset, measurement input						100
Level 3 | Derivatives | Price | Total return swaps | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative asset, measurement input		101
Level 3 | Derivatives | Price | Total return swaps | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative asset, measurement input		106
Level 3 | Derivatives | Price | Total return swaps | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative asset, measurement input		103
Level 3 | Derivatives | Price | Total return swaps | Market approach | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		101				95
Level 3 | Derivatives | Price | Total return swaps | Market approach | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		106				100
Level 3 | Derivatives | Price | Total return swaps | Market approach | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		103				97
Level 3 | Derivatives | Price | Unfunded commitments | Market approach
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		99				99
Level 3 | Derivatives | Discount rate/yield | Variable funding note swaps | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		0.26	0.41
Level 3 | Derivatives | Constant prepayment rate | Variable funding note swaps | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		0.20	0.20
Level 3 | Derivatives | Constant default rate | Variable funding note swaps | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		0.02	0.02
Level 3 | Derivatives | Loss severity | Variable funding note swaps | Discounted cash flows
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		0.25	0.30
Level 3 | Derivatives | Default probability | Equity options | Option model/default rate
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability, measurement input		0	0
Level 3 | Derivatives | Price | Interest rate swaps
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative asset, measurement input		0.0800
Level 3 | FXCM term loan
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, fair value | $	$ 73,800,000	$ 72,800,000
Level 3 | FXCM term loan | Term based on the pay off (years) | Minimum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	0 months	0 months
Level 3 | FXCM term loan | Term based on the pay off (years) | Maximum
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	4 months	2 months
Level 3 | FXCM term loan | Term based on the pay off (years) | Weighted Average
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Trading assets, measurement input, term	3 months	2 months
Level 3 | Loans
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value | $	$ 8,661,000
Level 3 | Loans | Price
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Debt instrument, measurement input						50
Level 3 | Loans | Estimated recovery percentage
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Debt instrument, measurement input			0

Fair Value Disclosures (Summary

Fair Value Disclosures (Summary Of Gains (Losses) Due To Changes In Instrument Specific Credit Risk For Loans and Other Receivables And Loan Commitments Measured At Fair Value Under Fair Value Option) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financial Instruments [Line Items]
Loans and other receivables	$ 14,002	$ 24,846	$ 7,495	$ 27,715
Financial Instruments Sold
Financial Instruments [Line Items]
Loans	(2,708)	3,436	(2,467)	(7,286)
Loan commitments	(1,695)	82	(1,964)	229
Long-term debt
Financial Instruments [Line Items]
Changes in instrument specific credit risk	1,401	5,638	19,986	(14,141)
Other changes in fair value	(6,842)	(1,854)	33,626	2,786
Short-term Borrowings
Financial Instruments [Line Items]
Changes in instrument specific credit risk	0	19	0	1
Other changes in fair value	$ 0	$ (2,570)	$ 0	$ (37)

Fair Value Disclosures (Summa_2

Fair Value Disclosures (Summary Of Amount By Which Contractual Principal Exceeds Fair Value For Loans And Other Receivables Measured At Fair Value Under Fair Value Option) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Loans and other receivables	$ 896,470	$ 752,076
Loans and other receivables on nonaccrual status and/or 90 days or greater past due	167,355	159,462
Long-term debt and short-term borrowings	89,345	32,839
All loans and other receivables 90 days or greater past due	$ 33,700	$ 38,700

Fair Value Disclosures (Fair Va

Fair Value Disclosures (Fair Value Option Election Narrative) (Details) $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)directorshares	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)directorshares	Jun. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Jul. 13, 2018	Jul. 12, 2018	Dec. 31, 2017USD ($)shares
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Financial instruments owned trading assets, at fair value	$ 17,709,245		$ 17,709,245						$ 16,082,676
Jefferies Group
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Loans and other receivables on nonaccrual status and/or 90 days or greater past due	77,000		77,000						55,100
Loans and other receivables 90 days or greater past due	25,600		25,600						37,400
KCG
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Changes in fair value of investments reflected as principal transactions		$ 2,200			$ 93,400
HRG
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Cash consideration paid for shares	475,600		475,600
HRG Group/Spectrum Brands Holdings, Inc.
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Changes in fair value of investments reflected as principal transactions	(48,500)	$ (97,900)	(228,400)		$ 2,300
Spectrum Brands
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Financial instruments owned trading assets, at fair value	$ 561,500		$ 561,500						$ 789,900
Revenue of investee				$ 2,358,100		$ 2,222,700
Net income from continuing operations of investee				443,700		(46,000)
Net income (loss) of investee				941,600		249,200
Net income (loss) attributable to HRG				$ 847,700		$ 132,200
Number of directors appointed by Company | director	1		1
Spectrum Brands
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Shares owned, number | shares	7.5		7.5
Percentage of ownership owned	14.00%		14.00%				14.00%
Spectrum Brands | HRG
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Percentage of ownership owned							62.00%
HRG
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Shares owned, number | shares									46.6
Percentage of outstanding common stock owned									23.00%
Percentage of ownership owned								23.00%	23.00%

Derivative Financial Instrume_3

Derivative Financial Instruments (Fair Value And Related Number Of Derivative Contracts Categorized By Predominant Risk Exposure) (Details) $ in Thousands	Sep. 30, 2018USD ($)Contract	Dec. 31, 2017USD ($)Contract
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 3,523,745	$ 3,497,969
Fair Value, Liabilities	4,170,251	3,745,908
Net Amounts in Consolidated Statements of Financial Condition	189,645	179,488
Net Amounts in Consolidated Statements of Financial Condition	715,763	255,394
Rule change impact, derivative asset	189,645	179,488
Rule change impact, derivative liability	715,763	255,394
Designated as Accounting Hedges | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 0	$ 0
Number of Contracts, Assets | Contract	0	0
Fair Value, Liabilities	$ 30,018	$ 2,420
Number of Contracts, Liabilities | Contract	1	1
Not Designated as Accounting Hedges
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 3,523,745	$ 3,497,969
Fair Value, Liabilities	4,140,233	3,743,488
Counterparty/cash-collateral netting, Assets	(3,334,100)	(3,318,481)
Counterparty/cash-collateral netting, Liabilities	(3,454,488)	(3,490,514)
Net Amounts in Consolidated Statements of Financial Condition	189,645	179,488
Net Amounts in Consolidated Statements of Financial Condition	685,745	252,974
Not Designated as Accounting Hedges | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 766,233	$ 1,717,058
Number of Contracts, Assets | Contract	20,867	38,941
Fair Value, Liabilities	$ 892,562	$ 1,708,776
Number of Contracts, Liabilities | Contract	38,331	12,828
Not Designated as Accounting Hedges | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 234,641	$ 366,541
Number of Contracts, Assets | Contract	8,569	6,463
Fair Value, Liabilities	$ 223,565	$ 349,512
Number of Contracts, Liabilities | Contract	7,486	4,612
Not Designated as Accounting Hedges | Equity contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 2,491,005	$ 1,373,016
Number of Contracts, Assets | Contract	1,892,926	2,728,750
Fair Value, Liabilities	$ 2,987,654	$ 1,638,258
Number of Contracts, Liabilities | Contract	1,836,128	2,118,526
Not Designated as Accounting Hedges | Commodity contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 4,599	$ 3,093
Number of Contracts, Assets | Contract	6,331	7,249
Fair Value, Liabilities	$ 16,312	$ 5,141
Number of Contracts, Liabilities | Contract	3,585	6,047
Not Designated as Accounting Hedges | Credit contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 27,267	$ 38,261
Number of Contracts, Assets | Contract	172	130
Fair Value, Liabilities	$ 20,140	$ 41,801
Number of Contracts, Liabilities | Contract	76	191
Rule Change by London Clearing House | Interest rate contracts
Derivatives, Fair Value [Line Items]
Rule change impact, derivative asset		$ 800,000
Rule change impact, derivative liability		$ 800,000

Derivative Financial Instrume_4

Derivative Financial Instruments (Unrealized And Realized Gains (Losses) On Derivative Contracts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense on fair value hedge	$ 60	$ 1,537	$ 1,692	$ 4,390
Unrealized and realized gains (losses)	3,364	(159,304)	(229,146)	(285,866)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	13,951	(7,485)	36,053	2,555
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	(4,781)	481	6,737	3,341
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	1,019	(142,931)	(249,546)	(294,635)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	(6,845)	(1,422)	(23,150)	(3,260)
Credit contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	20	(7,947)	760	6,133
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense on fair value hedge	(1,161)	6,217	(22,363)	13,960
Long-term Debt
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense on fair value hedge	$ 1,221	$ (4,680)	$ 24,055	$ (9,570)

Derivative Financial Instrume_5

Derivative Financial Instruments (Remaining Contract Maturity Of Fair Value Of OTC Derivative Assets And Liabilities) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	$ 114,625
OTC derivative assets having maturity period of 1 to 5 years	179,056
OTC derivative assets having maturity period of greater than 5 years	98,168
OTC derivative assets cross-maturity netting	(105,568)
Total OTC derivative assets, net of cross-maturity netting	286,281
Cross product counterparty netting	(34,971)
Total OTC derivative assets included in Trading assets	251,310
OTC derivative liabilities having maturity period of 0 to 12 months	148,158
OTC derivative liabilities having maturity period of 1 to 5 years	292,346
OTC derivative liabilities having maturity period of greater than 5 years	211,617
OTC derivative liabilities cross-maturity netting	(105,568)
Total OTC derivative liabilities, net of cross-maturity netting	546,553
Cross product counterparty netting	(34,971)
Total OTC derivative liabilities included in Trading liabilities	511,582
Exchange traded derivative assets and other credit agreements	96,600
Cash collateral received	158,200
Exchange traded derivative liabilities and other credit agreements	482,800
Cash collateral pledged	278,600
Commodity swaps, options and forwards
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	738
OTC derivative assets having maturity period of 1 to 5 years	512
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	1,250
OTC derivative liabilities having maturity period of 0 to 12 months	12,234
OTC derivative liabilities having maturity period of 1 to 5 years	2,388
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	14,622
Equity swaps and options
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	10,226
OTC derivative assets having maturity period of 1 to 5 years	8,071
OTC derivative assets having maturity period of greater than 5 years	2,195
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	20,492
OTC derivative liabilities having maturity period of 0 to 12 months	15,125
OTC derivative liabilities having maturity period of 1 to 5 years	92,491
OTC derivative liabilities having maturity period of greater than 5 years	13,048
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	120,664
Credit default swaps
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	82
OTC derivative assets having maturity period of 1 to 5 years	21,802
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(11)
Total OTC derivative assets, net of cross-maturity netting	21,873
OTC derivative liabilities having maturity period of 0 to 12 months	17
OTC derivative liabilities having maturity period of 1 to 5 years	11,480
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(11)
Total OTC derivative liabilities, net of cross-maturity netting	11,486
Total return swaps
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	46,036
OTC derivative assets having maturity period of 1 to 5 years	29,910
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(4,334)
Total OTC derivative assets, net of cross-maturity netting	71,612
OTC derivative liabilities having maturity period of 0 to 12 months	67,526
OTC derivative liabilities having maturity period of 1 to 5 years	19,806
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(4,334)
Total OTC derivative liabilities, net of cross-maturity netting	82,998
Foreign currency forwards, swaps and options
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	42,326
OTC derivative assets having maturity period of 1 to 5 years	22,130
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(9,550)
Total OTC derivative assets, net of cross-maturity netting	54,906
OTC derivative liabilities having maturity period of 0 to 12 months	36,183
OTC derivative liabilities having maturity period of 1 to 5 years	17,496
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(9,550)
Total OTC derivative liabilities, net of cross-maturity netting	44,129
Fixed income forwards
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	2,113
OTC derivative assets having maturity period of 1 to 5 years	0
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	2,113
OTC derivative liabilities having maturity period of 0 to 12 months	685
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	685
Interest rate swaps
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	13,104
OTC derivative assets having maturity period of 1 to 5 years	96,631
OTC derivative assets having maturity period of greater than 5 years	95,973
OTC derivative assets cross-maturity netting	(91,673)
Total OTC derivative assets, net of cross-maturity netting	114,035
OTC derivative liabilities having maturity period of 0 to 12 months	16,388
OTC derivative liabilities having maturity period of 1 to 5 years	148,685
OTC derivative liabilities having maturity period of greater than 5 years	198,569
OTC derivative liabilities cross-maturity netting	(91,673)
Total OTC derivative liabilities, net of cross-maturity netting	$ 271,969

Derivative Financial Instrume_6

Derivative Financial Instruments (Counterparty Credit Quality With Respect To Fair Value Of OTC Derivatives Assets) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
A- or higher	$ 137,910
BBB- to BBB	20,490
BB or lower	74,097
Unrated	18,813
Total OTC derivative assets included in Trading assets	$ 251,310

Derivative Financial Instrume_7

Derivative Financial Instruments (Credit Related Derivative Contracts) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Index credit default swaps
Derivative [Line Items]
Notional amount	$ 18	$ 129
Single name credit default swaps
Derivative [Line Items]
Notional amount	75.3	218.2
Investment Grade | Index credit default swaps
Derivative [Line Items]
Notional amount	3	3
Investment Grade | Single name credit default swaps
Derivative [Line Items]
Notional amount	32.5	129.1
Non-investment grade | Index credit default swaps
Derivative [Line Items]
Notional amount	15	126
Non-investment grade | Single name credit default swaps
Derivative [Line Items]
Notional amount	39.9	89.1
Unrated | Index credit default swaps
Derivative [Line Items]
Notional amount	0	0
Unrated | Single name credit default swaps
Derivative [Line Items]
Notional amount	$ 2.9	$ 0

Derivative Financial Instrume_8

Derivative Financial Instruments (Contingent Features) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative instrument liabilities with credit-risk-related contingent features	$ 106.3	$ 95.1
Collateral posted	(59.3)	(86.4)
Collateral received	129.7	5.6
Return of and additional collateral required in the event of a credit rating downgrade below investment grade	$ 176.6	$ 14.3

Collateralized Transactions (Co

Collateralized Transactions (Collateral Pledged) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	$ 2,531,504	$ 2,843,911
Repurchase agreements	17,839,459	19,829,249
Total	20,370,963	22,673,160
Cash
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0
Repurchase agreements	4,361
Total	4,361
Corporate equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	2,214,433	2,353,798
Repurchase agreements	490,609	214,413
Total	2,705,042	2,568,211
Corporate debt securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	315,718	470,908
Repurchase agreements	1,496,127	2,336,702
Total	1,811,845	2,807,610
Mortgage- and asset-backed securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0	0
Repurchase agreements	2,667,439	2,562,268
Total	2,667,439	2,562,268
U.S. government and federal agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	1,353	19,205
Repurchase agreements	10,124,642	11,792,534
Total	10,125,995	11,811,739
Municipal securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0	0
Repurchase agreements	582,699	444,861
Total	582,699	444,861
Sovereign obligations
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0	0
Repurchase agreements	1,955,879	2,023,530
Total	1,955,879	2,023,530
Loans and other receivables
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0	0
Repurchase agreements	517,703	454,941
Total	$ 517,703	$ 454,941

Collateralized Transactions (_2

Collateralized Transactions (Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	$ 2,531,504	$ 2,843,911
Repurchase agreements	17,839,459	19,829,249
Total	20,370,963	22,673,160
Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	1,354,136	1,676,940
Repurchase agreements	8,122,962	10,780,474
Total	9,477,098	12,457,414
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	0	0
Repurchase agreements	2,733,400	4,058,228
Total	2,733,400	4,058,228
30 to 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	847,577	741,971
Repurchase agreements	4,342,923	3,211,464
Total	5,190,500	3,953,435
Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending arrangements	329,791	425,000
Repurchase agreements	2,640,174	1,779,083
Total	$ 2,969,965	$ 2,204,083

Collateralized Transactions (Na

Collateralized Transactions (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2018	Dec. 31, 2017
Collateralized Transactions [Abstract]
Fair value of securities received as collateral that may be sold or repledged	$ 25.2	$ 27.1

Securitization Activities (Acti

Securitization Activities (Activity Related To Securitizations Accounted For As Sales) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Securitization Activities [Abstract]
Transferred assets	$ 1,865.5	$ 1,009.1	$ 5,665.9	$ 2,677.7
Proceeds on new securitizations	1,866.2	1,017.2	5,668.6	2,703.3
Cash flows received on retained interests	$ 17.2	$ 8.7	$ 35.7	$ 22.7

Securitization Activities (Summ

Securitization Activities (Summary Of Retained Interests In SPEs) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Residential mortgage-backed securities
Securitization Activities [Line Items]
U.S. government agency residential mortgage-backed securities	$ 13,306	$ 6,383.5
Retained Interests	192.7	28.2
Commercial mortgage-backed securities
Securitization Activities [Line Items]
U.S. government agency commercial mortgage-backed securities	2,101.5	2,075.7
Retained Interests	276.1	81.4
CLOs
Securitization Activities [Line Items]
CLOs	3,442.3	3,957.8
Retained Interests	26.4	20.3
Consumer and other loans
Securitization Activities [Line Items]
Retained Interests	53	47.8
Consumer and Other Loans Securitization Assets	$ 648.9	$ 247.6

Available for Sale Securities_3

Available for Sale Securities and Other Investments (Amortized Cost, Gross Unrealized Gains and Losses and Estimated Fair Value of Available for Sale Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Debt securities, available for sale securities, amortized cost	$ 1,869,962	$ 627,922
Debt securities, available for sale securities, gross unrealized gains	149	335
Debt securities, available for sale securities, gross unrealized losses	1,691	182
Debt securities, available for sale securities, estimated fair value	1,868,420	628,075
Equity securities, available for sale securities, amortized cost		52,575
Equity securities, available for sale securities, gross unrealized gains		35,911
Equity securities, available for sale securities, gross unrealized losses		0
Equity securities, available for sale securities, estimated fair value		88,486
Available for sale securities, amortized cost Basis		680,497
Available for sale securities, gross unrealized gains		36,246
Available for sale securities, gross unrealized losses		182
Available-for-sale Securities		716,561
U.S. government securities
Schedule of Investments [Line Items]
Debt securities, available for sale securities, amortized cost	1,608,076	552,847
Debt securities, available for sale securities, gross unrealized gains	2	0
Debt securities, available for sale securities, gross unrealized losses	353	42
Debt securities, available for sale securities, estimated fair value	1,607,725	552,805
Residential mortgage-backed securities
Schedule of Investments [Line Items]
Debt securities, available for sale securities, amortized cost	147,294	34,381
Debt securities, available for sale securities, gross unrealized gains	138	272
Debt securities, available for sale securities, gross unrealized losses	754	92
Debt securities, available for sale securities, estimated fair value	146,678	34,561
Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Debt securities, available for sale securities, amortized cost	16,049	5,857
Debt securities, available for sale securities, gross unrealized gains	0	17
Debt securities, available for sale securities, gross unrealized losses	330	4
Debt securities, available for sale securities, estimated fair value	15,719	5,870
Other asset-backed securities
Schedule of Investments [Line Items]
Debt securities, available for sale securities, amortized cost	98,543	34,837
Debt securities, available for sale securities, gross unrealized gains	9	46
Debt securities, available for sale securities, gross unrealized losses	254	44
Debt securities, available for sale securities, estimated fair value	$ 98,298	34,839
Common stocks: Banks, trusts and insurance companies
Schedule of Investments [Line Items]
Equity securities, available for sale securities, amortized cost		35,071
Equity securities, available for sale securities, gross unrealized gains		17,500
Equity securities, available for sale securities, gross unrealized losses		0
Equity securities, available for sale securities, estimated fair value		52,571
Common stocks: Industrial, miscellaneous and all other
Schedule of Investments [Line Items]
Equity securities, available for sale securities, amortized cost		17,504
Equity securities, available for sale securities, gross unrealized gains		18,411
Equity securities, available for sale securities, gross unrealized losses		0
Equity securities, available for sale securities, estimated fair value		$ 35,915

Available for Sale Securities_4

Available for Sale Securities and Other Investments (Additional Information) (Details) $ in Millions	Sep. 30, 2018USD ($)
Investments, Debt and Equity Securities [Abstract]
Other investment not readily marketable, fair value	$ 233.7

Available for Sale Securities_5

Available for Sale Securities and Other Investments (Amortized Cost and Estimated Fair Value of Investments Classified as Available for Sale By Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amortized Cost
Due within one year, amortized cost	$ 1,608,076
Fixed maturities investments excluding mortgage-backed and asset-backed securities, amortized cost	1,608,076
Mortgage-backed and asset-backed securities, amortized cost	261,886
Debt securities, available for sale securities, amortized cost	1,869,962	$ 627,922
Estimated Fair Value
Due within one year, estimated fair value	1,607,725
Fixed maturities investments excluding mortgage-backed and asset-backed securities, estimated fair value	1,607,725
Mortgage-backed and asset-backed securities, estimated fair value	260,695
Debt securities, available for sale securities, estimated fair value	$ 1,868,420	$ 628,075

Variable Interest Entities (Ass

Variable Interest Entities (Assets And Liabilities Of Consolidated VIEs) (Details) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Variable Interest Entity [Line Items]
Cash		$ 4,895,788	$ 5,275,480	$ 5,016,932
Financial instruments owned		19,577,665	16,799,237
Securities purchased under agreement to resell		3,659,059	3,689,559
Receivables		5,864,815	5,419,015
Other		1,506,986	1,661,777
Total assets	[1]	48,948,669	47,169,108
Other secured financings		1,440,678	1,029,485
Total liabilities	[1]	38,155,533	36,478,536
Noncontrolling interests		25,566	33,022
Jefferies Group
Variable Interest Entity [Line Items]
Secured financings eliminated in consolidation		37,700	44,100
Consolidation, Eliminations
Variable Interest Entity [Line Items]
Intercompany payables		31,100	32,000
Securitization Vehicles
Variable Interest Entity [Line Items]
Cash		0	11,700
Financial instruments owned		0	37,600
Securities purchased under agreement to resell		1,043,400	729,300
Receivables		453,200	318,100
Other		25,800	15,500
Total assets		1,522,400	1,112,200
Other secured financings		1,478,300	1,073,500
Other		44,100	38,300
Total liabilities		$ 1,522,400	$ 1,111,800
[1]	Total assets include assets related to variable interest entities of $479.0 million and $382.9 million at September 30, 2018 and December 31, 2017, respectively, and Total liabilities include liabilities related to variable interest entities of $1,441.9 million and $1,031.0 million at September 30, 2018 and December 31, 2017, respectively. See Note 8 for additional information related to variable interest entities.

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)Contract	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Automobile loan receivables securitized	$ 290.9
Carrying Amount	575	$ 579.6
Other private investment vehicles
Variable Interest Entity [Line Items]
Carrying amount of equity investment	160.4	133
Unfunded equity commitment related to investments	10.3	9.1
Carrying Amount	160.4	133
Agency Mortgage-Backed Securitizations
Variable Interest Entity [Line Items]
Carrying Amount	2,622.2	1,829.6
Nonagency Mortgage- And Asset-Backed Securitizations
Variable Interest Entity [Line Items]
Carrying Amount	156.6	253.2
JCP Entities | Private Equity Vehicles
Variable Interest Entity [Line Items]
Equity commitments	139.3	148.1
Funded equity commitments	121.3	126.3
Carrying amount of equity investment	$ 34.1	$ 23.7
Foursight Capital Credit Facilities | Secured Debt
Variable Interest Entity [Line Items]
Number of warehouse credit commitment | Contract	2

Variable Interest Entities (Non

Variable Interest Entities (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Financial Statement Carrying Amount, Assets	$ 575	$ 579.6
Financial Statement Carrying Amount, Liabilities	0.7	8.9
Maximum Exposure to Loss	1,609.2	1,977.6
VIE Assets	12,221.2	12,386.9
CLOs
Variable Interest Entity [Line Items]
Financial Statement Carrying Amount, Assets	57	168.1
Financial Statement Carrying Amount, Liabilities	0.7	8.9
Maximum Exposure to Loss	784	1,030.4
VIE Assets	3,348	5,364.3
Consumer loan vehicles
Variable Interest Entity [Line Items]
Financial Statement Carrying Amount, Assets	323.5	254.8
Financial Statement Carrying Amount, Liabilities	0	0
Maximum Exposure to Loss	602.4	759.8
VIE Assets	3,441.8	2,322.7
Related party private equity vehicles
Variable Interest Entity [Line Items]
Financial Statement Carrying Amount, Assets	34.1	23.7
Financial Statement Carrying Amount, Liabilities	0	0
Maximum Exposure to Loss	52	45.4
VIE Assets	107.2	75
Other private investment vehicles
Variable Interest Entity [Line Items]
Financial Statement Carrying Amount, Assets	160.4	133
Financial Statement Carrying Amount, Liabilities	0	0
Maximum Exposure to Loss	170.8	142
VIE Assets	$ 5,324.2	$ 4,624.9

Loans to and Investments In A_3

Loans to and Investments In Associated Companies (Schedule Of Loans to and Investments In Associated Companies) (Details) - USD ($) $ in Thousands	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Jun. 05, 2018	Jun. 04, 2018	Dec. 31, 2017
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				$ 2,066,829	$ 2,125,098
Income (losses) related to associated companies	$ 18,867	$ 30,057		84,320	(84,413)
Income (losses) related to Jefferies associated companies	5,853	10,828		30,687	65,323
Contributions to (distributions from) associated companies, net				(134,300)	203,849
Other				403,365	41,123
Loans to and investments in associated companies, ending balance	2,450,901	2,350,980	$ 2,450,901	2,450,901	2,350,980
Noncontrolling interests	25,566		25,566	25,566				$ 33,022
Jefferies Finance
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				655,467	490,464
Income (losses) related to associated companies				0	0
Income (losses) related to Jefferies associated companies	5,931	13,509		36,497	63,685
Contributions to (distributions from) associated companies, net				43,470	109,899
Other				0	0
Loans to and investments in associated companies, ending balance	735,434	664,048	735,434	735,434	664,048
National Beef
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				0
Income (losses) related to associated companies	58,886	0	83,300	83,287	0
Income (losses) related to Jefferies associated companies				0
Contributions to (distributions from) associated companies, net				(48,656)
Other				592,239
Loans to and investments in associated companies, ending balance	$ 626,870		$ 626,870	$ 626,870
Percentage of ownership owned							79.00%
Equity method investment, ownership percentage	31.00%		31.00%	31.00%		31.00%
Jefferies LoanCore
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance					154,731
Income (losses) related to associated companies					0
Income (losses) related to Jefferies associated companies	$ 0	1,656		$ 0	8,030
Contributions to (distributions from) associated companies, net					43,714
Other					1,095
Loans to and investments in associated companies, ending balance		207,570			207,570
Berkadia
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				210,594	184,443
Income (losses) related to associated companies	28,350	34,839		80,092	67,979
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				(42,064)	(52,300)
Other				(1,054)	(174)
Loans to and investments in associated companies, ending balance	247,568	199,948	$ 247,568	247,568	199,948
FXCM
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				158,856	336,258
Income (losses) related to associated companies	(4,282)	(4,345)		(19,322)	(166,360)
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				0	0
Other				(513)	731
Loans to and investments in associated companies, ending balance	139,021	170,629	139,021	139,021	170,629
Garcadia companies
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				179,143	185,815
Income (losses) related to associated companies	691	12,565		21,646	38,536
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				(26,962)	(40,955)
Other				(173,827)	0
Loans to and investments in associated companies, ending balance	0	183,396	0	0	183,396
Linkem
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				192,136	154,000
Income (losses) related to associated companies	(7,770)	(9,533)		(20,534)	(26,557)
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				542	31,996
Other				(3,601)	33,979
Loans to and investments in associated companies, ending balance	168,543	193,418	168,543	168,543	193,418
HomeFed
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				341,874	302,231
Income (losses) related to associated companies	(7,783)	238		(3,338)	9,922
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				0	31,918
Other				0	0
Loans to and investments in associated companies, ending balance	338,536	344,071	338,536	338,536	344,071
Golden Queen
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				105,005	111,302
Income (losses) related to associated companies	(48,732)	(1,975)		(52,028)	(3,684)
Income (losses) related to Jefferies associated companies				0	0
Contributions to (distributions from) associated companies, net				8,441	(59)
Other				0	0
Loans to and investments in associated companies, ending balance	61,418	107,559	61,418	61,418	107,559
Noncontrolling interests	15,100		15,100	15,100				$ 30,500
Other
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Loans to and investments in associated companies, beginning balance				223,754	205,854
Income (losses) related to associated companies	(493)	(1,732)		(5,483)	(4,249)
Income (losses) related to Jefferies associated companies	(78)	(4,337)		(5,810)	(6,392)
Contributions to (distributions from) associated companies, net				(69,071)	79,636
Other				(9,879)	5,492
Loans to and investments in associated companies, ending balance	$ 133,511	$ 280,341	$ 133,511	$ 133,511	$ 280,341
Discontinued operations, disposed of by sale | National Beef
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Percentage of ownership owned						48.00%
Held-for-sale, not discontinued operations | Garcadia companies
Loans to and Investments in Associated Companies Rollforward [Roll Forward]
Percentage of equity method investment for sale	100.00%

Loans to and Investments In A_4

Loans to and Investments In Associated Companies (Jefferies Finance) (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Investments In Associated Companies [Line Items]
Other	$ 1,506,986,000		$ 1,506,986,000		$ 1,661,777,000
Payables, expense accruals and other liabilities	6,680,224,000		6,680,224,000		7,167,666,000
Financial instruments owned trading assets, at fair value	17,709,245,000		17,709,245,000		16,082,676,000
Jefferies Group
Investments In Associated Companies [Line Items]
Interest income and unfunded commitment fees related to facility commitment	300,000	$ 500,000	2,000,000	$ 3,300,000
Investment banking	71,100,000	104,200,000	282,100,000	243,500,000
Origination fees	12,100,000	0	45,500,000	2,500,000
Placement agent fees	$ 400,000	800,000	$ 3,100,000	4,700,000
Jefferies Finance
Investments In Associated Companies [Line Items]
Equity method investment, ownership percentage	50.00%		50.00%
Equity commitment	$ 750,000,000		$ 750,000,000
Funded equity commitments	706,500,000		$ 706,500,000
Investment commitment extension			1 year
Termination notice			60 days
Total line of credit facility commitment under joint venture	500,000,000		$ 500,000,000		500,000,000
Extension period			1 year
Line of credit facility, commitment of Jefferies, funded	0		$ 0		0
Line of credit facility commitment of Jefferies	250,000,000		250,000,000		250,000,000
Service fee income	13,300,000	$ 7,900,000	48,300,000	$ 37,400,000
Other	36,300,000		36,300,000		34,600,000
Payables, expense accruals and other liabilities	14,100,000		14,100,000		14,100,000
Foreign exchange contracts | Jefferies Finance
Investments In Associated Companies [Line Items]
Payables, expense accruals and other liabilities	$ 200,000		$ 200,000
Financial instruments owned trading assets, at fair value					$ 1,500,000

Loans to and Investments In A_5

Loans to and Investments In Associated Companies (Jefferies LoanCore) (Narrative) (Details) $ in Millions	Oct. 31, 2017USD ($)
Jefferies LoanCore
Investments In Associated Companies [Line Items]
Equity method investment, ownership percentage	48.50%
Jefferies LoanCore | Disposed of by sale, not discontinued operations | Jefferies Group
Investments In Associated Companies [Line Items]
Consideration for sale of business	$ 173.1
Period entitled to additional cash consideration	5 years

Loans to and Investments in A_6

Loans to and Investments in Associated Companies (National Beef) (Narrative) (Details) - USD ($) $ in Thousands	Jun. 05, 2018	Sep. 30, 2018	Jun. 04, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investment in associated company		$ 2,450,901		$ 2,066,829	$ 2,350,980	$ 2,125,098
National Beef
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			79.00%
Equity method investment, ownership percentage	31.00%	31.00%
Investment in associated company	$ 592,300	$ 626,870		$ 0
Weighted average useful life	15 years
National Beef | Discontinued operations, disposed of by sale
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned	48.00%
National Beef
Schedule of Equity Method Investments [Line Items]
Enterprise value	$ 2,300,000
Percentage of ownership owned		100.00%
Equity valuation	$ 1,900,000

Loans to and Investments In A_7

Loans to and Investments In Associated Companies (Berkadia) (Narrative) (Details) - Berkadia - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2009	Sep. 30, 2018
Investments In Associated Companies [Line Items]
Capital contributed	$ 217.2
Equity method investment, ownership percentage		50.00%
Surety policy issued		$ 1,500
Reimbursement of losses incurred, maximum percentage		50.00%
Commercial paper		$ 1,470

Loans to and Investments In A_8

Loans to and Investments In Associated Companies (FXCM) (Narrative) (Details) - Investment in FXCM - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Sep. 30, 2018
Investments In Associated Companies [Line Items]
Equity method investment, ownership percentage		50.00%
Equity method investment impairment	$ 130.2

Loans to and Investments In A_9

Loans to and Investments In Associated Companies (Garcadia) (Narrative) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)Dealership	Sep. 30, 2018USD ($)Dealership
Garcadia
Investments In Associated Companies [Line Items]
Number of automobile dealerships	28	28
Plan One | Garcadia
Investments In Associated Companies [Line Items]
Percentage of cash flows allocated from joint venture		65.00%
Plan One | Garff Enterprises, Inc
Investments In Associated Companies [Line Items]
Percentage of cash flows allocated from joint venture		35.00%
Plan Two | Garcadia
Investments In Associated Companies [Line Items]
Number of automobile dealerships	1	1
Percentage of cash flows allocated from joint venture		83.00%
Plan Three | Garcadia
Investments In Associated Companies [Line Items]
Number of automobile dealerships	4	4
Percentage of cash flows allocated from joint venture		71.00%
Garcadia | Held-for-sale, not discontinued operations
Investments In Associated Companies [Line Items]
Percentage of equity method investment for sale	100.00%
Proceeds from sale of equity method investments and associated real estate | $	$ 417.2
Pre-tax gain on sale of equity method investments and associated real estate | $	$ 221.7	$ 221.7

Loans to and Investments In _10

Loans to and Investments In Associated Companies (Linkem) (Narrative) (Details) - Linkem	9 Months Ended
	Sep. 30, 2018
Investments In Associated Companies [Line Items]
Equity method investment, ownership percentage	42.00%
Stated interest rate on convertible notes	5.00%
Percentage of ownership upon conversion of note	54.00%
Equity method investment, voting percentage	48.00%
Convertible Preferred Stock
Investments In Associated Companies [Line Items]
Equity method investment, ownership percentage	63.00%

Loans to and Investments In _11

Loans to and Investments In Associated Companies (HomeFed) (Narrative) (Details) - HomeFed	9 Months Ended
	Sep. 30, 2018directorshares
Investments In Associated Companies [Line Items]
Shares of common stock owned | shares	10,852,123
Equity method investment, ownership percentage	70.00%
Maximum voting rights as a percentage of total voting securities voting	45.00%
Number of directors appointed by Company | director	3
Company Chairman
Investments In Associated Companies [Line Items]
Ownership percentage of company	5.00%

Loans to and Investments In _12

Loans to and Investments In Associated Companies (Golden Queen Mining Company) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		57 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2013
Investments In Associated Companies [Line Items]
Contributions from noncontrolling interests		$ 113	$ 25,724
Gauss LLC
Investments In Associated Companies [Line Items]
Cash invested in Limited Liability Company				$ 93,000
Clay Family
Investments In Associated Companies [Line Items]
Contributions from noncontrolling interests				34,500
Golden Queen Mining Company, LLC | Gauss LLC
Investments In Associated Companies [Line Items]
Total investment in associated company	$ 127,500	$ 127,500		$ 127,500
Equity method investment, ownership percentage	50.00%	50.00%		50.00%
Golden Queen Mining Co, Ltd
Investments In Associated Companies [Line Items]
Percentage of ownership owned	50.00%	50.00%		50.00%	100.00%
Investment In Golden Queen
Investments In Associated Companies [Line Items]
Equity method investment impairment	$ 47,900	$ 47,900

Loans to and Investments in _13

Loans to and Investments in Associated Companies (Other) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Revenues	$ 3,341,369	$ 763,727
Income from continuing operations before extraordinary items	591,191	267,796
Net income	$ 591,191	$ 267,796

Financial Statement Offsettin_2

Financial Statement Offsetting (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative contracts, Assets
Gross Amounts	$ 3,523,745	$ 3,497,969
Netting in Consolidated Statements of Financial Condition	(3,334,100)	(3,318,481)
Net Amounts in Consolidated Statements of Financial Condition	189,645	179,488
Additional Amounts Available for Setoff	0	0
Available Collateral	0	0
Net Amount	189,645	179,488
Securities borrowing arrangements, Assets
Gross Amounts	7,369,908	7,721,803
Netting in Consolidated Statements of Financial Condition	0	0
Net Amounts in Consolidated Statements of Financial Condition	7,369,908	7,721,803
Additional Amounts Available for Setoff	(529,662)	(966,712)
Available Collateral	(1,088,612)	(1,032,629)
Net Amount	5,751,634	5,722,462
Reverse repurchase agreements, Assets
Gross Amounts	11,634,035	14,858,297
Netting in Consolidated Statements of Financial Condition	(7,974,976)	(11,168,738)
Net Amounts in Consolidated Statements of Financial Condition	3,659,059	3,689,559
Additional Amounts Available for Setoff	(187,426)	(463,973)
Available Collateral	(3,441,009)	(3,207,147)
Net Amount	30,624	18,439
Derivative contracts, Liabilities
Gross Amounts	4,170,251	3,745,908
Netting in Consolidated Statements of Financial Condition	(3,454,488)	(3,490,514)
Net Amounts in Consolidated Statements of Financial Condition	715,763	255,394
Additional Amounts Available for Setoff	0	0
Available Collateral	0	0
Net Amount	715,763	255,394
Securities lending arrangements, Liabilities
Gross Amounts	2,531,504	2,843,911
Netting in Consolidated Statements of Financial Condition	0	0
Net Amounts in Consolidated Statements of Financial Condition	2,531,504	2,843,911
Additional Amounts Available for Setoff	(529,662)	(966,712)
Available Collateral	(1,977,558)	(1,795,408)
Net Amount	24,284	81,791
Repurchase agreements, Liabilities
Gross Amounts	17,839,459	19,829,249
Netting in Consolidated Statements of Financial Condition	(7,974,976)	(11,168,738)
Net Amounts in Consolidated Statements of Financial Condition	9,864,483	8,660,511
Additional Amounts Available for Setoff	(187,426)	(463,973)
Available Collateral	(8,632,482)	(7,067,512)
Net Amount	1,044,575	1,129,026
Securities borrowing agreement, subject to review	5,717,100	5,678,600
Securities borrowing agreement, collateral received, subject to review	5,544,100	5,516,700
Repurchase agreement, net amount, subject to review	1,019,600	1,084,400
Repurchase agreements, collateral pledged, subject to review	$ 1,054,100	$ 1,115,900

Intangible Assets, Net and Go_3

Intangible Assets, Net and Goodwill (Schedule of Intangible Assets, Net And Goodwill) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 191,770	$ 741,030
Goodwill	1,703,128	1,722,150
Total intangible assets, net and goodwill	1,894,898	2,463,180
Exchange and clearing organization membership interests and registrations
Intangible Assets [Line Items]
Indefinite lived intangibles	8,475	8,551
Customer and other relationships
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	70,071	347,767
Intangibles, accumulated amortization	100,591	230,074
Trademarks and tradename
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	108,406	293,851
Intangibles, accumulated amortization	20,211	95,627
Supply contracts
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	0	86,160
Intangibles, accumulated amortization	0	57,440
Other
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	4,818	4,701
Intangibles, accumulated amortization	4,132	3,885
Other operations
Intangible Assets [Line Items]
Goodwill	3,859	3,859
National Beef
Intangible Assets [Line Items]
Goodwill	0	14,991
Jefferies Group
Intangible Assets [Line Items]
Goodwill	$ 1,699,269	$ 1,703,300

Intangible Assets, Net and Go_4

Intangible Assets, Net and Goodwill (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 05, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense on intangible assets	$ 3,300	$ 3,200	$ 9,900	$ 9,700
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Intangible assets	191,770		191,770			$ 741,030
Goodwill	$ 1,703,128		$ 1,703,128			1,722,150
National Beef | Discontinued operations, disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership owned					48.00%
Intangible assets						539,600
Goodwill						$ 15,000

Intangible Assets, Net and Go_5

Intangible Assets, Net and Goodwill (Schedule of Estimated Future Amortization Expense) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of current year	$ 3,359
2,019	13,439
2,020	13,439
2,021	13,052
2,022	$ 13,052

Short-Term Borrowings (Details)

Short-Term Borrowings (Details) € in Millions	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2018EUR (€)	Dec. 31, 2017USD ($)
Short-term Debt [Line Items]
Short-term borrowings	$ 382,006,000		$ 436,215,000
Interest rates on short-term borrowings outstanding	3.39%		2.51%
Floating rate puttable notes
Short-term Debt [Line Items]
Short-term borrowings	$ 57,985,000		$ 108,240,000
Debt matured amount | €		€ 41
Equity-linked notes
Short-term Debt [Line Items]
Short-term borrowings	0		23,324,000
Principal amount of debt issued	70,500,000
Debt matured amount	23,300,000
Bank loans
Short-term Debt [Line Items]
Short-term borrowings	324,021,000		$ 304,651,000
Line of Credit | Intraday Credit Facility
Short-term Debt [Line Items]
Credit facility maximum amount	$ 150,000,000
Line of Credit | Intraday Credit Facility | Federal funds effective rate
Short-term Debt [Line Items]
Debt instrument, basic spread on variable rate	0.50%	0.50%

Long-Term Debt (Schedule Of Ind

Long-Term Debt (Schedule Of Indebtedness) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Apr. 13, 2018	Dec. 31, 2017	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt	$ 7,777,425		$ 7,777,425			$ 7,885,783
Gains (losses) recognized in Interest expense on fair value hedge	60	$ 1,537	1,692	$ 4,390
Long-term debt, fair value	$ 709,557		$ 709,557			$ 606,956
5.50% Senior Notes due October 18, 2023
Debt Instrument [Line Items]
Interest rate	5.50%		5.50%			5.50%
Principal	$ 750,000		$ 750,000			$ 750,000
6.625% Senior Notes due October 23, 2043
Debt Instrument [Line Items]
Interest rate	6.625%		6.625%			6.625%
Principal	$ 250,000		$ 250,000			$ 250,000
5.125% Senior Notes, due April 13, 2018
Debt Instrument [Line Items]
Long-term debt	0		0			$ 682,338
Interest rate					5.125%	5.125%
Principal						$ 678,300
8.50% Senior Notes, due July 15, 2019
Debt Instrument [Line Items]
Long-term debt	$ 707,072		$ 707,072			$ 728,872
Interest rate	8.50%		8.50%			8.50%
Principal	$ 680,800		$ 680,800			$ 680,800
2.375% Euro Medium Term Notes, due May 20, 2020
Debt Instrument [Line Items]
Long-term debt	$ 578,896		$ 578,896			$ 593,334
Interest rate	2.375%		2.375%			2.375%
Principal	$ 579,850		$ 579,850			$ 594,725
6.875% Senior Notes, due April 15, 2021
Debt Instrument [Line Items]
Long-term debt	$ 795,967		$ 795,967			$ 808,157
Interest rate	6.875%		6.875%			6.875%
Principal	$ 750,000		$ 750,000			$ 750,000
2.25% Euro Medium Term Notes, due July 13, 2022
Debt Instrument [Line Items]
Long-term debt	$ 4,332		$ 4,332			$ 4,389
Interest rate	2.25%		2.25%			2.25%
Principal	$ 4,639		$ 4,639			$ 4,758
5.125% Senior Notes, due January 20, 2023
Debt Instrument [Line Items]
Long-term debt	$ 613,634		$ 613,634			$ 615,703
Interest rate	5.125%		5.125%			5.125%
Principal	$ 600,000		$ 600,000			$ 600,000
4.85% Senior Notes, due January 15, 2027
Debt Instrument [Line Items]
Long-term debt	$ 712,667		$ 712,667			$ 736,357
Interest rate	4.85%		4.85%			4.85%
Principal	$ 750,000		$ 750,000			$ 750,000
6.45% Senior Debentures, due June 8, 2027
Debt Instrument [Line Items]
Long-term debt	$ 374,211		$ 374,211			$ 375,794
Interest rate	6.45%		6.45%			6.45%
Principal	$ 350,000		$ 350,000			$ 350,000
3.875% Convertible Senior Debentures, due November 1, 2029
Debt Instrument [Line Items]
Long-term debt	0		0			$ 324,779
Interest rate						3.875%
Principal						$ 324,779
4.15% Senior Notes, due January 23, 2030
Debt Instrument [Line Items]
Long-term debt	$ 987,576		$ 987,576			0
Interest rate	4.15%		4.15%
Principal	$ 1,000,000		$ 1,000,000
6.25% Senior Debentures, due January 15, 2036
Debt Instrument [Line Items]
Long-term debt	$ 511,758		$ 511,758			$ 512,040
Interest rate	6.25%		6.25%			6.25%
Principal	$ 500,000		$ 500,000			$ 500,000
6.50% Senior Notes, due January 20, 2043
Debt Instrument [Line Items]
Long-term debt	$ 420,718		$ 420,718			$ 420,990
Interest rate	6.50%		6.50%			6.50%
Principal	$ 400,000		$ 400,000			$ 400,000
Structured Notes
Debt Instrument [Line Items]
Long-term debt	709,557		709,557			614,091
Long-term debt, fair value	709,600		709,600			607,000
Foursight Capital Credit Facilities
Debt Instrument [Line Items]
Long-term debt	138,033		138,033			170,455
Other
Debt Instrument [Line Items]
Long-term debt	74,613		74,613			112,654
Parent Company
Debt Instrument [Line Items]
Long-term debt	989,913		989,913			989,021
Parent Company | 5.50% Senior Notes due October 18, 2023
Debt Instrument [Line Items]
Long-term debt	743,203		743,203			742,348
Parent Company | 6.625% Senior Notes due October 23, 2043
Debt Instrument [Line Items]
Long-term debt	246,710		246,710			246,673
Subsidiaries
Debt Instrument [Line Items]
Long-term debt	6,787,512		6,787,512			6,896,762
Jefferies Group | 5.125% Senior Notes, due April 13, 2018
Debt Instrument [Line Items]
Interest rate					5.125%
Jefferies Group | 3.875% Convertible Senior Debentures, due November 1, 2029
Debt Instrument [Line Items]
Interest rate							3.875%
Jefferies Group | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	158,478		158,478			0
National Beef | Reducing Revolver Loan
Debt Instrument [Line Items]
Long-term debt	0		0			120,000
National Beef | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 0		0			$ 76,809
Interest rate swaps | Subsidiaries | 4.85% Senior Notes, due January 15, 2027
Debt Instrument [Line Items]
Gains (losses) recognized in Interest expense on fair value hedge			$ 24,100	$ (9,600)

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details)	1 Months Ended
	Jan. 31, 2018USD ($)	Sep. 30, 2018USD ($)Contract	Jun. 05, 2018	May 16, 2018USD ($)	Apr. 13, 2018	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt		$ 7,777,425,000					$ 7,885,783,000
National Beef
Debt Instrument [Line Items]
Percentage of ownership owned		100.00%
3.875% Convertible Senior Debentures, due November 1, 2029
Debt Instrument [Line Items]
Interest rate							3.875%
Long-term debt		$ 0					$ 324,779,000
3.875% Convertible Senior Debentures, due November 1, 2029 | Jefferies Group
Debt Instrument [Line Items]
Interest rate								3.875%
Redemption price as percentage of principal amount redeemed	100.00%
5.125% Senior Notes, due April 13, 2018
Debt Instrument [Line Items]
Interest rate					5.125%		5.125%
Long-term debt		$ 0					$ 682,338,000
5.125% Senior Notes, due April 13, 2018 | Jefferies Group
Debt Instrument [Line Items]
Interest rate					5.125%
Debt face amount						$ 668,300,000
4.15% Senior Notes, due January 23, 2030
Debt Instrument [Line Items]
Interest rate		4.15%
Long-term debt		$ 987,576,000					0
Structured Notes
Debt Instrument [Line Items]
Long-term debt		709,557,000					614,091,000
Structured Notes | Jefferies Group
Debt Instrument [Line Items]
Debt face amount		162,600,000
Revolving Credit Facility | Jefferies Group
Debt Instrument [Line Items]
Debt face amount				$ 160,000,000
Long-term debt		158,478,000					0
Revolving Credit Facility | National Beef
Debt Instrument [Line Items]
Long-term debt		0					76,809,000
Reducing Revolver Loan | National Beef
Debt Instrument [Line Items]
Long-term debt		0					120,000,000
Foursight Capital Credit Facilities
Debt Instrument [Line Items]
Long-term debt		138,033,000					170,455,000
Secured Debt | Foursight Capital Credit Facilities
Debt Instrument [Line Items]
Credit facility maximum amount		$ 225,000,000
Number of warehouse credit commitment | Contract		2
Senior Notes | 4.15% Senior Notes, due January 23, 2030 | Jefferies Group
Debt Instrument [Line Items]
Interest rate	4.15%
Debt face amount	$ 1,000,000,000
Line of Credit | Foursight Capital Credit Facilities | Foursight Capital
Debt Instrument [Line Items]
Assets pledged for indebtedness		$ 167,900,000
Discontinued operations, disposed of by sale | National Beef
Debt Instrument [Line Items]
Percentage of ownership owned			48.00%
Long-term debt							$ 199,200,000

Mezzanine Equity (Narrative) (D

Mezzanine Equity (Narrative) (Details) - USD ($)	Jun. 05, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Purchase Requirement [Line Items]
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustments prior to deconsolidation						$ 237,669,000
Redeemable noncontrolling interests		$ 21,400,000				21,400,000		$ 14,500,000
Mandatorily redeemable convertible preferred shares redemption value		$ 125,000,000				$ 125,000,000		$ 125,000,000
Dividends per common share (in dollars per share)		$ 0.125	$ 0.10	$ 0.10	$ 0.0625	$ 0.325	$ 0.225
Preferred stock dividend		$ 1,276,000		$ 1,172,000		$ 3,619,000	$ 3,203,000
3.25% Cumulative Convertible Preferred Shares
Purchase Requirement [Line Items]
Dividend rate on preferred stock						3.25%
Mandatorily redeemable convertible preferred shares redemption value		$ 125,000,000				$ 125,000,000
Mandatorily redeemable preferred stock, number of shares in conversion		4,162,200				4,162,200
Mandatorily redeemable preferred stock, effective conversion price per share		$ 30.03				$ 30.03
Minimum dividend considered for additional quarterly payments		0.0625				$ 0.0625
Preferred stock dividend						$ 3,600,000	$ 3,200,000
Mandatorily redeemable preferred shares callable price per share		$ 1,000				$ 1,000
Discontinued operations, disposed of by sale | National Beef
Purchase Requirement [Line Items]
Percentage of ownership owned	48.00%
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustments prior to deconsolidation	$ 237,700,000

Mezzanine Equity (Schedule Of R

Mezzanine Equity (Schedule Of Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance			$ 426,593
Income allocated to redeemable noncontrolling interests	$ 390	$ 36,216	37,294	$ 64,538
Increase in fair value of redeemable noncontrolling interests			(28,136)	(24,404)
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation			(237,669)
Ending balance	21,385		21,385
National Beef
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance			412,128	321,962
Income allocated to redeemable noncontrolling interests		36,600	37,141	65,088
Distributions to redeemable noncontrolling interests			(70,681)	(37,029)
Increase in fair value of redeemable noncontrolling interests			21,404	24,404
Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustment prior to deconsolidation			(237,669)	0
Deconsolidation of National Beef			(162,323)	0
Ending balance	$ 0	$ 374,425	$ 0	$ 374,425

Compensation Plans (Details)

Compensation Plans (Details) - USD ($) shares in Thousands	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation		$ 12,800,000	$ 11,100,000	$ 37,975,000	$ 31,494,000
Tax benefit for issuance of share-based awards		4,000,000	$ 4,000,000	10,000,000	$ 11,200,000
Total unrecognized compensation cost related to nonvested share-based awards	$ 131,500,000	$ 131,500,000		$ 131,500,000
Employee service share-based compensation, unrecognized compensation costs on nonvested awards, weighted average period of recognition	2 years 4 months 24 days
Potential maximum increase to common shares outstanding from restricted stock and other shares (in shares)	20,557	20,557		20,557
Restricted cash awards, cost expected to be recognized	$ 446,900,000	$ 446,900,000		$ 446,900,000
Restricted cash awards, cost expected to be recognized, period	2 years
Sign-on and Retention Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				4 years
Amortization period				4 years
Other Shares Issuable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other shares issuable (in shares)	871	871		871
Future Service Required | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, nonvested (in shares)	9,424	9,424		9,424
Future Service Required | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, nonvested (in shares)	1,862	1,862		1,862
No Future Service Required | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, vested (in shares)	10,262	10,262		10,262
Senior Executives Compensation Plan 2018 | Senior Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement, targeted long-term compensation				$ 25,000,000
Performance measurement period				3 years
Performance measurement benchmark, growth date in TSR and ROTDE				8.00%
Performance measurement benchmark, growth date in TSR (less than)				5.00%
Additional incentive compensation				50.00%
Performance measurement benchmark, growth date in TSR (up to)				12.00%
Senior Executives Compensation Plan 2018 | Senior Executives | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement, targeted long-term compensation				$ 16,000,000
Performance measurement benchmark, growth date in TSR				8.00%
Senior Executives Compensation Plan 2018 | Senior Executives | Long-term Cash
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement, targeted long-term compensation				$ 9,000,000
Performance measurement benchmark, growth date in ROTDE				8.00%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Summary Of Accumulated Other Comprehensive Income, Net Of Taxes) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	$ 10,646,751	$ 10,138,979	$ 10,641,577	$ 10,303,649
Net unrealized gains on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	542,790	572,085
Net unrealized foreign exchange losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	(180,926)	(101,400)
Net unrealized losses on instrument specific credit risk
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	(18,916)	(34,432)
Net unrealized gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	446	(1,138)
Net minimum pension liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	(55,649)	(62,391)
AOCI Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Equity	$ 287,745	$ 372,724

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income Reclassifications) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues	$ 1,458,977	$ 1,102,593	$ 3,863,914	$ 3,735,702
Reclassification for the period, net of tax			14,193	(5,352)
Net unrealized losses on available for sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for the period, tax			37	14
Net unrealized foreign exchange losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for the period, tax			(16)	1,086
Net unrealized losses on instrument specific credit risk
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for the period, tax			126	0
Amortization of defined benefit pension plan actuarial gains (losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for the period, net of tax			(1,398)	(1,297)
Reclassification for the period, tax			(508)	(604)
Other pension
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for the period, net of tax			(5,344)	1,231
Reclassification for the period, tax			0	(1,231)
Reclassification out of Accumulated Other Comprehensive Income | Net unrealized foreign exchange losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income and other expenses			20,459	(5,310)
Other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues	296,548	67,811	440,537	366,335
Other | Reclassification out of Accumulated Other Comprehensive Income | Net unrealized losses on available for sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues			105	24
Principal transactions
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues	$ 116,204	$ 84,143	315,622	725,780
Principal transactions | Reclassification out of Accumulated Other Comprehensive Income | Net unrealized losses on instrument specific credit risk
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues			$ 371	$ 0

Accumulated Other Comprehensi_5

Accumulated Other Comprehensive Income (Narrative) (Details) $ in Thousands, € in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2018EUR (€)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Reclassification adjustment from AOCI related to pension plan		$ 479	$ 438	$ 6,742	$ 66
German Plan | Pension Plan | Jefferies Bache Limited
Defined Benefit Plan Disclosure [Line Items]
Payment to transfer defined benefit obligation and insurance contracts | €	€ 6.5
Reclassification adjustment from AOCI related to pension plan				$ 5,300

Revenues from Contracts with _3

Revenues from Contracts with Customers (Schedule of Components of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 780,079		$ 2,343,048
Revenue from other sources	678,898		1,520,866
Total revenues	1,458,977	$ 1,102,593	3,863,914	$ 3,735,702
Commissions and other fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	155,417		461,023
Total revenues	155,417	139,082	461,023	437,547
Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	460,043		1,400,331
Total revenues	460,043	475,702	1,400,331	1,235,586
Manufacturing revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	94,029		307,129
Total revenues	94,029	81,939	307,129	243,482
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	70,590		174,565
Principal transactions
Disaggregation of Revenue [Line Items]
Revenue from other sources	116,204		315,622
Total revenues	116,204	84,143	315,622	725,780
Interest income
Disaggregation of Revenue [Line Items]
Revenue from other sources	336,736		939,272
Total revenues	336,736	$ 253,916	939,272	$ 726,972
Other
Disaggregation of Revenue [Line Items]
Revenue from other sources	$ 225,958		$ 265,972

Revenues from Contracts with _4

Revenues from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 780,079	$ 2,343,048
Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	697,685	2,082,546
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63,428	204,079
Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18,966	56,423
Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	627,805	1,898,133
Reportable Segments | Jefferies Group | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	545,998	1,638,828
Reportable Segments | Jefferies Group | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	62,914	203,103
Reportable Segments | Jefferies Group | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18,893	56,202
Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
All other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	152,274	444,915
All other | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	151,687	443,718
All other | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	514	976
All other | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	73	221
Equities
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	159,571	471,161
Equities | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	159,571	471,161
Fixed Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,007	10,511
Fixed Income | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,007	10,511
Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	460,043	1,400,331
Investment banking | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	460,043	1,400,331
Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,184	16,130
Asset Management | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,184	16,130
Manufacturing revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	94,029	307,129
Manufacturing revenues | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues | All other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	94,029	307,129
Oil and gas revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	46,506	106,741
Oil and gas revenues | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues | All other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	46,506	106,741
Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,739	31,045
Other revenues | Reportable Segments | Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues | All other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 11,739	$ 31,045

Revenues from Contracts with _5

Revenues from Contracts with Customers (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Jun. 05, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Receivables related to revenue from contracts with customers	$ 259.1	$ 259.1		$ 469.3
Deferred revenue	16.3	16.3		15.5
Deferred revenue, revenue recognized	6.3	20.8
Capitalized contract cost	4.8	4.8
Expenses related to capitalized costs to fulfill a contract	$ 1.5	$ 1.5
National Beef
Disaggregation of Revenue [Line Items]
Percentage of ownership owned	100.00%	100.00%
Jefferies Group
Disaggregation of Revenue [Line Items]
Revenue related to performance obligation satisfied	$ 4.4	$ 18.3
Revenue associated with distribution services, a portion of which related to prior period	$ 4.6	$ 13.5
National Beef | Discontinued operations, disposed of by sale
Disaggregation of Revenue [Line Items]
Receivables related to revenue from contracts with customers				$ 183.4
Percentage of ownership owned			48.00%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Taxes [Line Items]
Unrecognized tax benefits	$ 237.8		$ 226.4
Decrease of income tax provision	43.9
Interest included in unrecognized tax benefits	63		57.4
Tax benefit from repatriation of foreign earnings		$ 31.9
Increase of income tax expense related to Tax Cuts and Jobs Act Of 2017	3.8
Jefferies Group
Income Taxes [Line Items]
Unrecognized tax benefits	$ 184		$ 177.8

Common Share and Earnings (Lo_3

Common Share and Earnings (Loss) Per Common Share (Earnings Per Share Computation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator for earnings per share:
Net income attributable to Jefferies Financial Group Inc. common shareholders	$ 192,635	$ 99,351	$ 1,042,689	$ 438,952
Allocation of earnings to participating securities	(1,054)	(368)	(5,049)	(1,692)
Net income attributable to Jefferies Financial Group Inc. common shareholders for basic earnings per share	191,581	98,983	1,037,640	437,260
Adjustment to allocation of earnings to participating securities related to diluted shares	3	(2)	34	3
Mandatorily redeemable convertible preferred share dividends	1,276	0	0	3,203
Net income attributable to Jefferies Financial Group Inc. common shareholders for diluted earnings per share	$ 192,860	$ 98,981	$ 1,037,674	$ 440,466
Denominator for earnings per share:
Weighted average common shares outstanding	332,191,000	358,039,000	343,829,000	359,031,000
Denominator for basic earnings per share – weighted average shares	341,434,000	367,828,000	353,300,000	368,736,000
Mandatorily redeemable convertible preferred shares (in shares)	4,162,000	0	0	4,162,000
Denominator for diluted earnings (loss) per share (in shares)	350,307,000	370,198,000	357,169,000	375,233,000
Weighted average shares of participating securities (in shares)	1,888,700	1,366,700	1,700,700	1,433,500
Restricted Stock with Future Service Required
Denominator for earnings per share:
Weighted average shares of restricted stock outstanding with future service required	(1,879,000)	(1,320,000)	(1,681,000)	(1,377,000)
Restricted Stock Units with No Future Service Required
Denominator for earnings per share:
Weighted average RSUs outstanding with no future service required (in shares)	11,122,000	11,109,000	11,152,000	11,082,000
Stock options
Denominator for earnings per share:
Dilutive effect of share-based payment awards (in shares)	5,000	23,000	13,000	22,000
Restricted Stock Units | Senior Executive Compensation Plan
Denominator for earnings per share:
Dilutive effect of share-based payment awards (in shares)	4,706,000	2,347,000	3,856,000	2,313,000

Common Share and Earnings (Lo_4

Common Share and Earnings (Loss) Per Common Share (Narrative) (Details) - shares	9 Months Ended
	Sep. 30, 2018	Jul. 31, 2018	Apr. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Earnings Per Share [Line Items]
Number of shares authorized to be repurchased		25,000,000	25,000,000
Remaining number of shares authorized to be repurchased	23,880,517			12,500,000
Stock repurchased during period (in shares)	26,119,483
3.875% Convertible Senior Debentures, due November 1, 2029
Earnings Per Share [Line Items]
Convertible notes interest rate					3.875%
3.875% Convertible Senior Debentures, due November 1, 2029 | Convertible Debt Securities
Earnings Per Share [Line Items]
Convertible notes interest rate	3.875%					3.875%

Commitments, Contingencies an_3

Commitments, Contingencies and Guarantees (Commitments and Contingencies) (Details) $ in Millions	Sep. 30, 2018USD ($)
Commitments And Guarantee Obligations [Line Items]
2,018	$ 5,968.2
2,019	455.6
2020 and 2021	128.4
2022 and 2023	32.5
2024 and Later	14.7
Maximum Payout	$ 6,599.4
Guarantor obligation settled period	3 days
Equity commitments
Commitments And Guarantee Obligations [Line Items]
2,018	$ 280
2,019	56.9
2020 and 2021	31.7
2022 and 2023	0
2024 and Later	9.8
Maximum Payout	378.4
Loan commitments
Commitments And Guarantee Obligations [Line Items]
2,018	0
2,019	250
2020 and 2021	54.4
2022 and 2023	32.5
2024 and Later	0
Maximum Payout	336.9
Underwriting commitments
Commitments And Guarantee Obligations [Line Items]
2,018	411
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	411
Forward starting reverse repos
Commitments And Guarantee Obligations [Line Items]
2,018	3,159.4
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	3,159.4
Forward starting repos
Commitments And Guarantee Obligations [Line Items]
2,018	2,057.8
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	2,057.8
Other unfunded commitments
Commitments And Guarantee Obligations [Line Items]
2,018	60
2,019	148.7
2020 and 2021	42.3
2022 and 2023	0
2024 and Later	4.9
Maximum Payout	255.9
Forward starting securities purchased under agreements to resell settled
Commitments And Guarantee Obligations [Line Items]
Maximum Payout	$ 3,141.9

Commitments, Contingencies an_4

Commitments, Contingencies and Guarantees (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Commitments Contingencies And Guarantees [Line Items]
Loan commitments outstanding to clients	$ 86,300,000
Fair value of derivative contracts meeting the definition of a guarantee	216,900,000
Contractual obligations	$ 6,599,400,000
Standby Letters of Credit
Commitments Contingencies And Guarantees [Line Items]
Expiration period maximum	1 year
Berkadia
Commitments Contingencies And Guarantees [Line Items]
Surety policy issued	$ 1,500,000,000
Reimbursement of losses incurred, maximum percentage	50.00%
Aggregate amount of commercial paper outstanding	$ 1,470,000,000
Jefferies Finance
Commitments Contingencies And Guarantees [Line Items]
Line of credit facility, commitment of Jefferies, funded	0	$ 0
Line of credit facility commitment of Jefferies	250,000,000	$ 250,000,000
Jefferies Group | Standby Letters of Credit
Commitments Contingencies And Guarantees [Line Items]
Letters of credit	51,800,000
Other subsidiaries
Commitments Contingencies And Guarantees [Line Items]
Letters of credit	1,100,000
Jefferies Capital Partners LLC and Its Private Equity Funds
Commitments Contingencies And Guarantees [Line Items]
Equity commitments	18,100,000
Other Investments
Commitments Contingencies And Guarantees [Line Items]
Equity commitments	316,700,000
Alternative Asset Management Platforms
Commitments Contingencies And Guarantees [Line Items]
Equity commitments	$ 280,000,000

Commitments, Contingencies an_5

Commitments, Contingencies and Guarantees (Guarantees) (Details) - Derivative Notional Amount $ in Millions	Sep. 30, 2018USD ($)
Derivative contracts – non-credit related
Guarantee Obligations [Line Items]
2,018	$ 10,898.5
2,019	5,978.6
2020 and 2021	2,948.5
2022 and 2023	1,015
2024 and Later	454.6
Notional/ Maximum Payout	21,295.2
Written derivative contracts – credit related
Guarantee Obligations [Line Items]
2,018	0
2,019	0
2020 and 2021	36.4
2022 and 2023	33.8
2024 and Later	0
Notional/ Maximum Payout	70.2
Derivatives
Guarantee Obligations [Line Items]
2,018	10,898.5
2,019	5,978.6
2020 and 2021	2,984.9
2022 and 2023	1,048.8
2024 and Later	454.6
Notional/ Maximum Payout	$ 21,365.4

Net Capital Requirements (Detai

Net Capital Requirements (Details) - Jefferies LLC $ in Millions	Sep. 30, 2018USD ($)
Net Capital Requirements [Line Items]
Net Capital	$ 1,917.6
Excess Net Capital	$ 1,806.2

Other Fair Value Information (D

Other Fair Value Information (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term borrowings	$ 382,006	$ 436,215
Long-term debt	7,777,425	7,885,783
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	663,508	579,071
Short-term borrowings	382,006	412,891
Long-term debt	7,067,868	7,278,827
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	644,184	565,285
Short-term borrowings	382,006	412,891
Long-term debt	$ 7,113,515	$ 7,678,210

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Private Equity Related Funds
Related Party Transaction [Line Items]
Loans to and/or equity investments in related funds	$ 34.1		$ 34.1		$ 23.7
Net gains (losses) from private equity related funds	0.2	$ (0.4)	10.2	$ (9.8)
Officers and Employees
Related Party Transaction [Line Items]
Loans outstanding to related party	51.2		51.2		45.6
Berkadia | Affiliated Entity | Jefferies Group
Related Party Transaction [Line Items]
Purchase commitment	748.8		748.8		864.1
HRG | Affiliated Entity | Jefferies Group
Related Party Transaction [Line Items]
Revenue from related parties	3		3
FXCM | Payables, expense accruals and other liabilities | Affiliated Entity | Jefferies Group
Related Party Transaction [Line Items]
OTC foreign exchange contracts	$ 12.3		$ 12.3		$ 17

Discontinued Operations (Narrat

Discontinued Operations (Narrative) (Details) $ in Thousands	Jun. 05, 2018USD ($)	Sep. 30, 2018USD ($)director	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)director	Sep. 30, 2018USD ($)director	Sep. 30, 2017USD ($)	Jun. 04, 2018	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income allocated to redeemable noncontrolling interests		$ 390	$ 36,216		$ 37,294	$ 64,538
Income from discontinued operations before income taxes			137,800		140,000	244,900
Income (loss) related to associated companies		18,867	30,057		84,320	(84,413)
Consolidated income before income taxes		272,692	25,548		347,970	412,799
Gain on disposal of discontinued operations, net of taxes		0	0		643,921	0
Investment in associated company		$ 2,450,901	2,350,980	$ 2,450,901	$ 2,450,901	2,350,980		$ 2,066,829	$ 2,125,098
National Beef
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership owned							79.00%
Equity method investment, ownership percentage	31.00%	31.00%		31.00%	31.00%
Income (loss) related to associated companies		$ 58,886	0	$ 83,300	$ 83,287	0
Distributions received				48,700
Investment in associated company	$ 592,300	$ 626,870		$ 626,870	$ 626,870			$ 0
Marfrig Global Foods S.A.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership owned		51.00%		51.00%	51.00%
Ownership percentage to be acquired further from other equity owners	3.00%
National Beef
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership owned		100.00%		100.00%	100.00%
Number of directors appointed by Company | director		2		2	2
Lockup period related to divestiture of businesses					5 years
Income allocated to redeemable noncontrolling interests			$ 36,600		$ 37,141	$ 65,088
Consolidated income before income taxes				$ 276,500
Equity valuation	$ 1,900,000
Enterprise value	$ 2,300,000
Discontinued operations, disposed of by sale | National Beef
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership owned	48.00%
Cash from sale of subsidiary	$ 907,700
Pre-tax gain on disposal of discontinued operations					873,500
Pre-tax gain on disposal of discontinued operation, portion related to remeasurement to fair value					352,400
Gain on disposal of discontinued operations, net of taxes					$ 643,900

Discontinued Operations (Summar

Discontinued Operations (Summary of discontinued operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Expenses:
Income tax provision	$ 0	$ 53,490	$ 47,045	$ 90,856
Income from discontinued operations, net of income tax provision	$ 0	120,989	130,063	219,151
National Beef | Discontinued operations, disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		2,039,299	3,142,071	5,476,274
Expenses:
Compensation and benefits		10,505	17,414	29,649
Cost of sales		1,816,480	2,884,983	5,030,887
Interest expense		1,713	4,316	5,781
Depreciation and amortization		26,664	43,959	73,522
Selling, general and other expenses		9,458	14,291	26,428
Total expenses		1,864,820	2,964,963	5,166,267
Income from discontinued operations before income taxes		174,479	177,108	310,007
Income tax provision		53,490	47,045	90,856
Income from discontinued operations, net of income tax provision		120,989	130,063	219,151
National Beef | Discontinued operations, disposed of by sale | Beef processing services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		2,038,821	3,137,611	5,472,339
National Beef | Discontinued operations, disposed of by sale | Interest income
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		58	131	230
National Beef | Discontinued operations, disposed of by sale | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		$ 420	$ 4,329	$ 3,705

Segment Information (Schedule O

Segment Information (Schedule Of Segment Reporting Information, By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Net Revenues	$ 1,150,846	$ 857,223	$ 2,957,440	$ 3,020,610
Consolidated income before income taxes	272,692	25,548	347,970	412,799
Depreciation and amortization expenses	32,295	28,760	92,360	82,129
Parent Company interest
Segment Reporting Information [Line Items]
Consolidated income before income taxes	(14,755)	(14,737)	(44,251)	(44,201)
FXCM
Segment Reporting Information [Line Items]
Consolidated income before income taxes	(2,900)	(2,000)	(2,900)	(148,700)
Principal transactions	1,300	2,300	16,400	17,600
Reportable Segments
Segment Reporting Information [Line Items]
Net Revenues	783,441	804,824	2,434,163	2,386,224
Consolidated income before income taxes	71,591	111,801	281,214	326,278
Depreciation and amortization expenses	18,027	16,793	53,428	49,476
Reportable Segments | Jefferies Group
Segment Reporting Information [Line Items]
Net Revenues	774,749	802,909	2,419,410	2,381,967
Consolidated income before income taxes	86,154	128,112	336,922	383,094
Depreciation and amortization expenses	17,175	15,928	50,829	46,877
Reportable Segments | Corporate
Segment Reporting Information [Line Items]
Net Revenues	8,692	1,915	14,753	4,257
Consolidated income before income taxes	(14,563)	(16,311)	(55,708)	(56,816)
Depreciation and amortization expenses	852	865	2,599	2,599
All other
Segment Reporting Information [Line Items]
Net Revenues	367,405	52,399	523,277	634,386
Consolidated income before income taxes	215,856	(71,516)	111,007	130,722
Depreciation and amortization expenses	$ 14,268	$ 11,967	$ 38,932	$ 32,653

Segment Information (Narrative)

Segment Information (Narrative) (Details) - USD ($) $ in Thousands	Jun. 05, 2018	Jan. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 04, 2018
Segment Reporting Information [Line Items]
Interest expense			$ 28,837	$ 25,612	$ 74,614	$ 76,762
Pre-tax gain from sale of subsidiary					221,712	178,236
Parent Company interest
Segment Reporting Information [Line Items]
Interest expense			14,800	14,700	44,300	44,200
All other
Segment Reporting Information [Line Items]
Interest expense			$ 14,000	$ 10,900	30,300	32,600
Discontinued operations, disposed of by sale | National Beef
Segment Reporting Information [Line Items]
Percentage of ownership owned	48.00%
Cash from sale of subsidiary	$ 907,700
Held-for-sale, not discontinued operations | Garcadia
Segment Reporting Information [Line Items]
Percentage of equity method investment for sale			100.00%
Pre-tax gain on sale of equity method investments and associated real estate			$ 221,700		$ 221,700
Disposed of by sale, not discontinued operations | Conwed
Segment Reporting Information [Line Items]
Percentage of ownership owned		100.00%
Cash from sale of subsidiary		$ 295,000
Pre-tax gain from sale of subsidiary						$ 178,200
Maximum | Disposed of by sale, not discontinued operations | Conwed
Segment Reporting Information [Line Items]
Potential earn-out payment to be received from sale of subsidiary		$ 40,000
National Beef
Segment Reporting Information [Line Items]
Percentage of ownership owned							79.00%
Equity method investment, ownership percentage	31.00%		31.00%		31.00%