Jefferies Financial (JEF) 10-K 27 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 15, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Central Index Key	96,223
Entity Registrant Name	LEUCADIA NATIONAL CORP
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		356,252,768
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 8,673,116,957

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents		$ 5,275,480	$ 3,807,558
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations		578,014	857,337
Financial instruments owned, including securities pledged of $10,842,051 and $9,706,881:
Trading assets, at fair value		15,512,730	14,985,237
Available for sale securities		716,561	301,049
Total financial instruments owned		16,229,291	15,286,286
Investments in managed funds		569,946	515,318
Loans to and investments in associated companies		2,066,829	2,125,098
Securities borrowed		7,721,803	7,743,562
Securities purchased under agreements to resell		3,689,559	3,862,488
Receivables		5,419,015	4,425,178
Property, equipment and leasehold improvements, net		750,403	709,242
Intangible assets, net and goodwill		2,463,180	2,513,678
Deferred tax asset, net		743,811	1,461,815
Assets held for sale		0	128,083
Other assets		1,661,777	1,635,664
Total assets	[1]	47,169,108	45,071,307
LIABILITIES
Short-term borrowings		436,215	525,842
Trading liabilities, at fair value		8,454,965	8,388,619
Securities loaned		2,843,911	2,819,132
Securities sold under agreements to repurchase		8,660,511	6,791,676
Other secured financings		1,029,485	1,026,429
Payables, expense accruals and other liabilities		7,167,666	7,373,708
Long-term debt		7,885,783	7,380,443
Total liabilities	[1]	36,478,536	34,305,849
Commitments and contingencies
MEZZANINE EQUITY
Redeemable noncontrolling interests		426,593	336,809
Mandatorily redeemable convertible preferred shares		125,000	125,000
EQUITY
Common shares, par value $1 per share, authorized 600,000,000 shares; 356,227,038 and 359,425,061 shares issued and outstanding, after deducting 60,165,980 and 56,947,654 shares held in treasury		356,227	359,425
Additional paid-in capital		4,676,038	4,812,587
Accumulated other comprehensive income		372,724	310,697
Retained earnings		4,700,968	4,645,391
Total Leucadia National Corporation shareholders’ equity		10,105,957	10,128,100
Noncontrolling interests		33,022	175,549
Total equity		10,138,979	10,303,649
Total		$ 47,169,108	$ 45,071,307
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Consolidated Statements of Fin3

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Assets	[1]	$ 47,169,108	$ 45,071,307
Liabilities	[1]	36,478,536	34,305,849
ASSETS
Securities pledged		$ 10,842,051	$ 9,706,881
EQUITY
Common shares, par value (USD per share)		$ 1	$ 1
Common shares, authorized		600,000,000	600,000,000
Common shares, issued and outstanding after deducting shares held in treasury		356,227,038	359,425,061
Treasury stock, shares		60,165,980	56,947,654
Variable Interest Entities
Assets	[1]	$ 382,900	$ 815,800
Liabilities	[1]	$ 1,031,000	$ 1,284,700
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Beef processing services	$ 7,353,663	$ 7,021,902	$ 7,396,869
Commissions	593,257	611,574	659,002
Principal transactions	931,576	603,822	642,824
Investment banking	1,764,285	1,193,973	1,417,807
Interest income	993,537	926,255	955,240
Net realized securities gains	23,028	29,542	62,957
Other	748,508	488,186	549,228
Total revenues	12,407,854	10,875,254	11,683,927
Interest	107,859	108,703	115,804
Net revenues	11,436,393	10,062,617	10,886,458
Expenses:
Cost of sales	7,045,007	6,850,807	7,677,233
Compensation and benefits	1,993,776	1,730,585	1,665,465
Floor brokerage and clearing fees	174,506	167,205	199,780
Interest	107,859	108,703	115,804
Depreciation and amortization	208,910	211,593	224,133
Selling, general and other expenses	817,620	831,892	757,788
Total expenses	10,347,678	9,900,785	10,640,203
Income from continuing operations before income taxes and income (loss) related to associated companies	1,088,715	161,832	246,255
Income (loss) related to associated companies	(74,901)	154,598	110,281
Income from continuing operations before income taxes	1,013,814	316,430	356,536
Income tax provision	760,967	122,109	109,947
Income from continuing operations	252,847	194,321	246,589
Income from discontinued operations, net of income tax provision of $0, $0 and $231	0	0	429
Gain on disposal of discontinued operations, net of income tax provision of $0, $0 and $2,743	0	0	5,093
Net income	252,847	194,321	252,111
Net loss attributable to the noncontrolling interests	3,455	1,426	4,996
Net (income) loss attributable to the redeemable noncontrolling interests	(84,576)	(65,746)	26,543
Preferred stock dividends	(4,375)	(4,063)	(4,063)
Net income attributable to Leucadia National Corporation common shareholders	$ 167,351	$ 125,938	$ 279,587
Basic earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)	$ 0.45	$ 0.34	$ 0.73
Income (loss) from discontinued operations (USD per share)	0	0	0
Gain on disposal of discontinued operations (USD per share)	0	0	0.01
Net income (USD per share)	0.45	0.34	0.74
Diluted earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)	0.45	0.34	0.73
Income (loss) from discontinued operations (USD per share)	0	0	0
Gain on disposal of discontinued operations (USD per share)	0	0	0.01
Net income (USD per share)	$ 0.45	$ 0.34	$ 0.74
Amounts attributable to Leucadia National Corporation common shareholders:
Income from continuing operations, net of taxes	$ 167,351	$ 125,938	$ 274,065
Income from discontinued operations, net of taxes	0	0	429
Gain on disposal of discontinued operations, net of taxes	0	0	5,093
Net income attributable to Leucadia National Corporation common shareholders	$ 167,351	$ 125,938	$ 279,587
Dividends per common share (USD per share)	$ 0.3250	$ 0.25	$ 0.25
Investment Banking and Capital Markets Segment
Revenues:
Interest	$ 971,461	$ 812,637	$ 797,469
Expenses:
Interest	$ 971,461	$ 812,637	$ 797,469

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Income tax provision (benefit) from discontinued operations	$ 0	$ 0	$ 231
Income tax provision (benefit) related to gain on disposal of discontinued operations	$ 0	$ 0	$ 2,743

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 252,847	$ 194,321	$ 252,111
Other comprehensive income (loss):
Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $3,450, $2,262 and $(5,029)	5,923	3,900	(9,057)
Less: reclassification adjustment for net (gains) losses included in net income, net of income tax provision (benefit) of $124, $2 and $6,068	(212)	(4)	(10,930)
Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $3,326, $2,260 and $(11,097)	5,711	3,896	(19,987)
Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $14,616, $(3,530) and $(5,174)	78,493	(121,581)	(36,477)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income, net of income tax provision (benefit) of $1,086, $0 and $0	5,310	0	0
Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $13,530, $(3,530) and $(5,174)	83,803	(121,581)	(36,477)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, net of income tax provision (benefit) of $(13,215), $(4,251) and $0	(21,394)	(6,494)	0
Net change in unrealized instrument specific credit risk gains (losses), net of income tax provision (benefit) of $(13,215), $(4,251) and $0	(21,394)	(6,494)	0
Net unrealized gains (losses) on cash flow hedges arising during the period, net of income tax provision (benefit) of $(593), $0 and $0	(936)	0	0
Net change in unrealized cash flow hedges gains (losses), net of income tax provision (benefit) of $(593), $0 and $0	(936)	0	0
Net pension gains (losses) arising during the period, net of income tax provision (benefit) of $2,018, $(2,516) and $7,152	3,526	(5,451)	17,073
Less: reclassification adjustment for pension (gains) losses included in net income, net of income tax provision (benefit) of $(2,042), $(700) and $(17,159)	(517)	(1,534)	(31,102)
Net change in pension liability benefits, net of income tax provision (benefit) of $4,060, $(1,816) and $24,311	4,043	(3,917)	48,175
Other comprehensive income (loss), net of income taxes	71,227	(128,096)	(8,289)
Comprehensive income	324,074	66,225	243,822
Comprehensive loss attributable to the noncontrolling interests	3,455	1,426	4,996
Comprehensive (income) loss attributable to the redeemable noncontrolling interests	(84,576)	(65,746)	26,543
Preferred stock dividends	(4,375)	(4,063)	(4,063)
Comprehensive income (loss) attributable to Leucadia National Corporation common shareholders	$ 238,578	$ (2,158)	$ 271,298

Consolidated Statements of Com7

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit)	$ 3,450	$ 2,262	$ (5,029)
Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit)	124	2	6,068
Net change in unrealized holding gains (losses) on investments, tax provision (benefit)	3,326	2,260	(11,097)
Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit)	14,616	(3,530)	(5,174)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit)	1,086	0	0
Net change in unrealized foreign exchange gains (losses), tax provision (benefit)	13,530	(3,530)	(5,174)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, income tax provision (benefit)	(13,215)	(4,251)	0
Net change in unrealized instrument specific credit risk gains (losses), income tax provision (benefit)	(13,215)	(4,251)	0
Net unrealized gains (losses) on derivatives arising during the period, tax provision (benefit)	(593)	0	0
Net change in unrealized derivative gains (losses), tax provision (benefit)	(593)	0	0
Net pension and postretirement gains (losses) arising during the period, tax provision (benefit)	2,018	(2,516)	7,152
Less: reclassification adjustment for pension and postretirement (gains) losses included in net income (loss), tax provision (benefit)	(2,042)	(700)	(17,159)
Net change in pension liability and postretirement benefits, tax provision (benefit)	$ 4,060	$ (1,816)	$ 24,311

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net cash flows from operating activities:
Net income	$ 252,847	$ 194,321	$ 252,111
Adjustments to reconcile net income to net cash provided by (used for) operations:
Deferred income tax provision	712,055	118,631	134,016
Depreciation and amortization of property, equipment and leasehold improvements	146,179	144,116	164,067
Other amortization	17,860	22,673	8,006
Share-based compensation	48,384	33,597	74,087
Provision for doubtful accounts	45,868	34,252	20,168
Net securities gains	(23,028)	(29,542)	(62,957)
Income related to associated companies	(34,494)	(171,782)	(185,998)
Distributions from associated companies	143,286	191,455	223,658
Net losses related to property and equipment, and other assets	31,670	83,053	29,776
Gain on sale of subsidiaries	(179,605)	0	0
Gain on disposal of discontinued operations	0	0	(7,836)
Change in estimated litigation reserve	0	0	(96,500)
Net change in:
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	280,703	(107,771)	2,691,028
Trading assets	(596,780)	2,687,399	1,380,230
Investments in managed funds	(52,897)	75,144	(295,342)
Securities borrowed	50,660	(805,779)	(127,060)
Securities purchased under agreements to resell	234,740	(112,777)	56,377
Receivables from brokers, dealers and clearing organizations	(555,109)	(488,623)	551,021
Receivables from customers of securities operations	(732,344)	340,690	58,233
Other receivables	(248,217)	(162,748)	(145,634)
Other assets	2,987	(283,234)	83,414
Trading liabilities	(25,663)	1,727,698	(2,011,277)
Securities loaned	381	(122,946)	420,929
Securities sold under agreements to repurchase	1,838,793	(3,144,433)	(688,355)
Payables to brokers, dealers and clearing organizations	(1,079,516)	569,246	486,841
Payables to customers of securities operations	366,721	(483,188)	(3,455,080)
Trade payables, expense accruals and other liabilities	427,115	361,295	(225,711)
Other	236	(61,900)	(93,967)
Net cash provided by (used for) operating activities	1,072,832	608,847	(761,755)
Net cash flows from investing activities:
Acquisitions of property, equipment and leasehold improvements, and other assets	(193,473)	(318,678)	(295,894)
Proceeds from disposals of property and equipment, and other assets	30,833	62,463	22,820
Proceeds from sale of subsidiary, net of expenses and cash of operations sold	289,767	0	0
Proceeds from disposal of discontinued operations, net of expenses and cash of operations sold	0	0	5,842
Acquisitions, net of cash acquired	0	(9,673)	0
Advances on notes, loans and other receivables	(39,953)	(342,281)	(420,219)
Collections on notes, loans and other receivables	270,689	121,825	153,004
Loans to and investments in associated companies	(3,305,791)	(763,528)	(1,492,060)
Capital distributions and loan repayment from associated companies	3,106,423	703,108	1,389,262
Proceeds from sale of associated companies	173,105	0	0
Deconsolidation of subsidiary entities	(21,129)	(326)	(16,512)
Purchases of investments (other than short-term)	(1,146,595)	(739,298)	(873,831)
Proceeds from maturities of investments	344,223	162,393	379,629
Proceeds from sales of investments	443,300	483,360	1,931,656
Other	1,339	978	(2,532)
Net cash provided by (used for) investing activities	(47,262)	(639,657)	781,165
Net cash flows from financing activities:
Issuance of debt, net of issuance costs	2,095,559	1,020,050	363,595
Other changes in short-term borrowings, net	23,324	204,882	298,659
Repayment of debt	(1,401,104)	(962,515)	(1,316,494)
Net change in other secured financings	1,248	116,702	205,231
Net change in bank overdrafts	(5,650)	(46,536)	0
Issuance of common shares	1,501	1,062	1,223
Net contributions from (distributions to) redeemable noncontrolling interests	(90,233)	(52,889)	5,165
Distributions to noncontrolling interests	(12,031)	(18,544)	(7,277)
Contributions from noncontrolling interests	40,072	154,522	15,469
Purchase of common shares for treasury	(100,477)	(95,020)	(125,754)
Dividends paid	(117,407)	(91,296)	(92,550)
Other	(1)	488	750
Net cash provided by (used for) financing activities	434,801	230,906	(651,983)
Effect of foreign exchange rate changes on cash	10,687	(25,980)	(5,554)
Change in cash classified as assets held for sale	(3,136)	(5,206)	0
Net increase (decrease) in cash and cash equivalents	1,467,922	168,910	(638,127)
Cash and cash equivalents at January 1,	3,807,558	3,638,648	4,276,775
Cash and cash equivalents at December 31,	$ 5,275,480	$ 3,807,558	$ 3,638,648

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	Non-controlling Interests
Beginning balance at Dec. 31, 2014	$ 10,370,022	$ 367,499	$ 5,059,508	$ 447,082	$ 4,428,069	$ 10,302,158	$ 67,864
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	274,591				279,587	279,587	(4,996)
Other comprehensive income (loss), net of taxes	(8,289)			(8,289)		(8,289)
Contributions from noncontrolling interests	16,189					0	16,189
Distributions to noncontrolling interests	(7,277)					0	(7,277)
Deconsolidation of asset management entities	(8,193)					0	(8,193)
Change in interest in consolidated subsidiary	0		(1,092)			(1,092)	1,092
Share-based compensation expense	74,087		74,087			74,087
Change in fair value of redeemable noncontrolling interests	(26,325)		(26,325)			(26,325)
Purchase of common shares for treasury	(125,754)	(5,953)	(119,801)			(125,754)
Dividends ($.25, $.25 and $.325 per common share for year ended 2015, 2016, 2017)	(94,674)				(94,674)	(94,674)
Other	1,513	1,071	442			1,513
Ending balance at Dec. 31, 2015	10,465,890	362,617	4,986,819	438,793	4,612,982	10,401,211	64,679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	124,512				125,938	125,938	(1,426)
Other comprehensive income (loss), net of taxes	(128,096)			(128,096)		(128,096)
Contributions from noncontrolling interests	154,522					0	154,522
Distributions to noncontrolling interests	(18,544)					0	(18,544)
Deconsolidation of asset management entities	(9,709)					0	(9,709)
Change in interest in consolidated subsidiary	0		(261)			(261)	261
Reclassification to redeemable noncontrolling interest	(14,234)					0	(14,234)
Share-based compensation expense	33,597		33,597			33,597
Change in fair value of redeemable noncontrolling interests	(115,963)		(115,963)			(115,963)
Purchase of common shares for treasury	(95,020)	(5,434)	(89,586)			(95,020)
Dividends ($.25, $.25 and $.325 per common share for year ended 2015, 2016, 2017)	(93,529)				(93,529)	(93,529)
Other	223	2,242	(2,019)			223
Ending balance at Dec. 31, 2016	10,303,649	359,425	4,812,587	310,697	4,645,391	10,128,100	175,549
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	163,896				167,351	167,351	(3,455)
Other comprehensive income (loss), net of taxes	71,227			71,227		71,227
Contributions from noncontrolling interests	40,072					0	40,072
Distributions to noncontrolling interests	(12,031)					0	(12,031)
Deconsolidation of real estate entity	(167,163)					0	(167,163)
Share-based compensation expense	48,384		48,384			48,384
Change in fair value of redeemable noncontrolling interests	(94,937)		(94,937)			(94,937)
Purchase of common shares for treasury	(100,477)	(4,024)	(96,453)			(100,477)
Dividends ($.25, $.25 and $.325 per common share for year ended 2015, 2016, 2017)	(120,974)				(120,974)	(120,974)
Other	7,333	826	6,457			7,283	50
Ending 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]
Reclassification of tax effects from accumulated other comprehensive income	$ 0			$ (9,200)	$ 9,200

Consolidated Statements of Ch10

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Common shares, par value (USD per share)			$ 1	$ 1	$ 1
Dividends per common share (USD per share)	$ 0.10	$ 0.0625	$ 0.325	$ 0.25	$ 0.25

Nature of Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations Leucadia National Corporation (“Leucadia” or the “Company”) is a diversified holding company focused on long-term value creation to maximize shareholder value. We continuously review acquisitions of businesses, securities and assets that have the potential for significant long-term value creation, invest in a broad array of businesses, and evaluate the retention and disposition of our existing operations and holdings. Changes in the mix of our businesses and investments should be expected. Our financial services businesses and investments include Jefferies (investment banking and capital markets), Leucadia Asset Management (asset management), Berkadia (commercial mortgage banking, investment sales and servicing), HomeFed (real estate company), FXCM (provider of online foreign exchange trading services) and Foursight Capital (vehicle finance). We also own and have investments in a diverse array of other businesses, including National Beef (beef processing), HRG Group ("HRG") (consumer products), Garcadia (automobile dealerships), Linkem (fixed wireless broadband services in Italy), Vitesse Energy and JETX Energy (oil and gas production and development), Idaho Timber (manufacturing) and Golden Queen (gold and silver mining). The structure of each of our investments was tailored to the unique opportunity each transaction presented. Our investments may be reflected in our consolidated results as consolidated subsidiaries, equity investments, securities or in other ways, depending on the structure of our specific holdings. Jefferies is the largest independent U.S. headquartered global full-service, integrated securities and investment banking firm. In March 2013, Jefferies became an indirect wholly-owned subsidiary of Leucadia, yet retains a separate credit rating and continues to be a separate SEC reporting company. Through Jefferies, we own 50% of Jefferies Finance LLC ("Jefferies Finance"), our joint venture with Massachusetts Mutual Life Insurance Company. Jefferies Finance is a commercial finance company whose primary focus is the origination and syndication of senior secured debt of middle market and growth companies in the form of term and revolving loans. Through Jefferies, we also owned a 48.5% voting interest in Jefferies LoanCore, LLC ("Jefferies LoanCore"), a joint venture with the Government of Singapore Investment Corporation, the Canadian Pension Plan Investment Board and LoanCore, LLC. Jefferies LoanCore originates, purchases and securitizes commercial real estate loans throughout the U.S. On October 31, 2017, Jefferies sold all of its membership interests in Jefferies LoanCore for approximately $173.1 million , the estimated book value as of October 31, 2017. In addition, Jefferies 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. Jefferies has a November 30 th year-end, which it retains for standalone reporting purposes. We reflect Jefferies in our consolidated financial statements utilizing a one month lag. We have reviewed Jefferies business and internal operating results for the month of December 2017 for the purpose of evaluating whether financial statement disclosures or adjustments are required in this Annual Report on Form 10-K, and we have concluded that, other than the effects of the Tax Cuts and Jobs Act of 2017 (the "Tax Act"), no additional disclosures or adjustments are warranted. See Note 20 to our consolidated financial statements for additional information. Leucadia Asset Management ("LAM") supports and develops focused alternative asset management businesses led by distinct management teams. These include Folger Hill Asset Management LLC ("Folger Hill"), a multi-manager discretionary long/short equity hedge fund platform; Topwater Capital, a first-loss product; CoreCommodity Management LLC, an asset manager that focuses on commodities strategies; Tenacis Capital, a systematic macro investment platform; Lake Hill, an electronic trader in listed options and futures across asset classes; as well as several other smaller businesses. In addition, several investment management businesses, including Jefferies Strategic Investments Division, operate under Jefferies and are included under our marketing of the LAM platform. Berkadia Commercial Mortgage LLC ("Berkadia"), our 50 -50 equity method joint venture with Berkshire Hathaway Inc., provides capital solutions, investment sales advisory and mortgage servicing for multifamily and commercial properties. We own an approximate 70% equity method interest of HomeFed, which owns and develops residential and mixed use real estate properties. We have contractually agreed to limit our voting rights to 45% of HomeFed's total voting securities voting on any matter. HomeFed is a public company traded on the NASD OTC Bulletin Board. Our investment in FXCM Group, LLC ("FXCM") and associated companies consist of a senior secured term loan due January 2019, ( $69.9 million principal outstanding at December 31, 2017 ); a 50% voting interest in FXCM and up to 75% of all distributions. FXCM's six -member board is comprised of three directors appointed by Leucadia and three directors appointed by Global Brokerage Holdings, LLC ("Global Brokerage Holdings"). See Notes 4 and 10 to our consolidated financial statements for additional information. We own 100% of Foursight Capital, an auto loan originator and servicer, and 85% of Chrome Capital, which owns and manages a portfolio of leases on used Harley-Davidson motorcycles and is in the process of winding down. We own 78.9% 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. National Beef operates two beef processing facilities, three consumer-ready processing facilities and a wet blue tanning facility, all located in the U.S. National Beef operates one of the largest wet blue tanning facilities in the world that sells processed hides to tanners that produce finished leather for the automotive, luxury goods, apparel and furniture industries. National Beef owns Kansas City Steak Company, LLC, which sells portioned beef and other products directly to customers through the internet, direct mail and direct response television. National Beef also owns a refrigerated and livestock transportation and logistics company that provides transportation services for National Beef and third parties. We own approximately 23% of HRG Group, Inc. ("HRG"), a publicly traded company (NYSE: HRG), and we reflect this investment at fair value based on quoted market prices. HRG primarily owns approximately 59% of Spectrum Brands, a publicly traded (NYSE: SPB) global consumer products company. HRG sold its approximate 80% interest in Fidelity & Guaranty Life, a life insurance and annuity products company and 100% interest in Front Street, a long-term reinsurance company to CF Corporation in the fourth quarter of 2017. Garcadia is an equity method joint venture that owns and operates 28 automobile dealerships in California, Texas, Iowa and Michigan. We own approximately 75% of Garcadia and have board representation and votes equal to the other member of the joint venture. We own approximately 42% of the common shares of Linkem, as well as convertible preferred shares which, if converted, would increase our ownership to approximately 53% of Linkem's common equity at December 31, 2017 . Linkem provides residential broadband services using LTE technologies deployed over the 3.5 GHz spectrum band. Linkem operates in Italy, which has few cable television systems and poor broadband alternatives. Linkem is accounted for under the equity method. Vitesse Energy, LLC ("Vitesse") is our 96% owned consolidated subsidiary that acquires and develops 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. JETX Energy, LLC ("JETX"), formerly Juneau Energy, LLC, is our 98% owned consolidated subsidiary that engages in the development and production of oil and gas from onshore, unconventional resource areas. JETX currently has non-operated working interests and acreage in east Texas. Idaho Timber is our consolidated subsidiary engaged in the manufacture and distribution of various wood products, including the following principal activities: remanufacturing dimension lumber; remanufacturing, bundling and bar coding of home center boards for large retailers; and production of pine dimension lumber and 5/4” radius-edge, pine decking. Golden Queen Mining Company, LLC ("Golden Queen") owns the Soledad Mountain project, an open pit, heap leach gold and silver mining project in Kern County, California, which commenced gold and silver production in March 2016. We and the Clay family have formed and made contributions to a limited liability company, controlled by us, through which we invested in Golden Queen for the development and operation of the project. Our effective ownership of Golden Queen is approximately 35% and is accounted for under the equity method. Conwed Plastics ("Conwed") was our consolidated subsidiary that manufactured and marketed lightweight plastic netting used for building and construction, erosion and sediment control, packaging, agricultural purposes, carpet padding, filtration, consumer products and other purposes. 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 (net of working capital adjustments) on the sale of Conwed in Other revenues during the year ended December 31, 2017 .

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies 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. Consolidation Our policy is to consolidate all entities in which we can vote a majority of the outstanding voting stock. In addition, we consolidate entities which meet the definition of a variable interest entity for which we are the primary beneficiary. The primary beneficiary is the party who has the power to direct the activities of a variable interest entity that most significantly impact the entity’s economic performance and who has 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. We consider special allocations of cash flows and preferences, if any, to determine amounts allocable to noncontrolling interests. All intercompany transactions and balances are eliminated in consolidation. In situations where we have significant influence, but not control, of an entity that does not qualify as a variable interest entity, we apply either the equity method of accounting or fair value accounting pursuant to the fair value option election under GAAP. We have also formed nonconsolidated investment vehicles with third-party investors that are typically organized as partnerships or limited liability companies. Our subsidiaries may act as general partner or managing member for these investment vehicles and have generally provided the third-party investors with termination or “kick-out” rights. Revenue Recognition Policies Beef Processing and Other Operations Revenues are recognized when the following conditions are met: (1) collectibility is reasonably assured; (2) title to the product has passed or the service has been rendered and earned; (3) persuasive evidence of an arrangement exists; and (4) there is a fixed or determinable price. National Beef’s revenues are recognized based on the terms of the sale, which for beef processing operations is typically upon delivery to customers. Manufacturing revenues are recognized when title passes. Investment Banking Activities Commissions and Other Fees. All customer securities transactions are reported in the Consolidated Statements of Financial Condition on a settlement date basis with related income reported on a trade date basis. We permit 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. These arrangements are accounted for on an accrual basis and, as we are not the primary obligor for these arrangements, netted against commission revenues in the Consolidated Statements of Operations. In addition, we earn asset-based fees associated with the management and supervision of assets, account services and administration related to customer accounts. Principal Transactions. Trading assets and trading liabilities (all of which are recorded on a trade-date basis) are carried at fair value with gains and losses reflected in Principal transaction revenues in the Consolidated Statements of Operations, except for derivatives accounted for as hedges (see Hedge Accounting section, herein and Note 5). Fees received on loans carried at fair value are also recorded within Principal transaction revenues. Investment Banking. Underwriting revenues and fees from mergers and acquisitions, restructuring and other investment banking advisory assignments or engagements are recorded when the services related to the underlying transactions are completed under the terms of the assignment or engagement. Expenses associated with such assignments are deferred until reimbursed by the client, the related revenue is recognized or the engagement is otherwise concluded. Expenses are recorded net of client reimbursements and netted against revenues. Unreimbursed expenses with no related revenues are included in Selling, general and administrative expenses in the Consolidated Statements of Operations. Interest Revenue and Expense. Interest expense that is deducted from Revenues to arrive at Net revenues is related to Jefferies operations. Contractual interest on Trading assets and Trading liabilities is recognized on an accrual basis as a component of Interest income and Interest expense. Interest flows on derivative trading transactions and dividends are included as part of the fair valuation of these contracts and recognized in Principal transactions in the Consolidated Statements of Operations rather than as a component of interest income or expense. Interest on short- and long-term borrowings is recorded on an accrual basis, except for those for which we have elected the fair value option, as Interest expense. Discounts/premiums arising on long-term debt are accreted/amortized to Interest expense using the effective yield method over the remaining lives of the underlying debt obligations. Interest revenue related to Securities borrowed and Securities purchased under agreements to resell activities and interest expense related to Securities loaned and Securities sold under agreements to repurchase activities are recognized on an accrual basis. Hedge Accounting Jefferies applies hedge accounting using interest rate swaps designated as fair value hedges of changes in the benchmark interest rate of fixed rate senior long-term debt. Jefferies interest rate swaps are included as derivative contracts in Trading assets and Trading liabilities in the Consolidated Statements of Financial Condition. Jefferies uses regression analysis to perform ongoing prospective and retrospective assessments of the effectiveness of these hedging relationships. A hedging relationship is deemed effective if the change in fair value of the interest rate swap and the change in the fair value of the long-term debt due to changes in the benchmark interest rate offset within a range of 80% to 125% . The impact of valuation adjustments related to Jefferies own credit spreads and counterparty credit spreads are included in the assessment of effectiveness. For qualifying fair value hedges of benchmark interest rates, the change in the fair value of the derivative and the change in fair value of the long-term debt provide offset of one another, and together with any resulting ineffectiveness, are recorded in Interest expense. See Note 5 for further information. Cash Equivalents Cash equivalents include highly liquid investments, including money market funds and certificates of deposit, not held for resale with original maturities of three months or less. Cash and Securities Segregated and on Deposit for Regulatory Purposes or Deposited With Clearing and Depository Organizations In accordance with Rule 15c3-3 of the Securities Exchange Act of 1934, Jefferies LLC, as a broker-dealer carrying client accounts, is subject to requirements related to maintaining cash or qualified securities in a segregated reserve account for the exclusive benefit of its clients. Certain other entities are also obligated by rules mandated by their primary regulators to segregate or set aside cash or equivalent securities to satisfy regulations, promulgated to protect customer assets. In addition, certain exchange and/or clearing organizations require cash and/or securities to be deposited by us to conduct day to day activities. Financial Instruments and Fair Value Trading assets and Trading liabilities are recorded at fair value, either as required by accounting pronouncements or through the fair value option election. Gains and losses on trading assets and trading liabilities are recognized in our Consolidated Statements of Operations in Principal transactions. Available for sale securities are reflected at fair value, with unrealized gains and losses reflected as a separate component of equity, net of taxes. When sold, realized gains and losses on available for sale securities are reflected in the caption Net realized securities gains. The cost of securities sold is based on average cost. Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (the exit price). Fair Value Hierarchy In determining fair value, we maximize the use of observable inputs and minimize the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from independent sources. Unobservable inputs reflect our assumptions that market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. We apply a hierarchy to categorize our fair value measurements broken down into three levels based on the transparency of inputs as follows: Level 1: Quoted prices are available in active markets for identical assets or liabilities as of the reported date. Valuation adjustments and block discounts are not applied to Level 1 instruments. Level 2: Pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reported date. The nature of these financial instruments includes cash instruments for which quoted prices are available but traded less frequently, derivative instruments fair values for which have been derived using model inputs that are directly observable in the market, or can be derived principally from or corroborated by observable market data, and instruments that are fair valued using other financial instruments, the parameters of which can be directly observed. Level 3: Instruments that have little to no pricing observability as of the reported date. These financial instruments are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment or estimation. Financial instruments are valued at quoted market prices, if available. Certain financial instruments have bid and ask prices that can be observed in the marketplace. For financial instruments whose inputs are based on bid-ask prices, the financial instrument is valued at the point within the bid-ask range that meets our best estimate of fair value. We use prices and inputs that are current as of the measurement date. For financial instruments that do not have readily determinable fair values using quoted market prices, the determination of fair value is based upon consideration of available information, including types of financial instruments, current financial information, restrictions on dispositions, fair values of underlying financial instruments and quotations for similar instruments. The valuation of financial instruments may include the use of valuation models and other techniques. Adjustments to valuations derived from valuation models may be made when, in management’s judgment, features of the financial instrument such as its complexity, the market in which the financial instrument is traded and risk uncertainties about market conditions require that an adjustment be made to the value derived from the models. Adjustments from the price derived from a valuation model reflect management’s judgment that other participants in the market for the financial instrument being measured at fair value would also consider in valuing that same financial instrument. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. The availability of observable inputs can vary and is affected by a wide variety of factors, including, for example, the type of financial instrument and market conditions. As the observability of prices and inputs may change for a financial instrument from period to period, this condition may cause a transfer of an instrument among the fair value hierarchy levels. Transfers among the levels are recognized at the beginning of each period. The degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. Valuation Process for Financial Instruments The Jefferies Independent Price Verification ("IPV") Group, which is part of the Jefferies finance department, in partnership with Jefferies Risk Management, is responsible for establishing Jefferies valuation policies and procedures. The IPV Group and Risk Management, which are independent of business functions, play an important role and serve as a control function in determining that Jefferies financial instruments are appropriately reflected at fair value. This is particularly important where prices or valuations that require inputs are less observable. In the event that observable inputs are not available, the control processes are designed to assure that the valuation approach utilized is appropriate and consistently applied and that the assumptions are reasonable. The IPV Group reports to the Jefferies Global Controller and is subject to the oversight of the IPV Committee, which includes senior members of Jefferies finance department and other personnel. Jefferies independent price verification policies and procedures are reviewed, at a minimum, annually and changes to the policies require the approval of the IPV Committee. Price Testing Process . Jefferies business units are responsible for determining the fair value of Jefferies financial instruments using approved valuation models and methodologies. In order to ensure that the business unit valuations represent a fair value exit price, the IPV Group tests and validates the fair value of the financial instruments inventory. In the testing process, the IPV Group obtains prices and valuation inputs from sources independent of Jefferies, consistently adheres to established procedures set forth in the valuation policies for sourcing prices and valuation inputs and utilizing valuation methodologies. Sources used to validate fair value prices and inputs include, but are not limited to, exchange data, recently executed transactions, pricing data obtained from third party vendors, pricing and valuation services, broker quotes and observed comparable transactions. To the extent discrepancies between the business unit valuations and the pricing or valuations resulting from the price testing process are identified, such discrepancies are investigated by the IPV Group and fair values are adjusted, as appropriate. The IPV Group maintains documentation of its testing, results, rationale and recommendations and prepares a monthly summary of its valuation results. This process also forms the basis for the classification of fair values within the fair value hierarchy (i.e., Level 1, Level 2 or Level 3). The IPV Group utilizes the additional expertise of Risk Management personnel in valuing more complex financial instruments and financial instruments with less or limited pricing observability. The results of the valuation testing are reported to the IPV Committee on a monthly basis, which discusses the results and determines the financial instrument fair values in the consolidated financial statements. At each quarter end, the overall valuation results, as determined by the IPV Committee, are presented to the Jefferies Audit Committee. Judgment exercised in determining Level 3 fair value measurements is supplemented by daily analysis of profit and loss performed by the Product Control functions. Gains and losses, which result from changes in fair value, are evaluated and corroborated daily based on an understanding of each trading desk's overall risk positions and developments in a particular market on the given day. Valuation techniques generally rely on recent transactions of suitably comparable financial instruments and use the observable inputs from those comparable transactions as a validation basis for Level 3 inputs. Level 3 fair value measurements are further validated through subsequent sales testing and market comparable sales, if such information is available. Level 3 fair value measurements require documentation of the valuation rationale applied, which is reviewed for consistency in application from period to period. Third Party Pricing Information . Pricing information obtained from external data providers (including independent pricing services and brokers) may incorporate a range of market quotes from dealers, recent market transactions and benchmarking model derived prices to quoted market prices and trade data for comparable securities. External pricing data is subject to evaluation for reasonableness by the IPV Group using a variety of means including comparisons of prices to those of similar product types, quality and maturities, consideration of the narrowness or wideness of the range of prices obtained, knowledge of recent market transactions and an assessment of the similarity in prices to comparable dealer offerings in a recent time period. Jefferies processes challenges the appropriateness of pricing information obtained from external data providers (including independent pricing services and brokers) to validate the data for consistency with the definition of a fair value exit price. Jefferies process includes understanding and evaluating the external data providers’ valuation methodologies. For corporate, U.S. government and agency, municipal debt securities, and loans, to the extent independent pricing services or broker quotes are utilized in Jefferies valuation process, the vendor service providers are collecting and aggregating observable market information as to recent trade activity and active bid-ask submissions. The composite pricing information received from the independent pricing service is thus not based on unobservable inputs or proprietary models. For mortgage- and other asset-backed securities, collateralized debt obligations ("CDOs") and collateralized loan obligations ("CLOs"), the independent pricing services use a matrix evaluation approach incorporating both observable yield curves and market yields on comparable securities as well as implied inputs from observed trades for comparable securities in order to determine prepayment speeds, cumulative default rates and loss severity. Further, Jefferies considers pricing data from multiple service providers as available as well as compares pricing data to prices observed for recent transactions, if any, in order to corroborate valuation inputs. Model Review Process . If a pricing model is used to determine fair value, the pricing model is reviewed for theoretical soundness and appropriateness by Risk Management, independent from the trading desks, and then approved by Risk Management to be used in the valuation process. Review and approval of a model for use may include benchmarking the model against relevant third party valuations, testing sample trades in the model, backtesting the results of the model against actual trades and stress-testing the sensitivity of the pricing model using varying inputs and assumptions. In addition, recently executed comparable transactions and other observable market data are considered for purposes of validating assumptions underlying the model. Models are independently reviewed and validated by Risk Management annually or more frequently if market conditions or use of the valuation model changes. Investments in Managed Funds Investments in managed funds include our investments in funds managed by us and our investments in related party managed funds. Investments in nonconsolidated managed funds are accounted for at fair value based on the net asset value (“NAV”) of the funds provided by the fund managers with gains or losses included in the Consolidated Statements of Operations. Asset management fees and investment income from managed funds include revenues we earn from management, administrative and performance fees from funds and accounts managed by us, revenues from management and performance fees we earn from related-party managed funds and investment income from our investments in these funds. We earn fees in connection with management and investment advisory services performed for various funds and managed accounts. These fees are based on assets under management or an agreed upon notional amount and may include performance fees based upon the performance of the funds. Management and administrative fees are generally recognized over the period that the related service is provided. Generally, performance fees are earned when the return on assets under management exceeds certain benchmark returns, “high-water marks” or other performance targets. Performance fees are accrued (or reversed) on a monthly basis based on measuring performance to date versus any relevant benchmark return hurdles stated in the investment management agreement. Performance fees are not subject to adjustment once the measurement period ends (generally annual periods) and the performance fees have been realized. Loans to and Investments in Associated Companies Loans to and investments in associated companies include investments in private equity and other operating entities in which we exercise significant influence over operating and capital decisions and loans issued in connection with such investments. Loans to and investments in associated companies are accounted for using the equity method. See Note 10 for additional information regarding certain of these investments. Under the equity method of accounting, our share of the investee’s underlying net income or loss is recorded as Income (loss) related to associated companies, or as part of Other revenues if such investees are considered to be an extension of our business. Income (loss) for investees for which the fair value option was elected is reported as Principal transactions revenues. Receivables At December 31, 2017 and 2016 , Receivables include receivables from brokers, dealers and clearing organizations of $2,635.2 million and $2,062.9 million , respectively, and receivables from customers of securities operations of $1,563.8 million and $843.1 million , respectively. Securities Borrowed and Securities Loaned Securities borrowed and securities loaned are carried at the amounts of cash collateral advanced and received in connection with the transactions and accounted for as collateralized financing transactions. In connection with both trading and brokerage activities, Jefferies borrows securities to cover short sales and to complete transactions in which customers have failed to deliver securities by the required settlement date, and lend securities to other brokers and dealers for similar purposes. Jefferies has an active securities borrowed and lending matched book business in which it borrows securities from one party and lends them to another party. When Jefferies borrows securities, it generally provides cash to the lender as collateral, which is reflected in the Consolidated Statements of Financial Condition as Securities borrowed. Jefferies earns interest revenues on this cash collateral. Similarly, when Jefferies lends securities to another party, that party provides cash to Jefferies as collateral, which is reflected in the Consolidated Statements of Financial Condition as Securities loaned. Jefferies pays interest expense on the cash collateral received from the party borrowing the securities. The initial collateral advanced or received approximates or is greater than the fair value of the securities borrowed or loaned. Jefferies monitors the fair value of the securities borrowed and loaned on a daily basis and requests additional collateral or returns excess collateral, as appropriate. Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase Securities purchased under agreements to resell and Securities sold under agreements to repurchase (collectively "repos") are accounted for as collateralized financing transactions and are recorded at their contracted resale or repurchase amount plus accrued interest. Jefferies earns and incurs interest over the term of the repo, which is reflected in Interest revenue and Interest expense in the Consolidated Statements of Operations on an accrual basis. Repos are presented in the Consolidated Statements of Financial Condition on a net-basis-by counterparty, where permitted by GAAP. The fair value of the underlying securities is monitored daily versus the related receivable or payable balances. Should the fair value of the underlying securities decline or increase, additional collateral is requested or excess collateral is returned, as appropriate. Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are provided principally on the straight-line method over the estimated useful lives of the assets or, if less, the term of the underlying lease. Impairment of Long-Lived Assets We evaluate our long-lived assets for impairment whenever events or changes in circumstances indicate, in management’s judgment, that the carrying value of such assets may not be recoverable. When testing for impairment, we group our long-lived assets with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities (or asset group). The determination of whether an asset group is recoverable is based on management’s estimate of undiscounted future cash flows directly attributable to the asset group as compared to its carrying value. If the carrying amount of the asset group is greater than the undiscounted cash flows, an impairment loss would be recognized for the amount by which the carrying amount of the asset group exceeds its estimated fair value. In 2015, we recorded impairment charges in Selling, general and other expenses of $27.7 million , primarily related to a $20.3 million impairment at JETX and an impairment charge related to National Beef's Brawley plant of $4.7 million . For the oil and gas impairment test related to proved properties, we compare expected undiscounted future net cash flows to the unamortized capitalized cost of the asset. If the future undiscounted net cash flows are lower than the unamortized capital cost, we reduce the capitalized cost to fair market value. We used a third party reserve report in which the cash flows were calculated using West Texas Intermediate (oil) and Henry Hub (gas) NYMEX futures prices as of December 31, 2015. For one of our oil fields, the future undiscounted net cash flows were lower than the unamortized capital cost and as a result, we wrote off the total capital cost. In 2016, JETX recorded impairment charges in Selling, general and other expenses of $56.3 million related to write-downs of unproved oil and gas properties. JETX assesses its unproved oil and gas properties for impairment based on remaining lease terms, drilling results or future plans to develop acreage and they record impairment expense for any decline in value. In the third quarter of 2016, JETX curtailed development of both its southern acreage in the East Eagle Ford and its Houston County acreage. As a result, an impairment was recorded for the difference between the carrying value and the estimated net realizable value of the acreage. In 2017, JETX decided to focus on its other higher returning acreage and as a result wrote off the remaining carrying value for its Houston County acreage. JETX recorded an impairment charge of $10.1 million in Selling, general and other expenses in the third quarter of 2017 related to the write-down of unproved oil and gas properties. Substantially all of our operating businesses sell products or services that are impacted by general economic conditions in the U.S. and to a lesser extent internationally. In recent years, general economic conditions reduced the demand for products or services sold by our operating subsidiaries and/or resulted in reduced pricing for products or services. A worsening of current economic conditions could cause a decline in estimated future cash flows expected to be generated by our operations and investments. If future undiscounted cash flows are estimated to be less than the carrying amounts of the asset groups used to generate those cash flows in subsequent reporting periods, particularly for those with large investments in intangible assets, property and equipment and other long-lived assets (for example, Jefferies, National Beef, manufacturing, oil and gas production and development and certain associated company investments), impairment charges would have to be recorded. Intangible Assets, Net and Goodwill Intangible Assets . Intangible assets deemed to have finite lives are generally amortized on a straight-line basis over their estimated useful lives, where the useful life is the period over which the asset is expected to contribute directly, or indirectly, to our future cash flows. Intangible assets are reviewed for impairment on an interim basis when certain events or circumstances exist. If future undiscounted cash flows are estimated to be less than the carrying amounts of the asset groups used to generate those cash flows in subsequent reporting periods, particularly for those with large investments in amortizable intangible assets, impairment charges would have to be recorded. An intangible asset with an indefinite useful life is not amortized but assessed for impairment annually, or more frequently, when certain events or circumstances exist indicating an assessment for impairment is necessary. Impairment exists when the carrying amount exceeds its fair value. Fair value will be determined using valuation techniques consistent with what a market participant would use. All of our indefinite-lived intangible assets were recognized in connection with the Jefferies acquisition, and our annual impairment testing date for Jefferies is as of August 1. Goodwill. At acquisition, we allocate the cost of a business acquisition to the specific tangible and intangible assets acquired and liabilities assumed based upon their fair values. Significant judgments and estimates are often made by management to determine these values, and may include the use of appraisals, consideration of market quotes for similar transactions, use of discounted cash flow techniques or consideration of other information we believe to be relevant. Any excess of the cost of a business acquisition over the fair values of the net assets and liabilities acquired is recorded as goodwill, which is not amortized to expense. Substantially all of our goodwill was recognized in connection with the Jefferies acquisition. At least annually, and more frequently if warranted, we will assess whether goodwill has been impaired. If the estimated fair value exceeds the carrying value, goodwill at the reporting unit level is not impaired. If the estimated fair value is less than carrying value, further analysis is necessary to determine the amount of impairment, if any, by comparing the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The fair values will be based on widely accepted 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 market capitalization, price-to-book multiples of comparable exchange traded companies, multiples of merger and acquisitions of similar businesses and/or projected cash flows. The estimates and assumptions used in determining fair value could have a significant effect on whether or not an impairment charge is recorded and the magnitude of suc

Accounting Developments

Accounting Developments	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting Developments	Accounting Developments Accounting Developments - Adopted Accounting Standards Share-Based Payments to Employees. In January 2017, we adopted the Financial Accounting Standards Board's ("FASB") new guidance that simplifies and improves accounting for share-based payments. The amendments include the recognition of all excess tax benefits and tax deficiencies as income tax expense or benefit in the statement of operations and changes to the timing of recognition of excess tax benefits, the accounting for forfeitures, classification of awards as either equity or liabilities and classification on the statement of cash flows. The adoption of this guidance did not have a significant impact on our consolidated financial statements. We elected to account for forfeitures as they occur, which results in dividends and dividend equivalents originally charged against retained earnings for forfeited shares to be reclassified to compensation expense in the period in which the forfeiture occurs. Income Statement - Reporting Comprehensive Income. In February 2018, the FASB issued new guidance that allows companies the option to reclassify from accumulated other comprehensive income to retained earnings stranded tax effects resulting from the newly enacted federal corporate income tax rate. The amount of the reclassification would be the difference between the historical corporate income tax rate and the newly enacted corporate income tax rate. This will eliminate the stranded tax effects associated with the change in the federal corporate income tax rate in the Tax Act and would improve the usefulness of information reported to financial statement users. The Company uses the portfolio approach relating to the release of stranded tax effects. Under the portfolio approach, the net unrealized gains or losses recorded in accumulated other comprehensive income would be eliminated only on the date the entire portfolio of available for sale securities is sold or otherwise disposed of. The guidance is effective for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. We adopted this guidance as of December 31, 2017 and elected to make the reclassification, resulting in a reclassification adjustment of $9.2 million . Accounting Developments - Accounting Standards to be Adopted in Future Periods 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 this new 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 and services. This guidance is effective for interim and annual periods beginning after December 15, 2017. We have adopted the new guidance as of January 1, 2018 using the modified retrospective approach with a cumulative-effect adjustment to opening retained earnings of approximately $8 million . Our implementation efforts included the identification of revenue streams within the scope of the guidance, the evaluation of certain revenue contracts and education and discussion with our consolidated subsidiaries. Based on our assessment, the impact of the adoption of the new guidance does not have a material impact on our consolidated financial statements. The below focuses on our two largest consolidated subsidiaries, whose combined revenues comprise more than 92% of our Net revenues in the Consolidated Statements of Operations for the year ended December 31, 2017. For Jefferies, as the new revenue recognition guidance 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 its revenues most closely associated with financial instruments, including Principal transaction revenues, Interest income and Interest expense. The new revenue standard primarily impacts the following of Jefferies revenue recognition and presentation accounting policies: • 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, revenue from these activities is recognized within Principal transaction 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 on 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 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., meeting a specified benchmark rate) and are recognized only to the extent it is not 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. National Beef earns over 95% of its revenues through the sale of beef, pork and beef by-products. Agreements with customers for these sales typically consist of the type and quantity of products to be delivered, the unit price of each product, the estimated delivery date and credit and payment terms. The transaction price is generally fixed at this time and revenue is recognized when the customer takes control of the product. The impact of the new guidance does not materially impact how revenue is recognized for this revenue stream. 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 do not believe the new guidance related to equity investments and the presentation and disclosure requirements of financial instruments will have a material impact on our consolidated financial statements. We have adopted the new guidance as of January 1, 2018 with a cumulative-effect increase to opening retained earnings of approximately $28 million and a corresponding decrease to Accumulated other comprehensive income. 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. Leases. In February 2016, the FASB issued new guidance that affects the accounting and disclosure requirements for leases. The FASB requires the recognition of lease assets and lease liabilities on the statement of financial condition. The guidance is effective for annual and interim periods beginning after December 15, 2018. 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 for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. 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. The guidance is effective for annual and interim periods beginning after December 15, 2017. We do not believe the new guidance will have a material impact on our consolidated financial statements. Goodwill. In January 2017, the FASB issued new guidance for simplifying goodwill impairment testing. The guidance is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted. We do not believe the new guidance will 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. The guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. We do not believe the new guidance will have a material impact on our consolidated financial statements. 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. The guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. 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 for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. We are currently evaluating the impact of the new guidance on our consolidated financial statements.

Fair Value Disclosures

Fair Value Disclosures	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Disclosures The following is a summary of our financial instruments, trading liabilities and long-term debt that are accounted for at fair value on a recurring basis, excluding Investments at fair value based on NAV (within trading assets) of $20.2 million and $24.3 million , respectively, by level within the fair value hierarchy at December 31, 2017 and 2016 (in thousands): 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 $ 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 $ — $ 606,956 $ — $ — $ 606,956 December 31, 2016 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 2,522,977 $ 92,839 $ 21,739 $ — $ 2,637,555 Corporate debt securities — 2,675,020 25,005 — 2,700,025 Collateralized debt obligations and collateralized loan obligations — 54,306 54,354 — 108,660 U.S. government and federal agency securities 2,389,397 56,726 — — 2,446,123 Municipal securities — 708,469 27,257 — 735,726 Sovereign obligations 1,432,556 990,492 — — 2,423,048 Residential mortgage-backed securities — 960,494 38,772 — 999,266 Commercial mortgage-backed securities — 296,405 20,580 — 316,985 Other asset-backed securities — 63,587 40,911 — 104,498 Loans and other receivables — 1,557,233 81,872 — 1,639,105 Derivatives 3,825 4,616,822 6,429 (4,255,998 ) 371,078 Investments at fair value — — 314,359 — 314,359 FXCM term loan — — 164,500 — 164,500 Total trading assets, excluding investments at fair value based on NAV $ 6,348,755 $ 12,072,393 $ 795,778 $ (4,255,998 ) $ 14,960,928 Available for sale securities: Corporate equity securities $ 79,425 $ — $ — $ — $ 79,425 Corporate debt securities — 179 — — 179 U.S. government securities 174,933 — — — 174,933 Residential mortgage-backed securities — 19,133 — — 19,133 Commercial mortgage-backed securities — 8,337 — — 8,337 Other asset-backed securities — 19,042 — — 19,042 Total available for sale securities $ 254,358 $ 46,691 $ — $ — $ 301,049 Liabilities: Trading liabilities: Corporate equity securities $ 1,593,548 $ 16,806 $ 313 $ — $ 1,610,667 Corporate debt securities — 1,718,424 523 — 1,718,947 U.S. government and federal agency securities 976,497 — — — 976,497 Sovereign obligations 1,375,590 1,253,754 — — 2,629,344 Loans — 801,977 378 — 802,355 Derivatives 2,566 4,867,586 9,870 (4,229,213 ) 650,809 Total trading liabilities $ 3,948,201 $ 8,658,547 $ 11,084 $ (4,229,213 ) $ 8,388,619 Other secured financings $ — $ 41,350 $ 418 $ — $ 41,768 Long-term debt $ — $ 248,856 $ — $ — $ 248,856 (1) Represents counterparty and cash collateral netting across the levels of the fair value hierarchy for positions with the same counterparty. 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. 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 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 CDOs and 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. To the extent external price quotations are not available or recent transactions have not been observed, valuation techniques incorporating interest rate yield curves and country spreads for bonds of similar issuers, seniority and maturity are used to determine fair value of sovereign bonds or obligations. Sovereign government obligations are classified in Level 1 or Level 2 of the fair value hierarchy, primarily based on the country of issuance. 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 securities and are generally measured using market price quotations from external pricing services and categorized within Level 2 of the fair value hierarchy. • Agency Residential Interest-Only and Inverse Interest-Only Securities ("agency Inverse IOs"): The fair value of agency Inverse IOs is estimated using expected future cash flow techniques that incorporate prepayment models and other prepayment assumptions to amortize the underlying mortgage loan collateral. 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 weighted average coupon, loan-to-value, credit scores, geographic location, maximum and average loan size, originator, servicer, and weighted average loan age. Agency Inverse IOs are categorized within Level 2 of the fair value hierarchy. We also use vendor data in developing our assumptions, as appropriate. • 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 for 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 and prices observed from recently executed market transactions and are categorized within Level 2 and Level 3 of the fair value hierarchy. 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 and Level 3 of the fair value hierarchy. Valuations are primarily determined using pricing data obtained from external pricing services and broker quotes and prices observed from recently executed market transactions. Loans and Other Receivables • Corporate Loans: Corporate loans categorized within Level 2 of the fair value hierarchy are measured based on market price quotations where market price quotations from external pricing services 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 flow 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. 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 incorporating an evaluation for various factors, including prepayment speeds, default rates and cash flow structures as well as the likelihood of pricing levels in the current market environment. 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 trade activity 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 valuations models, such as Black-Scholes, using observable valuation inputs from the principal market. Exchange quotes and/or valuation inputs are generally obtained from external vendors and pricing services. Brokers quotes are validated directly through observable and tradeable quotes. Listed derivative contracts that use unadjusted exchange close prices are generally classified 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 the 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. • National Beef Derivatives: National Beef uses futures contracts in order to reduce its exposure associated with entering into firm commitments to purchase live cattle at prices determined prior to the delivery of the cattle as well as firm commitments to sell certain beef products at sales prices determined prior to shipment. The futures contracts and their related firm purchase commitments are accounted for at fair value, which are classified as Level 1 or Level 2 within the fair value hierarchy. Certain firm commitments for live cattle purchases and all firm commitments for sales are treated as normal purchases and sales and therefore not marked to market. Fair values classified as Level 1 are calculated based on the quoted market prices of identical assets or liabilities compared to National Beef's cost of those same assets or liabilities. Fair values classified as Level 2 are calculated based on the difference between the contracted price for live cattle and the relevant quoted market price for live cattle futures. • Oil Futures Derivatives: Vitesse uses swaps and call and put options in order to reduce exposure to future oil price fluctuations. Vitesse accounts for the derivative instruments at fair value, which are classified as Level 2 within the fair value hierarchy. Fair values classified as 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 included in Trading assets on the Consolidated Statements of Financial Condition 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 analysis 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 defined benefit plan in Germany. Fair value for the insurance contracts are determined using a third party and is categorized within Level 3 of the fair value hierarchy. Investment in FXCM 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 year ended December 31, 2017 , interest accrued at 20.5% per annum. During the year ended December 31, 2017 , we received $114.9 million of principal and interest from FXCM and $69.9 million of principal remained outstanding under the term loan as of December 31, 2017 . Through December 31, 2017 , we have received cumulatively $331.6 million of principal, interest and fees from our initial $279.0 million investment in FXCM. Through September 1, 2016, the total amount of our investment in FXCM was 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, were included within Principal transactions in the Consolidated Statements of Operations. We recorded gains (losses) in Principal transactions of $23.2 million during the year ended December 31, 2017 from our term loan and $(54.6) million and $491.3 million during the years ended December 31, 2016 and 2015, respectively, from our term loan and related rights. On September 1, 2016, we, Global Brokerage Inc. ("Global Brokerage") and 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 during 2016 and 2017 extended the repayment date of the remaining loan balance 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 Leucadia, to require a sale of FXCM beginning in January 2018. Distributions to Leucadia 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 amendment 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 December 31, 2017 and 2016 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. 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 ("NFA") 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. FXCM also implemented a restructuring plan that included the termination of approximately 22% of its global workforce. The proceeds from the sale of the U.S. accounts, net of closure and severance costs, as well as regulatory capital released after the sale, has been used to pay down the Leucadia term loan. 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 under the equity method 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 ( $72.8 million ) and the investment in associated company ( $158.9 million ), which totaled $231.7 million at December 31, 2017 . 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 10, 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. In 2015, we recorded impairment charges in Selling, general and other expenses of $27.7 million , primarily related to a $20.3 million impairment at JETX and an impairment charge related to National Beef's Brawley plant (which was closed in 2014) of $4.7 million . JETX owns both proved and unproved oil and gas properties that are included in Other assets in our Consolidated Statements of Financial Condition. For the oil and gas impairment test related to proved properties, we compare expected undiscounted future net cash flows to the unamortized capitalized cost of the asset. If the future undiscounted net cash flows are lower than the unamortized capital cost, we reduce the capitalized cost to fair market value. We used a third party reserve report in which the cash flows were calculated using West Texas Intermediate (oil) and Henry Hub (gas) NYMEX futures prices as of December 31, 2015. For one of our oil fields, the undiscounted net cash flows were lower than the unamortized capital cost and as a result, we wrote off the total capital cost. In the third quarter of 2016, JETX curtailed development of both its southern acreage in the East Eagle Ford and its Houston County acreage and performed an impairment analysis of these unproved oil and gas properties. To measure the estimated fair value of the unproved properties, we used unobservable Level 3 inputs, which took into account the following factors: remaining lease terms, drilling results and/or future plans to develop the acreage. The estimated fair value of JETX's southern acreage in the East Eagle Ford and its Houston County acreage totaled $51.6 million , which was $55.0 million lower than the carrying value as of the end of third quarter of 2016. As a result, an impairment charge of $55.0 million was recorded in Selling, general and other expenses in the third quarter of 2016. In the third quarter of 2017, JETX decided to focus on its other higher returning acreage and as a result JETX wrote off the remaining carrying value for its Houston County acreage. JETX recorded an impairment charge of $10.1 million in Selling, general and other expenses in the third quarter of 2017 related to the write-down of unproved oil and gas properties. Investments at Fair Value Based on NAV and Investments in Managed Funds Investments at fair value based on NAV and Investments in managed funds include investments in hedge funds, fund of funds, private equity funds and other funds, which are measured at the NAV of the funds provided by the fund managers and are excluded from 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) 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 Fund (6) 154,805 — — Total $ 590,104 $ 19,084 December 31, 2016 Equity Long/Short Hedge Funds (2) $ 363,256 $ — (2) Fixed Income and High Yield Hedge Funds (3) 772 — — Fund of Funds (4) 230 — — Equity Funds (5) 42,179 20,295 — Multi-asset Fund (6) 133,190 — — Total $ 539,627 $ 20,295 (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, in primarily equity securities in domestic and internatio

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Off-Balance Sheet Risk Jefferies has contractual commitments arising in the ordinary course of business for securities loaned or purchased under agreements to resell, repurchase agreements, future purchases and sales of foreign currencies, securities transactions on a when-issued basis and underwriting. Each of these financial instruments and activities contains varying degrees of off-balance sheet risk whereby the fair values of the securities underlying the financial instruments may be in excess of, or less than, the contract amount. The settlement of these transactions is not expected to have a material effect upon our consolidated financial statements. 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 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 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 4 and 24 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 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 derivative activities, Jefferies may enter into International Swaps and Derivative Association, Inc. (“ISDA”) master netting agreements or similar agreements with counterparties. See Note 11 for additional information with respect to financial statement offsetting. The following tables present 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 December 31, 2017 and 2016 . 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 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) (3,318,481 ) (3,490,514 ) Total derivatives not designated as accounting hedges $ 179,488 $ 252,974 Total per Consolidated Statement of Financial Condition (2) $ 179,488 $ 255,394 December 31, 2016 Derivatives not designated as accounting hedges: Interest rate contracts $ 3,282,245 29,032 $ 3,159,457 34,845 Foreign exchange contracts 529,669 7,826 516,869 8,319 Equity contracts 786,987 2,843,329 1,169,201 2,414,715 Commodity contracts 1,906 2,766 6,430 7,289 Credit contracts 26,269 311 28,065 20,084 Total 4,627,076 4,880,022 Counterparty/cash-collateral netting (1) (4,255,998 ) (4,229,213 ) Total per Consolidated Statement of Financial Condition (2) $ 371,078 $ 650,809 (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. The following table provides information related to gains (losses) recognized in Interest expense of Jefferies in the Consolidated Statements of Operations on a fair value hedge for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Interest rate swaps $ (2,091 ) $ — $ — Long-term debt 8,124 — — Total $ 6,033 $ — $ — The following table presents unrealized and realized gains (losses) on derivative contracts which are primarily recognized in Principal transactions revenues in the Consolidated Statements of Operations for the years ended December 31, 2017, 2016 and 2015 , which are utilized in connection with our client activities and our economic risk management activities (in thousands): 2017 2016 2015 Interest rate contracts $ 3,171 $ (36,559 ) $ (36,792 ) Foreign exchange contracts 4,376 20,401 36,233 Equity contracts (319,775 ) (635,305 ) (137,219 ) Commodity contracts (9,049 ) (3,339 ) (13,625 ) Credit contracts 1,959 5,013 (16,223 ) Total $ (319,318 ) $ (649,789 ) $ (167,626 ) The net gains (losses) on derivative contracts in the table above are one of a number of activities comprising Jefferies business activities and are before consideration of economic hedging transactions, which generally offset the net gains (losses) included above. Jefferies substantially mitigates its exposure to market risk on its cash instruments through derivative contracts, which generally provide offsetting revenues, and Jefferies 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 December 31, 2017 (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 $ — $ 4 $ — $ (4 ) $ — Equity swaps and options 3,082 7,053 2,137 (1,442 ) 10,830 Credit default swaps 567 105 17,344 (5,625 ) 12,391 Total return swaps 34,228 1,581 — (193 ) 35,616 Foreign currency forwards, swaps and options 108,465 31,235 — (62,812 ) 76,888 Interest rate swaps, options and forwards 28,111 166,403 74,048 (83,534 ) 185,028 Total $ 174,453 $ 206,381 $ 93,529 $ (153,610 ) 320,753 Cross product counterparty netting (23,732 ) Total OTC derivative assets included in Trading assets $ 297,021 (1) At December 31, 2017 , we held exchange traded derivative assets, other derivatives assets and other credit agreements with a fair value of $28.4 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 December 31, 2017 , cash collateral received was $146.0 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 $ 2,772 $ 301 $ — $ (4 ) $ 3,069 Equity swaps and options 78 172,670 3,780 (1,442 ) 175,086 Credit default swaps 104 16,540 3,953 (5,625 ) 14,972 Total return swaps 28,920 1,517 — (193 ) 30,244 Foreign currency forwards, swaps and options 91,640 31,173 — (62,812 ) 60,001 Fixed income forwards 8,512 — — — 8,512 Interest rate swaps, options and forwards 16,544 96,484 151,624 (83,534 ) 181,118 Total $ 148,570 $ 318,685 $ 159,357 $ (153,610 ) 473,002 Cross product counterparty netting (23,732 ) Total OTC derivative liabilities included in Trading liabilities $ 449,270 (1) At December 31, 2017 , we held exchange traded derivative liabilities, other derivative liabilities and other credit agreements with a fair value of $124.1 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 December 31, 2017 , cash collateral pledged was $318.0 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 December 31, 2017 , 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 $ 173,843 BBB- to BBB+ 40,565 BB+ or lower 48,338 Unrated 34,275 Total $ 297,021 (1) Jefferies utilizes internal credit ratings determined by the Jefferies 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 Total Notional 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 December 31, 2016 Credit protection sold: Index credit default swaps $ 54.0 $ 92.0 $ 146.0 Single name credit default swaps 122.4 261.2 $ 383.6 Contingent Features Certain of Jefferies 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 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 derivative instruments in liability positions. The aggregate fair value of all derivative instruments with such credit-risk-related contingent features that are in a liability position at December 31, 2017 and 2016 is $95.1 million and $70.6 million , respectively, for which Jefferies has posted collateral of $80.8 million and $44.4 million , respectively, in the normal course of business. If the credit-risk-related contingent features underlying these agreements were triggered on December 31, 2017 and 2016 , Jefferies would have been required to post an additional $14.3 million and $26.1 million , respectively, of collateral to its counterparties. Other Derivatives National Beef uses futures contracts in order to reduce its exposure associated with entering into firm commitments to purchase live cattle at prices determined prior to the delivery of the cattle as well as firm commitments to sell certain beef products at sales prices determined prior to shipment. National Beef accounts for the futures contracts at fair value. Firm commitments for sales are treated as normal sales and therefore not marked to market. Certain firm commitments to purchase cattle, are marked to market when a price has been agreed upon, otherwise they are treated as normal purchases and, therefore, not marked to market. The gains and losses associated with the change in fair value of the futures contracts and offsetting gains and losses associated with changes in the market value of certain of the firm purchase commitments are recorded to Beef processing services revenue and Cost of sales in the period of change. Vitesse uses swaps and call and put options in order to reduce exposure to future oil price fluctuations. Vitesse 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	12 Months Ended
	Dec. 31, 2017
Collateralized Transactions [Abstract]
Collateralized Transactions	Collateralized Transactions Jefferies 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 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 returns excess collateral, as appropriate. Jefferies pledges financial instruments as collateral under repurchase agreements, securities lending agreements and other secured arrangements, including clearing arrangements. Jefferies 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 on 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 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 securities — 2,023,530 2,023,530 Loans and other receivables — 454,941 454,941 Total $ 2,843,911 $ 19,829,249 $ 22,673,160 December 31, 2016 Corporate equity securities $ 2,046,243 $ 66,291 $ 2,112,534 Corporate debt securities 731,276 1,907,888 2,639,164 Mortgage- and asset-backed securities — 2,171,480 2,171,480 U.S. government and federal agency securities 41,613 9,232,624 9,274,237 Municipal securities — 553,010 553,010 Sovereign securities — 2,625,079 2,625,079 Loans and other receivables — 455,960 455,960 Total $ 2,819,132 $ 17,012,332 $ 19,831,464 Contractual Maturity Overnight and Continuous Up to 30 Days 30 to 90 Days Greater than 90 Days Total 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 December 31, 2016 Securities lending arrangements $ 2,131,891 $ 39,673 $ 104,516 $ 543,052 $ 2,819,132 Repurchase agreements 9,147,176 2,008,119 3,809,533 2,047,504 17,012,332 Total $ 11,279,067 $ 2,047,792 $ 3,914,049 $ 2,590,556 $ 19,831,464 Jefferies receives securities as collateral under resale agreements, securities borrowing transactions and customer margin loans. Jefferies also receives securities as collateral in connection with securities-for-securities transactions in which it is the lender of securities. In many instances, Jefferies 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 December 31, 2017 and 2016 , the approximate fair value of securities received as collateral by Jefferies that may be sold or repledged was $27.1 billion and $25.5 billion , respectively. A substantial portion of these securities have been sold or repledged.

Securitization Activities

Securitization Activities	12 Months Ended
	Dec. 31, 2017
Securitization Activities [Abstract]
Securitization Activities	Securitization Activities Jefferies 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 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 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 is not considered the primary beneficiary for these SPEs. Jefferies 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 generally receives cash proceeds in connection with the transfer of assets to an SPE. Jefferies 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 applies fair value accounting to the securities. The following table presents activity related to Jefferies securitizations that were accounted for as sales in which it had continuing involvement during the years ended December 31, 2017, 2016 and 2015 (in millions): 2017 2016 2015 Transferred assets $ 4,552.9 $ 5,786.0 $ 5,770.5 Proceeds on new securitizations 4,594.5 5,809.0 5,811.3 Cash flows received on retained interests 28.7 28.2 31.2 Jefferies 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 securitizations at December 31, 2017 and 2016 . The following table summarizes Jefferies retained interests in SPEs where it transferred assets and has continuing involvement and received sale accounting treatment (in millions): December 31, 2017 December 31, 2016 Securitization Type Total Assets Retained Interests Total Assets Retained Interests U.S. government agency residential mortgage-backed securities $ 6,383.5 $ 28.2 $ 7,584.9 $ 31.0 U.S. government agency commercial mortgage-backed securities 2,075.7 81.4 1,806.3 29.6 CLOs 3,957.8 20.3 4,102.2 37.0 Consumer and other loans 247.6 47.8 395.7 25.3 Total assets represent the unpaid principal amount of assets in the SPEs in which Jefferies 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 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 may make a market in the securities issued by these SPEs. In these market-making transactions, Jefferies 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 purchased securities through these market-making activities and Jefferies 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 9. Foursight Capital also utilized 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 9 for further information on securitization activities and VIEs.

Available for Sale Securities

Available for Sale Securities	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Available for Sale Securities	Available for Sale Securities The amortized cost, gross unrealized gains and losses and estimated fair value of investments classified as available for sale at December 31, 2017 and 2016 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value 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 $ 680,497 $ 36,246 $ 182 $ 716,561 2016 Bonds and notes: U.S. government securities $ 174,938 $ 8 $ 13 $ 174,933 Residential mortgage-backed securities 19,129 108 104 19,133 Commercial mortgage-backed securities 8,275 64 2 8,337 Other asset-backed securities 18,918 124 — 19,042 All other corporates 180 — 1 179 Total fixed maturities 221,440 304 120 221,624 Equity securities: Common stocks: Banks, trusts and insurance companies 35,071 15,115 — 50,186 Industrial, miscellaneous and all other 17,946 11,293 — 29,239 Total equity securities 53,017 26,408 — 79,425 $ 274,457 $ 26,712 $ 120 $ 301,049 The amortized cost and estimated fair value of investments classified as available for sale at December 31, 2017 , 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 $ 552,847 $ 552,805 552,847 552,805 Mortgage-backed and asset-backed securities 75,075 75,270 $ 627,922 $ 628,075 At December 31, 2017 , the unrealized losses on investments which have been in a continuous unrealized loss position for 12 months or longer were not significant.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Variable Interest Entity, Measure of Activity [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 the power to direct the activities of a VIE that most significantly impact the entity’s economic performance and 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; • Real estate investments; • Warehouse funding arrangements for client-sponsored consumer loan vehicles and CLOs through participation certificates 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 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. December 31, 2017 December 31, 2016 Securitization Vehicles Securitization Vehicles Real Estate Investment Vehicles Cash $ 11.7 $ 18.4 $ 2.2 Financial instruments owned 37.6 86.6 — Securities purchased under agreements to resell (1) 729.3 733.5 — Receivables 318.1 277.7 296.9 Loans to and investments in associated companies — — 108.7 Other 15.5 14.5 10.8 Total assets $ 1,112.2 $ 1,130.7 $ 418.6 Other secured financings (2) $ 1,073.5 $ 1,083.8 $ — Long-term debt — 24.1 243.9 Other (3) 38.3 22.3 11.7 Total liabilities $ 1,111.8 $ 1,130.2 $ 255.6 Noncontrolling interests $ — $ — $ 98.7 (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 $44.1 million and $57.6 million of the secured financing represents an amount held by Jefferies in inventory and eliminated in consolidation at December 31, 2017 and 2016 , respectively. (3) Includes $32.0 million and $20.0 million at December 31, 2017 and 2016 , respectively, of intercompany payables that are eliminated in consolidation. Securitization Vehicles. Jefferies is the primary beneficiary of mortgage-backed financing vehicles to which Jefferies sells agency and non-agency residential and commercial mortgage loans and mortgage-backed securities pursuant to the terms of a master repurchase agreement. Jefferies manages the assets within these vehicles. Jefferies 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 general credit and each such VIE’s assets are not available to satisfy any other debt. Jefferies is also the primary beneficiary of securitization vehicles associated with their financing of consumer and small business loans. In the creation of the securitization vehicles, Jefferies was involved in the decisions made during the establishment and design of the entities and holds variable interests consisting of the securities retained that could potentially be significant. The assets of the VIEs consist of the small business loans and term loans backed by consumer installment receivables, which are available for the benefit of the vehicles' beneficial interest holders. The creditors of the VIEs do not have recourse to Jefferies general credit and the assets of the VIEs are not available to satisfy any other debt. At December 31, 2017 and 2016 , 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 year ended December 31, 2017 , a pool of automobile loan receivables aggregating $186.5 million was 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. Real Estate Investment Vehicles. At December 31, 2016, 54 Madison, which we consolidated as a result of our control of the 54 Madison investment committee, had real estate investments in which it is the primary beneficiary. 54 Madison was involved in the decisions made during the establishment and design of the investment entities. 54 Madison's variable interests consisted of its investment in and management of the assets within these entities. The assets of these VIEs consisted primarily of financing note receivables and investments in associated companies, which were available for the benefit of the VIEs' debt holders. The debt holders of these VIEs had recourse to 54 Madison's general credit and the assets of the VIEs were not available to satisfy any other debt. As a result of the sale of our interest in the general partnership during 2017, 54 Madison has been deconsolidated and is reflected in Loans to and investments in associated companies at December 31, 2017. 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 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 December 31, 2016 CLOs $ 264.7 $ 4.8 $ 930.0 $ 4,472.9 Consumer loan vehicles 90.3 — 219.6 985.5 Related party private equity vehicles 37.6 — 63.6 155.6 Real estate investment vehicles 90.3 — 101.8 85.6 Other private investment vehicles 84.0 — 95.8 4,529.7 Total $ 566.9 $ 4.8 $ 1,410.8 $ 10,229.3 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 underwrites securities issued in CLO transactions on behalf of sponsors and provides advisory services to the sponsors. Jefferies may also sell corporate loans to the CLOs. Jefferies 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 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; • Investments in variable funding notes issued by CLOs; and • A guarantee to a CLO managed by Jefferies Finance, whereby Jefferies guarantees certain of the obligations of Jefferies Finance to the CLO. Consumer Loan Vehicles. Jefferies 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 may provide structuring and advisory services and act as an underwriter or placement agent for securities issued by the vehicles. Jefferies does not control the activities of these entities. Related Party Private Equity Vehicles. Jefferies committed to invest equity in private equity funds (the "JCP Funds") managed by Jefferies Capital Partners, LLC (the "JCP Manager"). Additionally, Jefferies committed to invest equity in the general partners of the JCP Funds (the "JCP General Partners") and the JCP Manager. Jefferies 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 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. Jefferies total equity commitment in the JCP Entities was $148.1 million , of which $126.3 million and $125.1 million has been funded as of December 31, 2017 and 2016 , respectively. The carrying value of Jefferies equity investments in the JCP Entities was $23.7 million and $37.6 million at December 31, 2017 and 2016 , respectively. Jefferies 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. Jefferies has also provided a guarantee of a portion of Energy Partners I, LP's obligations under a credit agreement (“Energy Partners Credit Agreement”). Energy Partners I, LP is a private equity fund owned and managed by certain of our employees. The maximum exposure to loss of the guarantee was $3.0 million as of December 31, 2016 . Energy Partners I, LP has assets consisting primarily of debt and equity investments. The Energy Partners Credit Agreement was terminated in April 2017. Real Estate Investment Vehicles. 54 Madison has committed to invest $98.0 million in real estate investment vehicles, of which $86.5 million was funded as of December 31, 2016 . 54 Madison's maximum exposure to loss was limited to its carrying value and unfunded equity commitment. 54 Madison was not the primary beneficiary of the investment vehicles as it did not have the power to control the most important activities of the VIEs. The assets of the VIEs consisted primarily of investments in real estate projects. As a result of the sale of our interest in the general partner during 2017, the 54 Madison fund has been deconsolidated and is reflected in Loans to and investments in associated companies at December 31, 2017. Other Private Investment Vehicles. The carrying amount of our equity investment was $133.0 million and $84.0 million at December 31, 2017 and 2016 , respectively. Our unfunded equity commitment related to these investments totaled $9.1 million and $11.8 million at December 31, 2017 and 2016 , 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 secondary trading and market-making activities, Jefferies 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 has no other involvement with the related SPEs and therefore does not consolidate these entities. Jefferies 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 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 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 may retain unsold senior and/or subordinated interests at the time of securitization in the form of securities issued by the SPEs. Jefferies 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 role and interest in the resecuritization trusts. Most resecuritizations in which Jefferies is involved are in connection with investors seeking securities with specific risk and return characteristics. As such, Jefferies has concluded that the decision-making power is shared between Jefferies 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 does not consolidate the resecuritization VIEs. At December 31, 2017 and 2016 , Jefferies held $1,829.6 million and $1,002.2 million of agency mortgage-backed securities, respectively, and $253.2 million and $439.4 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 maximum exposure to loss on these securities is limited to the carrying value of its investments in these securities. Mortgage- and other asset-backed securitization vehicles discussed within this section are not included in the above table containing information about Jefferies 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. 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 4 and 10 for further discussion.

Loans to and Investments in Ass

Loans to and Investments in Associated Companies	12 Months Ended
	Dec. 31, 2017
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 for the years ended December 31, 2017, 2016 and 2015 accounted for under the equity method of accounting is as follows (in thousands): Loans to and investments in associated companies as of December 31, 2016 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2017 Jefferies Finance $ 490,464 $ — $ 90,204 $ 74,799 $ — $ 655,467 Jefferies LoanCore (2) 154,731 — 22,368 (3,994 ) (173,105 ) — Berkadia 184,443 93,801 — (67,384 ) (266 ) 210,594 FXCM 336,258 (177,644 ) — — 242 158,856 Garcadia Companies 185,815 48,198 — (54,870 ) — 179,143 Linkem 154,000 (32,561 ) — 31,996 38,701 192,136 HomeFed 302,231 7,725 — 31,918 — 341,874 Golden Queen (3) 111,302 (7,733 ) — 1,436 — 105,005 54 Madison (4) (5) 161,400 (6,224 ) — 35,204 (67,370 ) 123,010 Other 44,454 (463 ) (3,177 ) 31,837 28,093 100,744 Total $ 2,125,098 $ (74,901 ) $ 109,395 $ 80,942 $ (173,705 ) $ 2,066,829 Loans to and investments in associated companies as of December 31, 2015 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2016 Jefferies Finance $ 528,575 $ — $ (1,761 ) $ (36,350 ) $ — $ 490,464 Jefferies LoanCore 288,741 — 21,221 (155,231 ) — 154,731 Berkadia 190,986 94,201 — (100,766 ) 22 184,443 FXCM (6) — 1,919 — — 334,339 336,258 Garcadia Companies 172,660 52,266 — (39,111 ) — 185,815 Linkem 150,149 (22,867 ) — 33,303 (6,585 ) 154,000 HomeFed 275,378 23,893 — 2,960 — 302,231 Golden Queen (3) 114,323 (3,021 ) — — — 111,302 54 Madison (4) — 4,255 — 153,503 3,642 161,400 Other 36,557 3,952 (2,276 ) 9,622 (3,401 ) 44,454 Total $ 1,757,369 $ 154,598 $ 17,184 $ (132,070 ) $ 328,017 $ 2,125,098 Loans to and investments in associated companies as of December 31, 2014 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2015 Jefferies Finance $ 508,891 $ — $ 40,884 $ (21,200 ) $ — $ 528,575 Jefferies LoanCore 258,947 — 36,554 (6,760 ) — 288,741 Berkadia 208,511 78,092 — (89,560 ) (6,057 ) 190,986 Garcadia Companies 167,939 53,182 — (48,461 ) — 172,660 Linkem 159,054 (15,577 ) — 21,138 (14,466 ) 150,149 HomeFed 271,782 3,596 — — — 275,378 Golden Queen (3) 103,598 (1,775 ) — 12,500 — 114,323 Other 33,846 (7,237 ) (1,721 ) 11,483 186 36,557 Total $ 1,712,568 $ 110,281 $ 75,717 $ (120,860 ) $ (20,337 ) $ 1,757,369 (1) Primarily classified in Investment banking revenues and Other revenues. (2) On October 31, 2017, Jefferies sold all of its membership interests in Jefferies LoanCore for approximately $173.1 million . (3) At December 31, 2017, 2016 and 2015 , the balance reflects $30.5 million , $32.8 million and $33.7 million , respectively, related to a noncontrolling interest. (4) At December 31, 2016 , the balance reflects $95.3 million related to noncontrolling interests. (5) As discussed further below, on November 30, 2017, we sold our interest in the general partner of the 54 Madison fund and as a result no longer control the 54 Madison investment committee. We retained two of the four seats on the investment committee and continue to have significant influence over the fund. We therefore deconsolidated the 54 Madison fund and account for our interest under the equity method of accounting. (6) As discussed more fully in Note 4, in 2016, we amended the terms of our loan and associated rights with FXCM. Through the amendments, we converted our participation rights for a 50% voting interest in FXCM. Our term loan remains classified within Trading assets, at fair value. Jefferies Finance Jefferies Finance, a joint venture entity pursuant to an agreement with Massachusetts Mutual Life Insurance Company ("MassMutual"), 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. 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 December 31, 2017 , Jefferies and MassMutual each had equity commitments to Jefferies Finance of $750.0 million . At December 31, 2017 , approximately $636.2 million of Jefferies commitment was funded. The investment commitment is scheduled to expire on March 1, 2018 with automatic one year extensions absent a 60 -day termination notice by either party. In addition, Jefferies and MassMutual have entered into a Secured Revolving Credit Facility, 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 for a total committed amount of $500.0 million at December 31, 2017 and 2016 . Advances are shared equally between Jefferies and MassMutual. The facility is scheduled to mature on March 1, 2018 with automatic one year extensions absent a 60 -day termination notice by either party. At December 31, 2017 , none of Jefferies $250.0 million commitment was funded. Jefferies recognized interest income and unfunded commitment fees related to the facility of $3.9 million , $1.3 million and $2.5 million during 2017, 2016 and 2015 , respectively. Jefferies 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 earned fees of $327.9 million , $112.6 million and $122.7 million during 2017, 2016 and 2015 , respectively, which are recognized in Investment banking revenues in the Consolidated Statements of Operations. In addition, Jefferies paid fees to Jefferies Finance in respect of certain loans originated by Jefferies Finance of $2.4 million , $0.5 million and $5.9 million during 2017, 2016 and 2015 , respectively, which are recognized within Selling, general and other expenses in the Consolidated Statements of Operations. During the years ended December 31, 2017, 2016 and 2015 , Jefferies acted as a placement agent for CLOs managed by Jefferies Finance, for which Jefferies recognized fees of $6.1 million , $2.6 million and $6.2 million , respectively, which are included in Investment banking revenues in the Consolidated Statements of Operations. At December 31, 2017 and 2016 , Jefferies held securities issued by CLOs managed by Jefferies Finance, which are included in Trading assets. At December 31, 2016 , Jefferies provided a guarantee, whereby Jefferies is required to make certain payments to a CLO in the event Jefferies Finance was unable to meet its obligations to the CLO. The CLO was terminated in October 2017. Additionally, Jefferies 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. Jefferies acted as underwriter in connection with senior notes issued by Jefferies Finance, for which Jefferies recognized underwriting fees of $1.3 million during the year ended December 31, 2015, which are included in Investment banking revenues in the Consolidated Statements of Operations. Under a service agreement, Jefferies charged Jefferies Finance $50.7 million , $46.1 million and $51.7 million for services provided during 2017, 2016 and 2015 , respectively. At December 31, 2017 , Jefferies had a receivable from Jefferies Finance, included within 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 . At December 31, 2016 , Jefferies had a payable to Jefferies Finance, included in Payables, expense accruals and other liabilities in the Consolidated Statement of Financial Condition of $5.8 million . Jefferies enters into OTC foreign exchange contracts with Jefferies Finance as to which, at December 31, 2017 , we had $1.5 million included in Trading assets in our Consolidated Statements of Financial Condition. 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 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 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. Jefferies LoanCore had entered into master repurchase agreements with Jefferies. During 2017, 2016 and 2015 , Jefferies recognized interest income and fees related to these agreements of $0.6 million , $8.4 million and $10.7 million , respectively. In connection with such master repurchase agreements, at December 31, 2016 , Jefferies had securities purchased with agreements to resell from Jefferies LoanCore of $68.1 million . Jefferies also enters into OTC foreign exchange contracts with Jefferies LoanCore. In connection with these contracts, Jefferies had $8.3 million at December 31, 2016 recorded in Payables, expense accruals and other liabilities in the Consolidated Statement of Financial Condition. 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. Through December 31, 2017 , cumulative cash distributions received by Leucadia from this investment aggregated $562.0 million . 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 December 31, 2017 , the aggregate amount of commercial paper outstanding was $1.47 billion . FXCM As discussed more fully in Note 4, at December 31, 2017 , Leucadia has a 50% voting interest in FXCM and a senior secured term loan to FXCM due January 2018. 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, trade name, leases and long-term debt over their respective useful lives. Based on the February 2017 actions described further in Note 4, 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 described further in Note 4, 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 is a joint venture between us and Garff Enterprises, Inc. ("Garff") that owns and operates 28 automobile dealerships comprised of domestic and foreign automobile makers. The Garcadia joint venture agreement specifies that we and Garff shall have equal board representation and equal votes on all matters affecting Garcadia, and that all operating cash flows from Garcadia will be allocated 65% to us and 35% to Garff, with the exception of one dealership from which we receive 83% of all operating cash flows and four other dealerships from which we receive 71% of all operating cash flows. Garcadia’s strategy is to acquire automobile dealerships in primary or secondary market locations meeting its specified return criteria. Linkem We own approximately 42% of the common shares of Linkem, a fixed wireless broadband services provider in Italy. In addition, we own 5% convertible preferred stock, which is automatically convertible to common shares in 2020. If all of our convertible preferred stock was converted, it would increase our ownership to approximately 53% of Linkem’s common equity at December 31, 2017 . We have approximately 48% of the total voting securities of Linkem. The excess of our investment in Linkem’s common shares over our share of underlying book value is being amortized to expense over 12 years. HomeFed At December 31, 2017 , 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 4.8% of HomeFed is beneficially owned by our Chairman at December 31, 2017 . 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 During 2014 and 2015, we invested $83.0 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 $117.5 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 $117.5 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 as the voting rights of the investors are not proportional to their obligations to absorb the expected losses and their rights to receive the expected residual returns, given the provision of services to the joint venture by Golden Queen Mining Co. Ltd. Golden Queen Mining Co. Ltd. has entered into an agreement with the joint venture for the provision of executive officers, financial, managerial, administrative and other services, and office space and equipment. 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. The excess of Gauss LLC's investment in Golden Queen's underlying book value is being amortized to expense over the estimated life of mine gold and silver sales. 54 Madison We own approximately 48.1% of 54 Madison, a fund that seeks long-term capital appreciation through investment in real estate development and similar projects. Prior to November 30, 2017, we consolidated 54 Madison as a result of our control of the 54 Madison investment committee. 54 Madison invests both in projects which they consolidate and projects where they have significant influence and utilize the equity method of accounting. Based on total committed capital of the 54 Madison fund, all projects of this fund have already been identified and launched. On November 30, 2017, we sold our interest in the general partner of the 54 Madison fund and as a result no longer control the 54 Madison investment committee. We retained two of the four seats on the 54 Madison investment committee and continue to have significant influence over the fund, including a number of protective rights such as the right to block material investments, divestitures and changes outside of agreed upon parameters. We therefore deconsolidated the 54 Madison fund on November 30, 2017 and account for our interest under the equity method of accounting. We account for our equity interest in the 54 Madison fund on a one quarter lag. Other The following table provides summarized data for associated companies as of December 31, 2017 and 2016 and for the three years ended December 31, 2017 (in thousands): 2017 2016 Assets $ 16,340,643 $ 16,964,850 Liabilities 11,920,465 13,097,022 Noncontrolling interest 169,274 132,789 2017 2016 2015 Revenues $ 4,883,063 $ 4,275,016 $ 3,946,252 Income from continuing operations before extraordinary items 503,489 422,167 398,369 Net income 438,881 430,291 398,369 The Company’s income related to associated companies 34,494 171,782 185,998 Except for our investment in Berkadia and Jefferies Finance, we have not provided any guarantees, nor are we contingently liable for any of the liabilities reflected in the above table. All such liabilities are non-recourse to us. Our exposure to adverse events at the investee companies is limited to the book value of our investment. See Note 24 for further discussion of these guarantees. Included in consolidated retained earnings at December 31, 2017 is approximately $202.9 million of undistributed earnings of the associated companies accounted for under the equity method of accounting.

Financial Statement Offsetting

Financial Statement Offsetting	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Financial Statement Offsetting	Financial Statement Offsetting In connection with Jefferies derivative activities and securities financing activities, Jefferies 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; securities lending transactions – master securities lending agreements; and repurchase transactions – master repurchase agreements. 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 derivative ISDA master netting agreements, Jefferies 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 has not determined an agreement to be enforceable, the related amounts are not offset. Master netting agreements are a critical component of Jefferies risk management processes as part of reducing counterparty credit risk and managing liquidity risk. Jefferies 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 Statement of Financial Condition Net Amounts in Consolidated Statement of Financial Condition Additional Amounts Available for Setoff (1) Available Collateral (2) Net Amount (3) 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 Assets at December 31, 2016 Derivative contracts $ 4,627,076 $ (4,255,998 ) $ 371,078 $ — $ — $ 371,078 Securities borrowing arrangements $ 7,743,562 $ — $ 7,743,562 $ (710,611 ) $ (647,290 ) $ 6,385,661 Reverse repurchase agreements $ 14,083,144 $ (10,220,656 ) $ 3,862,488 $ (176,275 ) $ (3,591,654 ) $ 94,559 Liabilities at December 31, 2016 Derivative contracts $ 4,880,022 $ (4,229,213 ) $ 650,809 $ — $ — $ 650,809 Securities lending arrangements $ 2,819,132 $ — $ 2,819,132 $ (710,611 ) $ (2,064,299 ) $ 44,222 Repurchase agreements $ 17,012,332 $ (10,220,656 ) $ 6,791,676 $ (176,275 ) $ (5,780,909 ) $ 834,492 (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 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 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. At December 31, 2016 , amounts include $6,337.5 million of securities borrowing arrangements, for which we have received securities collateral of $6,146.0 million , and $810.4 million of repurchase agreements, for which we have pledged securities collateral of $834.2 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	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net and Goodwill	Intangible Assets, Net and Goodwill A summary of intangible assets, net and goodwill at December 31, 2017 and 2016 is as follows (in thousands): 2017 2016 Indefinite lived intangibles: Exchange and clearing organization membership interests and registrations $ 8,551 $ 9,041 Amortizable intangibles: Customer and other relationships, net of accumulated amortization of $230,074 and $198,674 347,767 378,136 Trademarks and tradename, net of accumulated amortization of $95,627 and $78,778 293,851 309,382 Supply contracts, net of accumulated amortization of $57,440 and $47,867 86,160 95,733 Other, net of accumulated amortization of $3,885 and $2,914 4,701 5,672 Total intangible assets, net 741,030 797,964 Goodwill: National Beef 14,991 14,991 Jefferies 1,703,300 1,696,864 Other operations 3,859 3,859 Total goodwill 1,722,150 1,715,714 Total intangible assets, net and goodwill $ 2,463,180 $ 2,513,678 Amortization expense on intangible assets was $58.2 million , $63.4 million and $63.9 million for the years ended December 31, 2017, 2016 and 2015 , respectively. The estimated aggregate future amortization expense for the intangible assets for each of the next five years is as follows (in thousands): 2018 $ 58,454 2019 58,454 2020 58,454 2021 58,067 2022 57,984 Goodwill Impairment Testing 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 values are 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, multiples of mergers and acquisitions of similar businesses, projected cash flows and/or market capitalization. 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 at August 1, 2017. The results of our annual impairment test related to Jefferies, National Beef and other operations indicated goodwill was not impaired.

Property, Equipment and Leaseho

Property, Equipment and Leasehold Improvements, Net	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Equipment and Leasehold Improvements, Net	Property, Equipment and Leasehold Improvements, Net A summary of property, equipment and leasehold improvements, net at December 31, 2017 and 2016 is as follows (in thousands): Depreciable Lives (in years) 2017 2016 Land, buildings and leasehold improvements 2-25 $ 408,886 $ 379,927 Beef processing machinery and equipment 2-15 360,975 330,453 Other machinery and equipment 3-15 32,012 30,716 Corporate aircraft 10 104,952 104,862 Furniture, fixtures and office equipment 3-10 379,051 323,276 Construction in progress N/A 72,560 54,693 Other 3-10 3,425 3,441 1,361,861 1,227,368 Accumulated depreciation and amortization (611,458 ) (518,126 ) $ 750,403 $ 709,242

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Short-Term Borrowings	Short-Term Borrowings Jefferies short-term borrowings, which mature in one year or less, are as follows at December 31, 2017 and 2016 (in thousands): 2017 2016 Bank loans (1) $ 304,651 $ 372,301 Secured revolving loan facilities — 57,086 Floating rate puttable notes 108,240 96,455 Equity-linked notes 23,324 — Total short-term borrowings $ 436,215 $ 525,842 (1) Bank loans include loans entered into, pursuant to a Master Loan Agreement, between the Bank of New York and Jefferies. At December 31, 2017 and 2016 , the weighted average interest rate on short-term borrowings outstanding was 2.51% and 1.77% per annum, respectively. During the year ended December 31, 2017 , Jefferies issued equity-linked notes with a principal amount of $30.6 million which matured in July 2017 and $4.2 million , which matured in September 2017. The remaining equity-linked notes will mature in the first quarter of 2018. See Note 4 for further information. During 2016, Jefferies issued floating rate puttable notes with an aggregate principal amount of €91.0 million . The Bank of New York Mellon agrees to make revolving intraday credit advances (“Intraday Credit Facility”) for an aggregate committed amount of $150.0 million . The Intraday Credit Facility contains a financial covenant, which includes a minimum regulatory net capital requirement. Interest is based on the higher of the Federal funds effective rate plus 0.5% or the prime rate. At December 31, 2017 , Jefferies was in compliance with debt covenants under the Intraday Credit Facility. In December 2015, Jefferies entered into a secured revolving loan facility (“Secured Revolving Loan Facility”) whereby the lender agreed to make available a revolving loan facility in a maximum principal amount of $50.0 million to purchase eligible receivables that met certain requirements as defined in the Secured Revolving Loan Facility agreement. Interest was based on an annual rate equal to the lesser of the LIBOR rate plus 4.25% or the maximum rate as defined in the Secured Revolving Loan Facility agreement. The Secured Revolving Loan Facility was terminated effective January 24, 2017.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [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 at December 31, 2017 and 2016 are as follows (dollars in thousands): 2017 2016 Parent Company Debt: Senior Notes: 5.50% Senior Notes due October 18, 2023, $750,000 principal $ 742,348 $ 741,264 6.625% Senior Notes due October 23, 2043, $250,000 principal 246,673 246,627 Total long-term debt – Parent Company 989,021 987,891 Subsidiary Debt (non-recourse to Parent Company): Jefferies: 5.125% Senior Notes, due April 13, 2018, $678,300 and $800,000 principal 682,338 817,813 8.5% Senior Notes, due July 15, 2019, $680,800 and $700,000 principal 728,872 778,367 2.375% Euro Medium Term Notes, due May 20, 2020, $594,725 and $529,975 principal 593,334 528,250 6.875% Senior Notes, due April 15, 2021, $750,000 principal 808,157 823,797 2.25% Euro Medium Term Notes, due July 13, 2022, $4,758 and $4,240 principal 4,389 3,848 5.125% Senior Notes, due January 20, 2023, $600,000 principal 615,703 618,355 4.85% Senior Notes, due January 15, 2027, $750,000 principal (1) 736,357 — 6.45% Senior Debentures, due June 8, 2027, $350,000 principal 375,794 377,806 3.875% Convertible Senior Debentures, due November 1, 2029, $324,779 and $345,000 principal 324,779 346,163 6.25% Senior Debentures, due January 15, 2036, $500,000 principal 512,040 512,396 6.50% Senior Notes, due January 20, 2043, $400,000 principal 420,990 421,333 Structured Notes (2) (3) 614,091 255,203 National Beef Reducing Revolver Loan 120,000 — National Beef Revolving Credit Facility 76,809 — National Beef Term Loan — 273,811 54 Madison Term Loans — 406,028 Foursight Capital Credit Facilities 170,455 97,138 Other 112,654 132,244 Total long-term debt – subsidiaries 6,896,762 6,392,552 Long-term debt $ 7,885,783 $ 7,380,443 (1) Amount includes a decrease of $8.1 million at December 31, 2017 associated with an interest rate swap based on its designation as a fair value hedge. See Notes 2 and 5 for further information. (2) Includes $607.0 million and $248.9 million at fair value at December 31, 2017 and 2016 , respectively. (3) Of the $614.1 million of structured notes at December 31, 2017 , $7.1 million matures in 2018, $6.0 million matures in 2019, $25.0 million matures in 2022 and the remaining $576.0 million matures in 2024 or thereafter. At December 31, 2017 , $2.2 billion of consolidated assets (primarily receivables, property and equipment and other assets) are pledged for indebtedness aggregating $484.3 million , principally for National Beef and Foursight Capital subsidiary debt. The aggregate annual mandatory redemptions of all long-term debt during the five year period ending December 31, 2022 are as follows: 2018 - $1,016.3 million ; 2019 - $777.7 million ; 2020 - $125.2 million ; 2021 - $766.5 million ; and 2022 - $232.5 million . Parent Company Debt Our senior note indentures contain covenants that restrict our ability to incur more Indebtedness or issue Preferred Stock of Subsidiaries unless, at the time of such incurrence or issuance, the Company meets a specified ratio of Consolidated Debt to Consolidated Tangible Net Worth, limit the ability of the Company and Material Subsidiaries to incur, in certain circumstances, Liens, limit the ability of Material Subsidiaries to incur Funded Debt in certain circumstances, and contain other terms and restrictions all as defined in the senior note indentures. We have the ability to incur substantial additional indebtedness or make distributions to our shareholders and still remain in compliance with these restrictions. If we are unable to meet the specified ratio, we would not be able to issue additional Indebtedness or Preferred Stock, but our inability to meet the applicable ratio would not result in a default under our senior note indentures. The senior note indentures do not restrict the payment of dividends. Subsidiary Debt During 2017, $20.2 million of Jefferies 3.875% Convertible Senior Debentures due 2029 (original principal amount of $345.0 million ) were called. In November 2017, all of the remaining 3.875% Convertible Senior Debentures 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. During the year ended December 31, 2017 , Jefferies issued structured notes with a total principal amount of approximately $329.9 million , net of retirements. Structured notes of $607.0 million and $248.9 million at December 31, 2017 and 2016 , respectively, 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 transaction revenues. In January 2018, Jefferies issued 4.15% senior notes with a principal amount of $1.0 billion , due 2030. In January 2017, Jefferies issued 4.85% senior notes with a principal amount of $750.0 million , due 2027. In June 2017, National Beef entered into a Third Amended and Restated Credit Agreement (the "Debt Agreement"). The Debt Agreement matures in June 2022 and includes a $275.0 million reducing revolver loan and a $275.0 million revolving credit facility. The reducing revolver loan commitment decreases by $13.8 million on each annual anniversary of the Debt Agreement. The Debt Agreement is secured by a first priority lien on substantially all of the assets of National Beef and its subsidiaries and includes customary covenants including a single financial covenant that requires National Beef to maintain a minimum tangible net worth as defined in the Debt Agreement; at December 31, 2017 , National Beef was in compliance with the covenants. At December 31, 2017 , National Beef’s outstanding debt under the Debt Agreement consisted of a reducing revolver loan with an outstanding balance of $120.0 million and $80.0 million drawn on the revolving credit facility. The reducing revolver loan and the revolving credit facility bear interest at the Base Rate or the LIBOR Rate (as defined in the Debt Agreement), plus a margin ranging from .75% to 2.75% depending upon certain financial ratios and the rate selected. At December 31, 2017 , the interest rate on the outstanding reducing revolver loan was 3.3% and the interest rate on the outstanding revolving credit facility was 3.3% . Borrowings under the reducing revolver loan and the revolving credit facility are available for National Beef’s working capital requirements, capital expenditures and other general corporate purposes. Unused capacity under the revolving credit facility can also be used to issue letters of credit; letters of credit aggregating $13.9 million were outstanding at December 31, 2017 . Amounts available under the revolving credit facility are subject to a borrowing base calculation primarily comprised of receivable and inventory balances; amounts available under the reducing revolver facility are constrained only by the annual reduction in the commitment amount. At December 31, 2017 , after deducting outstanding amounts and issued letters of credit, $87.1 million of the unused revolving credit facility and $155.0 million of the reducing revolver commitment was available to National Beef. 54 Madison seeks long-term capital appreciation through real estate development and similar projects. Many of these development projects are funded through long-term debt at the project level. The debt holders do not have recourse to the Leucadia parent company. As discussed further in Note 10, due to the sale of our interest in the general partner of the 54 Madison fund, the 54 Madison fund and its long-term debt was deconsolidated during 2017. At December 31, 2017 , Foursight Capital’s credit facilities consisted of two warehouse credit commitments aggregating $225.0 million , which mature in March 2019 and July 2020. The 2019 credit facility bears interest based on the three-month LIBOR plus a credit spread fixed through its maturity and the 2020 credit facility bears interest based on the one-month LIBOR plus a credit spread fixed through its maturity. As a condition of the 2019 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 $200.5 million at December 31, 2017 .

Mezzanine Equity

Mezzanine Equity	12 Months Ended
	Dec. 31, 2017
Temporary Equity Disclosure [Abstract]
Mezzanine Equity	Mezzanine Equity Redeemable Noncontrolling Interests Redeemable noncontrolling interests primarily relate to National Beef and are held by its minority owners, USPB, NBPCo Holdings and the chief executive officer of National Beef. The holders of these interests share in the profits and losses of National Beef on a pro rata basis with us. However, the minority owners have the right to require us to purchase their interests under certain specified circumstances at fair value (put rights), and we also have the right to purchase their interests under certain specified circumstances at fair value (call rights). Holders of the put rights had from December 30, 2016 through January 29, 2017 to make an election that would require us to purchase up to one-third of their interests. The holders of the put rights did not make such election. The holders will again have the right to make an election that requires us to purchase up to one-third on December 30, 2018, and the remainder on December 30, 2021. In addition, USPB may elect to exercise their put rights following the termination of the cattle supply agreement, and the chief executive officer following the termination of his employment. Our call rights with respect to USPB may be exercised following the termination of the cattle supply agreement or after USPB’s ownership interest is less than 20% of their interest held at the time we acquired National Beef. Our call rights with respect to other members may be exercised after the ten year anniversary of our acquisition of National Beef if such member’s ownership interest is less than 50% of the interest held at the time we acquired National Beef. Additionally, we may acquire the chief executive officer’s interest following the termination of his employment. 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 during the years ended December 31, 2017 and 2016 (in thousands): 2017 2016 As of January 1, $ 321,962 $ 189,358 Income allocated to redeemable noncontrolling interests 85,277 68,811 Distributions to redeemable noncontrolling interests (90,048 ) (53,701 ) Increase in fair value of redeemable noncontrolling interests charged to additional paid-in capital 94,937 117,494 Balance, December 31, $ 412,128 $ 321,962 At acquisition, we prepared a projection of future cash flows of National Beef, which was used along with other information to allocate the purchase price to National Beef’s individual assets and liabilities. At December 31, 2017 , we calculated the fair value of the redeemable noncontrolling interests by updating our estimate of future cash flows. The projected future cash flows consider estimated revenue growth, cost of sales changes, capital expenditures and other unobservable inputs. However, the most significant unobservable inputs affecting the estimate of fair value are the discount rate ( 12.20% ) and the terminal growth rate ( 2.00% ) used to calculate the capitalization rate of the terminal value. The table below is a sensitivity analysis which shows the fair value of the redeemable noncontrolling interests using the assumed discount and the terminal growth rates and fair values under different rate assumptions as of December 31, 2017 (dollars in millions): Discount Rates Terminal Growth Rates 11.95% 12.20% 12.45% 1.75 % $ 417.6 $ 407.6 $ 398.1 2.00 % $ 422.4 $ 412.1 $ 402.3 2.25 % $ 427.5 $ 416.9 $ 406.8 The projection of future cash flows is updated with input from National Beef personnel. The estimate is reviewed by personnel at our corporate office as part of the normal process for the preparation of our quarterly and annual financial statements. At December 31, 2017 and 2016 , redeemable noncontrolling interests also includes other redeemable noncontrolling interests of $14.5 million and $14.8 million , respectively, primarily related to our oil and gas production and development businesses. Mandatorily Redeemable Convertible Preferred Shares In connection with our acquisition of Jefferies 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 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. This increased the preferred stock dividend from $4.1 million for the year ended December 31, 2016 to $4.4 million for the year ended December 31, 2017 . 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	12 Months Ended
	Dec. 31, 2017
Share-based Compensation [Abstract]
Compensation Plans	Compensation Plans Incentive Plan Upon completion of our combination with Jefferies, we assumed its 2003 Incentive Compensation Plan, as Amended and Restated July 25, 2013 (the "Incentive Plan"). The Incentive Plan allows awards in the form of incentive stock options (within the meaning of Section 422 of the Internal Revenue Code), nonqualified stock options, stock appreciation rights, restricted stock, unrestricted stock, performance awards, restricted stock units ("RSUs"), dividend equivalents or other share-based awards. RSUs give a participant the right to receive fully vested shares at the end of a specified deferral period allowing a participant to hold an interest tied to common stock on a tax deferred basis. Prior to settlement, RSUs carry no voting or dividend rights associated with the stock ownership, but dividend equivalents are accrued to the extent there are dividends declared on the underlying common shares as cash amounts or as deemed reinvestments in additional RSUs. Restricted stock and 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. Awards granted to senior executives related to the 2015 fiscal year did not meet performance targets, and as a result, compensation expense has been adjusted to reflect the reduced number of shares that have vested. The Deferred Compensation Plan (the “DCP”) has been implemented under the Incentive Plan. The DCP permits eligible executive officers and other employees to defer cash compensation, some or all of which may be deemed invested in stock units. A portion of the deferrals may also be directed to notional investments in a money market fund or certain of the employee investment opportunities. Stock units generally have been acquired at a discounted price, which encourages employee participation in the DCP and enhances long-term retention of equity interests by participants and aligns executive interests with those of shareholders. Amounts recognized as compensation cost under the DCP have not been significant. The shares to be delivered in connection with DCP stock units and options are drawn from the Incentive Plan. The Incentive Plan’s “evergreen” share reservation was terminated on March 21, 2014; the number of equity awards available under the Incentive Plan was set at 20,000,000 . At December 31, 2017 , 11,883,293 common shares remained available for new grants under the Incentive Plan. Shares issued pursuant to the DCP reduce the shares available under the Incentive Plan. The following table details the activity in restricted stock during the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts): Weighted- Average Grant Date Fair Value Balance at January 1, 2015 3,383 $ 27.00 Grants 602 $ 18.63 Forfeited (94 ) $ 28.12 Fulfillment of service requirement (1,887 ) $ 26.87 Balance at December 31, 2015 2,004 $ 24.56 Grants 356 $ 18.23 Forfeited (24 ) $ 26.90 Fulfillment of service requirement (974 ) $ 25.65 Balance at December 31, 2016 1,362 $ 22.09 Grants 391 $ 23.65 Forfeited — $ — Fulfillment of service requirement (611 ) $ 23.73 Balance at December 31, 2017 1,142 $ 21.75 The following table details the activity in RSUs during the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts): Weighted-Average Grant Date Fair Value Future Service Required No Future Service Required Future Service Required No Future Service Required Balance at January 1, 2015 4,238 8,467 $ 26.90 $ 26.79 Grants — 121 $ — $ 18.95 Distributions of underlying shares — (229 ) $ — $ 22.34 Forfeited (626 ) — $ 26.90 $ — Fulfillment of service requirement (224 ) 224 $ 26.90 $ 26.90 Balance at December 31, 2015 3,388 8,583 $ 26.90 $ 26.68 Grants — 128 $ — $ 14.21 Distributions of underlying shares — (1,683 ) $ — $ 26.59 Forfeited — — $ — $ — Fulfillment of service requirement (3,320 ) 3,320 $ 26.90 $ 26.90 Balance at December 31, 2016 68 10,348 $ 26.90 $ 26.61 Grants — 104 $ — $ 21.55 Distributions of underlying shares — (175 ) $ — $ 26.46 Forfeited — — $ — $ — Fulfillment of service requirement (36 ) 36 $ 26.90 $ 26.90 Balance at December 31, 2017 32 10,313 $ 26.90 $ 26.57 During 2017 and 2016 , grants include approximately 89,000 and 108,000 , respectively, of dividend equivalents declared on RSUs; the weighted-average grant date fair values of the dividend equivalents were approximately $21.03 and $13.53 , respectively. Senior Executive Compensation Plan In February 2016, the Compensation Committee of our Board of Directors approved an executive compensation plan for our CEO and our President (together, our "Senior Executives") in respect of 2016 (the "2016 Plan") that is based on performance metrics achieved over a three -year period from 2016 through 2018. The Compensation Committee eliminated cash incentive bonuses for 2016 and 100% of each of our CEO and President's compensation beyond their base salaries is composed entirely of performance based RSUs that vest at the end of 2018 if certain performance criteria are met. Any vested RSUs will be subject to a post-vesting, three -year holding period such that no vested RSUs can be sold or transferred until the first quarter of 2022. Performance-vesting of the award is based equally on the compound annual growth rates of Leucadia's Total Shareholder Return ("TSR"), which is measured from the December 31, 2015 stock price of $17.39 , and Leucadia's Return on Tangible Deployable Equity ("ROTDE"), the annual, two- and three-year results of which is used to determine vesting. 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. In January 2017, the Compensation Committee of our Board of Directors approved an executive compensation plan for our Senior Executives in respect of 2017 (the "2017 Plan") that is based on performance metrics achieved over a three -year period from 2017 through 2019. This executive compensation plan is identical to the 2016 Plan, described above, where cash incentive bonuses were eliminated. 100% of each of our CEO and President's compensation beyond their base salaries is composed entirely of performance based RSUs that will vest at the end of 2019 if certain performance criteria are met. Any vested RSUs are subject to a post-vesting, three -year holding period such that no vested RSUs can be sold or transferred until the first quarter of 2023. Performance-vesting of the award is based equally on the compound annual growth rates of Leucadia's TSR, which is measured from the December 30, 2016 stock price of $23.25 , and Leucadia's ROTDE, the annual, two- and three-year results of which are used to determine vesting. If Leucadia's TSR and ROTDE annual compound growth rates are less than 4% , our Senior Executives will not receive any incentive compensation. If Leucadia's TSR and ROTDE grow between 4% and 8% on a compounded basis over the three -year measurement period, each of our Senior Executives will be eligible to receive between 846,882 and 1,693,766 RSUs related to the 2016 Plan and 537,634 and 1,075,268 RSUs related to the 2017 Plan. 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. When determining whether RSUs will vest, the calculation will be weighted equally between TSR and ROTDE. If TSR growth was below minimum thresholds, but ROTDE growth was above minimum thresholds, our Senior Executives would still be eligible to receive some number of vested RSUs based on ROTDE growth. The TSR award contains a market condition and compensation expense is recognized over the service period and will not be reversed if the market condition is not met. The ROTDE award contains a performance condition and compensation expense is recognized over the service period if it is determined that it is probable that the performance condition will be achieved. The following table details the activity in RSUs related to the senior executive compensation plan during the years ended December 31, 2017 and 2016 (in thousands, except per share amounts): Target Number of Shares Weighted- Average Grant Date Fair Value Balance at December 31, 2015 — $ — Grants 3,434 $ 9.68 Forfeited — $ — Balance at December 31, 2016 3,434 $ 9.68 Grants 2,221 $ 19.06 Forfeited — $ — Balance at December 31, 2017 5,655 $ 13.37 During 2017 and 2016 , grants include approximately 70,000 and 47,000 , respectively, of dividend equivalents declared on RSUs; the weighted-average grant date fair values of the dividend equivalents were approximately $21.04 and $13.63 , respectively. The Compensation Committee of the Leucadia Board of Directors approved an executive compensation plan effective January 1, 2018 that extends Leucadia’s current compensation plans for 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 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 Leucadia’s 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 Leucadia’s 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. Directors’ Plan Upon completion of our combination with Jefferies, we also assumed the 1999 Directors' Stock Compensation Plan, as Amended and Restated July 25, 2013 (the "Directors' Plan"). Under the Directors’ Plan, we issue each nonemployee director of Leucadia $120,000 of restricted stock or RSUs each year. These grants are made on the date directors are elected or reelected at our annual shareholders’ meeting. These shares vest over three years from the date of grant and are expensed over the requisite service period. At December 31, 2017 , 321,026 common shares were issuable upon settlement of outstanding RSUs and 297,926 shares are available for future grants. Other Compensation Plans Other Stock-Based Plans. Historically, Jefferies also sponsored an Employee Stock Purchase Plan and an Employee Stock Ownership Plan, both of which were assumed by us in connection with the Jefferies acquisition. Amounts related to these plans have not been significant. Prior to the acquisition of Jefferies, we had two share-based compensation plans: a fixed stock option plan and a senior executive warrant plan. • 1999 Stock Option Plan . This plan provided for the issuance of stock options and stock appreciation rights to non-employee directors and certain employees at not less than the fair market value of the underlying stock at the date of grant. Options granted to employees under this plan were intended to qualify as incentive stock options to the extent permitted under the Internal Revenue Code and became exercisable in five equal annual installments starting one year from date of grant. Options granted to non-employee directors became exercisable in four equal annual installments starting one year from date of grant. No stock appreciation rights have been granted. In March 2014, we ceased issuing options and rights under our option plan. No shares remain available for future grants under this plan. • Senior Executive Warrant Plan. The warrants to purchase 2,000,000 common shares that were granted in 2011 to each of our then Chairman and then President expired unexercised during the first quarter of 2016. We had recorded share-based compensation expense related to this grant of warrants of $1.0 million for the year ended December 31, 2015. No shares remain available for future grants under this warrant plan. At December 31, 2017 and 2016 , 331,312 and 641,478 , respectively, of our common shares were reserved for stock options. A summary of activity with respect to our stock options during the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands, except per share amounts): Common Shares Subject to Option Weighted- Average Exercise Prices Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Balance at January 1, 2015 1,640 $ 24.91 Granted — $ — Exercised (2 ) $ 21.66 $ 6 Cancelled (977 ) $ 24.88 Balance at December 31, 2015 661 $ 24.97 Granted — $ — Exercised — $ — $ — Cancelled (20 ) $ 30.49 Balance at December 31, 2016 641 $ 24.80 Granted — $ — Exercised (20 ) $ 22.75 $ 65 Cancelled (290 ) $ 26.98 Balance at December 31, 2017 331 $ 23.03 1 year $ 1,156 Exercisable at December 31, 2017 264 $ 23.07 1 year $ 911 Restricted Cash Awards. Jefferies provides compensation to new and existing employees in the form of loans and/or other cash awards which are subject to ratable vesting terms with service requirements. These awards are amortized to compensation expense over the relevant service period. At December 31, 2017 , the remaining unamortized amount of these awards was $481.6 million and is included within Other assets in the Consolidated Statement of Financial Condition. Stock-Based Compensation Expense Compensation and benefits expense included $48.4 million , $33.6 million and $74.1 million for the years ended December 31, 2017, 2016 and 2015 , 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 $17.3 million , $12.4 million and $27.3 million for the years ended December 31, 2017, 2016 and 2015 , respectively. As of December 31, 2017 , total unrecognized compensation cost related to nonvested share-based compensation plans was $68.0 million ; this cost is expected to be recognized over a weighted-average period of 1.7 years. The net tax detriment related to share-based compensation plans recognized in additional paid-in capital was $4.2 million and $5.9 million during the years ended December 31, 2016 and 2015 , respectively. At December 31, 2017 , there were 1,142,000 shares of restricted stock outstanding with future service required, 5,687,000 RSUs outstanding with future service required (including target RSUs issuable under the senior executive compensation plan), 10,313,000 RSUs outstanding with no future service required and 887,000 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 16,887,000 .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
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 at December 31, 2017, 2016 and 2015 is as follows (in thousands): 2017 2016 2015 Net unrealized gains on available for sale securities $ 572,085 $ 561,497 $ 557,601 Net unrealized foreign exchange losses (101,400 ) (184,829 ) (63,248 ) Net unrealized losses in instrument specific credit risk (34,432 ) (6,494 ) — Net unrealized losses on cash flow hedges (1,138 ) — — Net minimum pension liability (62,391 ) (59,477 ) (55,560 ) $ 372,724 $ 310,697 $ 438,793 For the years ended December 31, 2017 and 2016 , 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 Statement of Operations 2017 2016 Net unrealized gains on available for sale securities, net of income tax provision of $124 and $2 $ 212 $ 4 Net realized securities gains Net unrealized foreign exchange losses, net of income tax provision of $1,086 and $0 (5,310 ) — Other income and other expenses Amortization of defined benefit pension plan actuarial losses, net of income tax benefit of $(811) and $(700) (1,748 ) (1,534 ) Compensation and benefits, which includes pension expense. See Note 19 for information on this component. Other pension, net of income tax benefit of $(1,231) and $0 1,231 — Income tax provision (benefit) Total reclassifications for the period, net of tax $ (5,615 ) $ (1,530 )

Pension Plans and Postretiremen

Pension Plans and Postretirement Benefits	12 Months Ended
	Dec. 31, 2017
Pension and Other Postretirement Benefit Expense [Abstract]
Pension Plans and Postretirement Benefits	Pension Plans and Postretirement Benefits U.S. Pension Plans Pursuant to the agreement to sell one of our former subsidiaries, WilTel Communications Group, LLC, the responsibility for WilTel’s defined benefit pension plan was retained by us. All benefits under this plan were frozen as of October 30, 2005. Prior to the acquisition of Jefferies, Jefferies sponsored a defined benefit pension plan covering certain employees; benefits under that plan were frozen as of December 31, 2005. Late in 2015, we launched a limited time voluntary lump sum offer to approximately 4,000 of the deferred vested participants of the WilTel plan. Approximately 2,400 participants accepted the lump sum offer and benefit payments totaling $110.7 million were paid out of plan assets. We also recorded a $40.7 million settlement charge in 2015 related to the participant acceptances. A summary of activity with respect to both plans is as follows (in thousands): 2017 2016 Change in projected benefit obligation: Projected benefit obligation, beginning of year $ 205,405 $ 207,025 Interest cost 8,119 8,464 Actuarial (gains) losses 6,644 (544 ) Benefits paid (8,911 ) (9,540 ) Projected benefit obligation, end of year $ 211,257 $ 205,405 Change in plan assets: Fair value of plan assets, beginning of year $ 127,514 $ 117,719 Actual return on plan assets 22,192 2,947 Employer contributions 12,417 19,100 Benefits paid (8,911 ) (9,540 ) Administrative expenses (2,406 ) (2,712 ) Fair value of plan assets, end of year $ 150,806 $ 127,514 Funded status at end of year $ (60,451 ) $ (77,891 ) As of December 31, 2017 and 2016 , $51.3 million and $58.9 million , respectively, of the net amount recognized in the Consolidated Statements of Financial Condition was reflected as a charge to Accumulated other comprehensive income (substantially all of which were cumulative losses) and $60.5 million and $77.9 million , respectively, was reflected as accrued pension cost. The following table summarizes the components of net periodic pension cost and other amounts recognized in other comprehensive income (loss) excluding taxes (in thousands): 2017 2016 2015 Components of net periodic pension cost: Interest cost $ 8,119 $ 8,464 $ 12,958 Expected return on plan assets (7,689 ) (7,589 ) (10,581 ) Settlement charge — — 40,973 Actuarial losses 2,207 1,908 6,963 Net periodic pension cost $ 2,637 $ 2,783 $ 50,313 Amounts recognized in other comprehensive income (loss): Net (gain) loss arising during the period $ (5,453 ) $ 6,811 $ (24,186 ) Settlement charge — — (40,973 ) Amortization of net loss (2,207 ) (1,908 ) (6,963 ) Total recognized in other comprehensive income (loss) $ (7,660 ) $ 4,903 $ (72,122 ) Net amount recognized in net periodic benefit cost and other comprehensive income (loss) $ (5,023 ) $ 7,686 $ (21,809 ) The amounts in Accumulated other comprehensive income at the end of each year have not yet been recognized as components of net periodic pension cost in the Consolidated Statements of Operations. The estimated net loss that will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost in 2018 is $2.5 million . We expect to pay $8.9 million of employer contributions in 2018 . We use a December 31 measurement date for the WilTel plan and a November 30 date for the Jefferies plan. The assumptions used are as follows: 2017 2016 WilTel Plan Discount rate used to determine benefit obligation 3.51 % 3.85 % Weighted-average assumptions used to determine net pension cost: Discount rate 3.85 % 4.00 % Expected long-term return on plan assets 7.00 % 7.00 % Jefferies Plan Discount rate used to determine benefit obligation 3.60 % 3.90 % Weighted-average assumptions used to determine net pension cost: Discount rate 3.90 % 4.10 % Expected long-term return on plan assets 6.25 % 6.25 % The following pension benefit payments are expected to be paid (in thousands): 2018 $ 9,943 2019 9,915 2020 9,666 2021 9,577 2022 10,233 2023 – 2027 67,493 U.S. Plan Assets The information below on the plan assets for the WilTel plan and the Jefferies plan is presented separately for the plans as the investments are managed independently. Cash equivalents are valued at cost, which approximates fair value and are categorized in Level 1 of the fair value hierarchy. The estimated fair values for securities measured using Level 1 inputs are determined using publicly quoted market prices in active markets for identical assets. Certain fixed income securities are measured using Level 2 inputs. Although these securities trade in brokered markets, the market for certain securities is sometimes inactive. Valuation inputs include benchmark yields, reported trades, broker dealer quotes, issuer spreads, two sided markets, benchmark securities, bids, offers, reference data, and industry and economic events. Neither plan had any assets classified within Level 3 of the fair value hierarchy. WilTel Plan Assets. At December 31, 2017 and 2016 , the WilTel plan assets at fair value consisted of the following (in thousands): Fair Value Measurements Using Total Level 1 Level 2 2017 Cash and cash equivalents $ 539 $ 539 $ — Growth Portfolio 65,625 — 65,625 Liability-Driven Investing Portfolio 31,693 — 31,693 Total $ 97,857 $ 539 $ 97,318 2016 Cash and cash equivalents $ 919 $ 919 $ — Growth Portfolio 51,852 — 51,852 Liability-Driven Investing Portfolio 24,751 — 24,751 Total $ 77,522 $ 919 $ 76,603 The current investment objectives are designed to close the funding gap while mitigating funded status volatility through a combination of liability hedging and investment returns. As plan funded status improves, the asset allocation will move along a predetermined, de-risking glide path that reallocates capital from growth assets to liability-hedging assets in order to reduce funded status volatility and lock in funded status gains. Plan assets are split into two separate portfolios, each with different asset mixes and objectives: • The Growth Portfolio consists of global equities and high yield investments. • The Liability-Driven Investing ("LDI") Portfolio consists of long duration credit bonds and a suite of long duration, Treasury-based instruments designed to provide capital-efficient interest rate exposure as well as target specific maturities. The objective of the LDI Portfolio is to seek to achieve performance similar to the WilTel plan's liability by seeking to match the interest rate sensitivity and credit sensitivity. The LDI Portfolio is managed to mitigate volatility in funded status deriving from changes in the discounted value of benefit obligations from market movements in the interest rate and credit components of the underlying discount curve. To develop the assumption for the expected long-term rate of return on plan assets, we considered the following underlying assumptions: 2.25% current expected inflation, 1.0% to 1.5% real rate of return for long duration risk free investments and an additional 1.0% to 1.5% return premium for corporate credit risk. For U.S. and international equity, we assume an equity risk premium over cash equals to 4.0% . We then weighted these assumptions based on invested assets and assumed that investment expenses were offset by expected returns in excess of benchmarks, which resulted in the selection of the 7.0% expected long-term rate of return assumption for 2017 . Jefferies Plan Assets. At December 31, 2017 and 2016 , the Jefferies plan assets at fair value consisted of the following (in thousands): Fair Value Measurements Using Total (1) Level 1 Level 2 2017 Common collective trusts $ 52,949 $ — $ 52,949 Total $ 52,949 $ — $ 52,949 2016 Cash and cash equivalents $ 1,135 $ 1,135 $ — Listed equity securities (2) 32,342 32,342 — Fixed income securities: Corporate debt securities 4,906 — 4,906 Foreign corporate debt securities 1,835 — 1,835 U.S. government securities 5,370 5,370 — Agency mortgage-backed securities 3,330 — 3,330 Commercial mortgage-backed securities 591 — 591 Asset-backed securities 483 — 483 Total $ 49,992 $ 38,847 $ 11,145 (1) There are no plan assets classified within Level 3 of the fair value hierarchy. (2) Listed equity securities are diversified across a spectrum of primarily U.S. large-cap companies. Investment Policies and Strategies - Assets in the plan are invested under guidelines adopted by Jefferies Administrative Committee of the U.S. Pension Plan. Because the U.S. Pension Plan exists to provide a vehicle for funding future benefit obligations, the investment objectives of the portfolio take into account the nature and timing of future plan liabilities. The policy recognizes that the portfolio’s long-term investment performance and its ability to meet the plan’s overall objectives are dependent on the strategic asset allocation, which includes adequate diversification among assets classes. In May 2017, Jefferies entered into an agreement with an external investment manager to invest and manage the plan’s assets under a strategy using a combination of two portfolios. The investment manager allocates the plan’s assets between a growth portfolio and a liability-driven portfolio according to certain target allocations and tolerance bands that are agreed to by Jefferies Administrative Committee of the U.S. Pension Plan. Such target allocations will take into consideration the plan’s funded ratio. The manager will also monitor the strategy and, as the plan’s funded ratio changes over time, will rebalance the strategy, if necessary, to be within the agreed tolerance bands and target allocations. The portfolios are comprised of certain common collective investment trusts that are established and maintained by the investment manager. German Pension Plan In connection with the acquisition of Jefferies Bache from Prudential in 2011, Jefferies acquired a defined benefit pension plan located in Germany for the benefit of eligible employees of Jefferies Bache in that territory. The German pension plan has no plan assets and is therefore unfunded; however, Jefferies has purchased insurance contracts from multi-national insurers held in the name of Jefferies Bache Limited to provide for the plan’s future obligations. The investment in these insurance contracts is included in Financial instruments owned - Trading assets in the Consolidated Statements of Financial Condition and has a fair value of $16.0 million and $15.2 million at December 31, 2017 and 2016 , respectively. All costs relating to the plan (including insurance premiums and other costs as computed by the insurers) are paid by Jefferies. In connection with the acquisition, Prudential agreed that any insurance premiums and funding obligations related to pre-acquisition date service will be reimbursed to Jefferies by Prudential. 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 which will release Jefferies from any and all obligations under the German Pension Plan. Subject to certain precedent conditions being fulfilled, this transaction is expected to be completed in the first quarter of 2018. In addition, on December 28, 2017, Jefferies entered into an agreement with Prudential under which it received $3.25 million as consideration for the release of Prudential by Jefferies from their indemnity relating to the German Pension Plan defined benefit pension obligations. The provisions and assumptions used in the German pension plan are based on local conditions in Germany. Jefferies did not contribute to the plan during the year ended December 31, 2017 . The following tables summarize the changes in the projected benefit obligation and the components of net periodic pension cost for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 Change in projected benefit obligation: Projected benefit obligation, beginning of year $ 24,166 $ 23,545 Interest cost 426 529 Actuarial (gains) losses (91 ) 1,157 Benefits paid (1,233 ) (1,104 ) Currency adjustment 2,976 39 Projected benefit obligation, end of year $ 26,244 $ 24,166 2017 2016 2015 Components of net periodic pension cost: Interest cost $ 426 $ 529 $ 523 Net amortization 353 326 325 Net periodic pension cost $ 779 $ 855 $ 848 The amounts in Accumulated other comprehensive income at December 31, 2017 and 2016 are charges of $5.3 million and $5.7 million , respectively. The following are assumptions used to determine the actuarial present value of the projected benefit obligation and net periodic pension benefit cost for the years ended December 31, 2017 and 2016 : 2017 2016 Projected benefit obligation Discount rate 1.80 % 1.70 % Rate of compensation increase (1) N/A N/A Net periodic pension benefit cost Discount rate 1.70 % 2.20 % Rate of compensation increase (1) N/A N/A (1) There were no active participants in the plan at December 31, 2017 and 2016 . The following pension benefit payments are expected to be paid (in thousands): 2018 $ 1,303 2019 1,275 2020 1,329 2021 1,339 2022 1,320 2023 – 2027 6,571 Other We have defined contribution pension plans covering certain employees. Contributions and costs are a percent of each covered employee’s salary. Amounts charged to expense related to such plans were $8.9 million , $9.6 million and $9.6 million for the years ended December 31, 2017, 2016 and 2015 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes for continuing operations for each of the three years in the period ended December 31, 2017 was as follows (in thousands): 2017 2016 2015 Current taxes: U.S. Federal $ 413 $ (574 ) $ 709 U.S. state and local 33,845 8,672 (25,308 ) Foreign 14,654 (4,620 ) 3,504 Total current 48,912 3,478 (21,095 ) Deferred taxes: U.S. Federal 694,207 108,241 134,590 U.S. state and local 9,697 8,335 4,552 Foreign 8,151 2,055 (8,100 ) Total deferred 712,055 118,631 131,042 Total income tax provision $ 760,967 $ 122,109 $ 109,947 On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Act. The Tax Act makes broad and complex changes to the U.S. tax code that will impact many areas of taxation, including, but not limited to, (1) reduction of the U.S. federal corporate tax rate from 35% to 21% ; (2) elimination of the corporate alternative minimum tax; (3) the introduction of the base erosion anti-abuse tax, a new minimum tax; (4) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (5) a new provision designed to tax global intangible low-taxed income; (6) a new limitation on deductible interest expense; (7) the repeal of the domestic production activity deduction; (8) limitations on the deductibility of certain executive compensation; (9) limitations on the use of foreign tax credits to reduce U.S. income tax liability; (10) limitations on NOLs generated after December 31, 2017, to 80% of taxable income; (11) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that is payable over 8 years ; and (12) bonus depreciation that will allow for full expensing of qualified property. 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 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 ASC 740, Income Taxes. SAB 118 provides a three-step process to be 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 and therefore 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 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 over the next 12 months, 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. In connection with our initial analysis, we have recorded a discrete tax expense of $450.5 million as a provisional estimate of the impact of the Tax Act, including the portion related to Jefferies, during 2017 increasing our effective tax rate by 44.4% to 75.1% . This provisional estimate primarily consists of a $415.0 million expense related to the revaluation of our deferred tax asset and a $35.5 million expense related to the deemed repatriation of foreign earnings. Additionally, for the year ended December 31, 2017 , our provision for income taxes was reduced by a $31.9 million benefit resulting from the repatriation of Jefferies earnings from certain of its foreign subsidiaries, along with their associated foreign tax credits. For the year ended December 31, 2016 , our provision for income taxes included a $24.9 million charge related to previously issued stock awards. The majority of the awards expired during the first quarter of 2016. The tax deductions associated with the remainder of the awards was less than the compensation cost recognized for financial reporting purposes. For the year ended December 31, 2015 , we recorded a benefit related to certain state and local net operating loss carryforwards which we believe are more likely than not to be realized in the future, a significant portion of which resulted from enacted state and local tax law changes. The following table presents the U.S. and non-U.S. components of income from continuing operations before income taxes for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 U.S. $ 944,014 $ 337,374 $ 336,856 Non-U.S. (1) 69,800 (20,944 ) 19,680 Income from continuing operations before income taxes $ 1,013,814 $ 316,430 $ 356,536 (1) For purposes of this table, non-U.S. income is defined as income generated from operations located outside the U.S. For each of the three years in the period ended December 31, 2017 , income tax expense differed from the amounts computed by applying the U.S. Federal statutory income tax rate of 35% to income from continuing operations before income taxes as a result of the following (dollars in thousands): 2017 2016 2015 Amount Percent Amount Percent Amount Percent Computed expected federal income tax $ 354,835 35.0 % $ 110,751 35.0 % $ 124,788 35.0 % Increase (decrease) in income taxes resulting from: State and local income taxes, net of federal income tax benefit 19,938 2.0 1,045 0.3 (6,928 ) (1.9 ) International operations (including foreign rate differential) (11,577 ) (1.1 ) (3,137 ) (1.0 ) (11,474 ) (3.2 ) Increase (decrease) in valuation allowance — — 2,825 0.9 (13,227 ) (3.7 ) Permanent differences 7,474 0.7 7,523 2.4 13,892 3.9 Tax exempt income (3,850 ) (0.4 ) (4,640 ) (1.5 ) (6,789 ) (1.9 ) Foreign tax credits (32,974 ) (3.2 ) — — (7,240 ) (2.0 ) (Income) loss allocated to noncontrolling interest, not subject to tax (28,392 ) (2.8 ) (22,512 ) (7.1 ) 11,039 3.1 Excess stock detriment 161 — 24,907 7.9 — — Revaluation of deferred tax asset 415,000 40.9 — — — — Transition tax 35,500 3.5 — — — — Other 4,852 0.5 5,347 1.7 5,886 1.5 Actual income tax provision $ 760,967 75.1 % $ 122,109 38.6 % $ 109,947 30.8 % The following table presents a reconciliation of gross unrecognized tax benefits for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 Balance at beginning of period $ 148,848 $ 150,867 $ 148,590 Increases based on tax positions related to the current period 18,619 5,045 3,475 Increases based on tax positions related to prior periods 10,358 3,697 22,030 Decreases based on tax positions related to prior periods (8,805 ) (9,414 ) (15,349 ) Decreases related to settlements with taxing authorities — (1,347 ) (7,879 ) Balance at end of period $ 169,020 $ 148,848 $ 150,867 Net interest expense related to unrecognized tax benefits was $9.7 million , $8.6 million and $4.2 million for the years ended December 31, 2017, 2016 and 2015 , respectively. At December 31, 2017 and 2016 , we had interest accrued of approximately $57.4 million and $47.7 million , respectively, included in Payables, expense accruals and other liabilities in the Consolidated Statements of Financial Condition. No material penalties were accrued for the years ended December 31, 2017 and 2016 . The statute of limitations with respect to our federal income tax returns has expired for all years through 2012. Our 2013 federal tax return is currently under examination by the Internal Revenue Service. Our New York State and New York City income tax returns are currently being audited for the 2012 to 2014 period and 2011 to 2012 period, respectively. Prior to becoming a wholly-owned subsidiary, Jefferies 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 is currently under examination by the Internal Revenue Service and other major tax jurisdictions. The statute of limitations with respect to Jefferies federal income tax returns has expired for all years through 2012. We do not expect that resolution of these examinations will have a significant effect on our consolidated financial position, but could have a significant impact on the consolidated results of operations for the period in which resolution occurs. Over the next twelve months, we believe it is reasonably possible that various tax examinations will be concluded and statutes of limitation will expire which would have the effect of reducing the balance of unrecognized tax benefits by $14.0 million . If recognized, the total amount of unrecognized tax benefits reflected in the table above would lower our effective income tax rate. The principal components of deferred taxes at December 31, 2017 and 2016 are as follows (in thousands): 2017 2016 Deferred tax asset: Net operating loss carryover $ 599,839 $ 1,262,584 Compensation and benefits 213,340 309,100 Long-term debt 11,799 54,102 Other assets 97,061 155,028 Tax credits 93,026 10,749 Securities valuation reserves 3,012 12,345 Intangible assets, net and goodwill 270 311 Other liabilities 21,605 39,188 1,039,952 1,843,407 Valuation allowance (93,758 ) (106,042 ) 946,194 1,737,365 Deferred tax liability: Unrealized gains on investments (8,060 ) (998 ) Amortization of intangible assets (71,583 ) (107,437 ) Property and equipment (8,209 ) (14,228 ) Investment in FXCM (37,942 ) (117,594 ) Transition tax (35,165 ) — Other (41,424 ) (35,293 ) (202,383 ) (275,550 ) Net deferred tax asset $ 743,811 $ 1,461,815 As of December 31, 2017 , we have consolidated U.S. federal NOLs of $1.2 billion that may be used to offset the taxable income of any member of our consolidated tax group. In addition, we have $1.2 billion of U.S. federal NOLs that are only available to offset the taxable income of certain subsidiaries. Federal NOLs begin to expire in 2023, with a substantial amount expiring between 2023 and 2025. We have various state NOLs that expire at different times, which are reflected in the above table to the extent our estimate of future taxable income will be apportioned to those states. We have gross foreign net operating loss carryforwards of approximately $68.6 million . There is a valuation allowance with respect to $10.0 million of these foreign net operating loss carryforwards. Uncertainties that may affect the utilization of our tax attributes include future operating results, tax law changes, rulings by taxing authorities regarding whether certain transactions are taxable or deductible and expiration of carryforward periods. Under certain circumstances, the ability to use the NOLs and future deductions could be substantially reduced if certain changes in ownership were to occur. In order to reduce this possibility, our certificate of incorporation includes a charter restriction that prohibits transfers of our common stock under certain circumstances. We are currently evaluating the impact of the Tax Act on our indefinite reinvestment assertion. At December 31, 2016 , we had approximately $157.0 million of earnings attributable to foreign subsidiaries that were indefinitely reinvested abroad and for which no U.S. federal income tax provision had been recorded. Accordingly, deferred tax liabilities of approximately $55.0 million had not been recorded with respect to these earnings at December 31, 2016 .

Net Realized Securities Gains (

Net Realized Securities Gains (Losses)	12 Months Ended
	Dec. 31, 2017
Gain (Loss) on Investments [Abstract]
Net Realized Securities Gains (Losses)	Net Realized Securities Gains (Losses) The following summarizes net realized securities gains (losses) for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 Net realized gains (losses) on securities $ 13 $ (286 ) $ 14,112 Other (1) 23,015 29,828 48,845 $ 23,028 $ 29,542 $ 62,957 (1) In 2017, primarily relates to a $19.7 million security gain from an investment in a non-public security. In 2015, primarily relates to a recovery of $35.0 million of an investment in a non-public security written down in prior years. Proceeds from sales of investments classified as available for sale were $0.4 billion , $0.5 billion and $1.9 billion during 2017 , 2016 and 2015 , respectively. Gross gains of $16.9 million and gross losses of $2.8 million were realized on these sales during 2015 . Gross gains and gross losses for 2017 and 2016 were not material.

Other Results of Operations Inf

Other Results of Operations Information	12 Months Ended
	Dec. 31, 2017
Nonoperating Income (Expense) [Abstract]
Other Results of Operations Information	Other Results of Operations Information Other revenue for each of the three years in the period ended December 31, 2017 consists of the following (in thousands): 2017 2016 2015 Manufacturing revenues $ 326,197 $ 412,826 $ 391,920 Losses from managed funds (8,118 ) (69,038 ) (37,237 ) Asset management fees 28,831 29,492 34,777 Dividend income (452 ) 3,856 5,482 Income from associated companies classified as other revenues 75,889 17,184 75,717 Revenues of oil and gas production and development businesses 61,541 49,890 45,939 Gain on sale of Conwed 178,236 — — Other 86,384 43,976 32,630 $ 748,508 $ 488,186 $ 549,228 Taxes, other than income or payroll, amounted to $39.6 million , $35.4 million and $21.9 million for the years ended December 31, 2017, 2016 and 2015 , respectively. Advertising costs amounted to $21.6 million , $20.0 million and $18.1 million for the years ended December 31, 2017, 2016 and 2015 , respectively.

Common Shares and Earnings Per

Common Shares and Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Common Shares and Earnings Per Common Share	Common Shares and Earnings Per Common Share Basic and diluted earnings per share amounts were calculated by dividing net income by the weighted-average number of common shares outstanding. The numerators and denominators used to calculate basic and diluted earnings per share are as follows for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Numerator for earnings per share: Net income attributable to Leucadia National Corporation common shareholders $ 167,351 $ 125,938 $ 279,587 Allocation of earnings to participating securities (1) (610 ) (574 ) (4,711 ) Net income attributable to Leucadia National Corporation common shareholders for basic earnings per share 166,741 125,364 274,876 Adjustment to allocation of earnings to participating securities related to diluted shares (1) (14 ) (19 ) (34 ) Mandatorily redeemable convertible preferred share dividends — — — Net income attributable to Leucadia National Corporation common shareholders for diluted earnings per share $ 166,727 $ 125,345 $ 274,842 Denominator for earnings per share: Denominator for basic earnings per share – weighted-average shares 368,197 371,211 372,430 Stock options 24 — 1 Senior executive compensation plan awards 2,480 307 — Mandatorily redeemable convertible preferred shares — — — Denominator for diluted earnings per share 370,701 371,518 372,431 (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 1,401,000 , 1,986,800 and 6,500,000 for the years ended December 31, 2017, 2016 and 2015 , respectively. Dividends declared on participating securities during the years ended December 31, 2017, 2016 and 2015 were $0.4 million , $0.4 million and $1.5 million , respectively. Undistributed earnings are allocated to participating securities based upon their right to share in earnings if all earnings for the period had been distributed. Options to purchase 656,894 and 1,000,137 weighted-average shares of common stock were outstanding during the years ended December 31, 2016 and 2015 , respectively, but were not included in the computation of diluted per share amounts as the effect was antidilutive. Amounts for 2017 were not material. For the years ended December 31, 2016 and 2015, weighted-average common shares of 923,077 and 4,000,000 , respectively, related to outstanding warrants to purchase common shares at $33.33 per share, were not included in the computation of diluted per share amounts as the effect was antidilutive. The warrants expired in the first quarter of 2016. For the years ended December 31, 2017, 2016 and 2015 , 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. For the years ended December 31, 2017, 2016 and 2015 , 4,162,200 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. At December 31, 2017 , we are authorized to repurchase 12,500,000 common shares.

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Guarantees	Commitments, Contingencies and Guarantees Commitments We and our subsidiaries rent office space and office equipment under noncancellable operating leases with terms varying principally from one to twenty-two years. Rental expense (net of sublease rental income) was $80.8 million , $80.4 million and $84.0 million for the years ended December 31, 2017, 2016 and 2015 , respectively. Future minimum annual rentals (exclusive of month-to-month leases, real estate taxes, maintenance and certain other charges) under these leases at December 31, 2017 are as follows (in thousands): 2018 $ 94,734 2019 84,110 2020 68,195 2021 62,507 2022 59,844 Thereafter 638,441 1,007,831 Less: sublease income (29,633 ) $ 978,198 Effective December 30, 2004, National Beef finalized an agreement with the City of Dodge City, Kansas, whereby in consideration of certain improvements made to the city water and wastewater systems, National Beef committed to make a series of service charge payments totaling $19.3 million over a 20 year period, of which $4.9 million remains as of December 31, 2017 . Payments under the commitment will be approximately $0.8 million in each of the years 2018 through 2019, with the remaining balance of $3.3 million to be paid in subsequent years. The following table summarizes commitments associated with certain business activities (in millions): Expected Maturity Date 2018 2019 2020 2022 2024 Maximum Payout Equity commitments (1) $ 33.5 $ 0.2 $ 18.7 $ — $ 125.8 $ 178.2 Loan commitments (1) 277.7 — 56.5 — — 334.2 Mortgage-related and other purchase commitments — 177.7 — — — 177.7 Underwriting commitments 11.0 — — — — 11.0 Forward starting reverse repos (2) 3,211.1 — — — — 3,211.1 Forward starting repos (2) 2,987.9 — — — — 2,987.9 Other unfunded commitments (1) 218.8 122.9 18.3 153.0 — 513.0 $ 6,740.0 $ 300.8 $ 93.5 $ 153.0 $ 125.8 $ 7,413.1 (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 December 31, 2017 , $3,207.4 million within forward starting securities purchased under agreements to resell and $2,982.8 million within securities sold under agreements to repurchase settled within three business days. Equity Commitments. Equity commitments include commitments to invest in Jefferies 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 are managed by a team led by Brian P. Friedman, our President and a Director. As of December 31, 2017 , Jefferies outstanding commitments relating to Jefferies Capital Partners, LLC and its private equity funds was $22.0 million . See Note 10 for additional information regarding Jefferies investment in Jefferies Finance. Our equity commitments also include our commitment to invest in 54 Madison, a fund which targets real estate projects. We plan to invest a cumulative total of $202.5 million to this fund, of which we have already contributed $144.8 million . Capital commitments are contingent upon approval of the related investment by the investment committee, of which we have two of the four seats. Through December 31, 2017 , approved unfunded commitments totaled $28.0 million . Additionally, as of December 31, 2017 , we have other equity commitments to invest up to $14.4 million in various other investments. Loan Commitments. From time to time Jefferies 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. As of December 31, 2017 , Jefferies has $68.3 million of outstanding loan commitments to clients. Loan commitments outstanding as of December 31, 2017 , also include Jefferies portion of the outstanding secured revolving credit facility provided to Jefferies Finance to support loan underwritings by Jefferies Finance. At December 31, 2017 , none of Jefferies $250.0 million commitment was funded. In August 2014, we and Solomon Kumin established Folger Hill; we committed to provide Folger Hill with a three -year, $20.0 million revolving credit facility to fund its start-up and initial operating expenses. During the third quarter of 2017, the facility was amended to extend the maturity date until December 31, 2018 and to provide for an optional termination right for the Company with ten days prior written notice. As of December 31, 2017 , $10.2 million has been provided to Folger Hill under the revolving credit facility. Mortgage-Related and Other Purchase Commitments. Jefferies enters into forward contracts to purchase mortgage participation certificates, mortgage-backed securities and consumer loans. The mortgage participation certificates evidence interests in mortgage loans insured by the Federal Housing Administration and the mortgage-backed securities are insured or guaranteed by Fannie Mae, Freddie Mac or Ginnie Mae. Jefferies frequently securitizes the mortgage participation certificates and mortgage-backed securities. The fair value of mortgage-related and other purchase commitments recorded in the Consolidated Statement of Financial Condition at December 31, 2017 was $37.6 million . Underwriting Commitments. In connection with investment banking activities, Jefferies may from time to time provide underwriting commitments to its clients in connection with capital raising transactions. Forward Starting Reverse Repos and Repos. Jefferies 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 dealer activities cause it to make markets and trade in a variety of derivative instruments. Certain derivative contracts that Jefferies 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 maximum potential payout under these contracts. The following table summarizes the notional amounts associated with our derivative contracts meeting the definition of a guarantee under GAAP as of December 31, 2017 (in millions): Expected Maturity Date Guarantee Type 2018 2019 2020 2022 2024 Notional/ Maximum Payout Derivative contracts – non-credit related $ 24,454.8 $ 2,420.2 $ 150.5 $ 45.9 $ 466.3 $ 27,537.7 Written derivative contracts – credit related — 42.0 20.5 155.7 — 218.2 Total derivative contracts $ 24,454.8 $ 2,462.2 $ 171.0 $ 201.6 $ 466.3 $ 27,755.9 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 substantially mitigates its exposure to market risk on these contracts through hedges, such as other derivative contracts and/or cash instruments and Jefferies manages the risk associated with these contracts in the context of its overall risk management framework. Jefferies 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 $243.6 million as of December 31, 2017 . 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. As of December 31, 2017 , the aggregate amount of commercial paper outstanding was $1.47 billion . Other Guarantees. Jefferies is a member of various exchanges and clearing houses. In the normal course of business Jefferies provides guarantees to securities clearinghouses 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 clearinghouse, other members would be required to meet these shortfalls. To mitigate these performance risks, the exchanges and clearinghouses often require members to post collateral. Jefferies obligations under such guarantees could exceed the collateral amounts posted. Jefferies maximum potential liability under these arrangements cannot be quantified; however, the potential for Jefferies to be required to make payments under such guarantees is deemed remote. Accordingly, no liability has been recognized for these arrangements. Indemnification. In connection with the 2013 sale of Empire Insurance Company, we agreed to indemnify the buyer for certain of Empire’s lease obligations that were assumed by another subsidiary of ours as part of the sale of Empire. Our subsidiary was subsequently sold in 2014 to HomeFed as part of the real estate transaction with HomeFed. Although HomeFed has agreed to indemnify us for these lease obligations, our indemnification obligation under the Empire transaction remains. The primary lease expires in 2018 and the aggregate amount of lease obligation as of December 31, 2017 was approximately $9.8 million . Substantially all of the space under the primary lease has been sublet to various third-party tenants for the full length of the lease term in amounts in excess of the obligations under the primary lease. Standby Letters of Credit. At December 31, 2017 , Jefferies 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 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 $15.0 million at December 31, 2017 . Primarily all letters of credit expire within one year.

Net Capital Requirements

Net Capital Requirements	12 Months Ended
	Dec. 31, 2017
Brokers and Dealers [Abstract]
Net Capital Requirements	Net Capital Requirements Jefferies 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 dully-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. In November 2017, Jefferies Execution Services, Inc. merged with and into Jefferies LLC, with Jefferies LLC as the surviving entity. Jefferies LLC’s net capital and excess net capital as of December 31, 2017 were $1,418.9 million and $1,330.2 million , respectively. FINRA is the designated examining authority for Jefferies U.S. broker-dealer and the NFA is the designated self-regulatory organization for Jefferies LLC as an FCM. Certain other U.S. and non-U.S. subsidiaries of Jefferies 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 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	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [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): December 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Other Assets: Notes and loans receivable (1) $ 579,071 $ 565,285 $ 962,938 $ 958,377 Financial Liabilities: Short-term borrowings (2) 412,891 412,891 525,842 525,842 Long-term debt (3) 7,278,827 7,678,210 7,131,587 7,221,459 (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	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Jefferies Capital Partners Related Funds. Jefferies 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 December 31, 2017 and 2016 are Jefferies equity investments in Private Equity Related Funds of $23.7 million and $37.7 million , respectively. Net losses aggregating $11.7 million , $2.3 million and $26.2 million were recorded in Other revenues related to the Private Equity Related Funds for the years ended December 31, 2017, 2016 and 2015 , respectively. For further information regarding our commitments and funded amounts to the Private Equity Related Funds, see Notes 9 and 24 . Berkadia Commercial Mortgage, LLC. At December 31, 2017 and 2016 , Jefferies has commitments to purchase $864.1 million and $817.0 million , respectively, in agency commercial mortgage-backed securities from Berkadia. Officers, Directors and Employees. We have $45.6 million and $41.2 million of loans outstanding to certain officers and employees (none of whom are an executive officer or director of the Company) at December 31, 2017 and 2016 , 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. At December 31, 2016, Jefferies provided a guarantee of a credit agreement for a private equity fund owned by Jefferies employees and in April 2017 this guarantee was terminated. National Beef. National Beef participates in a cattle supply agreement with a minority owner and holder of a redeemable noncontrolling interest in National Beef. Under this agreement, National Beef has agreed to purchase 735,385 head of cattle each year (subject to adjustment), from the members of the minority owner, with prices based on those published by the U.S. Department of Agriculture, subject to adjustments for cattle performance. National Beef obtained approximately 24% and 27% of its cattle requirements under this agreement during 2017 and 2016 , respectively. National Beef also enters into transactions with an affiliate of another minority owner and holder of a redeemable noncontrolling interest in National Beef to buy and sell a limited number of beef products. During the year ended December 31, 2017 , sales to this affiliate were $31.7 million and purchases were $13.4 million . During the year ended December 31, 2016 , sales to this affiliate were $30.9 million and purchases were $14.8 million . At December 31, 2017 and 2016 , amounts due from and payable to these related parties were not significant. HomeFed. During 2014, we sold to HomeFed substantially all of our then owned real estate properties and operations as well as cash of approximately $14.0 million , in exchange for 7,500,000 newly issued unregistered HomeFed common shares. As discussed in Note 10, as a result of a 1998 distribution to all of our shareholders, approximately 4.8% of HomeFed is beneficially owned by our Chairman at December 31, 2017 . Three of our executives serve on the board of directors of HomeFed, including our Chairman who serves as HomeFed’s Chairman, and our President. 54 Madison. At December 31, 2016 , approximately $230.2 million , of long-term debt held by 54 Madison is owed to minority owners of 54 Madison. The interest rate on these long-term notes range between 4.2% and 6.0% . As a result of the sale of our interest in the general partner during 2017, the 54 Madison fund has been deconsolidated and is reflected in Loans to and investments in associated companies at December 31, 2017 . In the first quarter of 2016, 54 Madison purchased the equity interests in a real estate investment from a minority owner of 54 Madison for $86.5 million . See Note 10 for information on transactions with Jefferies Finance and Jefferies LoanCore.

Discontinued Operations and Ass

Discontinued Operations and Assets Held for Sale	12 Months Ended
	Dec. 31, 2017
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Discontinued Operations and Assets Held for Sale	Discontinued Operations and Assets Held for Sale 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. At December 31, 2016, the net book value of our investment in Conwed was $100.6 million . A pre-tax gain of $178.2 million (net of working capital adjustments) was recognized during the year ended December 31, 2017. The sale of Conwed did not meet the GAAP criteria to be classified as a discontinued operation. Assets held for sale at December 31, 2016, which primarily relate to Conwed, are as follows (in thousands): Cash $ 5,206 Receivables 15,297 Property, equipment and leasehold improvements, net 18,664 Intangible assets, net and goodwill 56,854 Inventory 19,069 Other assets 12,993 $ 128,083 Liabilities held for sale at December 31, 2016 were $14.7 million and are included in Payables, expense accruals and other liabilities. Gain on disposal of discontinued operations for the year ended December 31, 2015, primarily relates to additional consideration received related to the 2012 sale of our small Caribbean-based telecommunications provider, and a reversal of a legal reserve.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
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, National Beef, and Corporate and other. Jefferies is a global full-service, integrated securities and investment banking firm. National Beef processes and markets fresh boxed beef, consumer-ready beef, beef by-products and wet blue leather for domestic and international markets. Corporate and other assets primarily consist of financial instruments owned, the deferred tax asset (exclusive of Jefferies deferred tax asset), cash and cash equivalents. Corporate and other revenues primarily consist of interest, other income and net realized securities gains and losses. We do not allocate Corporate and other revenues or overhead expenses to the operating units. All other consists of our other financial services businesses and investments and our other 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, FXCM and HomeFed. Our other merchant banking businesses and investments primarily include Idaho Timber, Conwed, Vitesse, JETX, and our investments in HRG, Garcadia, Linkem and Golden Queen. Certain information concerning our segments for the years ended December 31, 2017, 2016 and 2015 is presented in the following table. Consolidated subsidiaries are reflected as of the date a majority controlling interest was acquired. As discussed above, Jefferies is reflected in our consolidated financial statements utilizing a one month lag. 2017 2016 2015 (In thousands) Net Revenues: Reportable Segments: Jefferies $ 3,207,097 $ 2,421,055 $ 2,476,133 National Beef 7,358,948 7,027,243 7,402,419 Corporate and other 62,847 88,590 78,122 Total net revenues related to reportable segments 10,628,892 9,536,888 9,956,674 All other (1) 807,501 525,729 950,784 Intercompany eliminations (2) — — (21,000 ) Total consolidated net revenues $ 11,436,393 $ 10,062,617 $ 10,886,458 Income (loss) from continuing operations before income taxes: Reportable Segments: Jefferies $ 527,804 $ 43,508 $ 119,165 National Beef 407,312 329,022 (123,915 ) Corporate and other (78,926 ) 18,386 (44,295 ) Income (loss) from continuing operations before income taxes related to reportable segments 856,190 390,916 (49,045 ) All other (1) 216,567 (15,605 ) 492,762 Parent Company interest (58,943 ) (58,881 ) (87,181 ) Total consolidated income from continuing operations before income taxes $ 1,013,814 $ 316,430 $ 356,536 Depreciation and amortization expenses: Reportable Segments: Jefferies $ 62,668 $ 60,206 $ 92,165 National Beef 98,515 94,482 89,317 Corporate and other 5,178 3,619 3,744 Total depreciation and amortization expenses related to reportable segments 166,361 158,307 185,226 All other 42,549 53,286 38,907 Total consolidated depreciation and amortization expenses $ 208,910 $ 211,593 $ 224,133 Identifiable assets employed: Reportable Segments: Jefferies (3) $ 39,575,732 $ 36,992,096 $ 38,607,786 National Beef 1,460,539 1,498,317 1,514,249 Corporate and other 2,006,536 1,935,118 1,777,199 Identifiable assets employed related to reportable segments 43,042,807 40,425,531 41,899,234 All other 4,196,622 4,728,457 4,581,673 Intercompany eliminations (70,321 ) (82,681 ) (149,723 ) Total consolidated assets $ 47,169,108 $ 45,071,307 $ 46,331,184 (1) All other revenue and income from continuing operations before income taxes include $23.2 million and $(154.5) million , respectively, of realized and unrealized gains (losses) relating to our investment in FXCM for the year ended December 31, 2017 . All other revenue and income from continuing operations before income taxes include $(54.6) million and $491.3 million of realized and unrealized gains (losses) relating to our investment in FXCM for the years ended December 31, 2016 and 2015 , respectively. (2) Revenue intercompany elimination for 2015 relates to an investment banking and advisory fee paid to Jefferies in connection with our entering into the agreement with FXCM. (3) At December 31, 2017, 2016 and 2015 , includes $213.0 million , $337.6 million and $320.2 million , respectively, of Jefferies deferred tax asset, net. Net revenues for Jefferies are recorded in the geographic region in which the position was risk-managed, in the case of investment banking, in which the senior coverage banker is located, or for asset management, according to the location of the investment advisor. Net revenues by geographic region for Jefferies for the years ended December 31, 2017, 2016 and 2015 were as follows (in thousands): 2017 2016 2015 Americas (1) $ 2,611,729 $ 1,876,796 $ 1,887,899 Europe (2) 489,583 458,046 510,044 Asia 105,785 86,213 78,190 $ 3,207,097 $ 2,421,055 $ 2,476,133 (1) Substantially all relates to U.S. results. (2) Substantially all relates to U.K. results. Approximately 88.8% , 89.2% and 89.5% of National Beef's revenues for the years ended December 31, 2017, 2016 and 2015 , respectively, relate to sales made in the U.S. The remainder of National Beef's revenues primarily relate to sales made in Asia. Consolidated net revenues exclusive of Jefferies and National Beef principally relate to the U.S. for 2017, 2016 and 2015 . Net realized securities gains for Corporate and other aggregated $23.0 million , $16.4 million and $63.0 million during 2017, 2016 and 2015 , respectively. Interest expense classified as a component of Net revenues relates to Jefferies. For the years ended December 31, 2017, 2016 and 2015 , interest expense classified as a component of Expenses was primarily comprised of National Beef ( $6.7 million , $12.9 million and $16.6 million , respectively), parent company interest ( $58.9 million , $58.9 million and $87.2 million , respectively) and all other ( $42.2 million , $36.9 million and $12.0 million , respectively).

Exit Costs

Exit Costs	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Exit Costs	Exit Costs Jefferies Bache. On April 9, 2015, Jefferies entered into an agreement with Société Générale S.A. (the "Agreement") to transfer certain client exchange and over-the-counter transactions associated with Jefferies Futures business for the net book value of the over-the-counter transactions, calculated in accordance with certain principles set forth in the Agreement, plus the repayment of certain margin loans in respect of certain exchange transactions. In addition, Jefferies initiated a plan to substantially exit the remaining aspects of its futures business, which was completed during the second quarter of 2016. In addition, Jefferies terminated its $750.0 million credit facility on July 31, 2015. During the year ended December 31, 2015, Jefferies recognized costs of $3.8 million related to the Credit Facility. During the years ended December 31, 2016 and 2015, Jefferies recorded restructuring and impairment costs as follows (in thousands): 2016 2015 Severance costs $ 279 $ 30,327 Accelerated amortization of restricted stock and restricted cash awards 41 7,922 Accelerated amortization of capitalized software — 19,745 Contract termination costs 1,234 11,247 Selling, general and other expenses 300 3,853 Total $ 1,854 $ 73,094 Of the above costs, $0.3 million and $28.7 million for the years ended December 31, 2016 and 2015, respectively, are of a non-cash nature. Severance costs and amortization of restricted stock and restricted cash awards are recorded as Compensation and benefits, amortization of capitalized software is recorded as Depreciation and amortization and contract termination costs are recorded as Selling, general and other expenses in the Consolidated Statements of Operations.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data	Selected Quarterly Financial Data (Unaudited) First Quarter (1) Second Quarter (2) Third Quarter (3) Fourth Quarter (4) (In thousands, except per share amounts) 2017 Net revenues $ 2,867,982 $ 2,732,380 $ 2,896,522 $ 2,939,509 Income (loss) from continuing operations $ 293,923 $ 74,062 $ 136,767 $ (251,905 ) Net (income) loss attributable to the noncontrolling interest $ 523 $ 1,446 $ (28 ) $ 1,514 Net income attributable to the redeemable noncontrolling interests $ (12,022 ) $ (16,300 ) $ (36,216 ) $ (20,038 ) Preferred stock dividends $ (1,016 ) $ (1,015 ) $ (1,172 ) $ (1,172 ) Net income (loss) attributable to Leucadia National Corporation common shareholders $ 281,408 $ 58,193 $ 99,351 $ (271,601 ) Basic earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ 0.76 $ 0.16 $ 0.27 $ (0.74 ) Number of shares used in calculation 369,267 369,212 367,828 366,000 Diluted earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ 0.75 $ 0.16 $ 0.27 $ (0.74 ) Number of shares used in calculation 375,721 371,552 370,198 366,000 2016 Net revenues $ 2,015,106 $ 2,625,358 $ 2,676,375 $ 2,745,778 Income (loss) from continuing operations $ (218,602 ) $ 70,612 $ 176,206 $ 166,105 Net (income) loss attributable to the noncontrolling interest $ 1,052 $ 760 $ 1,870 $ (2,256 ) Net income attributable to the redeemable noncontrolling interests $ (4,314 ) $ (13,068 ) $ (22,702 ) $ (25,662 ) Preferred stock dividends $ (1,016 ) $ (1,015 ) $ (1,016 ) $ (1,016 ) Net income (loss) attributable to Leucadia National Corporation common shareholders $ (222,880 ) $ 57,289 $ 154,358 $ 137,171 Basic earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ (0.60 ) $ 0.15 $ 0.41 $ 0.37 Number of shares used in calculation 372,367 372,556 370,404 369,299 Diluted earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ (0.60 ) $ 0.15 $ 0.41 $ 0.37 Number of shares used in calculation 372,367 372,556 374,567 374,693 (1) The first quarter of 2017 includes a pre-tax gain of $179.9 million related to the sale of Conwed Plastics, revenue of $175.2 million related to the increase in fair value of our investment in HRG and a pre-tax charge of $130.2 million related to an impairment of our equity investment in FXCM. Net revenues for the first quarter of 2016 were impacted by a volatile and turbulent period in the capital markets, which primarily impacted Jefferies and our other market sensitive businesses. Net revenues in the first quarter of 2016 include losses of $82.2 million from Jefferies investment in two equity block positions, including KCG, and a loss of $53.2 million from a decline in fair value of our FXCM investment. The first quarter of 2016 also includes revenue of $65.6 million related to the increase in a corporate trading asset held at fair value. (2) The second quarter of 2017 includes losses of $75.0 million from a decrease in fair value of our investment in HRG and revenue of $95.8 million from an increase in fair value of Jefferies investment in KCG. Net revenues in the second quarter of 2016 includes revenue of $55.8 million from an increase in fair value of Jefferies investment in KCG and a loss of $47.9 million from a decline in fair value of our FXCM investment. (3) The third quarter of 2017 includes losses of $97.9 million from a decrease in fair value of our investment in HRG. The third quarter of 2016 includes revenue of $91.8 million from an increase in fair value of our investment in HRG and revenue of $42.7 million from an increase in fair value of our FXCM investment. The third quarter of 2016 also includes a pre-tax charge of $55.0 million related to an impairment of JETX's unproved oil and gas properties in the East Eagle Ford and Houston County. (4) As discussed further in Note 20, the fourth quarter of 2017 includes a discrete tax charge of $450.5 million as a provisional estimate of the impact of the Tax Act. This provisional estimate primarily consists of a $415.0 million expense related to the revaluation of our deferred tax assets and a $35.5 million expense related to the deemed repatriation of foreign earnings. In 2017 and 2016 , the totals of quarterly per share amounts may not equal annual per share amounts because of changes in outstanding shares during the year.

Schedule I - Condensed Financia

Schedule I - Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule I - Condensed Financial Information of Registrant	Schedule I - Condensed Financial Information of Registrant LEUCADIA NATIONAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Financial Condition December 31, 2017 and 2016 (Dollars in thousands, except par value) 2017 2016 ASSETS Cash and cash equivalents $ 12,317 $ 105,222 Financial instruments owned: Trading assets, at fair value 200,804 223,218 Available for sale securities 16,378 15,635 Total financial instruments owned 217,182 238,853 Investments in subsidiaries 18,615,819 18,412,037 Advances to subsidiaries 542,976 235,879 Investments in associated companies 288,382 273,518 Deferred tax asset, net 205,773 346,684 Other assets 8,815 13,993 Total $ 19,891,264 $ 19,626,186 LIABILITIES Accrued interest payable $ 11,447 $ 11,447 Pension liabilities 52,841 69,152 Other payables, expense accruals and other liabilities 31,919 39,284 Advances from subsidiaries 8,575,079 8,265,312 Long-term debt 989,021 987,891 Total liabilities 9,660,307 9,373,086 Commitments and contingencies MEZZANINE EQUITY Mandatorily redeemable convertible preferred shares 125,000 125,000 EQUITY Common shares, par value $1 per share, authorized 600,000,000 shares; 356,227,038 and 359,425,061 shares issued and outstanding, after deducting 60,165,980 and 56,947,654 shares held in treasury 356,227 359,425 Additional paid-in capital 4,676,038 4,812,587 Accumulated other comprehensive income 372,724 310,697 Retained earnings 4,700,968 4,645,391 Total Leucadia National Corporation shareholders’ equity 10,105,957 10,128,100 Total $ 19,891,264 $ 19,626,186 See accompanying notes to condensed financial statements. Schedule I - Condensed Financial Information of Registrant, continued LEUCADIA NATIONAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Operations For the years ended December 31, 2017, 2016 and 2015 (In thousands, except per share amounts) 2017 2016 2015 Revenues: Principal transactions $ (9,754 ) $ 16,735 $ 491,341 Other 277 2,300 1,477 Total revenues (9,477 ) 19,035 492,818 Expenses: Compensation and benefits 47,462 39,693 58,899 WilTel pension 2,957 2,989 50,836 Interest 58,943 58,881 87,181 Intercompany interest expense 361,446 293,527 241,906 Selling, general and other expenses 20,821 19,244 26,784 491,629 414,334 465,606 Income (loss) from continuing operations before income taxes, income related to associated companies and equity in earnings of subsidiaries (501,106 ) (395,299 ) 27,212 Income related to associated companies 3,183 21,195 3,479 Income (loss) from continuing operations before income taxes and equity in earnings of subsidiaries (497,923 ) (374,104 ) 30,691 Income tax provision (benefit) (47,329 ) (117,699 ) 267 Income (loss) from continuing operations before equity in earnings of subsidiaries (450,594 ) (256,405 ) 30,424 Equity in earnings of subsidiaries, net of taxes 622,320 386,406 247,704 Income from continuing operations 171,726 130,001 278,128 Equity in income from discontinued operations, net of taxes — — 429 Equity in gain on disposal of discontinued operations, net of taxes — — 5,093 Net income 171,726 130,001 283,650 Preferred stock dividends (4,375 ) (4,063 ) (4,063 ) Net income attributable to Leucadia National Corporation common shareholders $ 167,351 $ 125,938 $ 279,587 Basic earnings per common share attributable to Leucadia National Corporation common shareholders: Income from continuing operations $ 0.45 $ 0.34 $ 0.73 Income from discontinued operations — — — Gain on disposal of discontinued operations — — 0.01 Net income $ 0.45 $ 0.34 $ 0.74 Diluted earnings per common share attributable to Leucadia National Corporation common shareholders: Income from continuing operations $ 0.45 $ 0.34 $ 0.73 Income from discontinued operations — — — Gain on disposal of discontinued operations — — 0.01 Net income $ 0.45 $ 0.34 $ 0.74 Dividends per common share $ 0.325 $ 0.250 $ 0.250 See accompanying notes to condensed financial statements. Schedule I - Condensed Financial Information of Registrant, continued LEUCADIA NATIONAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Comprehensive Income (Loss) For the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Net income $ 171,726 $ 130,001 $ 283,650 Other comprehensive income (loss): Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $3,450, $2,262 and $(5,029) 5,923 3,900 (9,057 ) Less: reclassification adjustment for net (gains) losses included in net income, net of income tax provision (benefit) of $124, $2 and $6,068 (212 ) (4 ) (10,930 ) Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $3,326, $2,260 and $(11,097) 5,711 3,896 (19,987 ) Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $14,616, $(3,530) and $(5,174) 78,493 (121,581 ) (36,477 ) Less: reclassification adjustment for foreign exchange (gains) losses included in net income, net of income tax provision (benefit) of $1,086, $0 and $0 5,310 — — Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $13,530, $(3,530) and $(5,174) 83,803 (121,581 ) (36,477 ) Net unrealized gains (losses) on instrument specific credit risk arising during the period, net of income tax provision (benefit) of $(13,215), $(4,251) and $0 (21,394 ) (6,494 ) — Net change in unrealized instrument specific credit risk gains (losses), net of income tax provision (benefit) of $(13,215), $(4,251) and $0 (21,394 ) (6,494 ) — Net unrealized gains (losses) on cash flow hedges arising during the period, net of income tax provision (benefit) of $(593), $0 and $0 (936 ) — — Net change in unrealized cash flow hedges gains (losses), net of income tax provision (benefit) of $(593), $0 and $0 (936 ) — — Net pension gains (losses) arising during the period, net of income tax provision (benefit) of $2,018, $(2,516) and $7,152 3,526 (5,451 ) 17,073 Less: reclassification adjustment for pension (gains) losses included in net income, net of income tax provision (benefit) of $(2,042), $(700) and $(17,159) 517 1,534 31,102 Net change in pension liability benefits, net of income tax provision (benefit) of $4,060, $(1,816) and $24,311 4,043 (3,917 ) 48,175 Other comprehensive income (loss), net of income taxes 71,227 (128,096 ) (8,289 ) Comprehensive income 242,953 1,905 275,361 Preferred stock dividends (4,375 ) (4,063 ) (4,063 ) Comprehensive income (loss) attributable to Leucadia National Corporation common shareholders $ 238,578 $ (2,158 ) $ 271,298 See accompanying notes to condensed financial statements. Schedule I - Condensed Financial Information of Registrant, continued LEUCADIA NATIONAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Cash Flows For the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Net cash flows from operating activities: Net income $ 171,726 $ 130,001 $ 283,650 Adjustments to reconcile net income to net cash used for operations: Deferred income tax provision (benefit) 116,942 (12,220 ) (2,457 ) Accretion of interest 975 921 1,788 Share-based compensation 48,384 33,597 74,087 Equity in earnings of subsidiaries (622,320 ) (386,406 ) (253,226 ) Income related to associated companies (3,183 ) (21,195 ) (3,479 ) Distributions from associated companies 5,641 1,861 312 Change in estimated litigation reserve — — (88,500 ) Net change in: Trading assets 22,415 (40,235 ) (615,768 ) Other assets 1,250 (708 ) (49,006 ) Accrued interest payable — — (10,982 ) Pension liabilities (8,461 ) (13,111 ) 49,835 Other payables, expense accruals and other liabilities (7,763 ) (23,218 ) 558 Income taxes receivable/payable, net (164,684 ) (90,898 ) 6,640 Other 2,316 1,262 5,110 Net cash used for operating activities (436,762 ) (420,349 ) (601,438 ) Net cash flows from investing activities: Investments in subsidiaries (365,381 ) (427,933 ) (637,400 ) Distributions from subsidiaries 753,193 868,612 119,695 Advances on notes, loans and other receivables — — (279,000 ) Collections on notes, loans and other receivables — 16,233 144,652 Investments in associated companies (45,457 ) (11,611 ) (8,101 ) Capital distributions from associated companies 2,796 1,501 1,317 Purchases of investments (other than short-term) (1,316 ) (2,242 ) (7,968 ) Other 1,886 150 276 Net cash provided by (used for) investing activities 345,721 444,710 (666,529 ) Net cash flows from financing activities: Repayment of debt — — (458,641 ) Advances from (to) subsidiaries, net 214,519 265,762 1,943,961 Issuance of common shares 1,501 1,062 1,223 Purchase of common shares for treasury (100,477 ) (95,020 ) (125,754 ) Dividends paid (117,407 ) (91,296 ) (92,550 ) Net cash provided by (used for) financing activities (1,864 ) 80,508 1,268,239 Net increase (decrease) in cash and cash equivalents (92,905 ) 104,869 272 Cash and cash equivalents at January 1, 105,222 353 81 Cash and cash equivalents at December 31, $ 12,317 $ 105,222 $ 353 See accompanying notes to condensed financial statements. Schedule I - Condensed Financial Information of Registrant, continued LEUCADIA NATIONAL CORPORATION (PARENT COMPANY ONLY) Notes to Condensed Financial Statements 1. Introduction and Basis of Presentation The notes to the consolidated financial statements of Leucadia National Corporation and Subsidiaries (the "Company") are incorporated by reference into this schedule. For purposes of these condensed non-consolidated financial statements, the Company's wholly-owned and majority owned subsidiaries are accounted for using the equity method of accounting ("equity method subsidiaries"). The Parent Company Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States (" GAAP"). The significant accounting policies of the Parent Company Financial Statements are those used by the Company on a consolidated basis, to the extent applicable. For further information regarding the significant accounting policies refer to Note 2, Significant Accounting Policies, in the Company's consolidated financial statements included in the 2017 10-K. The Company has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these financial statements in conformity with GAAP. The most important of these estimates and assumptions relate to fair value measurements, goodwill and intangible assets, the ability to realize deferred tax assets and the recognition and measurement of uncertain tax positions. Although these and other estimates and assumptions are based on the best available information, actual results could be materially different from these estimates. 2. Cash Flows Supplemental cash flow information related to the Parent Company for the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands): 2017 2016 2015 Cash paid during the year for: Interest $ 57,813 $ 57,813 $ 95,074 Income tax payments (refunds), net $ 1,440 $ (10,199 ) $ (2,332 ) Non-cash investing activities: Investments contributed to subsidiary $ 25,328 $ 423,009 $ — Investments transferred from subsidiary $ — $ 2,022 $ — Dividends received from subsidiaries $ 32,792 $ — $ — 3. Transactions with Subsidiaries The Parent Company has transactions with its equity method subsidiaries, many of which are structured as interest bearing advances to/from its subsidiaries. Intercompany interest expense primarily reflects the interest on funding advances incurred by the Parent to its wholly-owned subsidiary which holds assets related to its treasury function. Interest is incurred on funding advances based on the prime rate plus .125% . Although there is frequent cash movement between these subsidiaries and the Parent, they do not represent cash dividends. As such, the Parent Company received no cash dividends from its subsidiaries during the three years ended December 31, 2017 . Historically, excess cash was provided to the Parent Company by its subsidiaries in the form of loans rather than as distributions. Through a series of steps, the Parent Company is reducing these intercompany loans to zero . From January 1, 2018 through February 15, 2018, the Parent Company received non-cash dividends totaling $7.9 billion from its subsidiaries. Of this amount, $7.9 billion will be reflected as a decrease in our Investment in subsidiaries, $0.2 billion will be reflected as a decrease to Advances to subsidiaries and $8.1 billion will be reflected as a decrease to Advances from subsidiaries. 4. Commitments, Contingencies and Guarantees In the normal course of its business, the Parent Company has various commitments, contingencies and guarantees as described in Note 24, Commitments, Contingencies and Guarantees, and Note 16, Mezzanine Equity, in the Company's consolidated financial statements. 5. Restricted Net Assets For a discussion of the Company's regulatory requirements, see Note 25, Net Capital Requirements, in the Company's consolidated financial statements. Some of the Company's 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. At December 31, 2017 and 2016 , $6.1 billion and $6.0 billion , respectively, of net assets of the Parent Company's consolidated subsidiaries are restricted as to the payment of cash dividends, or the ability to make loans or advances to the Parent Company. At December 31, 2017 and 2016 , $5.1 billion and $4.8 billion , respectively, of these net assets are restricted as they reflect regulatory capital requirements or require regulatory approval prior to the payment of cash dividends and advances to the Parent Company. Included in retained earnings of the Parent Company at December 31, 2017 are $202.9 million of undistributed earnings of unconsolidated associated companies. For further information, see Note 10, Loans to and Investments in Associated Companies, in the Company's consolidated financial statements.

Significant Accounting Polici43

Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Consolidation	Consolidation Our policy is to consolidate all entities in which we can vote a majority of the outstanding voting stock. In addition, we consolidate entities which meet the definition of a variable interest entity for which we are the primary beneficiary. The primary beneficiary is the party who has the power to direct the activities of a variable interest entity that most significantly impact the entity’s economic performance and who has 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. We consider special allocations of cash flows and preferences, if any, to determine amounts allocable to noncontrolling interests. All intercompany transactions and balances are eliminated in consolidation. In situations where we have significant influence, but not control, of an entity that does not qualify as a variable interest entity, we apply either the equity method of accounting or fair value accounting pursuant to the fair value option election under GAAP. We have also formed nonconsolidated investment vehicles with third-party investors that are typically organized as partnerships or limited liability companies. Our subsidiaries may act as general partner or managing member for these investment vehicles and have generally provided the third-party investors with termination or “kick-out” rights.
Revenue Recognition Policies	Revenue Recognition Policies Beef Processing and Other Operations Revenues are recognized when the following conditions are met: (1) collectibility is reasonably assured; (2) title to the product has passed or the service has been rendered and earned; (3) persuasive evidence of an arrangement exists; and (4) there is a fixed or determinable price. National Beef’s revenues are recognized based on the terms of the sale, which for beef processing operations is typically upon delivery to customers. Manufacturing revenues are recognized when title passes. Investment Banking Activities Commissions and Other Fees. All customer securities transactions are reported in the Consolidated Statements of Financial Condition on a settlement date basis with related income reported on a trade date basis. We permit 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. These arrangements are accounted for on an accrual basis and, as we are not the primary obligor for these arrangements, netted against commission revenues in the Consolidated Statements of Operations. In addition, we earn asset-based fees associated with the management and supervision of assets, account services and administration related to customer accounts. Principal Transactions. Trading assets and trading liabilities (all of which are recorded on a trade-date basis) are carried at fair value with gains and losses reflected in Principal transaction revenues in the Consolidated Statements of Operations, except for derivatives accounted for as hedges (see Hedge Accounting section, herein and Note 5). Fees received on loans carried at fair value are also recorded within Principal transaction revenues. Investment Banking. Underwriting revenues and fees from mergers and acquisitions, restructuring and other investment banking advisory assignments or engagements are recorded when the services related to the underlying transactions are completed under the terms of the assignment or engagement. Expenses associated with such assignments are deferred until reimbursed by the client, the related revenue is recognized or the engagement is otherwise concluded. Expenses are recorded net of client reimbursements and netted against revenues. Unreimbursed expenses with no related revenues are included in Selling, general and administrative expenses in the Consolidated Statements of Operations. Interest Revenue and Expense. Interest expense that is deducted from Revenues to arrive at Net revenues is related to Jefferies operations. Contractual interest on Trading assets and Trading liabilities is recognized on an accrual basis as a component of Interest income and Interest expense. Interest flows on derivative trading transactions and dividends are included as part of the fair valuation of these contracts and recognized in Principal transactions in the Consolidated Statements of Operations rather than as a component of interest income or expense. Interest on short- and long-term borrowings is recorded on an accrual basis, except for those for which we have elected the fair value option, as Interest expense. Discounts/premiums arising on long-term debt are accreted/amortized to Interest expense using the effective yield method over the remaining lives of the underlying debt obligations. Interest revenue related to Securities borrowed and Securities purchased under agreements to resell activities and interest expense related to Securities loaned and Securities sold under agreements to repurchase activities are recognized on an accrual basis.
Hedge Accounting	Hedge Accounting Jefferies applies hedge accounting using interest rate swaps designated as fair value hedges of changes in the benchmark interest rate of fixed rate senior long-term debt. Jefferies interest rate swaps are included as derivative contracts in Trading assets and Trading liabilities in the Consolidated Statements of Financial Condition. Jefferies uses regression analysis to perform ongoing prospective and retrospective assessments of the effectiveness of these hedging relationships. A hedging relationship is deemed effective if the change in fair value of the interest rate swap and the change in the fair value of the long-term debt due to changes in the benchmark interest rate offset within a range of 80% to 125% . The impact of valuation adjustments related to Jefferies own credit spreads and counterparty credit spreads are included in the assessment of effectiveness. For qualifying fair value hedges of benchmark interest rates, the change in the fair value of the derivative and the change in fair value of the long-term debt provide offset of one another, and together with any resulting ineffectiveness, are recorded in Interest expense. See Note 5 for further information.
Cash Equivalents	Cash Equivalents Cash equivalents include highly liquid investments, including money market funds and certificates of deposit, not held for resale with original maturities of three months or less.
Cash and Securities Segregated and on Deposit for Regulatory Purposes or Deposited With Clearing and Depository Organizations	Cash and Securities Segregated and on Deposit for Regulatory Purposes or Deposited With Clearing and Depository Organizations In accordance with Rule 15c3-3 of the Securities Exchange Act of 1934, Jefferies LLC, as a broker-dealer carrying client accounts, is subject to requirements related to maintaining cash or qualified securities in a segregated reserve account for the exclusive benefit of its clients. Certain other entities are also obligated by rules mandated by their primary regulators to segregate or set aside cash or equivalent securities to satisfy regulations, promulgated to protect customer assets. In addition, certain exchange and/or clearing organizations require cash and/or securities to be deposited by us to conduct day to day activities.
Financial Instruments and Fair Value	Financial Instruments and Fair Value Trading assets and Trading liabilities are recorded at fair value, either as required by accounting pronouncements or through the fair value option election. Gains and losses on trading assets and trading liabilities are recognized in our Consolidated Statements of Operations in Principal transactions. Available for sale securities are reflected at fair value, with unrealized gains and losses reflected as a separate component of equity, net of taxes. When sold, realized gains and losses on available for sale securities are reflected in the caption Net realized securities gains. The cost of securities sold is based on average cost. Fair value is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (the exit price).
Fair Value Hierarchy	Fair Value Hierarchy In determining fair value, we maximize the use of observable inputs and minimize the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from independent sources. Unobservable inputs reflect our assumptions that market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. We apply a hierarchy to categorize our fair value measurements broken down into three levels based on the transparency of inputs as follows: Level 1: Quoted prices are available in active markets for identical assets or liabilities as of the reported date. Valuation adjustments and block discounts are not applied to Level 1 instruments. Level 2: Pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reported date. The nature of these financial instruments includes cash instruments for which quoted prices are available but traded less frequently, derivative instruments fair values for which have been derived using model inputs that are directly observable in the market, or can be derived principally from or corroborated by observable market data, and instruments that are fair valued using other financial instruments, the parameters of which can be directly observed. Level 3: Instruments that have little to no pricing observability as of the reported date. These financial instruments are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment or estimation. Financial instruments are valued at quoted market prices, if available. Certain financial instruments have bid and ask prices that can be observed in the marketplace. For financial instruments whose inputs are based on bid-ask prices, the financial instrument is valued at the point within the bid-ask range that meets our best estimate of fair value. We use prices and inputs that are current as of the measurement date. For financial instruments that do not have readily determinable fair values using quoted market prices, the determination of fair value is based upon consideration of available information, including types of financial instruments, current financial information, restrictions on dispositions, fair values of underlying financial instruments and quotations for similar instruments. The valuation of financial instruments may include the use of valuation models and other techniques. Adjustments to valuations derived from valuation models may be made when, in management’s judgment, features of the financial instrument such as its complexity, the market in which the financial instrument is traded and risk uncertainties about market conditions require that an adjustment be made to the value derived from the models. Adjustments from the price derived from a valuation model reflect management’s judgment that other participants in the market for the financial instrument being measured at fair value would also consider in valuing that same financial instrument. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. The availability of observable inputs can vary and is affected by a wide variety of factors, including, for example, the type of financial instrument and market conditions. As the observability of prices and inputs may change for a financial instrument from period to period, this condition may cause a transfer of an instrument among the fair value hierarchy levels. Transfers among the levels are recognized at the beginning of each period. The degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3.
Valuation Process for Financial Instruments	Valuation Process for Financial Instruments The Jefferies Independent Price Verification ("IPV") Group, which is part of the Jefferies finance department, in partnership with Jefferies Risk Management, is responsible for establishing Jefferies valuation policies and procedures. The IPV Group and Risk Management, which are independent of business functions, play an important role and serve as a control function in determining that Jefferies financial instruments are appropriately reflected at fair value. This is particularly important where prices or valuations that require inputs are less observable. In the event that observable inputs are not available, the control processes are designed to assure that the valuation approach utilized is appropriate and consistently applied and that the assumptions are reasonable. The IPV Group reports to the Jefferies Global Controller and is subject to the oversight of the IPV Committee, which includes senior members of Jefferies finance department and other personnel. Jefferies independent price verification policies and procedures are reviewed, at a minimum, annually and changes to the policies require the approval of the IPV Committee. Price Testing Process . Jefferies business units are responsible for determining the fair value of Jefferies financial instruments using approved valuation models and methodologies. In order to ensure that the business unit valuations represent a fair value exit price, the IPV Group tests and validates the fair value of the financial instruments inventory. In the testing process, the IPV Group obtains prices and valuation inputs from sources independent of Jefferies, consistently adheres to established procedures set forth in the valuation policies for sourcing prices and valuation inputs and utilizing valuation methodologies. Sources used to validate fair value prices and inputs include, but are not limited to, exchange data, recently executed transactions, pricing data obtained from third party vendors, pricing and valuation services, broker quotes and observed comparable transactions. To the extent discrepancies between the business unit valuations and the pricing or valuations resulting from the price testing process are identified, such discrepancies are investigated by the IPV Group and fair values are adjusted, as appropriate. The IPV Group maintains documentation of its testing, results, rationale and recommendations and prepares a monthly summary of its valuation results. This process also forms the basis for the classification of fair values within the fair value hierarchy (i.e., Level 1, Level 2 or Level 3). The IPV Group utilizes the additional expertise of Risk Management personnel in valuing more complex financial instruments and financial instruments with less or limited pricing observability. The results of the valuation testing are reported to the IPV Committee on a monthly basis, which discusses the results and determines the financial instrument fair values in the consolidated financial statements. At each quarter end, the overall valuation results, as determined by the IPV Committee, are presented to the Jefferies Audit Committee. Judgment exercised in determining Level 3 fair value measurements is supplemented by daily analysis of profit and loss performed by the Product Control functions. Gains and losses, which result from changes in fair value, are evaluated and corroborated daily based on an understanding of each trading desk's overall risk positions and developments in a particular market on the given day. Valuation techniques generally rely on recent transactions of suitably comparable financial instruments and use the observable inputs from those comparable transactions as a validation basis for Level 3 inputs. Level 3 fair value measurements are further validated through subsequent sales testing and market comparable sales, if such information is available. Level 3 fair value measurements require documentation of the valuation rationale applied, which is reviewed for consistency in application from period to period. Third Party Pricing Information . Pricing information obtained from external data providers (including independent pricing services and brokers) may incorporate a range of market quotes from dealers, recent market transactions and benchmarking model derived prices to quoted market prices and trade data for comparable securities. External pricing data is subject to evaluation for reasonableness by the IPV Group using a variety of means including comparisons of prices to those of similar product types, quality and maturities, consideration of the narrowness or wideness of the range of prices obtained, knowledge of recent market transactions and an assessment of the similarity in prices to comparable dealer offerings in a recent time period. Jefferies processes challenges the appropriateness of pricing information obtained from external data providers (including independent pricing services and brokers) to validate the data for consistency with the definition of a fair value exit price. Jefferies process includes understanding and evaluating the external data providers’ valuation methodologies. For corporate, U.S. government and agency, municipal debt securities, and loans, to the extent independent pricing services or broker quotes are utilized in Jefferies valuation process, the vendor service providers are collecting and aggregating observable market information as to recent trade activity and active bid-ask submissions. The composite pricing information received from the independent pricing service is thus not based on unobservable inputs or proprietary models. For mortgage- and other asset-backed securities, collateralized debt obligations ("CDOs") and collateralized loan obligations ("CLOs"), the independent pricing services use a matrix evaluation approach incorporating both observable yield curves and market yields on comparable securities as well as implied inputs from observed trades for comparable securities in order to determine prepayment speeds, cumulative default rates and loss severity. Further, Jefferies considers pricing data from multiple service providers as available as well as compares pricing data to prices observed for recent transactions, if any, in order to corroborate valuation inputs. Model Review Process . If a pricing model is used to determine fair value, the pricing model is reviewed for theoretical soundness and appropriateness by Risk Management, independent from the trading desks, and then approved by Risk Management to be used in the valuation process. Review and approval of a model for use may include benchmarking the model against relevant third party valuations, testing sample trades in the model, backtesting the results of the model against actual trades and stress-testing the sensitivity of the pricing model using varying inputs and assumptions. In addition, recently executed comparable transactions and other observable market data are considered for purposes of validating assumptions underlying the model. Models are independently reviewed and validated by Risk Management annually or more frequently if market conditions or use of the valuation model changes.
Investments in Managed Funds	Investments in Managed Funds Investments in managed funds include our investments in funds managed by us and our investments in related party managed funds. Investments in nonconsolidated managed funds are accounted for at fair value based on the net asset value (“NAV”) of the funds provided by the fund managers with gains or losses included in the Consolidated Statements of Operations. Asset management fees and investment income from managed funds include revenues we earn from management, administrative and performance fees from funds and accounts managed by us, revenues from management and performance fees we earn from related-party managed funds and investment income from our investments in these funds. We earn fees in connection with management and investment advisory services performed for various funds and managed accounts. These fees are based on assets under management or an agreed upon notional amount and may include performance fees based upon the performance of the funds. Management and administrative fees are generally recognized over the period that the related service is provided. Generally, performance fees are earned when the return on assets under management exceeds certain benchmark returns, “high-water marks” or other performance targets. Performance fees are accrued (or reversed) on a monthly basis based on measuring performance to date versus any relevant benchmark return hurdles stated in the investment management agreement. Performance fees are not subject to adjustment once the measurement period ends (generally annual periods) and the performance fees have been realized.
Loans to and Investments in Associated Companies	Loans to and Investments in Associated Companies Loans to and investments in associated companies include investments in private equity and other operating entities in which we exercise significant influence over operating and capital decisions and loans issued in connection with such investments. Loans to and investments in associated companies are accounted for using the equity method. See Note 10 for additional information regarding certain of these investments. Under the equity method of accounting, our share of the investee’s underlying net income or loss is recorded as Income (loss) related to associated companies, or as part of Other revenues if such investees are considered to be an extension of our business. Income (loss) for investees for which the fair value option was elected is reported as Principal transactions revenues.
Receivables	Receivables At December 31, 2017 and 2016 , Receivables include receivables from brokers, dealers and clearing organizations of $2,635.2 million and $2,062.9 million , respectively, and receivables from customers of securities operations of $1,563.8 million and $843.1 million , respectively.
Securities Borrowed And Securities Loaned	Securities Borrowed and Securities Loaned Securities borrowed and securities loaned are carried at the amounts of cash collateral advanced and received in connection with the transactions and accounted for as collateralized financing transactions. In connection with both trading and brokerage activities, Jefferies borrows securities to cover short sales and to complete transactions in which customers have failed to deliver securities by the required settlement date, and lend securities to other brokers and dealers for similar purposes. Jefferies has an active securities borrowed and lending matched book business in which it borrows securities from one party and lends them to another party. When Jefferies borrows securities, it generally provides cash to the lender as collateral, which is reflected in the Consolidated Statements of Financial Condition as Securities borrowed. Jefferies earns interest revenues on this cash collateral. Similarly, when Jefferies lends securities to another party, that party provides cash to Jefferies as collateral, which is reflected in the Consolidated Statements of Financial Condition as Securities loaned. Jefferies pays interest expense on the cash collateral received from the party borrowing the securities. The initial collateral advanced or received approximates or is greater than the fair value of the securities borrowed or loaned. Jefferies monitors the fair value of the securities borrowed and loaned on a daily basis and requests additional collateral or returns excess collateral, as appropriate.
Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase	Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase Securities purchased under agreements to resell and Securities sold under agreements to repurchase (collectively "repos") are accounted for as collateralized financing transactions and are recorded at their contracted resale or repurchase amount plus accrued interest. Jefferies earns and incurs interest over the term of the repo, which is reflected in Interest revenue and Interest expense in the Consolidated Statements of Operations on an accrual basis. Repos are presented in the Consolidated Statements of Financial Condition on a net-basis-by counterparty, where permitted by GAAP. The fair value of the underlying securities is monitored daily versus the related receivable or payable balances. Should the fair value of the underlying securities decline or increase, additional collateral is requested or excess collateral is returned, as appropriate.
Property, Equipment and Leasehold Improvements	Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are provided principally on the straight-line method over the estimated useful lives of the assets or, if less, the term of the underlying lease.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We evaluate our long-lived assets for impairment whenever events or changes in circumstances indicate, in management’s judgment, that the carrying value of such assets may not be recoverable. When testing for impairment, we group our long-lived assets with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities (or asset group). The determination of whether an asset group is recoverable is based on management’s estimate of undiscounted future cash flows directly attributable to the asset group as compared to its carrying value. If the carrying amount of the asset group is greater than the undiscounted cash flows, an impairment loss would be recognized for the amount by which the carrying amount of the asset group exceeds its estimated fair value. In 2015, we recorded impairment charges in Selling, general and other expenses of $27.7 million , primarily related to a $20.3 million impairment at JETX and an impairment charge related to National Beef's Brawley plant of $4.7 million . For the oil and gas impairment test related to proved properties, we compare expected undiscounted future net cash flows to the unamortized capitalized cost of the asset. If the future undiscounted net cash flows are lower than the unamortized capital cost, we reduce the capitalized cost to fair market value. We used a third party reserve report in which the cash flows were calculated using West Texas Intermediate (oil) and Henry Hub (gas) NYMEX futures prices as of December 31, 2015. For one of our oil fields, the future undiscounted net cash flows were lower than the unamortized capital cost and as a result, we wrote off the total capital cost. In 2016, JETX recorded impairment charges in Selling, general and other expenses of $56.3 million related to write-downs of unproved oil and gas properties. JETX assesses its unproved oil and gas properties for impairment based on remaining lease terms, drilling results or future plans to develop acreage and they record impairment expense for any decline in value. In the third quarter of 2016, JETX curtailed development of both its southern acreage in the East Eagle Ford and its Houston County acreage. As a result, an impairment was recorded for the difference between the carrying value and the estimated net realizable value of the acreage. In 2017, JETX decided to focus on its other higher returning acreage and as a result wrote off the remaining carrying value for its Houston County acreage. JETX recorded an impairment charge of $10.1 million in Selling, general and other expenses in the third quarter of 2017 related to the write-down of unproved oil and gas properties. Substantially all of our operating businesses sell products or services that are impacted by general economic conditions in the U.S. and to a lesser extent internationally. In recent years, general economic conditions reduced the demand for products or services sold by our operating subsidiaries and/or resulted in reduced pricing for products or services. A worsening of current economic conditions could cause a decline in estimated future cash flows expected to be generated by our operations and investments. If future undiscounted cash flows are estimated to be less than the carrying amounts of the asset groups used to generate those cash flows in subsequent reporting periods, particularly for those with large investments in intangible assets, property and equipment and other long-lived assets (for example, Jefferies, National Beef, manufacturing, oil and gas production and development and certain associated company investments), impairment charges would have to be recorded.
Intangible Assets, Net and Goodwill	Intangible Assets, Net and Goodwill Intangible Assets . Intangible assets deemed to have finite lives are generally amortized on a straight-line basis over their estimated useful lives, where the useful life is the period over which the asset is expected to contribute directly, or indirectly, to our future cash flows. Intangible assets are reviewed for impairment on an interim basis when certain events or circumstances exist. If future undiscounted cash flows are estimated to be less than the carrying amounts of the asset groups used to generate those cash flows in subsequent reporting periods, particularly for those with large investments in amortizable intangible assets, impairment charges would have to be recorded. An intangible asset with an indefinite useful life is not amortized but assessed for impairment annually, or more frequently, when certain events or circumstances exist indicating an assessment for impairment is necessary. Impairment exists when the carrying amount exceeds its fair value. Fair value will be determined using valuation techniques consistent with what a market participant would use. All of our indefinite-lived intangible assets were recognized in connection with the Jefferies acquisition, and our annual impairment testing date for Jefferies is as of August 1. Goodwill. At acquisition, we allocate the cost of a business acquisition to the specific tangible and intangible assets acquired and liabilities assumed based upon their fair values. Significant judgments and estimates are often made by management to determine these values, and may include the use of appraisals, consideration of market quotes for similar transactions, use of discounted cash flow techniques or consideration of other information we believe to be relevant. Any excess of the cost of a business acquisition over the fair values of the net assets and liabilities acquired is recorded as goodwill, which is not amortized to expense. Substantially all of our goodwill was recognized in connection with the Jefferies acquisition. At least annually, and more frequently if warranted, we will assess whether goodwill has been impaired. If the estimated fair value exceeds the carrying value, goodwill at the reporting unit level is not impaired. If the estimated fair value is less than carrying value, further analysis is necessary to determine the amount of impairment, if any, by comparing the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The fair values will be based on widely accepted 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 market capitalization, price-to-book multiples of comparable exchange traded companies, multiples of merger and acquisitions of similar businesses and/or projected cash flows. The estimates and assumptions used in determining fair value could have a significant effect on whether or not an impairment charge is recorded and the magnitude of such a charge. Adverse market or economic events could result in impairment charges in future periods. Our annual goodwill impairment testing date related to Jefferies is as of August 1 and National Beef as of December 31.
Inventories and Cost of Sales	Inventories and Cost of Sales National Beef’s inventories consist primarily of beef products, beef by-products and supplies, and are stated at the lower of cost or net realizable value, with cost principally determined under the first-in-first-out method for beef products and average cost for supplies. Manufacturing inventories are stated at the lower of cost or net realizable value, with cost principally determined under the first-in-first-out method. Manufacturing cost of sales principally includes product and manufacturing costs, inbound and outbound shipping costs and handling costs. National Beef and manufacturing inventories are classified as Other assets in the Consolidated Statements of Financial Condition.
Payables, Expense Accruals and other Liabilities	Payables, expense accruals and other liabilities At December 31, 2017 and 2016 , Payables, expense accruals and other liabilities include payables to brokers, dealers and clearing organizations of $2,228.9 million and $3,290.4 million , respectively, and payables to customers of securities operations of $2,664.0 million and $2,297.3 million , respectively.
Income Taxes	Income Taxes We record a valuation allowance to reduce our net deferred tax asset to the net amount that is more likely than not to be realized. If in the future we determine that it is more likely than not that we will be able to realize our net deferred tax asset in excess of our net recorded amount, an adjustment to increase the net deferred tax asset would increase income in such period. If in the future we were to determine that we would not be able to realize all or part of our recorded net deferred tax asset, an adjustment to decrease the net deferred tax asset would be charged to income in such period. We are required to consider all available evidence, both positive and negative, and to weigh the evidence when determining whether a valuation allowance is required and the amount of such valuation allowance. Generally, greater weight is required to be placed on objectively verifiable evidence when making this assessment, in particular on recent historical operating results. Our estimate of future taxable income considers all available evidence, both positive and negative, about our operating businesses and investments, includes an aggregation of individual projections for each significant operating business and investment, estimated apportionment factors for state and local taxing jurisdictions and includes all future years that we estimate we will have available net operating loss carryforwards (“NOLs”) (until 2035). We believe that our estimate of future taxable income is reasonable but inherently uncertain, and if our current or future operations and investments generate taxable income different than the projected amounts, further adjustments to the valuation allowance are possible. The current balance of the deferred tax valuation allowance principally reserves for NOLs of certain subsidiaries that are not available to offset income generated by other members of the consolidated tax return group. We also record reserves for unrecognized tax benefits based on our assessment of the probability of successfully sustaining tax filing positions. Interest and penalties, if any, are recorded as components of income tax expense. Management exercises significant judgment when assessing the probability of successfully sustaining tax filing positions, and in determining whether a contingent tax liability should be recorded and if so estimating the amount. If our tax filing positions are successfully challenged, payments could be required that are in excess of reserved amounts or we may be required to reduce the carrying amount of our net deferred tax asset, either of which could be significant to our Consolidated Statement of Financial Condition or results of operations.
Share-based Compensation	Share-based Compensation Share-based awards are measured based on the fair value of the award as determined in accordance with GAAP and recognized over the required service or vesting period. Certain executive share-based awards contain market, performance and service conditions. Market conditions are incorporated into the grant-date fair value 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. The fair value of options and warrants are estimated at the date of grant using the Black-Scholes option pricing model. Expected forfeitures are included in determining share-based compensation expense.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated to U.S. dollars using the currency exchange rates at the end of the relevant period. Revenues and expenses are translated at average exchange rates during the period. The effects of exchange rate changes on the translation of the balance sheets, net of hedging gains or losses and taxes, if any, are included in other comprehensive income (loss) in the Consolidated Statements of Comprehensive Income (Loss) and classified as Accumulated other comprehensive income in the Consolidated Statements of Financial Condition and Consolidated Statements of Changes in Equity. Gains or losses resulting from Jefferies foreign currency transactions are included in Principal transactions in the Consolidated Statements of Operations.
Earnings per Common Share	Earnings per Common Share Basic earnings per share ("EPS") is computed by dividing net earnings available to common shareholders by the weighted average number of common shares outstanding and certain other shares committed to be, but not yet issued. Net earnings available to common shareholders represent net earnings to common shareholders reduced by the allocation of earnings to participating securities. Losses are not allocated to participating securities. Common shares outstanding and certain other shares committed to be, but not yet issued, include restricted stock and restricted stock units ("RSUs") for which no future service is required. Diluted EPS is computed by dividing net earnings available to common shareholders plus dividends on dilutive mandatorily redeemable convertible preferred shares and interest on convertible notes by the weighted average number of common shares outstanding and certain other shares committed to be, but not yet issued, plus all dilutive common stock equivalents outstanding during the period. Unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and, therefore, are included in the earnings allocation in computing earnings per share under the two-class method of earnings per share. Restricted stock and RSUs granted as part of share-based compensation contain nonforfeitable rights to dividends and dividend equivalents, respectively, and therefore, prior to the requisite service being rendered for the right to retain the award, restricted stock and RSUs meet the definition of a participating security. As such, we calculate basic and diluted earnings per share under the two-class method. RSUs granted under the senior executive compensation plan are not considered participating securities as the rights to dividend equivalents are forfeitable.
Securitization Activities	Securitization Activities Jefferies engages in securitization activities related to corporate loans, consumer loans, commercial mortgage loans and mortgage-backed and other asset-backed securities. Such transfers of financial assets are accounted for as sales when Jefferies has relinquished control over the transferred assets. The gain or loss on sale of such financial assets depends, in part, on the previous carrying amount of the assets involved in the transfer allocated between the assets sold and the retained interests, if any, based upon their respective fair values at the date of sale. Jefferies may retain interests in the securitized financial assets as one or more tranches of the securitization. These retained interests are included within Trading assets in the Consolidated Statements of Financial Condition at fair value. Any changes in the fair value of such retained interests are recognized within Principal transactions in the Consolidated Statements of Operations. When a transfer of assets does not meet the criteria of a sale, the transfer is accounted for as a secured borrowing and Jefferies continues to recognize the assets of a secured borrowing, and recognize the associated financing in Other secured financings in the Consolidated Statements of Financial Condition. Beginning in 2014, another of our subsidiaries utilized a special purpose entity to securitize automobile loans receivable. This special purpose entity is a variable interest entity and our subsidiary is the primary beneficiary; the related assets and the secured borrowings are recognized in the Consolidated Statement of Financial Condition. These secured borrowings do not have recourse to our subsidiary’s general credit.
Contingencies	Contingencies In the normal course of business, we have been named, from time to time, as a defendant in legal and regulatory proceedings. We 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 recognize a liability for a contingency when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. If the reasonable estimate of a probable loss is a range, we accrue the most likely amount of such loss, and if such amount is not determinable, then we accrue the minimum in the range as the loss accrual. The determination of the outcome and loss estimates requires significant judgment on the part of management, can be highly subjective and is subject to significant change with the passage of time as more information becomes available. Estimating the ultimate impact of litigation matters is inherently uncertain, in particular because the ultimate outcome will rest on events and decisions of others that may not be within our power to control. We do not believe that any of our current litigation will have a significant adverse effect on our consolidated financial position, results of operations or liquidity; however, if amounts paid at the resolution of litigation are in excess of recorded reserve amounts, the excess could be significant in relation to results of operations for that period. For further information, see Note 24.
Accounting Developments	Accounting Developments - Accounting Standards to be Adopted in Future Periods 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 this new 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 and services. This guidance is effective for interim and annual periods beginning after December 15, 2017. We have adopted the new guidance as of January 1, 2018 using the modified retrospective approach with a cumulative-effect adjustment to opening retained earnings of approximately $8 million . Our implementation efforts included the identification of revenue streams within the scope of the guidance, the evaluation of certain revenue contracts and education and discussion with our consolidated subsidiaries. Based on our assessment, the impact of the adoption of the new guidance does not have a material impact on our consolidated financial statements. The below focuses on our two largest consolidated subsidiaries, whose combined revenues comprise more than 92% of our Net revenues in the Consolidated Statements of Operations for the year ended December 31, 2017. For Jefferies, as the new revenue recognition guidance 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 its revenues most closely associated with financial instruments, including Principal transaction revenues, Interest income and Interest expense. The new revenue standard primarily impacts the following of Jefferies revenue recognition and presentation accounting policies: • 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, revenue from these activities is recognized within Principal transaction 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 on 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 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., meeting a specified benchmark rate) and are recognized only to the extent it is not 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. National Beef earns over 95% of its revenues through the sale of beef, pork and beef by-products. Agreements with customers for these sales typically consist of the type and quantity of products to be delivered, the unit price of each product, the estimated delivery date and credit and payment terms. The transaction price is generally fixed at this time and revenue is recognized when the customer takes control of the product. The impact of the new guidance does not materially impact how revenue is recognized for this revenue stream. 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 do not believe the new guidance related to equity investments and the presentation and disclosure requirements of financial instruments will have a material impact on our consolidated financial statements. We have adopted the new guidance as of January 1, 2018 with a cumulative-effect increase to opening retained earnings of approximately $28 million and a corresponding decrease to Accumulated other comprehensive income. 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. Leases. In February 2016, the FASB issued new guidance that affects the accounting and disclosure requirements for leases. The FASB requires the recognition of lease assets and lease liabilities on the statement of financial condition. The guidance is effective for annual and interim periods beginning after December 15, 2018. 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 for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact this new guidance will have on our consolidated financial statements. 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. The guidance is effective for annual and interim periods beginning after December 15, 2017. We do not believe the new guidance will have a material impact on our consolidated financial statements. Goodwill. In January 2017, the FASB issued new guidance for simplifying goodwill impairment testing. The guidance is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted. We do not believe the new guidance will 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. The guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. We do not believe the new guidance will have a material impact on our consolidated financial statements. 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. The guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. 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 for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. We are currently evaluating the impact of the new guidance on our consolidated financial statements.

Significant Accounting Polici44

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information For the Year ended December 31, 2017 2016 2015 (In thousands) Cash paid during the year for: Interest $ 1,120,191 $ 957,140 $ 980,266 Income tax payments (refunds), net $ 15,361 $ (13,738 ) $ 510

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	12 Months Ended
	Dec. 31, 2017
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 and long-term debt that are accounted for at fair value on a recurring basis, excluding Investments at fair value based on NAV (within trading assets) of $20.2 million and $24.3 million , respectively, by level within the fair value hierarchy at December 31, 2017 and 2016 (in thousands): 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 $ 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 $ — $ 606,956 $ — $ — $ 606,956 December 31, 2016 Level 1 Level 2 Level 3 Counterparty and Cash Collateral Netting (1) Total Assets: Trading assets, at fair value: Corporate equity securities $ 2,522,977 $ 92,839 $ 21,739 $ — $ 2,637,555 Corporate debt securities — 2,675,020 25,005 — 2,700,025 Collateralized debt obligations and collateralized loan obligations — 54,306 54,354 — 108,660 U.S. government and federal agency securities 2,389,397 56,726 — — 2,446,123 Municipal securities — 708,469 27,257 — 735,726 Sovereign obligations 1,432,556 990,492 — — 2,423,048 Residential mortgage-backed securities — 960,494 38,772 — 999,266 Commercial mortgage-backed securities — 296,405 20,580 — 316,985 Other asset-backed securities — 63,587 40,911 — 104,498 Loans and other receivables — 1,557,233 81,872 — 1,639,105 Derivatives 3,825 4,616,822 6,429 (4,255,998 ) 371,078 Investments at fair value — — 314,359 — 314,359 FXCM term loan — — 164,500 — 164,500 Total trading assets, excluding investments at fair value based on NAV $ 6,348,755 $ 12,072,393 $ 795,778 $ (4,255,998 ) $ 14,960,928 Available for sale securities: Corporate equity securities $ 79,425 $ — $ — $ — $ 79,425 Corporate debt securities — 179 — — 179 U.S. government securities 174,933 — — — 174,933 Residential mortgage-backed securities — 19,133 — — 19,133 Commercial mortgage-backed securities — 8,337 — — 8,337 Other asset-backed securities — 19,042 — — 19,042 Total available for sale securities $ 254,358 $ 46,691 $ — $ — $ 301,049 Liabilities: Trading liabilities: Corporate equity securities $ 1,593,548 $ 16,806 $ 313 $ — $ 1,610,667 Corporate debt securities — 1,718,424 523 — 1,718,947 U.S. government and federal agency securities 976,497 — — — 976,497 Sovereign obligations 1,375,590 1,253,754 — — 2,629,344 Loans — 801,977 378 — 802,355 Derivatives 2,566 4,867,586 9,870 (4,229,213 ) 650,809 Total trading liabilities $ 3,948,201 $ 8,658,547 $ 11,084 $ (4,229,213 ) $ 8,388,619 Other secured financings $ — $ 41,350 $ 418 $ — $ 41,768 Long-term debt $ — $ 248,856 $ — $ — $ 248,856 (1) Represents counterparty and cash collateral netting across the levels of the fair value hierarchy for positions with the same counterparty.
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) 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 Fund (6) 154,805 — — Total $ 590,104 $ 19,084 December 31, 2016 Equity Long/Short Hedge Funds (2) $ 363,256 $ — (2) Fixed Income and High Yield Hedge Funds (3) 772 — — Fund of Funds (4) 230 — — Equity Funds (5) 42,179 20,295 — Multi-asset Fund (6) 133,190 — — Total $ 539,627 $ 20,295 (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, in primarily equity securities in domestic and international markets in both the public and private sectors. At December 31, 2017 and 2016 , 73% and 83% , respectively, of these investments are redeemable with 10 business days or less prior written notice, and 15% and 17% , respectively, 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 liquidate in one to six years. (6) 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 both December 31, 2017 and 2016 , investments representing approximately 12% 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 year ended December 31, 2017 (in thousands): Year Ended December 31, 2017 Balance, December 31, 2016 Total gains (losses) (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance at December 31, 2017 Changes in unrealized gains (losses) relating to instruments still held at December 31, 2017 (1) Assets: Trading assets: Corporate equity securities $ 21,739 $ 3,353 $ 896 $ (1,623 ) $ 52 $ — $ (2,147 ) $ 22,270 $ 2,606 Corporate debt securities 25,005 (3,723 ) 36,850 (34,077 ) (1,968 ) — 3,949 26,036 (3,768 ) CDOs and CLOs 54,354 (27,238 ) 112,239 (101,226 ) (367 ) — 4,422 42,184 (20,262 ) Municipal securities 27,257 (1,547 ) — (25,710 ) — — — — — Residential mortgage-backed securities 38,772 (10,817 ) 6,805 (26,193 ) (115 ) — 17,625 26,077 (7,201 ) Commercial mortgage-backed securities 20,580 (5,346 ) 3,275 (5,263 ) (1,018 ) — 191 12,419 (6,976 ) Other asset-backed securities 40,911 (17,705 ) 77,508 (8,613 ) (25,799 ) — (5,173 ) 61,129 (12,562 ) Loans and other receivables 81,872 24,794 63,768 (53,095 ) (34,622 ) — (35,413 ) 47,304 17,451 Investments at fair value 314,359 20,975 18,528 (22,818 ) (1,100 ) — — 329,944 22,999 Investment in FXCM 164,500 23,161 — — (114,861 ) — — 72,800 1,070 Liabilities: Trading liabilities: Corporate equity securities $ 313 $ 60 $ (373 ) $ 48 $ — $ — $ — $ 48 $ — Corporate debt securities 523 (1 ) — — — — — 522 1 Commercial mortgage-backed securities — 105 — — — — — 105 (105 ) Net derivatives (2) 3,441 (1,638 ) — — 5,558 456 (1,071 ) 6,746 (17,740 ) Loans 378 196 (385 ) 2,485 — — 812 3,486 (2,639 ) Other secured financings 418 (418 ) — — — — — — — (1) Realized and unrealized gains (losses) are reported in Principal transactions 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 year ended December 31, 2015 (in thousands). Year Ended December 31, 2015 Balance, December 31, 2014 Total gains (losses) (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance at December 31, 2015 Changes in unrealized gains (losses) relating to instruments still held at December 31, 2015 (1) Assets: Trading assets: Corporate equity securities $ 20,964 $ 11,154 $ 21,385 $ (6,391 ) $ — $ — $ (6,206 ) $ 40,906 $ 11,424 Corporate debt securities 22,766 (11,013 ) 21,534 (14,636 ) — — 7,225 25,876 (9,443 ) CDOs and CLOs 124,650 (66,332 ) 104,998 (107,381 ) (5,754 ) — 34,911 85,092 (48,514 ) Municipal securities — 10 — — (21,551 ) — 21,541 — — Sovereign Obligations — 47 1,032 (1,031 ) — — 72 120 39 Residential mortgage-backed securities 82,557 (12,951 ) 18,961 (31,762 ) (597 ) — 14,055 70,263 (4,498 ) Commercial mortgage-backed securities 26,655 (3,813 ) 3,480 (10,146 ) (6,861 ) — 5,011 14,326 (3,205 ) Other asset-backed securities 2,294 (990 ) 42,922 (1,299 ) (2 ) — — 42,925 (254 ) Loans and other receivables 97,258 (14,755 ) 792,345 (576,536 ) (124,365 ) — 15,342 189,289 (16,802 ) Investments at fair value 77,047 62,804 5,510 (425 ) (4,093 ) — 58,951 199,794 (1,964 ) Investments in FXCM — 491,341 279,000 — (144,652 ) — — 625,689 491,341 Liabilities: Trading liabilities: Corporate equity securities $ 38 $ — $ — $ — $ — $ — $ — $ 38 $ — Corporate debt securities 223 (110 ) (6,804 ) 6,691 — — — — — Net derivatives (2) (4,638 ) (7,310 ) (6,705 ) 13,522 37 2,437 2,415 (242 ) 4,754 Loans 14,450 (163 ) (2,059 ) 229 — — (1,988 ) 10,469 104 Other secured financings 30,825 — — — (15,704 ) 36,995 (51,572 ) 544 — (1) Realized and unrealized gains (losses) are reported in Principal transactions 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 year ended December 31, 2016 (in thousands): Year Ended December 31, 2016 Balance, December 31, 2015 Total gains (losses) (realized and unrealized) (1) Purchases Sales Settlements Issuances Net transfers into (out of) Level 3 Balance at December 31 ,2016 Changes in unrealized gains (losses) relating to instruments still held at December 31, 2016 (1) Assets: Trading assets: Corporate equity securities $ 40,906 $ (8,463 ) $ 3,365 $ (49 ) $ (671 ) $ — $ (13,349 ) $ 21,739 $ 291 Corporate debt securities 25,876 (16,230 ) 27,242 (29,347 ) (7,223 ) — 24,687 25,005 (18,799 ) CDOs and CLOS 85,092 (14,918 ) 52,316 (69,394 ) (2,750 ) — 4,008 54,354 (7,628 ) Municipal securities — (1,462 ) — — — — 28,719 27,257 (1,462 ) Sovereign obligations 120 5 — (125 ) — — — — — Residential mortgage backed securities 70,263 (9,612 ) 623 (12,249 ) (931 ) — (9,322 ) 38,772 (1,095 ) Commercial mortgage-backed securities 14,326 (7,550 ) 3,132 (2,024 ) (2,229 ) — 14,925 20,580 (7,243 ) Other asset-backed securities 42,925 (14,381 ) 133,986 (102,952 ) (8,769 ) — (9,898 ) 40,911 (18,056 ) Loans and other receivables 189,289 (42,566 ) 75,264 (69,262 ) (46,851 ) — (24,002 ) 81,872 (52,003 ) Investments at fair value 199,794 54,538 29,728 (542 ) (1,107 ) — 31,948 314,359 54,608 Investment in FXCM (2) 625,689 (54,634 ) — — (406,555 ) — — 164,500 (1,014 ) Liabilities: Trading liabilities: Corporate equity securities $ 38 $ — $ — $ 313 $ (38 ) $ — $ — $ 313 $ — Corporate debt securities — (27 ) — 550 — — — 523 — Net derivatives (3) (242 ) (1,760 ) — 11,101 31 2,067 (7,756 ) 3,441 (6,458 ) Loans 10,469 — — 378 — — (10,469 ) 378 — Other secured financings 544 (126 ) — — — — — 418 (126 ) (1) Realized and unrealized gains (losses) are reported in Principal transactions in the Consolidated Statements of Operations. (2) Includes $334.5 million related to the settlement of our participation rights for equity ownership in FXCM on September 1, 2016. We classify the equity ownership as a Loan to and investment in associated company at December 31, 2017 and 2016 . (3) Net derivatives represent Trading assets - Derivatives and Trading liabilities - Derivatives.
Quantitative Information About Significant Unobservable Inputs Used In Level 3 Fair Value Measurements	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 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 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 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 Significant 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% — December 31, 2016 Financial Instruments Owned Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Corporate equity securities $ 19,799 Non-exchange traded securities Market approach Underlying stock price $3 to $75 $15.0 Comparable pricing Underlying stock price $218 — Comparable asset price $11 — Present value Average silver production (tons per day) 666 — Corporate debt securities $ 25,005 Convertible bond model Discount rate/yield 9% — Volatility 40% — Market approach Transaction level $30 — CDOs and CLOs $ 33,016 Discounted cash flows Constant prepayment rate 10% to 20% 19 % Constant default rate 2% to 4% 2 % Loss severity 25% to 70% 40 % Yield 7% to 17% 12 % Scenario analysis Estimated recovery percentage 28% to 38% 31 % Residential mortgage-backed securities $ 38,772 Discounted cash flows Constant prepayment rate 0% to 11% 5 % Constant default rate 1% to 7% 3 % Loss severity 35% to 100% 62 % Yield 2% to 10% 6 % Commercial mortgage-backed securities $ 20,580 Discounted cash flows Yield 6% to 11% 8 % Cumulative loss rate 5% to 95% 39 % Other asset-backed securities $ 40,911 Discounted cash flows Constant prepayment rate 4% to 20% 14 % Constant default rate 0% to 31% 13 % Loss severity 0% to 100% 90 % Yield 4% to 17% 15 % Market approach Price $72 — Loans and other receivables $ 54,347 Market approach Discount rate/yield 2% to 4% 3 % EBITDA (a) multiple 3.3 — Transaction level $0.42 — Present value Average silver production (tons per day) 666 — Scenario analysis Estimated recovery percentage 6% to 50% 37 % Derivatives $ 6,429 Equity swaps Comparable pricing Comparable asset price $102 — Credit default swaps Market approach Credit spread 265 bps — Investments at fair value $ 67,383 Private equity securities Market approach Transaction Level $250 — Price $25,815,720 — Discount rate 15% to 30% 23 % Investment in FXCM $ 164,500 Term loan Discounted cash flows Term based on the pay off (years) 0 months to 0.5 years 0.4 years Trading Liabilities Fair Value (in thousands) Valuation Technique Significant Unobservable Input(s) Input/Range Weighted Average Derivatives $ 9,870 Equity options Option model Volatility 45% — Default rate Default probability 0% — Equity swaps Comparable pricing Comparable asset price $102 — Unfunded commitments Market approach Discount rate/yield 4% — Variable funding note swaps Discounted cash flows Constant prepayment rate 20% — Constant default rate 2% — Loss severity 25% — Yield 16% — (a) Earnings before interest, taxes, depreciation and amortization (“EBITDA”).
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 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 for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Financial instruments owned: Loans and other receivables $ 22,088 $ (68,812 ) $ (17,389 ) Financial instruments sold: Loans $ — $ 9 $ (162 ) Loan commitments $ 230 $ 5,509 $ 7,502 Long-term debt: Changes in instrument specific credit risk (1) $ (34,609 ) $ (10,745 ) $ — Other changes in fair value (2) $ 47,291 $ 30,995 $ — Short-term borrowings: Other changes in fair value (2) $ (681 ) $ — $ — (1) Changes in instrument specific credit risk related to structured notes are included in the Consolidated Statements of Comprehensive Income (Loss), net of taxes. (2) Other changes in fair value are included within 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 and long-term debt measured at fair value under the fair value option (in thousands): December 31, 2017 December 31, 2016 Financial instruments owned: Loans and other receivables (1) $ 752,076 $ 1,325,938 Loans and other receivables on nonaccrual status and/or greater than 90 days past due (1) (2) $ 159,462 $ 205,746 Long-term debt $ 32,839 $ 20,202 (1) Interest income is recognized separately from other changes in fair value and is included within Interest income in the Consolidated Statements of Operations. (2) Amounts include all loans and other receivables greater than 90 or more days past due by which contractual principal exceeds fair value of $38.7 million and $64.6 million at December 31, 2017 and 2016 , respectively.

Derivative Financial Instrume46

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value And Related Number Of Derivative Contracts Categorized By Predominant Risk Exposure	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 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) (3,318,481 ) (3,490,514 ) Total derivatives not designated as accounting hedges $ 179,488 $ 252,974 Total per Consolidated Statement of Financial Condition (2) $ 179,488 $ 255,394 December 31, 2016 Derivatives not designated as accounting hedges: Interest rate contracts $ 3,282,245 29,032 $ 3,159,457 34,845 Foreign exchange contracts 529,669 7,826 516,869 8,319 Equity contracts 786,987 2,843,329 1,169,201 2,414,715 Commodity contracts 1,906 2,766 6,430 7,289 Credit contracts 26,269 311 28,065 20,084 Total 4,627,076 4,880,022 Counterparty/cash-collateral netting (1) (4,255,998 ) (4,229,213 ) Total per Consolidated Statement of Financial Condition (2) $ 371,078 $ 650,809 (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.
Unrealized And Realized Gains (Losses) On Derivative Contracts	The following table provides information related to gains (losses) recognized in Interest expense of Jefferies in the Consolidated Statements of Operations on a fair value hedge for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Interest rate swaps $ (2,091 ) $ — $ — Long-term debt 8,124 — — Total $ 6,033 $ — $ — The following table presents unrealized and realized gains (losses) on derivative contracts which are primarily recognized in Principal transactions revenues in the Consolidated Statements of Operations for the years ended December 31, 2017, 2016 and 2015 , which are utilized in connection with our client activities and our economic risk management activities (in thousands): 2017 2016 2015 Interest rate contracts $ 3,171 $ (36,559 ) $ (36,792 ) Foreign exchange contracts 4,376 20,401 36,233 Equity contracts (319,775 ) (635,305 ) (137,219 ) Commodity contracts (9,049 ) (3,339 ) (13,625 ) Credit contracts 1,959 5,013 (16,223 ) Total $ (319,318 ) $ (649,789 ) $ (167,626 )
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 December 31, 2017 (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 $ — $ 4 $ — $ (4 ) $ — Equity swaps and options 3,082 7,053 2,137 (1,442 ) 10,830 Credit default swaps 567 105 17,344 (5,625 ) 12,391 Total return swaps 34,228 1,581 — (193 ) 35,616 Foreign currency forwards, swaps and options 108,465 31,235 — (62,812 ) 76,888 Interest rate swaps, options and forwards 28,111 166,403 74,048 (83,534 ) 185,028 Total $ 174,453 $ 206,381 $ 93,529 $ (153,610 ) 320,753 Cross product counterparty netting (23,732 ) Total OTC derivative assets included in Trading assets $ 297,021 (1) At December 31, 2017 , we held exchange traded derivative assets, other derivatives assets and other credit agreements with a fair value of $28.4 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 December 31, 2017 , cash collateral received was $146.0 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 $ 2,772 $ 301 $ — $ (4 ) $ 3,069 Equity swaps and options 78 172,670 3,780 (1,442 ) 175,086 Credit default swaps 104 16,540 3,953 (5,625 ) 14,972 Total return swaps 28,920 1,517 — (193 ) 30,244 Foreign currency forwards, swaps and options 91,640 31,173 — (62,812 ) 60,001 Fixed income forwards 8,512 — — — 8,512 Interest rate swaps, options and forwards 16,544 96,484 151,624 (83,534 ) 181,118 Total $ 148,570 $ 318,685 $ 159,357 $ (153,610 ) 473,002 Cross product counterparty netting (23,732 ) Total OTC derivative liabilities included in Trading liabilities $ 449,270 (1) At December 31, 2017 , we held exchange traded derivative liabilities, other derivative liabilities and other credit agreements with a fair value of $124.1 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 December 31, 2017 , cash collateral pledged was $318.0 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 December 31, 2017 , 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 $ 173,843 BBB- to BBB+ 40,565 BB+ or lower 48,338 Unrated 34,275 Total $ 297,021 (1) Jefferies utilizes internal credit ratings determined by the Jefferies 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 Total Notional 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 December 31, 2016 Credit protection sold: Index credit default swaps $ 54.0 $ 92.0 $ 146.0 Single name credit default swaps 122.4 261.2 $ 383.6

Collateralized Transactions (Ta

Collateralized Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
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 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 securities — 2,023,530 2,023,530 Loans and other receivables — 454,941 454,941 Total $ 2,843,911 $ 19,829,249 $ 22,673,160 December 31, 2016 Corporate equity securities $ 2,046,243 $ 66,291 $ 2,112,534 Corporate debt securities 731,276 1,907,888 2,639,164 Mortgage- and asset-backed securities — 2,171,480 2,171,480 U.S. government and federal agency securities 41,613 9,232,624 9,274,237 Municipal securities — 553,010 553,010 Sovereign securities — 2,625,079 2,625,079 Loans and other receivables — 455,960 455,960 Total $ 2,819,132 $ 17,012,332 $ 19,831,464 Contractual Maturity Overnight and Continuous Up to 30 Days 30 to 90 Days Greater than 90 Days Total 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 December 31, 2016 Securities lending arrangements $ 2,131,891 $ 39,673 $ 104,516 $ 543,052 $ 2,819,132 Repurchase agreements 9,147,176 2,008,119 3,809,533 2,047,504 17,012,332 Total $ 11,279,067 $ 2,047,792 $ 3,914,049 $ 2,590,556 $ 19,831,464

Securitization Activities (Tabl

Securitization Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Securitization Activities [Abstract]
Activity Related To Securitizations Accounted For As Sales	The following table presents activity related to Jefferies securitizations that were accounted for as sales in which it had continuing involvement during the years ended December 31, 2017, 2016 and 2015 (in millions): 2017 2016 2015 Transferred assets $ 4,552.9 $ 5,786.0 $ 5,770.5 Proceeds on new securitizations 4,594.5 5,809.0 5,811.3 Cash flows received on retained interests 28.7 28.2 31.2
Summary Of Retained Interests In SPEs	The following table summarizes Jefferies retained interests in SPEs where it transferred assets and has continuing involvement and received sale accounting treatment (in millions): December 31, 2017 December 31, 2016 Securitization Type Total Assets Retained Interests Total Assets Retained Interests U.S. government agency residential mortgage-backed securities $ 6,383.5 $ 28.2 $ 7,584.9 $ 31.0 U.S. government agency commercial mortgage-backed securities 2,075.7 81.4 1,806.3 29.6 CLOs 3,957.8 20.3 4,102.2 37.0 Consumer and other loans 247.6 47.8 395.7 25.3

Available for Sale Securities (

Available for Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Amortized Cost, Gross Unrealized Gains And Losses And Estimated Fair Value Of Available For Sale Investments	The amortized cost, gross unrealized gains and losses and estimated fair value of investments classified as available for sale at December 31, 2017 and 2016 are as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value 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 $ 680,497 $ 36,246 $ 182 $ 716,561 2016 Bonds and notes: U.S. government securities $ 174,938 $ 8 $ 13 $ 174,933 Residential mortgage-backed securities 19,129 108 104 19,133 Commercial mortgage-backed securities 8,275 64 2 8,337 Other asset-backed securities 18,918 124 — 19,042 All other corporates 180 — 1 179 Total fixed maturities 221,440 304 120 221,624 Equity securities: Common stocks: Banks, trusts and insurance companies 35,071 15,115 — 50,186 Industrial, miscellaneous and all other 17,946 11,293 — 29,239 Total equity securities 53,017 26,408 — 79,425 $ 274,457 $ 26,712 $ 120 $ 301,049
Amortized Cost And Estimated Fair Value Of Investments Classified As Available For Sale By Contractual Maturity	The amortized cost and estimated fair value of investments classified as available for sale at December 31, 2017 , 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 $ 552,847 $ 552,805 552,847 552,805 Mortgage-backed and asset-backed securities 75,075 75,270 $ 627,922 $ 628,075

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Variable Interest Entity, Measure of Activity [Abstract]
Assets And Liabilities Of Consolidated VIEs	The following table presents information about the assets and liabilities of our consolidated 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. December 31, 2017 December 31, 2016 Securitization Vehicles Securitization Vehicles Real Estate Investment Vehicles Cash $ 11.7 $ 18.4 $ 2.2 Financial instruments owned 37.6 86.6 — Securities purchased under agreements to resell (1) 729.3 733.5 — Receivables 318.1 277.7 296.9 Loans to and investments in associated companies — — 108.7 Other 15.5 14.5 10.8 Total assets $ 1,112.2 $ 1,130.7 $ 418.6 Other secured financings (2) $ 1,073.5 $ 1,083.8 $ — Long-term debt — 24.1 243.9 Other (3) 38.3 22.3 11.7 Total liabilities $ 1,111.8 $ 1,130.2 $ 255.6 Noncontrolling interests $ — $ — $ 98.7 (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 $44.1 million and $57.6 million of the secured financing represents an amount held by Jefferies in inventory and eliminated in consolidation at December 31, 2017 and 2016 , respectively. (3) Includes $32.0 million and $20.0 million at December 31, 2017 and 2016 , 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 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 December 31, 2016 CLOs $ 264.7 $ 4.8 $ 930.0 $ 4,472.9 Consumer loan vehicles 90.3 — 219.6 985.5 Related party private equity vehicles 37.6 — 63.6 155.6 Real estate investment vehicles 90.3 — 101.8 85.6 Other private investment vehicles 84.0 — 95.8 4,529.7 Total $ 566.9 $ 4.8 $ 1,410.8 $ 10,229.3

Loans to and Investments in A51

Loans to and Investments in Associated Companies (Tables)	12 Months Ended
	Dec. 31, 2017
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 for the years ended December 31, 2017, 2016 and 2015 accounted for under the equity method of accounting is as follows (in thousands): Loans to and investments in associated companies as of December 31, 2016 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2017 Jefferies Finance $ 490,464 $ — $ 90,204 $ 74,799 $ — $ 655,467 Jefferies LoanCore (2) 154,731 — 22,368 (3,994 ) (173,105 ) — Berkadia 184,443 93,801 — (67,384 ) (266 ) 210,594 FXCM 336,258 (177,644 ) — — 242 158,856 Garcadia Companies 185,815 48,198 — (54,870 ) — 179,143 Linkem 154,000 (32,561 ) — 31,996 38,701 192,136 HomeFed 302,231 7,725 — 31,918 — 341,874 Golden Queen (3) 111,302 (7,733 ) — 1,436 — 105,005 54 Madison (4) (5) 161,400 (6,224 ) — 35,204 (67,370 ) 123,010 Other 44,454 (463 ) (3,177 ) 31,837 28,093 100,744 Total $ 2,125,098 $ (74,901 ) $ 109,395 $ 80,942 $ (173,705 ) $ 2,066,829 Loans to and investments in associated companies as of December 31, 2015 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2016 Jefferies Finance $ 528,575 $ — $ (1,761 ) $ (36,350 ) $ — $ 490,464 Jefferies LoanCore 288,741 — 21,221 (155,231 ) — 154,731 Berkadia 190,986 94,201 — (100,766 ) 22 184,443 FXCM (6) — 1,919 — — 334,339 336,258 Garcadia Companies 172,660 52,266 — (39,111 ) — 185,815 Linkem 150,149 (22,867 ) — 33,303 (6,585 ) 154,000 HomeFed 275,378 23,893 — 2,960 — 302,231 Golden Queen (3) 114,323 (3,021 ) — — — 111,302 54 Madison (4) — 4,255 — 153,503 3,642 161,400 Other 36,557 3,952 (2,276 ) 9,622 (3,401 ) 44,454 Total $ 1,757,369 $ 154,598 $ 17,184 $ (132,070 ) $ 328,017 $ 2,125,098 Loans to and investments in associated companies as of December 31, 2014 Income (losses) related to associated companies Income (losses) related to Jefferies associated companies (1) Contributions to (distributions from) associated companies, net Other, including foreign exchange and unrealized gains (losses) Loans to and investments in associated companies as of December 31, 2015 Jefferies Finance $ 508,891 $ — $ 40,884 $ (21,200 ) $ — $ 528,575 Jefferies LoanCore 258,947 — 36,554 (6,760 ) — 288,741 Berkadia 208,511 78,092 — (89,560 ) (6,057 ) 190,986 Garcadia Companies 167,939 53,182 — (48,461 ) — 172,660 Linkem 159,054 (15,577 ) — 21,138 (14,466 ) 150,149 HomeFed 271,782 3,596 — — — 275,378 Golden Queen (3) 103,598 (1,775 ) — 12,500 — 114,323 Other 33,846 (7,237 ) (1,721 ) 11,483 186 36,557 Total $ 1,712,568 $ 110,281 $ 75,717 $ (120,860 ) $ (20,337 ) $ 1,757,369 (1) Primarily classified in Investment banking revenues and Other revenues. (2) On October 31, 2017, Jefferies sold all of its membership interests in Jefferies LoanCore for approximately $173.1 million . (3) At December 31, 2017, 2016 and 2015 , the balance reflects $30.5 million , $32.8 million and $33.7 million , respectively, related to a noncontrolling interest. (4) At December 31, 2016 , the balance reflects $95.3 million related to noncontrolling interests. (5) As discussed further below, on November 30, 2017, we sold our interest in the general partner of the 54 Madison fund and as a result no longer control the 54 Madison investment committee. We retained two of the four seats on the investment committee and continue to have significant influence over the fund. We therefore deconsolidated the 54 Madison fund and account for our interest under the equity method of accounting. (6) As discussed more fully in Note 4, in 2016, we amended the terms of our loan and associated rights with FXCM. Through the amendments, we converted our participation rights for a 50% voting interest in FXCM. Our term loan remains classified within Trading assets, at fair value.
Schedule Of Summarized Data For Investments In Associated Companies	The following table provides summarized data for associated companies as of December 31, 2017 and 2016 and for the three years ended December 31, 2017 (in thousands): 2017 2016 Assets $ 16,340,643 $ 16,964,850 Liabilities 11,920,465 13,097,022 Noncontrolling interest 169,274 132,789 2017 2016 2015 Revenues $ 4,883,063 $ 4,275,016 $ 3,946,252 Income from continuing operations before extraordinary items 503,489 422,167 398,369 Net income 438,881 430,291 398,369 The Company’s income related to associated companies 34,494 171,782 185,998

Financial Statement Offsetting

Financial Statement Offsetting (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Summary Of Offsetting Assets And 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 Statement of Financial Condition Net Amounts in Consolidated Statement of Financial Condition Additional Amounts Available for Setoff (1) Available Collateral (2) Net Amount (3) 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 Assets at December 31, 2016 Derivative contracts $ 4,627,076 $ (4,255,998 ) $ 371,078 $ — $ — $ 371,078 Securities borrowing arrangements $ 7,743,562 $ — $ 7,743,562 $ (710,611 ) $ (647,290 ) $ 6,385,661 Reverse repurchase agreements $ 14,083,144 $ (10,220,656 ) $ 3,862,488 $ (176,275 ) $ (3,591,654 ) $ 94,559 Liabilities at December 31, 2016 Derivative contracts $ 4,880,022 $ (4,229,213 ) $ 650,809 $ — $ — $ 650,809 Securities lending arrangements $ 2,819,132 $ — $ 2,819,132 $ (710,611 ) $ (2,064,299 ) $ 44,222 Repurchase agreements $ 17,012,332 $ (10,220,656 ) $ 6,791,676 $ (176,275 ) $ (5,780,909 ) $ 834,492 (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 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 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. At December 31, 2016 , amounts include $6,337.5 million of securities borrowing arrangements, for which we have received securities collateral of $6,146.0 million , and $810.4 million of repurchase agreements, for which we have pledged securities collateral of $834.2 million , which are subject to master netting agreements but we have not determined the agreements to be legally enforceable.

Intangible Assets, Net and Go53

Intangible Assets, Net and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets and goodwill	A summary of intangible assets, net and goodwill at December 31, 2017 and 2016 is as follows (in thousands): 2017 2016 Indefinite lived intangibles: Exchange and clearing organization membership interests and registrations $ 8,551 $ 9,041 Amortizable intangibles: Customer and other relationships, net of accumulated amortization of $230,074 and $198,674 347,767 378,136 Trademarks and tradename, net of accumulated amortization of $95,627 and $78,778 293,851 309,382 Supply contracts, net of accumulated amortization of $57,440 and $47,867 86,160 95,733 Other, net of accumulated amortization of $3,885 and $2,914 4,701 5,672 Total intangible assets, net 741,030 797,964 Goodwill: National Beef 14,991 14,991 Jefferies 1,703,300 1,696,864 Other operations 3,859 3,859 Total goodwill 1,722,150 1,715,714 Total intangible assets, net and goodwill $ 2,463,180 $ 2,513,678
Schedule of amortization expense	The estimated aggregate future amortization expense for the intangible assets for each of the next five years is as follows (in thousands): 2018 $ 58,454 2019 58,454 2020 58,454 2021 58,067 2022 57,984

Property, Equipment and Lease54

Property, Equipment and Leasehold Improvements, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary Of Property, Equipment And Leasehold Improvements	A summary of property, equipment and leasehold improvements, net at December 31, 2017 and 2016 is as follows (in thousands): Depreciable Lives (in years) 2017 2016 Land, buildings and leasehold improvements 2-25 $ 408,886 $ 379,927 Beef processing machinery and equipment 2-15 360,975 330,453 Other machinery and equipment 3-15 32,012 30,716 Corporate aircraft 10 104,952 104,862 Furniture, fixtures and office equipment 3-10 379,051 323,276 Construction in progress N/A 72,560 54,693 Other 3-10 3,425 3,441 1,361,861 1,227,368 Accumulated depreciation and amortization (611,458 ) (518,126 ) $ 750,403 $ 709,242

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Short-term Debt	Jefferies short-term borrowings, which mature in one year or less, are as follows at December 31, 2017 and 2016 (in thousands): 2017 2016 Bank loans (1) $ 304,651 $ 372,301 Secured revolving loan facilities — 57,086 Floating rate puttable notes 108,240 96,455 Equity-linked notes 23,324 — Total short-term borrowings $ 436,215 $ 525,842 (1) Bank loans include loans entered into, pursuant to a Master Loan Agreement, between the Bank of New York and Jefferies.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of outstanding debt	The principal amount (net of unamortized discounts, premiums and debt issuance costs), stated interest rate and maturity date of outstanding debt at December 31, 2017 and 2016 are as follows (dollars in thousands): 2017 2016 Parent Company Debt: Senior Notes: 5.50% Senior Notes due October 18, 2023, $750,000 principal $ 742,348 $ 741,264 6.625% Senior Notes due October 23, 2043, $250,000 principal 246,673 246,627 Total long-term debt – Parent Company 989,021 987,891 Subsidiary Debt (non-recourse to Parent Company): Jefferies: 5.125% Senior Notes, due April 13, 2018, $678,300 and $800,000 principal 682,338 817,813 8.5% Senior Notes, due July 15, 2019, $680,800 and $700,000 principal 728,872 778,367 2.375% Euro Medium Term Notes, due May 20, 2020, $594,725 and $529,975 principal 593,334 528,250 6.875% Senior Notes, due April 15, 2021, $750,000 principal 808,157 823,797 2.25% Euro Medium Term Notes, due July 13, 2022, $4,758 and $4,240 principal 4,389 3,848 5.125% Senior Notes, due January 20, 2023, $600,000 principal 615,703 618,355 4.85% Senior Notes, due January 15, 2027, $750,000 principal (1) 736,357 — 6.45% Senior Debentures, due June 8, 2027, $350,000 principal 375,794 377,806 3.875% Convertible Senior Debentures, due November 1, 2029, $324,779 and $345,000 principal 324,779 346,163 6.25% Senior Debentures, due January 15, 2036, $500,000 principal 512,040 512,396 6.50% Senior Notes, due January 20, 2043, $400,000 principal 420,990 421,333 Structured Notes (2) (3) 614,091 255,203 National Beef Reducing Revolver Loan 120,000 — National Beef Revolving Credit Facility 76,809 — National Beef Term Loan — 273,811 54 Madison Term Loans — 406,028 Foursight Capital Credit Facilities 170,455 97,138 Other 112,654 132,244 Total long-term debt – subsidiaries 6,896,762 6,392,552 Long-term debt $ 7,885,783 $ 7,380,443 (1) Amount includes a decrease of $8.1 million at December 31, 2017 associated with an interest rate swap based on its designation as a fair value hedge. See Notes 2 and 5 for further information. (2) Includes $607.0 million and $248.9 million at fair value at December 31, 2017 and 2016 , respectively. (3) Of the $614.1 million of structured notes at December 31, 2017 , $7.1 million matures in 2018, $6.0 million matures in 2019, $25.0 million matures in 2022 and the remaining $576.0 million matures in 2024 or thereafter.

Mezzanine Equity (Tables)

Mezzanine Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Temporary Equity Disclosure [Abstract]
Schedule Of Redeemable Noncontrolling Interests	The following table rolls forward National Beef’s redeemable noncontrolling interests activity during the years ended December 31, 2017 and 2016 (in thousands): 2017 2016 As of January 1, $ 321,962 $ 189,358 Income allocated to redeemable noncontrolling interests 85,277 68,811 Distributions to redeemable noncontrolling interests (90,048 ) (53,701 ) Increase in fair value of redeemable noncontrolling interests charged to additional paid-in capital 94,937 117,494 Balance, December 31, $ 412,128 $ 321,962
Sensitivity Analysis Of Fair Value Of Redeemable Noncontrolling Interests Using Discount And Terminal Growth Rates	The table below is a sensitivity analysis which shows the fair value of the redeemable noncontrolling interests using the assumed discount and the terminal growth rates and fair values under different rate assumptions as of December 31, 2017 (dollars in millions): Discount Rates Terminal Growth Rates 11.95% 12.20% 12.45% 1.75 % $ 417.6 $ 407.6 $ 398.1 2.00 % $ 422.4 $ 412.1 $ 402.3 2.25 % $ 427.5 $ 416.9 $ 406.8

Compensation Plans (Tables)

Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Activity of Restricted Stock	The following table details the activity in restricted stock during the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts): Weighted- Average Grant Date Fair Value Balance at January 1, 2015 3,383 $ 27.00 Grants 602 $ 18.63 Forfeited (94 ) $ 28.12 Fulfillment of service requirement (1,887 ) $ 26.87 Balance at December 31, 2015 2,004 $ 24.56 Grants 356 $ 18.23 Forfeited (24 ) $ 26.90 Fulfillment of service requirement (974 ) $ 25.65 Balance at December 31, 2016 1,362 $ 22.09 Grants 391 $ 23.65 Forfeited — $ — Fulfillment of service requirement (611 ) $ 23.73 Balance at December 31, 2017 1,142 $ 21.75
Activity of Restricted Stock Units	The following table details the activity in RSUs during the years ended December 31, 2017, 2016 and 2015 (in thousands, except per share amounts): Weighted-Average Grant Date Fair Value Future Service Required No Future Service Required Future Service Required No Future Service Required Balance at January 1, 2015 4,238 8,467 $ 26.90 $ 26.79 Grants — 121 $ — $ 18.95 Distributions of underlying shares — (229 ) $ — $ 22.34 Forfeited (626 ) — $ 26.90 $ — Fulfillment of service requirement (224 ) 224 $ 26.90 $ 26.90 Balance at December 31, 2015 3,388 8,583 $ 26.90 $ 26.68 Grants — 128 $ — $ 14.21 Distributions of underlying shares — (1,683 ) $ — $ 26.59 Forfeited — — $ — $ — Fulfillment of service requirement (3,320 ) 3,320 $ 26.90 $ 26.90 Balance at December 31, 2016 68 10,348 $ 26.90 $ 26.61 Grants — 104 $ — $ 21.55 Distributions of underlying shares — (175 ) $ — $ 26.46 Forfeited — — $ — $ — Fulfillment of service requirement (36 ) 36 $ 26.90 $ 26.90 Balance at December 31, 2017 32 10,313 $ 26.90 $ 26.57
Activity of Stock Options	A summary of activity with respect to our stock options during the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands, except per share amounts): Common Shares Subject to Option Weighted- Average Exercise Prices Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Balance at January 1, 2015 1,640 $ 24.91 Granted — $ — Exercised (2 ) $ 21.66 $ 6 Cancelled (977 ) $ 24.88 Balance at December 31, 2015 661 $ 24.97 Granted — $ — Exercised — $ — $ — Cancelled (20 ) $ 30.49 Balance at December 31, 2016 641 $ 24.80 Granted — $ — Exercised (20 ) $ 22.75 $ 65 Cancelled (290 ) $ 26.98 Balance at December 31, 2017 331 $ 23.03 1 year $ 1,156 Exercisable at December 31, 2017 264 $ 23.07 1 year $ 911
Senior Executive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Activity of Restricted Stock Units	The following table details the activity in RSUs related to the senior executive compensation plan during the years ended December 31, 2017 and 2016 (in thousands, except per share amounts): Target Number of Shares Weighted- Average Grant Date Fair Value Balance at December 31, 2015 — $ — Grants 3,434 $ 9.68 Forfeited — $ — Balance at December 31, 2016 3,434 $ 9.68 Grants 2,221 $ 19.06 Forfeited — $ — Balance at December 31, 2017 5,655 $ 13.37

Accumulated Other Comprehensi59

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
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 at December 31, 2017, 2016 and 2015 is as follows (in thousands): 2017 2016 2015 Net unrealized gains on available for sale securities $ 572,085 $ 561,497 $ 557,601 Net unrealized foreign exchange losses (101,400 ) (184,829 ) (63,248 ) Net unrealized losses in instrument specific credit risk (34,432 ) (6,494 ) — Net unrealized losses on cash flow hedges (1,138 ) — — Net minimum pension liability (62,391 ) (59,477 ) (55,560 ) $ 372,724 $ 310,697 $ 438,793
Schedule Of Accumulated Other Comprehensive Income Reclassifications	For the years ended December 31, 2017 and 2016 , 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 Statement of Operations 2017 2016 Net unrealized gains on available for sale securities, net of income tax provision of $124 and $2 $ 212 $ 4 Net realized securities gains Net unrealized foreign exchange losses, net of income tax provision of $1,086 and $0 (5,310 ) — Other income and other expenses Amortization of defined benefit pension plan actuarial losses, net of income tax benefit of $(811) and $(700) (1,748 ) (1,534 ) Compensation and benefits, which includes pension expense. See Note 19 for information on this component. Other pension, net of income tax benefit of $(1,231) and $0 1,231 — Income tax provision (benefit) Total reclassifications for the period, net of tax $ (5,615 ) $ (1,530 )

Pension Plans and Postretirem60

Pension Plans and Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Components Of Defined Benefit Pension Plans	A summary of activity with respect to both plans is as follows (in thousands): 2017 2016 Change in projected benefit obligation: Projected benefit obligation, beginning of year $ 205,405 $ 207,025 Interest cost 8,119 8,464 Actuarial (gains) losses 6,644 (544 ) Benefits paid (8,911 ) (9,540 ) Projected benefit obligation, end of year $ 211,257 $ 205,405 Change in plan assets: Fair value of plan assets, beginning of year $ 127,514 $ 117,719 Actual return on plan assets 22,192 2,947 Employer contributions 12,417 19,100 Benefits paid (8,911 ) (9,540 ) Administrative expenses (2,406 ) (2,712 ) Fair value of plan assets, end of year $ 150,806 $ 127,514 Funded status at end of year $ (60,451 ) $ (77,891 )
Components Of Net Periodic Pension Costs And Amounts Recognized In Other Comprehensive Income	The following table summarizes the components of net periodic pension cost and other amounts recognized in other comprehensive income (loss) excluding taxes (in thousands): 2017 2016 2015 Components of net periodic pension cost: Interest cost $ 8,119 $ 8,464 $ 12,958 Expected return on plan assets (7,689 ) (7,589 ) (10,581 ) Settlement charge — — 40,973 Actuarial losses 2,207 1,908 6,963 Net periodic pension cost $ 2,637 $ 2,783 $ 50,313 Amounts recognized in other comprehensive income (loss): Net (gain) loss arising during the period $ (5,453 ) $ 6,811 $ (24,186 ) Settlement charge — — (40,973 ) Amortization of net loss (2,207 ) (1,908 ) (6,963 ) Total recognized in other comprehensive income (loss) $ (7,660 ) $ 4,903 $ (72,122 ) Net amount recognized in net periodic benefit cost and other comprehensive income (loss) $ (5,023 ) $ 7,686 $ (21,809 )
Schedule Of Assumptions For Pension Plan	We use a December 31 measurement date for the WilTel plan and a November 30 date for the Jefferies plan. The assumptions used are as follows: 2017 2016 WilTel Plan Discount rate used to determine benefit obligation 3.51 % 3.85 % Weighted-average assumptions used to determine net pension cost: Discount rate 3.85 % 4.00 % Expected long-term return on plan assets 7.00 % 7.00 % Jefferies Plan Discount rate used to determine benefit obligation 3.60 % 3.90 % Weighted-average assumptions used to determine net pension cost: Discount rate 3.90 % 4.10 % Expected long-term return on plan assets 6.25 % 6.25 %
Schedule Of Expected Pension Benefit Payments	The following pension benefit payments are expected to be paid (in thousands): 2018 $ 9,943 2019 9,915 2020 9,666 2021 9,577 2022 10,233 2023 – 2027 67,493
U.S. Pension Plans | WilTel Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule Of Plan's Assets At Fair Value	At December 31, 2017 and 2016 , the WilTel plan assets at fair value consisted of the following (in thousands): Fair Value Measurements Using Total Level 1 Level 2 2017 Cash and cash equivalents $ 539 $ 539 $ — Growth Portfolio 65,625 — 65,625 Liability-Driven Investing Portfolio 31,693 — 31,693 Total $ 97,857 $ 539 $ 97,318 2016 Cash and cash equivalents $ 919 $ 919 $ — Growth Portfolio 51,852 — 51,852 Liability-Driven Investing Portfolio 24,751 — 24,751 Total $ 77,522 $ 919 $ 76,603
U.S. Pension Plans | Jefferies Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule Of Plan's Assets At Fair Value	At December 31, 2017 and 2016 , the Jefferies plan assets at fair value consisted of the following (in thousands): Fair Value Measurements Using Total (1) Level 1 Level 2 2017 Common collective trusts $ 52,949 $ — $ 52,949 Total $ 52,949 $ — $ 52,949 2016 Cash and cash equivalents $ 1,135 $ 1,135 $ — Listed equity securities (2) 32,342 32,342 — Fixed income securities: Corporate debt securities 4,906 — 4,906 Foreign corporate debt securities 1,835 — 1,835 U.S. government securities 5,370 5,370 — Agency mortgage-backed securities 3,330 — 3,330 Commercial mortgage-backed securities 591 — 591 Asset-backed securities 483 — 483 Total $ 49,992 $ 38,847 $ 11,145 (1) There are no plan assets classified within Level 3 of the fair value hierarchy. (2) Listed equity securities are diversified across a spectrum of primarily U.S. large-cap companies.
German Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule Of Assumptions For Pension Plan	The following are assumptions used to determine the actuarial present value of the projected benefit obligation and net periodic pension benefit cost for the years ended December 31, 2017 and 2016 : 2017 2016 Projected benefit obligation Discount rate 1.80 % 1.70 % Rate of compensation increase (1) N/A N/A Net periodic pension benefit cost Discount rate 1.70 % 2.20 % Rate of compensation increase (1) N/A N/A (1) There were no active participants in the plan at December 31, 2017 and 2016 .
Schedule Of Expected Pension Benefit Payments	The following pension benefit payments are expected to be paid (in thousands): 2018 $ 1,303 2019 1,275 2020 1,329 2021 1,339 2022 1,320 2023 – 2027 6,571
Changes in Projected Benefit Obligation	The following tables summarize the changes in the projected benefit obligation and the components of net periodic pension cost for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 Change in projected benefit obligation: Projected benefit obligation, beginning of year $ 24,166 $ 23,545 Interest cost 426 529 Actuarial (gains) losses (91 ) 1,157 Benefits paid (1,233 ) (1,104 ) Currency adjustment 2,976 39 Projected benefit obligation, end of year $ 26,244 $ 24,166
Components Of Pension Expense	2017 2016 2015 Components of net periodic pension cost: Interest cost $ 426 $ 529 $ 523 Net amortization 353 326 325 Net periodic pension cost $ 779 $ 855 $ 848

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule Of Provision For Income Taxes	The provision for income taxes for continuing operations for each of the three years in the period ended December 31, 2017 was as follows (in thousands): 2017 2016 2015 Current taxes: U.S. Federal $ 413 $ (574 ) $ 709 U.S. state and local 33,845 8,672 (25,308 ) Foreign 14,654 (4,620 ) 3,504 Total current 48,912 3,478 (21,095 ) Deferred taxes: U.S. Federal 694,207 108,241 134,590 U.S. state and local 9,697 8,335 4,552 Foreign 8,151 2,055 (8,100 ) Total deferred 712,055 118,631 131,042 Total income tax provision $ 760,967 $ 122,109 $ 109,947
Schedule of Income before Income Tax, U.S. and non-U.S.	The following table presents the U.S. and non-U.S. components of income from continuing operations before income taxes for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 U.S. $ 944,014 $ 337,374 $ 336,856 Non-U.S. (1) 69,800 (20,944 ) 19,680 Income from continuing operations before income taxes $ 1,013,814 $ 316,430 $ 356,536 (1) For purposes of this table, non-U.S. income is defined as income generated from operations located outside the U.S.
Schedule Of Reconciliation Of Expected Statutory Federal Income Tax To Actual Income Tax Provision (Benefit)	For each of the three years in the period ended December 31, 2017 , income tax expense differed from the amounts computed by applying the U.S. Federal statutory income tax rate of 35% to income from continuing operations before income taxes as a result of the following (dollars in thousands): 2017 2016 2015 Amount Percent Amount Percent Amount Percent Computed expected federal income tax $ 354,835 35.0 % $ 110,751 35.0 % $ 124,788 35.0 % Increase (decrease) in income taxes resulting from: State and local income taxes, net of federal income tax benefit 19,938 2.0 1,045 0.3 (6,928 ) (1.9 ) International operations (including foreign rate differential) (11,577 ) (1.1 ) (3,137 ) (1.0 ) (11,474 ) (3.2 ) Increase (decrease) in valuation allowance — — 2,825 0.9 (13,227 ) (3.7 ) Permanent differences 7,474 0.7 7,523 2.4 13,892 3.9 Tax exempt income (3,850 ) (0.4 ) (4,640 ) (1.5 ) (6,789 ) (1.9 ) Foreign tax credits (32,974 ) (3.2 ) — — (7,240 ) (2.0 ) (Income) loss allocated to noncontrolling interest, not subject to tax (28,392 ) (2.8 ) (22,512 ) (7.1 ) 11,039 3.1 Excess stock detriment 161 — 24,907 7.9 — — Revaluation of deferred tax asset 415,000 40.9 — — — — Transition tax 35,500 3.5 — — — — Other 4,852 0.5 5,347 1.7 5,886 1.5 Actual income tax provision $ 760,967 75.1 % $ 122,109 38.6 % $ 109,947 30.8 %
Schedule Of Reconciliation Of Unrecognized Tax Benefits	The following table presents a reconciliation of gross unrecognized tax benefits for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 Balance at beginning of period $ 148,848 $ 150,867 $ 148,590 Increases based on tax positions related to the current period 18,619 5,045 3,475 Increases based on tax positions related to prior periods 10,358 3,697 22,030 Decreases based on tax positions related to prior periods (8,805 ) (9,414 ) (15,349 ) Decreases related to settlements with taxing authorities — (1,347 ) (7,879 ) Balance at end of period $ 169,020 $ 148,848 $ 150,867
Schedule Of Principal Components Of Deferred Taxes	The principal components of deferred taxes at December 31, 2017 and 2016 are as follows (in thousands): 2017 2016 Deferred tax asset: Net operating loss carryover $ 599,839 $ 1,262,584 Compensation and benefits 213,340 309,100 Long-term debt 11,799 54,102 Other assets 97,061 155,028 Tax credits 93,026 10,749 Securities valuation reserves 3,012 12,345 Intangible assets, net and goodwill 270 311 Other liabilities 21,605 39,188 1,039,952 1,843,407 Valuation allowance (93,758 ) (106,042 ) 946,194 1,737,365 Deferred tax liability: Unrealized gains on investments (8,060 ) (998 ) Amortization of intangible assets (71,583 ) (107,437 ) Property and equipment (8,209 ) (14,228 ) Investment in FXCM (37,942 ) (117,594 ) Transition tax (35,165 ) — Other (41,424 ) (35,293 ) (202,383 ) (275,550 ) Net deferred tax asset $ 743,811 $ 1,461,815

Net Realized Securities Gains62

Net Realized Securities Gains (Losses) (Tables)	12 Months Ended
	Dec. 31, 2017
Gain (Loss) on Investments [Abstract]
Summary Of Net Securities Gains (Losses)	The following summarizes net realized securities gains (losses) for each of the three years in the period ended December 31, 2017 (in thousands): 2017 2016 2015 Net realized gains (losses) on securities $ 13 $ (286 ) $ 14,112 Other (1) 23,015 29,828 48,845 $ 23,028 $ 29,542 $ 62,957 (1) In 2017, primarily relates to a $19.7 million security gain from an investment in a non-public security. In 2015, primarily relates to a recovery of $35.0 million of an investment in a non-public security written down in prior years

Other Results of Operations I63

Other Results of Operations Information (Tables)	12 Months Ended
	Dec. 31, 2017
Nonoperating Income (Expense) [Abstract]
Schedule Of Other Income	Other revenue for each of the three years in the period ended December 31, 2017 consists of the following (in thousands): 2017 2016 2015 Manufacturing revenues $ 326,197 $ 412,826 $ 391,920 Losses from managed funds (8,118 ) (69,038 ) (37,237 ) Asset management fees 28,831 29,492 34,777 Dividend income (452 ) 3,856 5,482 Income from associated companies classified as other revenues 75,889 17,184 75,717 Revenues of oil and gas production and development businesses 61,541 49,890 45,939 Gain on sale of Conwed 178,236 — — Other 86,384 43,976 32,630 $ 748,508 $ 488,186 $ 549,228

Common Shares and Earnings Pe64

Common Shares and Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share Computation	The numerators and denominators used to calculate basic and diluted earnings per share are as follows for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Numerator for earnings per share: Net income attributable to Leucadia National Corporation common shareholders $ 167,351 $ 125,938 $ 279,587 Allocation of earnings to participating securities (1) (610 ) (574 ) (4,711 ) Net income attributable to Leucadia National Corporation common shareholders for basic earnings per share 166,741 125,364 274,876 Adjustment to allocation of earnings to participating securities related to diluted shares (1) (14 ) (19 ) (34 ) Mandatorily redeemable convertible preferred share dividends — — — Net income attributable to Leucadia National Corporation common shareholders for diluted earnings per share $ 166,727 $ 125,345 $ 274,842 Denominator for earnings per share: Denominator for basic earnings per share – weighted-average shares 368,197 371,211 372,430 Stock options 24 — 1 Senior executive compensation plan awards 2,480 307 — Mandatorily redeemable convertible preferred shares — — — Denominator for diluted earnings per share 370,701 371,518 372,431 (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 1,401,000 , 1,986,800 and 6,500,000 for the years ended December 31, 2017, 2016 and 2015 , respectively. Dividends declared on participating securities during the years ended December 31, 2017, 2016 and 2015 were $0.4 million , $0.4 million and $1.5 million , respectively. 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 an65

Commitments, Contingencies and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Commitments for Noncancelable Operating Leases	Future minimum annual rentals (exclusive of month-to-month leases, real estate taxes, maintenance and certain other charges) under these leases at December 31, 2017 are as follows (in thousands): 2018 $ 94,734 2019 84,110 2020 68,195 2021 62,507 2022 59,844 Thereafter 638,441 1,007,831 Less: sublease income (29,633 ) $ 978,198
Schedule of commitments	The following table summarizes commitments associated with certain business activities (in millions): Expected Maturity Date 2018 2019 2020 2022 2024 Maximum Payout Equity commitments (1) $ 33.5 $ 0.2 $ 18.7 $ — $ 125.8 $ 178.2 Loan commitments (1) 277.7 — 56.5 — — 334.2 Mortgage-related and other purchase commitments — 177.7 — — — 177.7 Underwriting commitments 11.0 — — — — 11.0 Forward starting reverse repos (2) 3,211.1 — — — — 3,211.1 Forward starting repos (2) 2,987.9 — — — — 2,987.9 Other unfunded commitments (1) 218.8 122.9 18.3 153.0 — 513.0 $ 6,740.0 $ 300.8 $ 93.5 $ 153.0 $ 125.8 $ 7,413.1 (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 December 31, 2017 , $3,207.4 million within forward starting securities purchased under agreements to resell and $2,982.8 million within securities sold under agreements to repurchase settled within three business days.
Schedule of Notional Amounts Associated with Derivative Contracts Meeting Definition Of Guarantee	The following table summarizes the notional amounts associated with our derivative contracts meeting the definition of a guarantee under GAAP as of December 31, 2017 (in millions): Expected Maturity Date Guarantee Type 2018 2019 2020 2022 2024 Notional/ Maximum Payout Derivative contracts – non-credit related $ 24,454.8 $ 2,420.2 $ 150.5 $ 45.9 $ 466.3 $ 27,537.7 Written derivative contracts – credit related — 42.0 20.5 155.7 — 218.2 Total derivative contracts $ 24,454.8 $ 2,462.2 $ 171.0 $ 201.6 $ 466.3 $ 27,755.9

Other Fair Value Information (T

Other Fair Value Information (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [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): December 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Other Assets: Notes and loans receivable (1) $ 579,071 $ 565,285 $ 962,938 $ 958,377 Financial Liabilities: Short-term borrowings (2) 412,891 412,891 525,842 525,842 Long-term debt (3) 7,278,827 7,678,210 7,131,587 7,221,459 (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 and A67

Discontinued Operations and Assets Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2017
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Schedule of Assets Held for Sale	Assets held for sale at December 31, 2016, which primarily relate to Conwed, are as follows (in thousands): Cash $ 5,206 Receivables 15,297 Property, equipment and leasehold improvements, net 18,664 Intangible assets, net and goodwill 56,854 Inventory 19,069 Other assets 12,993 $ 128,083

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule Of Segment Reporting Information, By Segment	Certain information concerning our segments for the years ended December 31, 2017, 2016 and 2015 is presented in the following table. Consolidated subsidiaries are reflected as of the date a majority controlling interest was acquired. As discussed above, Jefferies is reflected in our consolidated financial statements utilizing a one month lag. 2017 2016 2015 (In thousands) Net Revenues: Reportable Segments: Jefferies $ 3,207,097 $ 2,421,055 $ 2,476,133 National Beef 7,358,948 7,027,243 7,402,419 Corporate and other 62,847 88,590 78,122 Total net revenues related to reportable segments 10,628,892 9,536,888 9,956,674 All other (1) 807,501 525,729 950,784 Intercompany eliminations (2) — — (21,000 ) Total consolidated net revenues $ 11,436,393 $ 10,062,617 $ 10,886,458 Income (loss) from continuing operations before income taxes: Reportable Segments: Jefferies $ 527,804 $ 43,508 $ 119,165 National Beef 407,312 329,022 (123,915 ) Corporate and other (78,926 ) 18,386 (44,295 ) Income (loss) from continuing operations before income taxes related to reportable segments 856,190 390,916 (49,045 ) All other (1) 216,567 (15,605 ) 492,762 Parent Company interest (58,943 ) (58,881 ) (87,181 ) Total consolidated income from continuing operations before income taxes $ 1,013,814 $ 316,430 $ 356,536 Depreciation and amortization expenses: Reportable Segments: Jefferies $ 62,668 $ 60,206 $ 92,165 National Beef 98,515 94,482 89,317 Corporate and other 5,178 3,619 3,744 Total depreciation and amortization expenses related to reportable segments 166,361 158,307 185,226 All other 42,549 53,286 38,907 Total consolidated depreciation and amortization expenses $ 208,910 $ 211,593 $ 224,133 Identifiable assets employed: Reportable Segments: Jefferies (3) $ 39,575,732 $ 36,992,096 $ 38,607,786 National Beef 1,460,539 1,498,317 1,514,249 Corporate and other 2,006,536 1,935,118 1,777,199 Identifiable assets employed related to reportable segments 43,042,807 40,425,531 41,899,234 All other 4,196,622 4,728,457 4,581,673 Intercompany eliminations (70,321 ) (82,681 ) (149,723 ) Total consolidated assets $ 47,169,108 $ 45,071,307 $ 46,331,184 (1) All other revenue and income from continuing operations before income taxes include $23.2 million and $(154.5) million , respectively, of realized and unrealized gains (losses) relating to our investment in FXCM for the year ended December 31, 2017 . All other revenue and income from continuing operations before income taxes include $(54.6) million and $491.3 million of realized and unrealized gains (losses) relating to our investment in FXCM for the years ended December 31, 2016 and 2015 , respectively. (2) Revenue intercompany elimination for 2015 relates to an investment banking and advisory fee paid to Jefferies in connection with our entering into the agreement with FXCM. (3) At December 31, 2017, 2016 and 2015 , includes $213.0 million , $337.6 million and $320.2 million , respectively, of Jefferies deferred tax asset, net.
Schedule Of Net Revenues By Geographic Region	Net revenues by geographic region for Jefferies for the years ended December 31, 2017, 2016 and 2015 were as follows (in thousands): 2017 2016 2015 Americas (1) $ 2,611,729 $ 1,876,796 $ 1,887,899 Europe (2) 489,583 458,046 510,044 Asia 105,785 86,213 78,190 $ 3,207,097 $ 2,421,055 $ 2,476,133 (1) Substantially all relates to U.S. results. (2) Substantially all relates to U.K. results.

Exit Costs (Tables)

Exit Costs (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	During the years ended December 31, 2016 and 2015, Jefferies recorded restructuring and impairment costs as follows (in thousands): 2016 2015 Severance costs $ 279 $ 30,327 Accelerated amortization of restricted stock and restricted cash awards 41 7,922 Accelerated amortization of capitalized software — 19,745 Contract termination costs 1,234 11,247 Selling, general and other expenses 300 3,853 Total $ 1,854 $ 73,094

Selected Quarterly Financial 70

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Schedule Of Selected Quarterly Financial Data	First Quarter (1) Second Quarter (2) Third Quarter (3) Fourth Quarter (4) (In thousands, except per share amounts) 2017 Net revenues $ 2,867,982 $ 2,732,380 $ 2,896,522 $ 2,939,509 Income (loss) from continuing operations $ 293,923 $ 74,062 $ 136,767 $ (251,905 ) Net (income) loss attributable to the noncontrolling interest $ 523 $ 1,446 $ (28 ) $ 1,514 Net income attributable to the redeemable noncontrolling interests $ (12,022 ) $ (16,300 ) $ (36,216 ) $ (20,038 ) Preferred stock dividends $ (1,016 ) $ (1,015 ) $ (1,172 ) $ (1,172 ) Net income (loss) attributable to Leucadia National Corporation common shareholders $ 281,408 $ 58,193 $ 99,351 $ (271,601 ) Basic earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ 0.76 $ 0.16 $ 0.27 $ (0.74 ) Number of shares used in calculation 369,267 369,212 367,828 366,000 Diluted earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ 0.75 $ 0.16 $ 0.27 $ (0.74 ) Number of shares used in calculation 375,721 371,552 370,198 366,000 2016 Net revenues $ 2,015,106 $ 2,625,358 $ 2,676,375 $ 2,745,778 Income (loss) from continuing operations $ (218,602 ) $ 70,612 $ 176,206 $ 166,105 Net (income) loss attributable to the noncontrolling interest $ 1,052 $ 760 $ 1,870 $ (2,256 ) Net income attributable to the redeemable noncontrolling interests $ (4,314 ) $ (13,068 ) $ (22,702 ) $ (25,662 ) Preferred stock dividends $ (1,016 ) $ (1,015 ) $ (1,016 ) $ (1,016 ) Net income (loss) attributable to Leucadia National Corporation common shareholders $ (222,880 ) $ 57,289 $ 154,358 $ 137,171 Basic earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ (0.60 ) $ 0.15 $ 0.41 $ 0.37 Number of shares used in calculation 372,367 372,556 370,404 369,299 Diluted earnings (loss) per common share attributable to Leucadia National Corporation common shareholders: Net income (loss) $ (0.60 ) $ 0.15 $ 0.41 $ 0.37 Number of shares used in calculation 372,367 372,556 374,567 374,693 (1) The first quarter of 2017 includes a pre-tax gain of $179.9 million related to the sale of Conwed Plastics, revenue of $175.2 million related to the increase in fair value of our investment in HRG and a pre-tax charge of $130.2 million related to an impairment of our equity investment in FXCM. Net revenues for the first quarter of 2016 were impacted by a volatile and turbulent period in the capital markets, which primarily impacted Jefferies and our other market sensitive businesses. Net revenues in the first quarter of 2016 include losses of $82.2 million from Jefferies investment in two equity block positions, including KCG, and a loss of $53.2 million from a decline in fair value of our FXCM investment. The first quarter of 2016 also includes revenue of $65.6 million related to the increase in a corporate trading asset held at fair value. (2) The second quarter of 2017 includes losses of $75.0 million from a decrease in fair value of our investment in HRG and revenue of $95.8 million from an increase in fair value of Jefferies investment in KCG. Net revenues in the second quarter of 2016 includes revenue of $55.8 million from an increase in fair value of Jefferies investment in KCG and a loss of $47.9 million from a decline in fair value of our FXCM investment. (3) The third quarter of 2017 includes losses of $97.9 million from a decrease in fair value of our investment in HRG. The third quarter of 2016 includes revenue of $91.8 million from an increase in fair value of our investment in HRG and revenue of $42.7 million from an increase in fair value of our FXCM investment. The third quarter of 2016 also includes a pre-tax charge of $55.0 million related to an impairment of JETX's unproved oil and gas properties in the East Eagle Ford and Houston County. (4) As discussed further in Note 20, the fourth quarter of 2017 includes a discrete tax charge of $450.5 million as a provisional estimate of the impact of the Tax Act. This provisional estimate primarily consists of a $415.0 million expense related to the revaluation of our deferred tax assets and a $35.5 million expense related to the deemed repatriation of foreign earnings.

Schedule I - Condensed Financ71

Schedule I - Condensed Financial Information of Registrant (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Supplemental Cash Flow Information	Supplemental Cash Flow Information For the Year ended December 31, 2017 2016 2015 (In thousands) Cash paid during the year for: Interest $ 1,120,191 $ 957,140 $ 980,266 Income tax payments (refunds), net $ 15,361 $ (13,738 ) $ 510
Parent Company
Condensed Financial Statements, Captions [Line Items]
Supplemental Cash Flow Information	Supplemental cash flow information related to the Parent Company for the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands): 2017 2016 2015 Cash paid during the year for: Interest $ 57,813 $ 57,813 $ 95,074 Income tax payments (refunds), net $ 1,440 $ (10,199 ) $ (2,332 ) Non-cash investing activities: Investments contributed to subsidiary $ 25,328 $ 423,009 $ — Investments transferred from subsidiary $ — $ 2,022 $ — Dividends received from subsidiaries $ 32,792 $ — $ —

Nature of Operations (Details)

Nature of Operations (Details) $ in Thousands	Oct. 31, 2017USD ($)	Jan. 31, 2017USD ($)	Dec. 31, 2017USD ($)facilitydirector	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)facilitydirector	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Jan. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of associated companies					$ 173,105	$ 0	$ 0
Gain on sale of subsidiaries					179,605	$ 0	$ 0
FXCM
Schedule of Equity Method Investments [Line Items]
Senior secured term loan receivable			$ 69,900		$ 69,900			$ 300,000
Jefferies Finance
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			50.00%		50.00%
Jefferies LoanCore
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned	48.50%		48.50%		48.50%
Proceeds from sale of associated companies	$ 173,100
Period entitled to additional cash consideration	5 years
Berkadia
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			50.00%		50.00%
HomeFed Corporation
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			70.00%		70.00%
Percentage limit of voting rights contractually agreed			45.00%		45.00%
Number of directors appointed by Company | director			3		3
Foursight Capital
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary			100.00%		100.00%
Chrome Capital
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary			85.00%		85.00%
National Beef
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary			78.90%		78.90%
National Beef | Beef Processing Facility
Schedule of Equity Method Investments [Line Items]
Domestic facilities | facility			2		2
National Beef | Consumer-Ready Facility
Schedule of Equity Method Investments [Line Items]
Domestic facilities | facility			3		3
National Beef | Tanning Facility
Schedule of Equity Method Investments [Line Items]
Domestic facilities | facility			1		1
HRG
Schedule of Equity Method Investments [Line Items]
Percentage of outstanding common stock owned			23.00%		23.00%	23.00%
Spectrum Brands | Product Segment
Schedule of Equity Method Investments [Line Items]
Percentage of outstanding common stock owned			59.00%		59.00%
Vitesse Energy, LLC
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary			96.00%		96.00%
JETX Energy, LLC
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary			98.00%		98.00%
Garcadia Companies
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			75.00%		75.00%
Number of automobile dealerships | facility			28		28
Linkem
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			42.00%		42.00%
Percentage of ownership upon conversion of preferred shares			53.00%		53.00%
Golden Queen Mining Company, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			35.00%		35.00%
Investment in FXCM
Schedule of Equity Method Investments [Line Items]
Percentage of ownership owned			50.00%		50.00%	50.00%
Maximum percentage of all distributions			75.00%		75.00%
Number of board of directors | director			6		6
Number of directors appointed by Company | director			3		3
Number of directors appointed by co-investee | director			3		3
Jefferies LoanCore | Disposed of by Sale | Jefferies
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of associated companies	$ 173,100
Period entitled to additional cash consideration	5 years
Fidelity & Guaranty Life | HRG
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest sold			80.00%
Front Street | HRG
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest sold			100.00%
Conwed | Disposed of by Sale
Schedule of Equity Method Investments [Line Items]
Percentage interest owned in subsidiary		100.00%
Cash received from sale of subsidiary		$ 295,000
Gain on sale of subsidiaries				$ 179,900	$ 178,236
Maximum | Conwed | Disposed of by Sale
Schedule of Equity Method Investments [Line Items]
Potential earn-out payment to be received from sale of subsidiary		$ 40,000

Significant Accounting Polici73

Significant Accounting Policies (Details) - USD ($) $ in Thousands	Sep. 01, 2016	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Long Lived Assets Held-for-sale [Line Items]
Receivables from brokers, dealers and clearing organizations			$ 2,635,200	$ 2,062,900
Receivables from customers of securities operations			1,563,800	843,100
Payables to brokers, dealers and clearing organizations			2,228,900	3,290,400
Payables to customers of securities operations			2,664,000	2,297,300
Cash paid during the year for:
Interest			1,120,191	957,140	$ 980,266
Income tax payments (refunds), net			15,361	(13,738)	510
Loans to and investments in associated companies			2,066,829	2,125,098	1,757,369	$ 1,712,568
Transfer of investment from trading assets to loans to and investments in associated companies	$ 334,500			334,500
Selling, general and other expenses
Long Lived Assets Held-for-sale [Line Items]
Asset impairment charges		$ 10,100			27,700
National Beef | Selling, general and other expenses
Long Lived Assets Held-for-sale [Line Items]
Asset impairment charges					4,700
JETX Energy, LLC | Selling, general and other expenses
Long Lived Assets Held-for-sale [Line Items]
Asset impairment charges		$ 10,100		56,300	20,300
54 Madison
Cash paid during the year for:
Loans to and investments in associated companies			123,010	$ 161,400	$ 0
Total assets of deconsolidated entity			612,900
Total liabilities of deconsolidated entity			330,500
Noncontrolling interests of deconsolidated entity			$ 167,200
Minimum
Long Lived Assets Held-for-sale [Line Items]
Derivative hedging relationship effective percentage			80.00%
Maximum
Long Lived Assets Held-for-sale [Line Items]
Derivative hedging relationship effective percentage			125.00%

Accounting Developments (Detail

Accounting Developments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2018	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from accumulated other comprehensive income	$ 0
Retained earnings	$ 4,700,968		$ 4,645,391
Two largest consolidated subsidiaries revenue as percentage of total net revenues	92.00%
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from accumulated other comprehensive income	$ 9,200
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from accumulated other comprehensive income	$ (9,200)
Sale of beef, pork and beef by-products | Product Concentration Risk | Revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk, percentage	95.00%
Subsequent Event | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 8,000
Subsequent Event | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 28,000

Fair Value Disclosures - Schedu

Fair Value Disclosures - Schedule of Assets and Liabilities Measured on Recurring Basis at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value based on NAV	$ 20,200	$ 24,300
Assets:
Counterparty/cash-collateral netting, Assets	(3,318,481)	(4,255,998)
Total trading assets, excluding investments at fair value based on NAV	15,492,572	14,960,928
Total available for sale securities	716,561	301,049
Liabilities:
Counterparty/cash-collateral netting, Liabilities	(3,490,514)	(4,229,213)
Total trading liabilities	8,454,965	8,388,619
Short-term borrowings	23,324
Other secured financings		41,768
Long-term debt	606,956	248,856
Trading liabilities
Liabilities:
Corporate equity securities	1,753,437	1,610,667
Corporate debt securities	1,689,347	1,718,947
U.S. government and federal agency securities	1,430,737	976,497
Sovereign obligations	2,173,635	2,629,344
Loans	1,152,310	802,355
Derivatives	255,394	650,809
Counterparty/cash-collateral netting, Liabilities	(3,490,514)	(4,229,213)
Trading assets
Assets:
Corporate equity securities	3,058,033	2,637,555
Corporate debt securities	3,287,336	2,700,025
Collateralized debt obligations and collateralized loan obligations	181,350	108,660
U.S. government and federal agency securities	1,308,673	2,446,123
Municipal securities	710,513	735,726
Sovereign obligations	2,417,459	2,423,048
Loans and other receivables	1,667,885	1,639,105
Derivatives	179,488	371,078
Counterparty/cash-collateral netting, Assets	(3,318,481)	(4,255,998)
Investments at fair value	330,890	314,359
FXCM term loan	72,800	164,500
Available for sale securities
Assets:
Corporate equity securities	88,486	79,425
Corporate debt securities		179
U.S. government and federal agency securities	552,805	174,933
Residential mortgage-backed securities
Assets:
Total available for sale securities	34,561	19,133
Residential mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	1,479,371	999,266
Residential mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	34,561	19,133
Commercial mortgage-backed securities
Assets:
Total available for sale securities	5,870	8,337
Commercial mortgage-backed securities | Trading liabilities
Liabilities:
Commercial mortgage-backed securities	105
Commercial mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	520,534	316,985
Commercial mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	5,870	8,337
Other asset-backed securities
Assets:
Total available for sale securities	34,839	19,042
Other asset-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	278,240	104,498
Other asset-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	34,839	19,042
Level 1
Assets:
Total trading assets, excluding investments at fair value based on NAV	5,791,641	6,348,755
Total available for sale securities	641,291	254,358
Liabilities:
Total trading liabilities	4,618,008	3,948,201
Short-term borrowings	0
Other secured financings		0
Long-term debt	0	0
Level 1 | Trading liabilities
Liabilities:
Corporate equity securities	1,721,267	1,593,548
Corporate debt securities	0	0
U.S. government and federal agency securities	1,430,737	976,497
Sovereign obligations	1,216,643	1,375,590
Loans	0	0
Derivatives	249,361	2,566
Level 1 | Trading assets
Assets:
Corporate equity securities	2,975,463	2,522,977
Corporate debt securities	0	0
Collateralized debt obligations and collateralized loan obligations	0	0
U.S. government and federal agency securities	1,269,230	2,389,397
Municipal securities	0	0
Sovereign obligations	1,381,552	1,432,556
Loans and other receivables	0	0
Derivatives	165,396	3,825
Investments at fair value	0	0
FXCM term loan	0	0
Level 1 | Available for sale securities
Assets:
Corporate equity securities	88,486	79,425
Corporate debt securities		0
U.S. government and federal agency securities	552,805	174,933
Level 1 | Residential mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 1 | Residential mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 1 | Commercial mortgage-backed securities | Trading liabilities
Liabilities:
Commercial mortgage-backed securities	0
Level 1 | Commercial mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 1 | Commercial mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 1 | Other asset-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 1 | Other asset-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 2
Assets:
Total trading assets, excluding investments at fair value based on NAV	12,369,954	12,072,393
Total available for sale securities	75,270	46,691
Liabilities:
Total trading liabilities	7,307,269	8,658,547
Short-term borrowings	23,324
Other secured financings		41,350
Long-term debt	606,956	248,856
Level 2 | Trading liabilities
Liabilities:
Corporate equity securities	32,122	16,806
Corporate debt securities	1,688,825	1,718,424
U.S. government and federal agency securities	0	0
Sovereign obligations	956,992	1,253,754
Loans	1,148,824	801,977
Derivatives	3,480,506	4,867,586
Level 2 | Trading assets
Assets:
Corporate equity securities	60,300	92,839
Corporate debt securities	3,261,300	2,675,020
Collateralized debt obligations and collateralized loan obligations	139,166	54,306
U.S. government and federal agency securities	39,443	56,726
Municipal securities	710,513	708,469
Sovereign obligations	1,035,907	990,492
Loans and other receivables	1,620,581	1,557,233
Derivatives	3,323,278	4,616,822
Investments at fair value	946	0
FXCM term loan	0	0
Level 2 | Available for sale securities
Assets:
Corporate equity securities	0	0
Corporate debt securities		179
U.S. government and federal agency securities	0	0
Level 2 | Residential mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	1,453,294	960,494
Level 2 | Residential mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	34,561	19,133
Level 2 | Commercial mortgage-backed securities | Trading liabilities
Liabilities:
Commercial mortgage-backed securities	0
Level 2 | Commercial mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	508,115	296,405
Level 2 | Commercial mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	5,870	8,337
Level 2 | Other asset-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	217,111	63,587
Level 2 | Other asset-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	34,839	19,042
Level 3
Assets:
Total trading assets, excluding investments at fair value based on NAV	649,458	795,778
Total available for sale securities	0	0
Liabilities:
Total trading liabilities	20,202	11,084
Short-term borrowings	0
Other secured financings		418
Long-term debt	0	0
Level 3 | Trading liabilities
Liabilities:
Corporate equity securities	48	313
Corporate debt securities	522	523
U.S. government and federal agency securities	0	0
Sovereign obligations	0	0
Loans	3,486	378
Derivatives	16,041	9,870
Level 3 | Trading assets
Assets:
Corporate equity securities	22,270	21,739
Corporate debt securities	26,036	25,005
Collateralized debt obligations and collateralized loan obligations	42,184	54,354
U.S. government and federal agency securities	0	0
Municipal securities	0	27,257
Sovereign obligations	0	0
Loans and other receivables	47,304	81,872
Derivatives	9,295	6,429
Investments at fair value	329,944	314,359
FXCM term loan	72,800	164,500
Level 3 | Available for sale securities
Assets:
Corporate equity securities	0	0
Corporate debt securities		0
U.S. government and federal agency securities	0	0
Level 3 | Residential mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	26,077	38,772
Level 3 | Residential mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 3 | Commercial mortgage-backed securities | Trading liabilities
Liabilities:
Commercial mortgage-backed securities	105
Level 3 | Commercial mortgage-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	12,419	20,580
Level 3 | Commercial mortgage-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	0	0
Level 3 | Other asset-backed securities | Trading assets
Assets:
Mortgage- and asset-backed securities, assets	61,129	40,911
Level 3 | Other asset-backed securities | Available for sale securities
Assets:
Mortgage- and asset-backed securities, assets	$ 0	$ 0

Fair Value Disclosures - Invest

Fair Value Disclosures - Investment in FXCM Narrative (Details)	1 Months Ended	12 Months Ended			36 Months Ended
	Feb. 28, 2017	Dec. 31, 2017USD ($)director	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)director	Jan. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Unrealized and realized gains and interest income		$ 931,576,000	$ 603,822,000	$ 642,824,000
Equity method investments		2,066,829,000	2,125,098,000	1,757,369,000	$ 2,066,829,000		$ 1,712,568,000
FXCM
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Senior secured term loan receivable		69,900,000			69,900,000	$ 300,000,000
Loan receivable interest rate percentage						10.00%
Increase in Interest rate per annum each quarter						1.50%
Principal and interest payments received		$ 114,900,000
Loan receivable interest rate during period		20.50%
Principal, interest and fees received					331,600,000
Initial investment amount						$ 279,000,000
Unrealized and realized gains and interest income		$ 23,200,000	(54,600,000)	491,300,000
Number of terminated employees as percentage of global workforce	22.00%
Equity method investments		158,856,000	$ 336,258,000	$ 0	158,856,000
Carrying value of Senior Secured Term Loan receivable and rights to future distributions		$ 231,700,000			$ 231,700,000
FXCM | Maximum
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]
Percentage of ownership owned		50.00%	50.00%		50.00%
Maximum percentage of all distributions		75.00%			75.00%
Number of board of directors | director		6			6
Number of directors appointed by Company | director		3			3
Percentage of distributions from sale of assets or certain other events until loan repayment		100.00%			100.00%
Percentage of distributions from sale of assets or certain other events until next milestone amount		50.00%			50.00%
Distributions milestone after loan repayment		$ 350,000,000			$ 350,000,000
Percentage of distributions from sale of assets or certain other events until milestone two		90.00%			90.00%
Percentage of distributions from sale of assets or certain other events thereafter		60.00%			60.00%
Distributions milestone two after loan repayment		$ 600,000,000			$ 600,000,000
Investment in FXCM | Global Brokerage
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Percentage of ownership owned		50.00%			50.00%
Trading Securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
FXCM term loan		$ 72,800,000	$ 164,500,000		$ 72,800,000

Fair Value Disclosures - Nonrec

Fair Value Disclosures - Nonrecurring Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Oil and gas properties fair value			$ 51.6
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 | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate		15.00%
EBITDA multiple		5.4
Revenue multiple		1.5
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
Selling, general and other expenses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	$ 10.1				$ 27.7
Impairment of oil and gas properties			55
JETX Energy, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of oil and gas properties			$ 55
JETX Energy, LLC | Selling, general and other expenses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	$ 10.1			$ 56.3	20.3
National Beef | Selling, general and other expenses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges					$ 4.7

Fair Value Disclosures - Inve78

Fair Value Disclosures - Investments Measured at Fair Value Based on Net Asset Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 590,104	$ 539,627
Unfunded Commitments	19,084	20,295
Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	407,895	363,256
Unfunded Commitments	$ 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
Fixed Income and High Yield Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 417	$ 772
Unfunded Commitments	0	0
Fund of Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	189	230
Unfunded Commitments	0	0
Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	26,798	42,179
Unfunded Commitments	$ 19,084	20,295
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
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	6 years
Multi-asset Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 154,805	133,190
Unfunded Commitments	$ 0	$ 0
Percentage of investments redeemable	12.00%	12.00%
Notice period redemption of investments prior written notice period	30 days
Estimated period for the liquidation of the underlying assets		30 days
10 days or less prior written notice | Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of investments redeemable	73.00%	83.00%
Notice period redemption of investments prior written notice period	10 days	10 days
15 to 60 days prior written notice | Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of investments redeemable	15.00%	17.00%

Fair Value Disclosures - Level

Fair Value Disclosures - Level 3 Rollforwards (Details) - USD ($) $ in Thousands	Sep. 01, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains (losses) (realized and unrealized)		$ 5,900	$ (115,300)	$ 455,500
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains (losses) (realized and unrealized)		1,700	1,900	7,600
Transfer of investment from trading assets to loans to and investments in associated companies	$ 334,500		334,500
Corporate equity securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		313	38	38
Total gains (losses) (realized and unrealized)		60	0	0
Purchases		(373)	0	0
Sales		48	313	0
Settlements		0	(38)	0
Issuances		0	0	0
Net transfers into (out of) Level 3		0	0	0
Ending Balance		48	313	38
Change in unrealized gains/(losses) relating to instruments still held		0	0	0
Corporate debt securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		523	0	223
Total gains (losses) (realized and unrealized)		(1)	(27)	(110)
Purchases		0	0	(6,804)
Sales		0	550	6,691
Settlements		0	0	0
Issuances		0	0	0
Net transfers into (out of) Level 3		0	0	0
Ending Balance		522	523	0
Change in unrealized gains/(losses) relating to instruments still held		1	0	0
Commercial mortgage-backed securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		0
Total gains (losses) (realized and unrealized)		105
Purchases		0
Sales		0
Settlements		0
Issuances		0
Net transfers into (out of) Level 3		0
Ending Balance		105	0
Change in unrealized gains/(losses) relating to instruments still held		(105)
Net derivatives
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		3,441	(242)	(4,638)
Total gains (losses) (realized and unrealized)		(1,638)	(1,760)	(7,310)
Purchases		0	0	(6,705)
Sales		0	11,101	13,522
Settlements		5,558	31	37
Issuances		456	2,067	2,437
Net transfers into (out of) Level 3		(1,071)	(7,756)	2,415
Ending Balance		6,746	3,441	(242)
Change in unrealized gains/(losses) relating to instruments still held		(17,740)	(6,458)	4,754
Loans
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		378	10,469	14,450
Total gains (losses) (realized and unrealized)		196	0	(163)
Purchases		(385)	0	(2,059)
Sales		2,485	378	229
Settlements		0	0	0
Issuances		0	0	0
Net transfers into (out of) Level 3		812	(10,469)	(1,988)
Ending Balance		3,486	378	10,469
Change in unrealized gains/(losses) relating to instruments still held		(2,639)	0	104
Other secured financings
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		418	544	30,825
Total gains (losses) (realized and unrealized)		(418)	(126)	0
Purchases		0	0	0
Sales		0	0	0
Settlements		0	0	(15,704)
Issuances		0	0	36,995
Net transfers into (out of) Level 3		0	0	(51,572)
Ending Balance		0	418	544
Change in unrealized gains/(losses) relating to instruments still held		0	(126)	0
Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		21,739	40,906	20,964
Total gains (losses) (realized and unrealized)		3,353	(8,463)	11,154
Purchases		896	3,365	21,385
Sales		(1,623)	(49)	(6,391)
Settlements		52	(671)	0
Net transfers into (out of) Level 3		(2,147)	(13,349)	(6,206)
Ending Balance		22,270	21,739	40,906
Change in unrealized gains/(losses) relating to instruments still held		2,606	291	11,424
Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		25,005	25,876	22,766
Total gains (losses) (realized and unrealized)		(3,723)	(16,230)	(11,013)
Purchases		36,850	27,242	21,534
Sales		(34,077)	(29,347)	(14,636)
Settlements		(1,968)	(7,223)	0
Net transfers into (out of) Level 3		3,949	24,687	7,225
Ending Balance		26,036	25,005	25,876
Change in unrealized gains/(losses) relating to instruments still held		(3,768)	(18,799)	(9,443)
CDOs and CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		54,354	85,092	124,650
Total gains (losses) (realized and unrealized)		(27,238)	(14,918)	(66,332)
Purchases		112,239	52,316	104,998
Sales		(101,226)	(69,394)	(107,381)
Settlements		(367)	(2,750)	(5,754)
Net transfers into (out of) Level 3		4,422	4,008	34,911
Ending Balance		42,184	54,354	85,092
Change in unrealized gains/(losses) relating to instruments still held		(20,262)	(7,628)	(48,514)
Municipal securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		27,257	0	0
Total gains (losses) (realized and unrealized)		(1,547)	(1,462)	10
Purchases		0	0	0
Sales		(25,710)	0	0
Settlements		0	0	(21,551)
Net transfers into (out of) Level 3		0	28,719	21,541
Ending Balance		0	27,257	0
Change in unrealized gains/(losses) relating to instruments still held		0	(1,462)	0
Sovereign obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		0	120	0
Total gains (losses) (realized and unrealized)			5	47
Purchases			0	1,032
Sales			(125)	(1,031)
Settlements			0	0
Net transfers into (out of) Level 3			0	72
Ending Balance			0	120
Change in unrealized gains/(losses) relating to instruments still held			0	39
Residential mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		38,772	70,263	82,557
Total gains (losses) (realized and unrealized)		(10,817)	(9,612)	(12,951)
Purchases		6,805	623	18,961
Sales		(26,193)	(12,249)	(31,762)
Settlements		(115)	(931)	(597)
Net transfers into (out of) Level 3		17,625	(9,322)	14,055
Ending Balance		26,077	38,772	70,263
Change in unrealized gains/(losses) relating to instruments still held		(7,201)	(1,095)	(4,498)
Commercial mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		20,580	14,326	26,655
Total gains (losses) (realized and unrealized)		(5,346)	(7,550)	(3,813)
Purchases		3,275	3,132	3,480
Sales		(5,263)	(2,024)	(10,146)
Settlements		(1,018)	(2,229)	(6,861)
Net transfers into (out of) Level 3		191	14,925	5,011
Ending Balance		12,419	20,580	14,326
Change in unrealized gains/(losses) relating to instruments still held		(6,976)	(7,243)	(3,205)
Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		40,911	42,925	2,294
Total gains (losses) (realized and unrealized)		(17,705)	(14,381)	(990)
Purchases		77,508	133,986	42,922
Sales		(8,613)	(102,952)	(1,299)
Settlements		(25,799)	(8,769)	(2)
Net transfers into (out of) Level 3		(5,173)	(9,898)	0
Ending Balance		61,129	40,911	42,925
Change in unrealized gains/(losses) relating to instruments still held		(12,562)	(18,056)	(254)
Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		81,872	189,289	97,258
Total gains (losses) (realized and unrealized)		24,794	(42,566)	(14,755)
Purchases		63,768	75,264	792,345
Sales		(53,095)	(69,262)	(576,536)
Settlements		(34,622)	(46,851)	(124,365)
Net transfers into (out of) Level 3		(35,413)	(24,002)	15,342
Ending Balance		47,304	81,872	189,289
Change in unrealized gains/(losses) relating to instruments still held		17,451	(52,003)	(16,802)
Investments at fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		314,359	199,794	77,047
Total gains (losses) (realized and unrealized)		20,975	54,538	62,804
Purchases		18,528	29,728	5,510
Sales		(22,818)	(542)	(425)
Settlements		(1,100)	(1,107)	(4,093)
Net transfers into (out of) Level 3		0	31,948	58,951
Ending Balance		329,944	314,359	199,794
Change in unrealized gains/(losses) relating to instruments still held		22,999	54,608	(1,964)
Investment in FXCM
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		164,500	625,689	0
Total gains (losses) (realized and unrealized)			(54,634)	491,341
Purchases			0	279,000
Sales			0	0
Settlements			(406,555)	(144,652)
Net transfers into (out of) Level 3			0	0
Ending Balance			164,500	625,689
Change in unrealized gains/(losses) relating to instruments still held			(1,014)	$ 491,341
Investment in FXCM - Senior Secured Term Loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		164,500
Total gains (losses) (realized and unrealized)		23,161
Purchases		0
Sales		0
Settlements		(114,861)
Net transfers into (out of) Level 3		0
Ending Balance		72,800	$ 164,500
Change in unrealized gains/(losses) relating to instruments still held		$ 1,070

Fair Value Disclosures - Analys

Fair Value Disclosures - Analysis of Level 3 Assets and Liabilities Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	$ 38,200	$ 179,600	$ 236,700
Transfers of assets from Level 3 to Level 2	54,900	133,200	85,800
Net gains (losses) on Level 3 assets (realized and unrealized)	5,900	(115,300)	455,500
Net gains (losses) on Level 3 liabilities (realized and unrealized)	1,700	1,900	7,600
Excluded securities from unobservable quantitative information, assets	228,600	325,000
Excluded securities from unobservable quantitative information, liabilities	4,200	1,600
Other secured financings
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 3 to Level 2			51,600
Net gains (losses) on Level 3 liabilities (realized and unrealized)	(418)	(126)	0
Loans
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 3 to Level 2		10,500
Net gains (losses) on Level 3 liabilities (realized and unrealized)	196	0	(163)
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		19,400	69,800
Transfers of assets from Level 3 to Level 2		15,400	34,900
Net gains (losses) on Level 3 assets (realized and unrealized)	(27,238)	(14,918)	(66,332)
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	19,600	17,500
Transfers of assets from Level 3 to Level 2		26,800
Net gains (losses) on Level 3 assets (realized and unrealized)	(10,817)	(9,612)	(12,951)
Non-agency 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			30,400
Transfers of assets from Level 3 to Level 2			16,300
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		17,400	11,300
Transfers of assets from Level 3 to Level 2			6,300
Net gains (losses) on Level 3 assets (realized and unrealized)	(5,346)	(7,550)	(3,813)
Municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3		28,700	21,500
Net gains (losses) on Level 3 assets (realized and unrealized)	(1,547)	(1,462)	10
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		16,900
Transfers of assets from Level 3 to Level 2		26,800
Net gains (losses) on Level 3 assets (realized and unrealized)	(17,705)	(14,381)	(990)
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		13,800	20,100
Transfers of assets from Level 3 to Level 2	40,900	37,800	4,700
Net gains (losses) on Level 3 assets (realized and unrealized)	24,794	(42,566)	(14,755)
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	8,300	28,100	7,400
Net gains (losses) on Level 3 assets (realized and unrealized)	(3,723)	(16,230)	(11,013)
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		19,200	7,700
Net gains (losses) on Level 3 assets (realized and unrealized)	3,353	(8,463)	11,154
Investments at fair value
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3		31,900	74,700
Transfers of assets from Level 3 to Level 2			15,800
Net gains (losses) on Level 3 assets (realized and unrealized)	$ 20,975	$ 54,538	$ 62,804

Fair Value Disclosures - Quanti

Fair Value Disclosures - Quantitative Information about Significant Unobservable Inputs Used in Level 3 Fair Value Measurements (Details)	12 Months Ended
	Dec. 31, 2017USD ($)$ / shares$ / Asset$ / Bond	Dec. 31, 2016USD ($)T / d$ / shares$ / Asset$ / Bond	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Trading Liabilities	$ 3,486,000	$ 378,000	$ 10,469,000	$ 14,450,000
Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	22,270,000	21,739,000	40,906,000	20,964,000
Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	26,036,000	25,005,000	25,876,000	22,766,000
CDOs and CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	42,184,000	54,354,000	85,092,000	124,650,000
Residential mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	26,077,000	38,772,000	70,263,000	82,557,000
Commercial mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	12,419,000	20,580,000	14,326,000	26,655,000
Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	61,129,000	40,911,000	42,925,000	2,294,000
Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	47,304,000	81,872,000	189,289,000	97,258,000
Investments at fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	329,944,000	314,359,000	$ 199,794,000	$ 77,047,000
FXCM term loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	72,800,000	164,500,000
Financial Instruments Owned | Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Trading Liabilities	16,041,000
Financial Instruments Owned | Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	18,109,000	19,799,000
Financial Instruments Owned | Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	26,036,000	25,005,000
Financial Instruments Owned | CDOs and CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	38,845,000	33,016,000
Financial Instruments Owned | Residential mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	26,077,000	38,772,000
Financial Instruments Owned | Commercial mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	12,419,000	20,580,000
Financial Instruments Owned | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	61,129,000	40,911,000
Financial Instruments Owned | Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	46,121,000	54,347,000
Financial Instruments Owned | Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	9,295,000
Financial Instruments Owned | Derivatives | Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned		6,429,000
Financial Instruments Owned | Investments at fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	110,010,000
Financial Instruments Owned | FXCM term loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	$ 73,000	165,000
Trading Liabilities | Derivatives | Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Trading Liabilities		9,870,000
Private equity securities | Financial Instruments Owned | Investments at fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned		67,383,000
Level 3 | Financial Instruments Owned | Market approach | Corporate equity securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares	$ 3
Level 3 | Financial Instruments Owned | Market approach | Corporate equity securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares	$ 75
Level 3 | Financial Instruments Owned | Market approach | Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level		$ 30
Estimated recovery percentage	17.00%
Price (USD per bond) | $ / Bond	10
Level 3 | Financial Instruments Owned | Market approach | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	100	72
Level 3 | Financial Instruments Owned | Market approach | Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level		$ 0.42
Estimated recovery percentage	76.00%
EBITDA (a) multiple		3.3
Level 3 | Financial Instruments Owned | Market approach | Loans and other receivables | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield		2.00%
Price (USD per bond) | $ / Bond	54
Level 3 | Financial Instruments Owned | Market approach | Loans and other receivables | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield		4.00%
Price (USD per bond) | $ / Bond	100
Level 3 | Financial Instruments Owned | Market approach | Loans and other receivables | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield		3.00%
Price (USD per bond) | $ / Bond	95
Level 3 | Financial Instruments Owned | Market approach | Derivatives | Derivatives | Credit Default Swap [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit spread		2.65%
Level 3 | Financial Instruments Owned | Market approach | Derivatives | Derivatives | Total return swaps | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	101
Level 3 | Financial Instruments Owned | Market approach | Derivatives | Derivatives | Total return swaps | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	106
Level 3 | Financial Instruments Owned | Market approach | Derivatives | Derivatives | Total return swaps | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	103
Level 3 | Financial Instruments Owned | Market approach | Derivatives | Derivatives | Interest rate swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit spread	8.00%
Level 3 | Financial Instruments Owned | Comparable pricing | Derivatives | Derivatives | Equity swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Comparable asset price (USD per bond) | $ / Asset		102
Level 3 | Financial Instruments Owned | Convertible bond model | Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield	8.00%	9.00%
Volatility	40.00%	40.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | CDOs and CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate	20.00%
Constant default rate	2.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | CDOs and CLOs | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		10.00%
Discount rate/yield	3.00%
Constant default rate		2.00%
Loss severity	25.00%	25.00%
Yield		7.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | CDOs and CLOs | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		20.00%
Discount rate/yield	26.00%
Constant default rate		4.00%
Loss severity	30.00%	70.00%
Yield		17.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | CDOs and CLOs | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		19.00%
Discount rate/yield	12.00%
Constant default rate		2.00%
Loss severity	26.00%	40.00%
Yield		12.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Residential mortgage-backed securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		0.00%
Discount rate/yield	6.00%
Duration (years)	2 years
Constant default rate		1.00%
Loss severity		35.00%
Yield		2.00%
Cumulative loss rate	3.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Residential mortgage-backed securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		11.00%
Discount rate/yield	10.00%
Duration (years)	4 years
Constant default rate		7.00%
Loss severity		100.00%
Yield		10.00%
Cumulative loss rate	19.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Residential mortgage-backed securities | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		5.00%
Discount rate/yield	8.00%
Duration (years)	3 years
Constant default rate		3.00%
Loss severity		62.00%
Yield		6.00%
Cumulative loss rate	10.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Commercial mortgage-backed securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield	2.00%
Duration (years)	1 year
Yield		6.00%
Cumulative loss rate	8.00%	5.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Commercial mortgage-backed securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield	26.00%
Duration (years)	3 years
Yield		11.00%
Cumulative loss rate	65.00%	95.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Commercial mortgage-backed securities | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield	12.00%
Duration (years)	2 years
Yield		8.00%
Cumulative loss rate	44.00%	39.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Other asset-backed securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		4.00%
Discount rate/yield	5.00%
Duration (years)	1 year
Constant default rate		0.00%
Loss severity		0.00%
Yield		4.00%
Cumulative loss rate	0.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Other asset-backed securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		20.00%
Discount rate/yield	39.00%
Duration (years)	6 years
Constant default rate		31.00%
Loss severity		100.00%
Yield		17.00%
Cumulative loss rate	33.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | Other asset-backed securities | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate		14.00%
Discount rate/yield	9.00%
Duration (years)	2 years
Constant default rate		13.00%
Loss severity		90.00%
Yield		15.00%
Cumulative loss rate	23.00%
Level 3 | Financial Instruments Owned | Discounted cash flows | FXCM term loan | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term based on the pay off (years)	0 months	0 months
Level 3 | Financial Instruments Owned | Discounted cash flows | FXCM term loan | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term based on the pay off (years)	1 year	6 months
Level 3 | Financial Instruments Owned | Discounted cash flows | FXCM term loan | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Term based on the pay off (years)	2 months	4 months 24 days
Level 3 | Financial Instruments Owned | Present value | Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Average silver production (tons per day) | T / d		666
Level 3 | Financial Instruments Owned | Scenario analysis | CDOs and CLOs | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	8.00%	28.00%
Level 3 | Financial Instruments Owned | Scenario analysis | CDOs and CLOs | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	45.00%	38.00%
Level 3 | Financial Instruments Owned | Scenario analysis | CDOs and CLOs | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	26.00%	31.00%
Level 3 | Financial Instruments Owned | Scenario analysis | Commercial mortgage-backed securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	26.00%
Price (USD per bond) | $ / Bond	52
Level 3 | Financial Instruments Owned | Scenario analysis | Commercial mortgage-backed securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	32.00%
Price (USD per bond) | $ / Bond	56
Level 3 | Financial Instruments Owned | Scenario analysis | Commercial mortgage-backed securities | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	28.00%
Price (USD per bond) | $ / Bond	54
Level 3 | Financial Instruments Owned | Scenario analysis | Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	14.00%
Level 3 | Financial Instruments Owned | Scenario analysis | Loans and other receivables | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	13.00%	6.00%
Level 3 | Financial Instruments Owned | Scenario analysis | Loans and other receivables | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	107.00%	50.00%
Level 3 | Financial Instruments Owned | Scenario analysis | Loans and other receivables | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated recovery percentage	78.00%	37.00%
Level 3 | Trading Liabilities | Market approach | Derivatives | Derivatives | Total return swaps | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	101
Level 3 | Trading Liabilities | Market approach | Derivatives | Derivatives | Total return swaps | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	106
Level 3 | Trading Liabilities | Market approach | Derivatives | Derivatives | Total return swaps | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (USD per bond) | $ / Bond	103
Level 3 | Trading Liabilities | Market approach | Derivatives | Derivatives | Unfunded commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Discount rate/yield		4.00%
Price (USD per bond) | $ / Bond	99
Level 3 | Trading Liabilities | Comparable pricing | Derivatives | Derivatives | Equity swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Comparable asset price (USD per bond) | $ / Asset		102
Level 3 | Trading Liabilities | Discounted cash flows | Derivatives | Derivatives | Variable funding note swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Prepayment Rate	20.00%	20.00%
Discount rate/yield	26.00%
Constant default rate	2.00%	2.00%
Loss severity	25.00%	25.00%
Yield		16.00%
Level 3 | Trading Liabilities | Option model/default rate | Derivatives | Derivatives | Equity options
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Volatility		45.00%
Default probability	0.00%
Level 3 | Trading Liabilities | Default rate | Derivatives | Derivatives | Equity options
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Default probability		0.00%
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Market approach | Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares	$ 6
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Market approach | Corporate equity securities | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares		$ 3
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Market approach | Corporate equity securities | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares		75
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Market approach | Corporate equity securities | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares	$ 33	15
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Comparable pricing | Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying stock price (USD per share) | $ / shares		$ 218
Comparable asset price (USD per bond) | $ / Asset	7	11
Level 3 | Non-exchange traded securities | Financial Instruments Owned | Present value | Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Average silver production (tons per day) | T / d		666
Level 3 | Private equity securities | Financial Instruments Owned | Market approach | Investments at fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level		$ 250
Price (USD per bond) | $ / Bond	7	25,815,720
Discount rate	20.00%
Level 3 | Private equity securities | Financial Instruments Owned | Market approach | Investments at fair value | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level	$ 3
Discount rate		15.00%
Level 3 | Private equity securities | Financial Instruments Owned | Market approach | Investments at fair value | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level	250
Discount rate		30.00%
Level 3 | Private equity securities | Financial Instruments Owned | Market approach | Investments at fair value | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transaction level	$ 172
Discount rate		23.00%

Fair Value Disclosures - Summar

Fair Value Disclosures - Summary of Jefferies gains (losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans and other receivables	$ 22,088	$ (68,812)	$ (17,389)
Financial instruments sold
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans	0	9	(162)
Loan commitments	230	5,509	7,502
Long-term debt
Fair Value, Option, Quantitative Disclosures [Line Items]
Loan commitments	(34,609)	(10,745)	0
Other changes in fair value	47,291	30,995	0
Short-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Other changes in fair value	$ (681)	$ 0	$ 0

Fair Value Disclosures - Summ83

Fair Value Disclosures - Summary of Amount by Which Contractual Principal Exceeds Fair Value for Loans and Other Receivables and long-term debt Measured at Fair Value Under Fair Value Option (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Loans and other receivables	$ 752,076	$ 1,325,938
Loans and other receivables on nonaccrual status and/or greater than 90 days past due	159,462	205,746
Long-term debt	32,839	20,202
Loans and other receivables greater than 90 or more days past due	$ 38,700	$ 64,600

Fair Value Disclosures - Additi

Fair Value Disclosures - Additional Information (Details) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2017USD ($)directorshares	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)shares	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Securities borrowed	$ 7,721,803		$ 7,743,562
Securities loaned	2,843,911		2,819,132
Trading assets, at fair value	15,512,730		14,985,237
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	578,014		857,337
Jefferies Plan
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Aggregate fair value of loans and other receivables on nonaccrual status and/or greater than 90 days past due	55,100		29,800
Aggregate fair value of loans and other receivables greater than 90 days past due	37,400		18,900
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	93,400		19,600		$ 49,100
Advisory fees			2,900
Securities borrowed			9,200
Securities loaned			9,200
HRG
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Changes in fair value of investments reflected as principal transactions	$ 64,800		$ 93,200		$ (28,000)
Shares owned, number | shares	46.6		46.6
Percentage of outstanding common stock owned	23.00%		23.00%
Trading assets, at fair value	$ 789,900		$ 725,100
Cash consideration paid for shares	$ 475,600
Number of directors appointed | director	2
Revenue of investee		$ 5,008,500		$ 5,048,600		$ 4,753,800
Net income (loss) from continuing operations of investee		102,900		144,200		(219,700)
Net income (loss) of investee		273,200		(33,900)		(512,400)
Net income (loss) attributable to HRG		$ 106,000		$ (198,800)		$ (556,800)
Level 1 | US Treasury securities
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	$ 99,700		$ 99,900

Derivative Financial Instrume85

Derivative Financial Instruments - Fair Value and Related Number of Derivative Contracts (Details) $ in Thousands	Dec. 31, 2017USD ($)Contract	Dec. 31, 2016USD ($)Contract
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 3,497,969	$ 4,627,076
Fair Value, Liabilities	3,745,908	4,880,022
Counterparty/cash-collateral netting, Assets	(3,318,481)	(4,255,998)
Counterparty/cash-collateral netting, Liabilities	(3,490,514)	(4,229,213)
Total derivative assets	179,488	371,078
Total derivative liability	255,394	650,809
Designated as accounting hedges | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 0
Number of Contracts, Assets | Contract	0
Fair Value, Liabilities	$ 2,420
Number of Contracts, Liabilities | Contract	1
Not Designated as accounting hedges
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 3,497,969	4,627,076
Fair Value, Liabilities	3,743,488	4,880,022
Counterparty/cash-collateral netting, Assets	(3,318,481)	(4,255,998)
Counterparty/cash-collateral netting, Liabilities	(3,490,514)	(4,229,213)
Total derivative assets	179,488	371,078
Total derivative liability	252,974	650,809
Not Designated as accounting hedges | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 1,717,058	$ 3,282,245
Number of Contracts, Assets | Contract	38,941	29,032
Fair Value, Liabilities	$ 1,708,776	$ 3,159,457
Number of Contracts, Liabilities | Contract	12,828	34,845
Not Designated as accounting hedges | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 366,541	$ 529,669
Number of Contracts, Assets | Contract	6,463	7,826
Fair Value, Liabilities	$ 349,512	$ 516,869
Number of Contracts, Liabilities | Contract	4,612	8,319
Not Designated as accounting hedges | Equity contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 1,373,016	$ 786,987
Number of Contracts, Assets | Contract	2,728,750	2,843,329
Fair Value, Liabilities	$ 1,638,258	$ 1,169,201
Number of Contracts, Liabilities | Contract	2,118,526	2,414,715
Not Designated as accounting hedges | Commodity contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 3,093	$ 1,906
Number of Contracts, Assets | Contract	7,249	2,766
Fair Value, Liabilities	$ 5,141	$ 6,430
Number of Contracts, Liabilities | Contract	6,047	7,289
Not Designated as accounting hedges | Credit contracts
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 38,261	$ 26,269
Number of Contracts, Assets | Contract	130	311
Fair Value, Liabilities	$ 41,801	$ 28,065
Number of Contracts, Liabilities | Contract	191	20,084

Derivative Financial Instrume86

Derivative Financial Instruments - Unrealized and Realized Gains (Losses) on Derivative Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense of Jefferies	$ 6,033	$ 0	$ 0
Unrealized and realized gains (losses)	(319,318)	(649,789)	(167,626)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	3,171	(36,559)	(36,792)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	4,376	20,401	36,233
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	(319,775)	(635,305)	(137,219)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	(9,049)	(3,339)	(13,625)
Credit contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized and realized gains (losses)	1,959	5,013	(16,223)
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense of Jefferies	(2,091)	0	0
Long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in Interest expense of Jefferies	$ 8,124	$ 0	$ 0

Derivative Financial Instrume87

Derivative Financial Instruments - Remaining Contract Maturity of Fair Value of OTC Derivative Assets and Liabilities (Details) $ in Thousands	Dec. 31, 2017USD ($)
OTC Derivative Assets
0-12 Months	$ 174,453
1-5 Years	206,381
Greater Than 5 Years	93,529
Cross- Maturity Netting	(153,610)
Total	320,753
Cross product counterparty netting	(23,732)
Total	297,021
OTC Derivative Liabilities
0-12 Months	148,570
1-5 Years	318,685
Greater Than 5 Years	159,357
Cross-Maturity Netting	(153,610)
Total	473,002
Cross product counterparty netting	(23,732)
Total OTC derivative liabilities included in Trading liabilities	449,270
Exchange traded derivative assets and other credit agreements	28,400
Cash collateral received	146,000
Exchange traded derivative liabilities and other credit agreements	124,100
Cash collateral pledged	318,000
Commodity swaps, options and forwards
OTC Derivative Assets
0-12 Months	0
1-5 Years	4
Greater Than 5 Years	0
Cross- Maturity Netting	(4)
Total	0
OTC Derivative Liabilities
0-12 Months	2,772
1-5 Years	301
Greater Than 5 Years	0
Cross-Maturity Netting	(4)
Total	3,069
Equity swaps and options
OTC Derivative Assets
0-12 Months	3,082
1-5 Years	7,053
Greater Than 5 Years	2,137
Cross- Maturity Netting	(1,442)
Total	10,830
OTC Derivative Liabilities
0-12 Months	78
1-5 Years	172,670
Greater Than 5 Years	3,780
Cross-Maturity Netting	(1,442)
Total	175,086
Credit default swaps
OTC Derivative Assets
0-12 Months	567
1-5 Years	105
Greater Than 5 Years	17,344
Cross- Maturity Netting	(5,625)
Total	12,391
OTC Derivative Liabilities
0-12 Months	104
1-5 Years	16,540
Greater Than 5 Years	3,953
Cross-Maturity Netting	(5,625)
Total	14,972
Total return swaps
OTC Derivative Assets
0-12 Months	34,228
1-5 Years	1,581
Greater Than 5 Years	0
Cross- Maturity Netting	(193)
Total	35,616
OTC Derivative Liabilities
0-12 Months	28,920
1-5 Years	1,517
Greater Than 5 Years	0
Cross-Maturity Netting	(193)
Total	30,244
Foreign currency forwards, swaps and options
OTC Derivative Assets
0-12 Months	108,465
1-5 Years	31,235
Greater Than 5 Years	0
Cross- Maturity Netting	(62,812)
Total	76,888
OTC Derivative Liabilities
0-12 Months	91,640
1-5 Years	31,173
Greater Than 5 Years	0
Cross-Maturity Netting	(62,812)
Total	60,001
Fixed income forwards
OTC Derivative Liabilities
0-12 Months	8,512
1-5 Years	0
Greater Than 5 Years	0
Cross-Maturity Netting	0
Total	8,512
Interest rate swaps, options and forwards
OTC Derivative Assets
0-12 Months	28,111
1-5 Years	166,403
Greater Than 5 Years	74,048
Cross- Maturity Netting	(83,534)
Total	185,028
OTC Derivative Liabilities
0-12 Months	16,544
1-5 Years	96,484
Greater Than 5 Years	151,624
Cross-Maturity Netting	(83,534)
Total	$ 181,118

Derivative Financial Instrume88

Derivative Financial Instruments - Counterparty Credit Quality with Respect to Fair Value of OTC Derivatives Assets (Details) $ in Thousands	Dec. 31, 2017USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
A- or higher	$ 173,843
BBB- to BBB	40,565
BB or lower	48,338
Unrated	34,275
Total	$ 297,021

Derivative Financial Instrume89

Derivative Financial Instruments - Credit Related Derivative Contracts (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Index credit default swaps
Derivative [Line Items]
Derivative notional amount	$ 129	$ 146
Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	218.2	383.6
Investment Grade | Index credit default swaps
Derivative [Line Items]
Derivative notional amount	3	54
Investment Grade | Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	129.1	122.4
Non-investment Grade | Index credit default swaps
Derivative [Line Items]
Derivative notional amount	126	92
Non-investment Grade | Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	$ 89.1	$ 261.2

Derivative Financial Instrume90

Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative instruments in a liability position	$ 95.1	$ 70.6
Collateral posted for derivative instruments in a liability position	80.8	44.4
Potential additional collateral required for derivative instruments in a liability position	$ 14.3	$ 26.1

Collateralized Transactions - C

Collateralized Transactions - Collateral Pledged (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	$ 2,843,911	$ 2,819,132
Repurchase Agreements	19,829,249	17,012,332
Total	22,673,160	19,831,464
Corporate equity securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	2,353,798	2,046,243
Repurchase Agreements	214,413	66,291
Total	2,568,211	2,112,534
Corporate debt securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	470,908	731,276
Repurchase Agreements	2,336,702	1,907,888
Total	2,807,610	2,639,164
Mortgage- and asset-backed securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	2,562,268	2,171,480
Total	2,562,268	2,171,480
U.S. government and federal agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	19,205	41,613
Repurchase Agreements	11,792,534	9,232,624
Total	11,811,739	9,274,237
Municipal securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	444,861	553,010
Total	444,861	553,010
Sovereign securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	2,023,530	2,625,079
Total	2,023,530	2,625,079
Loans and other receivables
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	454,941	455,960
Total	$ 454,941	$ 455,960

Collateralized Transactions -92

Collateralized Transactions - Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	$ 2,843,911	$ 2,819,132
Repurchase Agreements	19,829,249	17,012,332
Total	22,673,160	19,831,464
Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	1,676,940	2,131,891
Repurchase Agreements	10,780,474	9,147,176
Total	12,457,414	11,279,067
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	0	39,673
Repurchase Agreements	4,058,228	2,008,119
Total	4,058,228	2,047,792
30 to 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	741,971	104,516
Repurchase Agreements	3,211,464	3,809,533
Total	3,953,435	3,914,049
Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities Lending Arrangements	425,000	543,052
Repurchase Agreements	1,779,083	2,047,504
Total	$ 2,204,083	$ 2,590,556

Collateralized Transactions - A

Collateralized Transactions - Additional Information (Details) - USD ($) $ in Billions	Dec. 31, 2017	Dec. 31, 2016
Collateralized Transactions [Abstract]
Fair value of securities received as collateral that may be sold or repledged	$ 27.1	$ 25.5

Securitization Activities - Act

Securitization Activities - Activity Related to Securitizations Accounted for as Sales (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securitization Activities [Abstract]
Transferred assets	$ 4,552.9	$ 5,786	$ 5,770.5
Proceeds on new securitizations	4,594.5	5,809	5,811.3
Cash flows received on retained interests	$ 28.7	$ 28.2	$ 31.2

Securitization Activities - Sum

Securitization Activities - Summary of Retained Interests in SPEs (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Residential mortgage-backed securities
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
U.S. government agency residential mortgage-backed securities	$ 6,383.5	$ 7,584.9
Retained Interests	28.2	31
Commercial mortgage-backed securities
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
U.S. government agency commercial mortgage-backed securities	2,075.7	1,806.3
Retained Interests	81.4	29.6
CLOs
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
CLOs	3,957.8	4,102.2
Retained Interests	20.3	37
Consumer and other loans
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Consumer and other loans	247.6	395.7
Retained Interests	$ 47.8	$ 25.3

Available for Sale Securities -

Available for Sale Securities - Schedule of Amortized Cost, Gross Unrealized Gains and Losses and Estimated Fair Value of Available for Sale Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Amortized Cost	$ 680,497	$ 274,457
Gross Unrealized Gains	36,246	26,712
Gross Unrealized Losses	182	120
Estimated Fair Value	716,561	301,049
U.S. government securities
Schedule of Investments [Line Items]
Amortized Cost	552,847	174,938
Gross Unrealized Gains	0	8
Gross Unrealized Losses	42	13
Estimated Fair Value	552,805	174,933
Residential mortgage-backed securities
Schedule of Investments [Line Items]
Amortized Cost	34,381	19,129
Gross Unrealized Gains	272	108
Gross Unrealized Losses	92	104
Estimated Fair Value	34,561	19,133
Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Amortized Cost	5,857	8,275
Gross Unrealized Gains	17	64
Gross Unrealized Losses	4	2
Estimated Fair Value	5,870	8,337
Other asset-backed securities
Schedule of Investments [Line Items]
Amortized Cost	34,837	18,918
Gross Unrealized Gains	46	124
Gross Unrealized Losses	44	0
Estimated Fair Value	34,839	19,042
All other corporates
Schedule of Investments [Line Items]
Amortized Cost		180
Gross Unrealized Gains		0
Gross Unrealized Losses		1
Estimated Fair Value		179
Bonds and notes
Schedule of Investments [Line Items]
Amortized Cost	627,922	221,440
Gross Unrealized Gains	335	304
Gross Unrealized Losses	182	120
Estimated Fair Value	628,075	221,624
Banks, trusts and insurance companies
Schedule of Investments [Line Items]
Amortized Cost	35,071	35,071
Gross Unrealized Gains	17,500	15,115
Gross Unrealized Losses	0	0
Estimated Fair Value	52,571	50,186
Industrial, miscellaneous and all other
Schedule of Investments [Line Items]
Amortized Cost	17,504	17,946
Gross Unrealized Gains	18,411	11,293
Gross Unrealized Losses	0	0
Estimated Fair Value	35,915	29,239
Equity securities
Schedule of Investments [Line Items]
Amortized Cost	52,575	53,017
Gross Unrealized Gains	35,911	26,408
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 88,486	$ 79,425

Available for Sale Securities97

Available for Sale Securities - Amortized Cost and Estimated Fair Value of Investments Classified as Available for Sale by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 680,497	$ 274,457
Estimated Fair Value	716,561	301,049
Bonds and notes
Schedule of Available-for-sale Securities [Line Items]
Due within one year, Amortized Cost	552,847
Fixed maturities investments excluding mortgage-backed and asset-backed securities, Amortized Cost	552,847
Mortgage-backed and asset-backed securities, Amortized Cost	75,075
Amortized Cost	627,922	221,440
Due within one year, Estimated Fair Value	552,805
Fixed maturities investments excluding mortgage-backed and asset-backed securities, Estimated Fair Value	552,805
Mortgage-backed and asset-backed securities, Estimated Fair Value	75,270
Estimated Fair Value	$ 628,075	$ 221,624

Variable Interest Entities - Sc

Variable Interest Entities - Schedule of Consolidated VIEs (Details) - USD ($) $ in Thousands		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Cash		$ 5,275,480		$ 3,807,558		$ 3,638,648	$ 4,276,775
Financial instruments owned		16,229,291		15,286,286
Securities purchased under agreement to resell		3,689,559		3,862,488
Receivables		5,419,015		4,425,178
Loans to and investments in associated companies		2,066,829		2,125,098
Other		1,661,777		1,635,664
Total assets		47,169,108	[1]	45,071,307	[1]	46,331,184
Other secured financings		1,029,485		1,026,429
Long-term debt		7,885,783		7,380,443
Total liabilities	[1]	36,478,536		34,305,849
Noncontrolling interests		33,022		175,549
Jefferies
Variable Interest Entity [Line Items]
Secured financings eliminated in consolidation		44,100		57,600
Securitization Vehicles
Variable Interest Entity [Line Items]
Cash		11,700		18,400
Financial instruments owned		37,600		86,600
Securities purchased under agreement to resell		729,300		733,500
Receivables		318,100		277,700
Loans to and investments in associated companies		0		0
Other		15,500		14,500
Total assets		1,112,200		1,130,700
Other secured financings		1,073,500		1,083,800
Long-term debt		0		24,100
Other		38,300		22,300
Total liabilities		1,111,800		1,130,200
Noncontrolling interests		0		0
Real Estate Investment Vehicles
Variable Interest Entity [Line Items]
Cash				2,200
Financial instruments owned				0
Securities purchased under agreement to resell				0
Receivables				296,900
Loans to and investments in associated companies				108,700
Other				10,800
Total assets				418,600
Other secured financings				0
Long-term debt				243,900
Other				11,700
Total liabilities				255,600
Noncontrolling interests				98,700
Eliminations
Variable Interest Entity [Line Items]
Total assets		(70,321)		(82,681)		$ (149,723)
Intercompany Payables		$ 32,000		$ 20,000
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Total maximum exposure to loss in non-consolidated VIEs	$ 1,977.6	$ 1,410.8
Financial statement carrying amount, assets	579.6	566.9
Related party private equity vehicles
Variable Interest Entity [Line Items]
Total maximum exposure to loss in non-consolidated VIEs	45.4	63.6
Financial statement carrying amount, assets	23.7	37.6
Real estate investment vehicles
Variable Interest Entity [Line Items]
Equity commitments		98
Funded equity commitments		86.5
Total maximum exposure to loss in non-consolidated VIEs		101.8
Financial statement carrying amount, assets		90.3
Other private investment vehicles
Variable Interest Entity [Line Items]
Carrying amount of equity investment	133	84
Total maximum exposure to loss in non-consolidated VIEs	142	95.8
Unfunded equity commitment related to investments	9.1	11.8
Financial statement carrying amount, assets	133	84
Agency mortgage-backed securities
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	1,829.6	1,002.2
Non-agency mortgage- and other asset-backed securities
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	253.2	439.4
Securitization Vehicles
Variable Interest Entity [Line Items]
Automobile loan receivables securitized	186.5
Energy Partners I, LP
Variable Interest Entity [Line Items]
Total maximum exposure to loss in non-consolidated VIEs		3
JCP Entities | Related party private equity vehicles
Variable Interest Entity [Line Items]
Equity commitments	148.1	148.1
Funded equity commitments	126.3	125.1
Carrying amount of equity investment	$ 23.7	$ 37.6

Variable Interest Entities -100

Variable Interest Entities - Schedule of Nonconsolidated VIEs (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	$ 579.6	$ 566.9
Financial statement carrying amount, liabilities	8.9	4.8
Maximum Exposure to Loss	1,977.6	1,410.8
VIE Assets	12,386.9	10,229.3
CLOs
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	168.1	264.7
Financial statement carrying amount, liabilities	8.9	4.8
Maximum Exposure to Loss	1,030.4	930
VIE Assets	5,364.3	4,472.9
Consumer loan vehicles
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	254.8	90.3
Financial statement carrying amount, liabilities	0	0
Maximum Exposure to Loss	759.8	219.6
VIE Assets	2,322.7	985.5
Related party private equity vehicles
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	23.7	37.6
Financial statement carrying amount, liabilities	0	0
Maximum Exposure to Loss	45.4	63.6
VIE Assets	75	155.6
Real estate investment vehicles
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets		90.3
Financial statement carrying amount, liabilities		0
Maximum Exposure to Loss		101.8
VIE Assets		85.6
Other private investment vehicles
Variable Interest Entity [Line Items]
Financial statement carrying amount, assets	133	84
Financial statement carrying amount, liabilities	0	0
Maximum Exposure to Loss	142	95.8
VIE Assets	$ 4,624.9	$ 4,529.7

Loans to and Investments in 101

Loans to and Investments in Associated Companies - Summary of Loans to and Investments in Associated Companies (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Proceeds from sale of associated companies		$ 173,105	$ 0	$ 0
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		2,125,098	1,757,369	1,712,568
Income (loss) related to associated companies		(74,901)	154,598	110,281
Income (losses) related to Jefferies associated companies		109,395	17,184	75,717
Contributions to (distributions from) associated companies, net		80,942	(132,070)	(120,860)
Other, including foreign exchange and unrealized gain (losses)		(173,705)	328,017	(20,337)
Loans to and investments in associated companies ending balance		2,066,829	2,125,098	1,757,369
Noncontrolling interests		33,022	175,549
Jefferies Finance
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		490,464	528,575	508,891
Income (loss) related to associated companies		0	0	0
Income (losses) related to Jefferies associated companies		90,204	(1,761)	40,884
Contributions to (distributions from) associated companies, net		74,799	(36,350)	(21,200)
Other, including foreign exchange and unrealized gain (losses)		0	0	0
Loans to and investments in associated companies ending balance		$ 655,467	490,464	528,575
Percentage of ownership owned		50.00%
Jefferies LoanCore
Investment [Line Items]
Proceeds from sale of associated companies	$ 173,100
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 154,731	288,741	258,947
Income (loss) related to associated companies		0	0	0
Income (losses) related to Jefferies associated companies		22,368	21,221	36,554
Contributions to (distributions from) associated companies, net		(3,994)	(155,231)	(6,760)
Other, including foreign exchange and unrealized gain (losses)		(173,105)	0	0
Loans to and investments in associated companies ending balance		$ 0	154,731	288,741
Percentage of ownership owned	48.50%	48.50%
Berkadia
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 184,443	190,986	208,511
Income (loss) related to associated companies		93,801	94,201	78,092
Income (losses) related to Jefferies associated companies		0	0	0
Contributions to (distributions from) associated companies, net		(67,384)	(100,766)	(89,560)
Other, including foreign exchange and unrealized gain (losses)		(266)	22	(6,057)
Loans to and investments in associated companies ending balance		$ 210,594	184,443	190,986
Percentage of ownership owned		50.00%
FXCM
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 336,258	0
Income (loss) related to associated companies		(177,644)	1,919
Income (losses) related to Jefferies associated companies		0	0
Contributions to (distributions from) associated companies, net		0	0
Other, including foreign exchange and unrealized gain (losses)		242	334,339
Loans to and investments in associated companies ending balance		158,856	336,258	0
Garcadia Companies
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		185,815	172,660	167,939
Income (loss) related to associated companies		48,198	52,266	53,182
Income (losses) related to Jefferies associated companies		0	0	0
Contributions to (distributions from) associated companies, net		(54,870)	(39,111)	(48,461)
Other, including foreign exchange and unrealized gain (losses)		0	0	0
Loans to and investments in associated companies ending balance		$ 179,143	185,815	172,660
Percentage of ownership owned		75.00%
Linkem
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 154,000	150,149	159,054
Income (loss) related to associated companies		(32,561)	(22,867)	(15,577)
Income (losses) related to Jefferies associated companies		0	0	0
Contributions to (distributions from) associated companies, net		31,996	33,303	21,138
Other, including foreign exchange and unrealized gain (losses)		38,701	(6,585)	(14,466)
Loans to and investments in associated companies ending balance		$ 192,136	154,000	150,149
Percentage of ownership owned		42.00%
HomeFed
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 302,231	275,378	271,782
Income (loss) related to associated companies		7,725	23,893	3,596
Income (losses) related to Jefferies associated companies		0	0	0
Contributions to (distributions from) associated companies, net		31,918	2,960	0
Other, including foreign exchange and unrealized gain (losses)		0	0	0
Loans to and investments in associated companies ending balance		$ 341,874	302,231	275,378
Percentage of ownership owned		70.00%
Golden Queen
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 111,302	114,323	103,598
Income (loss) related to associated companies		(7,733)	(3,021)	(1,775)
Income (losses) related to Jefferies associated companies		0	0	0
Contributions to (distributions from) associated companies, net		1,436	0	12,500
Other, including foreign exchange and unrealized gain (losses)		0	0	0
Loans to and investments in associated companies ending balance		105,005	111,302	114,323
Noncontrolling interests		$ 30,500	32,800	33,700
Percentage of ownership owned		35.00%
54 Madison
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 161,400	0
Income (loss) related to associated companies		(6,224)	4,255
Income (losses) related to Jefferies associated companies		0	0
Contributions to (distributions from) associated companies, net		35,204	153,503
Other, including foreign exchange and unrealized gain (losses)		(67,370)	3,642
Loans to and investments in associated companies ending balance		$ 123,010	161,400	0
Noncontrolling interests			95,300
Percentage of ownership owned		48.10%
Other
Equity Method Investment [Roll Forward]
Loans to and investments in associated companies beginning balance		$ 44,454	36,557	33,846
Income (loss) related to associated companies		(463)	3,952	(7,237)
Income (losses) related to Jefferies associated companies		(3,177)	(2,276)	(1,721)
Contributions to (distributions from) associated companies, net		31,837	9,622	11,483
Other, including foreign exchange and unrealized gain (losses)		28,093	(3,401)	186
Loans to and investments in associated companies ending balance		$ 100,744	$ 44,454	$ 36,557
Investment in FXCM
Equity Method Investment [Roll Forward]
Percentage of ownership owned		50.00%	50.00%
Jefferies LoanCore | Disposed of by Sale | Jefferies
Investment [Line Items]
Proceeds from sale of associated companies	$ 173,100

Loans to and Investments in 102

Loans to and Investments in Associated Companies - Jefferies Finance Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Investment banking	$ 1,764,285,000	$ 1,193,973,000	$ 1,417,807,000
Other assets	1,661,777,000	1,635,664,000
Payables, expense accruals and other liabilities	7,167,666,000	7,373,708,000
Proceeds from sale of associated companies	173,105,000	0	0
Trading assets, at fair value	15,512,730,000	14,985,237,000
Jefferies Finance
Investment [Line Items]
Equity commitment	750,000,000
Funded equity commitments	$ 636,200,000
Investment commitment extension	1 year
Termination notice	60 days
Total line of credit facility commitment under joint venture	$ 500,000,000	500,000,000
Credit facility, extension period	1 year
Funded portion of line of credit commitment	$ 0
Line of credit facility commitment of Jefferies	250,000,000
Other assets	34,600,000
Payables, expense accruals and other liabilities	14,100,000	5,800,000
Trading assets, at fair value	1,500,000
Jefferies
Investment [Line Items]
Interest income and unfunded commitment fees related to facility commitment	3,900,000	1,300,000	2,500,000
Investment banking	327,900,000	112,600,000	122,700,000
Origination fees	2,400,000	500,000	5,900,000
Placement agent fees	6,100,000	2,600,000	6,200,000
Service fee income	$ 50,700,000	$ 46,100,000	51,700,000
Net underwriting fees			$ 1,300,000

Loans to and Investments in 103

Loans to and Investments in Associated Companies - Jefferies LoanCore Narrative (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Proceeds from sale of associated companies		$ 173,105	$ 0	$ 0
Securities purchased under agreements to resell		3,689,559	3,862,488
Payables, expense accruals and other liabilities		$ 7,167,666	7,373,708
Jefferies LoanCore
Investment [Line Items]
Percentage of ownership owned	48.50%	48.50%
Proceeds from sale of associated companies	$ 173,100
Period entitled to additional cash consideration	5 years
Interest Income And Fees Related To Master Repurchase Agreement		$ 600	8,400	$ 10,700
Securities purchased under agreements to resell			68,100
Payables, expense accruals and other liabilities			$ 8,300
Jefferies LoanCore | Disposed of by Sale | Jefferies
Investment [Line Items]
Proceeds from sale of associated companies	$ 173,100
Period entitled to additional cash consideration	5 years

Loans to and Investments in 104

Loans to and Investments in Associated Companies - Berkadia Narrative (Details) - Berkadia - USD ($) $ in Millions	12 Months Ended	108 Months Ended
	Dec. 31, 2009	Dec. 31, 2017
Investment [Line Items]
Capital contributed	$ 217.2
Percentage of ownership owned		50.00%
Contributions to (distributions from) associated companies, net		$ 562
Surety policy issued		$ 1,500
Reimbursement of losses incurred, maximum percentage		50.00%
Commercial paper		$ 1,470

Loans to and Investments in 105

Loans to and Investments in Associated Companies - FXCM Narrative (Details) - Investment in FXCM - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Investments in and Advances to Affiliates [Line Items]
Percentage of ownership owned		50.00%	50.00%
Equity method investment impairment	$ 130.2

Loans to and Investments in 106

Loans to and Investments in Associated Companies - Garcadia Narrative (Details)	12 Months Ended
	Dec. 31, 2017facilityDealership
Garcadia Companies
Investment [Line Items]
Number of automobile dealerships | facility	28
Garcadia Companies | Garff
Investment [Line Items]
Number of automobile dealerships | facility	28
Plan One | Garcadia Companies
Investment [Line Items]
Corporate Joint Venture, Percentage of Cash Flows Allocated	65.00%
Plan One | Garff Enterprises, Inc
Investment [Line Items]
Corporate Joint Venture, Percentage of Cash Flows Allocated	35.00%
Plan Two | Garcadia Companies
Investment [Line Items]
Number of automobile dealerships | Dealership	1
Corporate Joint Venture, Percentage of Cash Flows Allocated	83.00%
Plan Three | Garcadia Companies
Investment [Line Items]
Number of automobile dealerships | Dealership	4
Corporate Joint Venture, Percentage of Cash Flows Allocated	71.00%

Loans to and Investments in 107

Loans to and Investments in Associated Companies - Linkem Narrative (Details) - Linkem	12 Months Ended
	Dec. 31, 2017
Investment [Line Items]
Percentage of ownership owned	42.00%
Dividend rate on preferred stock	5.00%
Percentage of ownership upon conversion of preferred shares	53.00%
Percentage of total voting securities	48.00%
Excess investment amortization period, years	12 years

Loans to and Investments in 108

Loans to and Investments in Associated Companies - HomeFed Narrative (Details) - HomeFed	Dec. 31, 2017directorshares
Investment [Line Items]
Shares of common stock owned | shares	10,852,123
Percentage of ownership owned	70.00%
Maximum voting rights as a percentage of total voting securities voting	45.00%
Number of executives from the Company | director	3
Company Chairman
Investment [Line Items]
Ownership percentage of company	4.80%

Loans to and Investments in 109

Loans to and Investments in Associated Companies - Golden Queen Mining Company Narrative (Details) - USD ($) $ in Millions	24 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2014
Golden Queen Mining Company, LLC
Investment [Line Items]
Prior ownership percentage			100.00%
Percentage of ownership owned		35.00%
Golden Queen Mining Co, Ltd
Investment [Line Items]
Ownership percentage		50.00%
Gauss LLC
Investment [Line Items]
Cash invested in Limited Liability Company	$ 83
Gauss LLC | Golden Queen Mining Company, LLC
Investment [Line Items]
Total investment in associated company		$ 117.5
Percentage of ownership owned		50.00%
Clay Family
Investment [Line Items]
Contributions from noncontrolling interests	$ 34.5

Loans to and Investments in 110

Loans to and Investments in Associated Companies - 54 Madison Narrative (Details) - 54 Madison	12 Months Ended
	Dec. 31, 2017Seat
Investments in and Advances to Affiliates [Line Items]
Percentage of ownership owned	48.10%
Number of seats in investment committee retained by Company	2
Number of seats in investment committee	4

Loans to and Investments in 111

Loans to and Investments in Associated Companies - Schedule of Summarized Data for Investments in Associated Companies (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Investments in and Advances to Affiliates [Line Items]
Assets		$ 47,169,108	[1]	$ 45,071,307	[1]	$ 46,331,184
Liabilities	[1]	36,478,536		34,305,849
Noncontrolling interests		33,022		175,549
The Company’s income related to associated companies		34,494		171,782		185,998
Undistributed earnings of equity method investments		202,900
Associated Companies
Investments in and Advances to Affiliates [Line Items]
Assets		16,340,643		16,964,850
Liabilities		11,920,465		13,097,022
Noncontrolling interests		169,274		132,789
Revenues		4,883,063		4,275,016		3,946,252
Income from continuing operations before extraordinary items		503,489		422,167		398,369
Net income		438,881		430,291		398,369
The Company’s income related to associated companies		$ 34,494		$ 171,782		$ 185,998
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Financial Statement Offsetti112

Financial Statement Offsetting (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Offsetting Derivative Assets [Abstract]
Derivative assets contracts, Gross Amounts	$ 3,497,969	$ 4,627,076
Derivative assets contracts, Netting in Consolidated Statement of Financial Condition	(3,318,481)	(4,255,998)
Total derivative assets	179,488	371,078
Derivative assets contracts, Additional Amounts Available for Setoff	0	0
Derivative assets contracts, Available Collateral	0	0
Derivative assets contracts, Net Amount	179,488	371,078
Gross Amounts	7,721,803	7,743,562
Netting in Consolidated Statement of Financial Condition	0	0
Net Amounts in Consolidated Statement of Financial Condition	7,721,803	7,743,562
Additional Amounts Available for Setoff	(966,712)	(710,611)
Available Collateral	(1,032,629)	(647,290)
Net Amount	5,722,462	6,385,661
Reverse repurchase agreements, Gross Amounts	14,858,297	14,083,144
Reverse repurchase agreements, Netting in Consolidated Statement of Financial Condition	(11,168,738)	(10,220,656)
Reverse repurchase agreements, Net Amounts in Consolidated Statement of Financial Condition	3,689,559	3,862,488
Reverse repurchase agreements, Additional Amounts Available for Setoff	(463,973)	(176,275)
Reverse repurchase agreements, Available Collateral	(3,207,147)	(3,591,654)
Reverse repurchase agreements, Net Amount	18,439	94,559
Offsetting Derivative Liabilities [Abstract]
Derivative liabilities contracts, Gross Amounts	3,745,908	4,880,022
Derivative liabilities contacts, Netting in Consolidated Statement of Financial Condition	(3,490,514)	(4,229,213)
Total derivative liability	255,394	650,809
Derivative liabilities contracts, Additional Amounts Available for Setoff	0	0
Derivative liabilities contracts, Available Collateral	0	0
Derivative liabilities contracts, Net Amount	255,394	650,809
Gross Amounts	2,843,911	2,819,132
Netting in Consolidated Statement of Financial Condition	0	0
Net Amounts in Consolidated Statement of Financial Condition	2,843,911	2,819,132
Additional Amounts Available for Setoff	(966,712)	(710,611)
Available Collateral	(1,795,408)	(2,064,299)
Net Amount	81,791	44,222
Repurchase agreements, Gross Amounts	19,829,249	17,012,332
Repurchase agreements, Netting in Consolidated Statement of Financial Condition	(11,168,738)	(10,220,656)
Repurchase agreements, Net Amounts in Consolidated Statement of Financial Condition	8,660,511	6,791,676
Repurchase agreements, Additional Amounts Available for Setoff	(463,973)	(176,275)
Repurchase agreements, Available Collateral	(7,067,512)	(5,780,909)
Repurchase agreements, Net Amount	1,129,026	834,492
Securities borrowing arrangements, subject to review	5,678,600	6,337,500
Securities borrowing arrangements, collateral received, subject to review	5,516,700	6,146,000
Repurchase agreements, subject to review	1,084,400	810,400
Repurchase agreements, collateral pledged, subject to review	$ 1,115,900	$ 834,200

Intangible Assets, Net and G113

Intangible Assets, Net and Goodwill - Schedule of Components (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets [Line Items]
Amortizable intangibles	$ 741,030	$ 797,964
Goodwill	1,722,150	1,715,714
Total intangible assets, net and goodwill	2,463,180	2,513,678
Other operations
Intangible Assets [Line Items]
Goodwill	3,859	3,859
National Beef
Intangible Assets [Line Items]
Goodwill	14,991	14,991
Jefferies
Intangible Assets [Line Items]
Goodwill	1,703,300	1,696,864
Customer and other relationships
Intangible Assets [Line Items]
Amortizable intangibles	347,767	378,136
Intangibles, accumulated amortization	230,074	198,674
Trademarks and tradename
Intangible Assets [Line Items]
Amortizable intangibles	293,851	309,382
Intangibles, accumulated amortization	95,627	78,778
Supply contracts
Intangible Assets [Line Items]
Amortizable intangibles	86,160	95,733
Intangibles, accumulated amortization	57,440	47,867
Other
Intangible Assets [Line Items]
Amortizable intangibles	4,701	5,672
Intangibles, accumulated amortization	3,885	2,914
Exchange and clearing organization membership interests and registrations
Intangible Assets [Line Items]
Indefinite lived intangibles	$ 8,551	$ 9,041

Intangible Assets, Net and G114

Intangible Assets, Net and Goodwill - Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense on intangible assets	$ 58,200	$ 63,400	$ 63,900
Future amortization expense, 2018	58,454
Future amortization expense, 2019	58,454
Future amortization expense, 2020	58,454
Future amortization expense, 2021	58,067
Future amortization expense, 2022	$ 57,984

Property, Equipment and Leas115

Property, Equipment and Leasehold Improvements, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 1,361,861	$ 1,227,368
Accumulated depreciation and amortization	(611,458)	(518,126)
Property, equipment and leasehold improvements, net	750,403	709,242
Land, buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 408,886	379,927
Land, buildings and leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives	2 years
Land, buildings and leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives	25 years
Beef processing machinery and equipment
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 360,975	330,453
Beef processing machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives	2 years
Beef processing machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives	15 years
Other machinery and equipment
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 32,012	30,716
Other machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives	3 years
Other machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives	15 years
Corporate aircraft
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 104,952	104,862
Depreciable Lives	10 years
Furniture, fixtures and office equipment
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 379,051	323,276
Furniture, fixtures and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives	3 years
Furniture, fixtures and office equipment | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives	10 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 72,560	54,693
Other
Property, Plant and Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 3,425	$ 3,441
Other | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives	3 years
Other | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives	10 years

Short-Term Borrowings (Details)

Short-Term Borrowings (Details) € in Millions	12 Months Ended		14 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016EUR (€)	Jan. 24, 2017	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Short-term Debt [Line Items]
Short-term borrowings	$ 436,215,000			$ 525,842,000
Debt interest rate	2.51%			1.77%
Floating rate puttable notes
Short-term Debt [Line Items]
Short-term borrowings	$ 108,240,000			$ 96,455,000
Debt issued during period | €		€ 91
Equity-linked notes
Short-term Debt [Line Items]
Short-term borrowings	23,324,000			0
Equity-linked notes matured in July 2017
Short-term Debt [Line Items]
Debt issued during period	30,600,000
Equity-linked notes matured in September 2017
Short-term Debt [Line Items]
Debt issued during period	4,200,000
Bank loans
Short-term Debt [Line Items]
Short-term borrowings	304,651,000			372,301,000
Credit Facility | Intraday Credit Facility
Short-term Debt [Line Items]
Committed amount	$ 150,000,000
Credit Facility | Intraday Credit Facility | Federal Funds Rate
Short-term Debt [Line Items]
Basis spread on variable rate	0.50%
Credit Facility | Secured Revolving Loan Facility
Short-term Debt [Line Items]
Committed amount					$ 50,000,000
Secured revolving loan facilities | Secured Revolving Loan Facility
Short-term Debt [Line Items]
Short-term borrowings	$ 0			$ 57,086,000
Secured revolving loan facilities | Secured Revolving Loan Facility | LIBOR
Short-term Debt [Line Items]
Basis spread on variable rate			4.25%

Long-Term Debt - Schedule of De

Long-Term Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt	$ 7,885,783	$ 7,380,443
Long-term debt, fair value	606,956	248,856
Structured notes matures in 2018	1,016,300
Structured notes matures in 2019	777,700
Structured notes matures in 2022	232,500
Parent Company
Debt Instrument [Line Items]
Long-term debt	989,021	987,891
Subsidiaries
Debt Instrument [Line Items]
Long-term debt	6,896,762	6,392,552
Credit Facility | Foursight Capital
Debt Instrument [Line Items]
Long-term debt	$ 170,455	$ 97,138
5.50% Senior Notes due October 18, 2023
Debt Instrument [Line Items]
Interest rate	5.50%	5.50%
Principal	$ 750,000	$ 750,000
5.50% Senior Notes due October 18, 2023 | Parent Company
Debt Instrument [Line Items]
Long-term debt	$ 742,348	$ 741,264
6.625% Senior Notes due October 23, 2043
Debt Instrument [Line Items]
Interest rate	6.625%	6.625%
Principal	$ 250,000	$ 250,000
6.625% Senior Notes due October 23, 2043 | Parent Company
Debt Instrument [Line Items]
Long-term debt	$ 246,673	$ 246,627
5.125% Senior Notes, due April 13, 2018
Debt Instrument [Line Items]
Interest rate	5.125%	5.125%
Principal	$ 678,300	$ 800,000
5.125% Senior Notes, due April 13, 2018 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 682,338	$ 817,813
8.5% Senior Notes, due July 15, 2019
Debt Instrument [Line Items]
Interest rate	8.50%	8.50%
Principal	$ 680,800	$ 700,000
8.5% Senior Notes, due July 15, 2019 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 728,872	$ 778,367
2.375% Euro Senior Notes, due May 20, 2020
Debt Instrument [Line Items]
Interest rate	2.375%	2.375%
Principal	$ 594,725	$ 529,975
2.375% Euro Senior Notes, due May 20, 2020 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 593,334	$ 528,250
6.875% Senior Notes, due April 15, 2021
Debt Instrument [Line Items]
Interest rate	6.875%	6.875%
Principal	$ 750,000	$ 750,000
6.875% Senior Notes, due April 15, 2021 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 808,157	$ 823,797
2.25% Euro Medium Term Notes, due July 13, 2022
Debt Instrument [Line Items]
Interest rate	2.25%	2.25%
Principal	$ 4,758	$ 4,240
2.25% Euro Medium Term Notes, due July 13, 2022 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 4,389	$ 3,848
5.125% Senior Notes, due January 20, 2023
Debt Instrument [Line Items]
Interest rate	5.125%	5.125%
Principal	$ 600,000	$ 600,000
5.125% Senior Notes, due January 20, 2023 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 615,703	$ 618,355
4.85% Senior Notes, due January 15, 2027
Debt Instrument [Line Items]
Interest rate	4.85%	0.00%
Principal	$ 750,000	$ 0
4.85% Senior Notes, due January 15, 2027 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	736,357	$ 0
4.85% Senior Notes, due January 15, 2027 | Subsidiaries | Interest rate swaps
Debt Instrument [Line Items]
Increase (Decrease) of Long-term Debt	$ 8,100
6.45% Senior Debentures, due June 8, 2027
Debt Instrument [Line Items]
Interest rate	6.45%	6.45%
Principal	$ 350,000	$ 350,000
6.45% Senior Debentures, due June 8, 2027 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 375,794	$ 377,806
3.875% Convertible Senior Debentures, due November 1, 2029
Debt Instrument [Line Items]
Interest rate	3.875%	3.875%	3.875%
Principal	$ 324,779	$ 345,000
3.875% Convertible Senior Debentures, due November 1, 2029 | Jefferies
Debt Instrument [Line Items]
Interest rate	3.875%
3.875% Convertible Senior Debentures, due November 1, 2029 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 324,779	$ 346,163
6.25% Senior Debentures, due January 15, 2036
Debt Instrument [Line Items]
Interest rate	6.25%	6.25%
Principal	$ 500,000	$ 500,000
6.25% Senior Debentures, due January 15, 2036 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 512,040	$ 512,396
6.50% Senior Notes, due January 20, 2043
Debt Instrument [Line Items]
Interest rate	6.50%	6.50%
Principal	$ 400,000	$ 400,000
6.50% Senior Notes, due January 20, 2043 | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	420,990	421,333
Structured Notes | Jefferies
Debt Instrument [Line Items]
Long-term debt, fair value	607,000	248,900
Structured Notes | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	614,091	255,203
Structured notes matures in 2018	7,100
Structured notes matures in 2019	6,000
Structured notes matures in 2022	25,000
Structured notes matures in 2024 and thereafter	576,000
Reducing Revolver Loan | National Beef
Debt Instrument [Line Items]
Long-term debt	$ 120,000	0
Interest rate	3.30%
Revolving Credit Facility | National Beef
Debt Instrument [Line Items]
Long-term debt	$ 76,809	0
Interest rate	3.30%
Term Loan | National Beef
Debt Instrument [Line Items]
Long-term debt	$ 0	273,811
Term Loan | 54 Madison
Debt Instrument [Line Items]
Long-term debt	0	406,028
Other | Subsidiaries
Debt Instrument [Line Items]
Long-term debt	$ 112,654	$ 132,244

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Contract	Jan. 31, 2018USD ($)	Jan. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015
Debt Instrument [Line Items]
Assets pledged for indebtedness	$ 2,200,000,000
Nonrecourse indebtedness collateralized by assets	484,300,000
Structured notes matures in 2018	1,016,300,000
Debt subject to mandatory redemption, 2019	777,700,000
Debt subject to mandatory redemption, 2020	125,200,000
Debt subject to mandatory redemption, 2021	766,500,000
Structured notes matures in 2022	232,500,000
Long-term debt, fair value	606,956,000			$ 248,856,000
Long-term debt	7,885,783,000			7,380,443,000
National Beef
Debt Instrument [Line Items]
Aggregate outstanding letters of credit	13,900,000
Foursight Capital | Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 170,455,000			$ 97,138,000
3.875% Convertible Senior Debentures, due November 1, 2029
Debt Instrument [Line Items]
Interest rate	3.875%			3.875%	3.875%
3.875% Convertible Senior Debentures, due November 1, 2029 | Jefferies
Debt Instrument [Line Items]
Debt called amount	$ 20,200,000
Interest rate	3.875%
Debt instrument, face amount	$ 345,000,000
Redemption price as percentage of principal amount redeemed	100.00%
Structured Notes | Jefferies
Debt Instrument [Line Items]
Debt Instrument, Principal Amount of Debt Issued, Net of Retirements	$ 329,900,000
Long-term debt, fair value	$ 607,000,000			$ 248,900,000
Revolving Credit Facility | National Beef
Debt Instrument [Line Items]
Interest rate	3.30%
Credit facility term loan, maximum amount	$ 275,000,000
Long-term debt	76,809,000			0
Amount drawn on debt	80,000,000
Revolving Credit Facility | National Beef | Maximum
Debt Instrument [Line Items]
Amount of revolver available	$ 87,100,000
Senior Notes Due 2027 | Jefferies | Senior Notes
Debt Instrument [Line Items]
Interest rate			4.85%
Debt instrument, face amount			$ 750,000,000
Reducing Revolver Loan | National Beef
Debt Instrument [Line Items]
Interest rate	3.30%
Credit facility term loan, maximum amount	$ 275,000,000
Decrease on each annual anniversary of debt agreement	13,800,000
Long-term debt	120,000,000			$ 0
Amount of revolver available	155,000,000
Foursight Credit Facilities | Foursight Capital | Credit Facility
Debt Instrument [Line Items]
Assets pledged for indebtedness	200,500,000
Credit facility term loan, maximum amount	$ 225,000,000
Number of warehouse credit commitment | Contract	2
Subsequent Event | Senior Notes Due 2030 | Jefferies | Senior Notes
Debt Instrument [Line Items]
Interest rate		4.15%
Debt instrument, face amount		$ 1,000,000,000
LIBOR | Revolving Credit Facility and Term Loan | National Beef | Minimum
Debt Instrument [Line Items]
Percentage added to base rate or LIBOR rate	0.75%
LIBOR | Revolving Credit Facility and Term Loan | National Beef | Maximum
Debt Instrument [Line Items]
Percentage added to base rate or LIBOR rate	2.75%

Mezzanine Equity - Additional I

Mezzanine Equity - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 30, 2021	Dec. 30, 2018	Jan. 29, 2017
Purchase Requirement [Line Items]
Redeemable noncontrolling interests			$ 426,593,000	$ 336,809,000
Mandatorily redeemable convertible preferred shares redemption value			$ 125,000,000	$ 125,000,000
Dividends per common share (USD per share)	$ 0.10	$ 0.0625	$ 0.325	$ 0.25	$ 0.25
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
Mandatory redeemable preferred stock, number of shares in conversion			4,162,200
Mandatory redeemable preferred stock, effective conversion price per share (USD per share)			$ 30.03
Minimum common dividend considered for additional quarterly payments (USD per share			$ 0.0625
Preferred stock dividend			$ 4,400,000	$ 4,100,000
Mandatorily redeemable preferred shares callable price per share (USD per share)			$ 1,000
Jefferies
Purchase Requirement [Line Items]
Dividend rate on preferred stock			3.25%
Other
Purchase Requirement [Line Items]
Redeemable noncontrolling interests			$ 14,500,000	$ 14,800,000
National Beef | Put Rights
Purchase Requirement [Line Items]
Put right interest percentage								33.33%
National Beef | Forecast | Put Rights
Purchase Requirement [Line Items]
Put right interest percentage						33.33%	33.33%
USPB | Call Rights | Maximum
Purchase Requirement [Line Items]
Ownership interests as a percent of original interest			20.00%
Other Members | Call Rights | Maximum
Purchase Requirement [Line Items]
Ownership interests as a percent of original interest			50.00%
Anniversary of acquisition			10 years

Mezzanine Equity - Schedule of

Mezzanine Equity - Schedule of Redeemable noncontrolling interests activity (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance				$ 336,809					$ 336,809
Income allocated to redeemable noncontrolling interests	$ 20,038	$ 36,216	$ 16,300	12,022	$ 25,662	$ 22,702	$ 13,068	$ 4,314	84,576	$ 65,746	$ (26,543)
Increase in fair value of redeemable noncontrolling interests charged to additional paid-in capital									(94,937)	(115,963)	(26,325)
Ending balance	426,593				336,809				426,593	336,809
National Beef
Redeemable Noncontrolling Interest [Roll Forward]
Beginning balance				$ 321,962				$ 189,358	321,962	189,358
Income allocated to redeemable noncontrolling interests									85,277	68,811
Distributions to redeemable noncontrolling interests									(90,048)	(53,701)
Increase in fair value of redeemable noncontrolling interests charged to additional paid-in capital									94,937	117,494
Ending balance	$ 412,128				$ 321,962				$ 412,128	$ 321,962	$ 189,358

Mezzanine Equity - Sensitivity

Mezzanine Equity - Sensitivity Analysis of Fair Value of Redeemable Noncontrolling Interests Using Discount and Terminal Growth Rates (Details) $ in Millions	Dec. 31, 2017USD ($)
Rate 1.75% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	1.75%
Rate 2.00% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	2.00%
Rate 2.25% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	2.25%
Discount Rate 11.95%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount growth rate assumed in determining fair value	11.95%
Discount Rate 11.95% | Rate 1.75% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 417.6
Discount Rate 11.95% | Rate 2.00% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	422.4
Discount Rate 11.95% | Rate 2.25% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 427.5
Discount Rate 12.20%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount growth rate assumed in determining fair value	12.20%
Discount Rate 12.20% | Rate 1.75% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 407.6
Discount Rate 12.20% | Rate 2.00% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	412.1
Discount Rate 12.20% | Rate 2.25% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 416.9
Discount Rate 12.45%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount growth rate assumed in determining fair value	12.45%
Discount Rate 12.45% | Rate 1.75% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 398.1
Discount Rate 12.45% | Rate 2.00% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	402.3
Discount Rate 12.45% | Rate 2.25% Terminal Growth Rates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 406.8

Compensation Plans - Incentive

Compensation Plans - Incentive Plan (Details) - $ / shares	Mar. 21, 2014	Dec. 31, 2017	Dec. 31, 2016
Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for grant	20,000,000
Stock available for grant		11,883,293
Incentive Plan | Sign-on and Retention Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for award granted		4 years
Award amortization period		4 years
Dividend Equivalents | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend equivalents declared on restricted stock units		89,000	108,000
Grants, weighted average grant date fair value (USD per share)		$ 21.03	$ 13.53

Compensation Plans - Activity o

Compensation Plans - Activity of Restricted Stock (Details) - Restricted Stock - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Nonvested balance, beginning of period (shares)	1,362	2,004	3,383
Grants (shares)	391	356	602
Forfeited (shares)	0	(24)	(94)
Fulfillment of service requirement (shares)	(611)	(974)	(1,887)
Nonvested balance, end of period (shares)	1,142	1,362	2,004
Weighted- Average Grant Date Fair Value
Nonvested balance, beginning of period (USD per share)	$ 22.09	$ 24.56	$ 27
Grants (USD per share)	23.65	18.23	18.63
Forfeited (USD per share)	0	26.90	28.12
Fulfillment of service requirement (USD per share)	23.73	25.65	26.87
Nonvested balance, end of period (USD per share)	$ 21.75	$ 22.09	$ 24.56

Compensation Plans - Schedule o

Compensation Plans - Schedule of Activity in RSUs (Details) - Restricted Stock Units (RSUs) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Future Service Required
Shares
Nonvested balance, beginning of period (shares)	68	3,388	4,238
Grants (shares)	0	0	0
Distributions of underlying shares	0	0	0
Forfeited (shares)	0	0	(626)
Fulfillment of service requirement (shares)	(36)	(3,320)	(224)
Nonvested balance, end of period (shares)	32	68	3,388
Weighted- Average Grant Date Fair Value
Nonvested balance, beginning of period (USD per share)	$ 26.90	$ 26.90	$ 26.90
Grants (USD per share)	0	0	0
Distribution of underlying shares (USD per share)	0	0	0
Forfeited (USD per share)	0	0	26.90
Fulfillment of service requirement (USD per share)	26.90	26.90	26.90
Nonvested balance, end of period (USD per share)	$ 26.90	$ 26.90	$ 26.90
No Future Service Required
Shares
Vested balance, beginning of period (shares)	10,348	8,583	8,467
Grants (shares)	104	128	121
Distributions of underlying shares	(175)	(1,683)	(229)
Forfeited (shares)	0	0	0
Fulfillment of service requirement (shares)	(36)	(3,320)	(224)
Vested balance, end of period (shares)	10,313	10,348	8,583
Weighted- Average Grant Date Fair Value
Balance, beginning of period (USD per share)	$ 26.61	$ 26.68	$ 26.79
Grants (USD per share)	21.55	14.21	18.95
Distribution of underlying shares (USD per share)	26.46	26.59	22.34
Forfeited (USD per share)	0	0	0
Fulfillment of service requirement (USD per share)	26.90	26.90	26.90
Balance, end of period, weighted average grant date fair value (USD per share)	$ 26.57	$ 26.61	$ 26.68
Senior Executive Compensation Plan
Shares
Nonvested balance, beginning of period (shares)	3,434	0
Grants (shares)	2,221	3,434
Forfeited (shares)	0	0
Nonvested balance, end of period (shares)	5,655	3,434	0
Weighted- Average Grant Date Fair Value
Nonvested balance, beginning of period (USD per share)	$ 9.68	$ 0
Grants (USD per share)	19.06	9.68
Forfeited (USD per share)	0	0
Nonvested balance, end of period (USD per share)	$ 13.37	$ 9.68	$ 0

Compensation Plans - Senior Exe

Compensation Plans - Senior Executive Compensation Plan Narrative (Details) - USD ($)	1 Months Ended		12 Months Ended		36 Months Ended
	Jan. 31, 2017	Feb. 29, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2020	Dec. 30, 2016	Dec. 31, 2015
Senior Executive Compensation Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, weighted average grant date fair value (USD per share)			$ 19.06	$ 9.68
Senior Executives | Senior Executive Compensation Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award performance measurement period	3 years	3 years	3 years
Percentage of compensation beyond base salary will be performance-based	100.00%	100.00%
Employee service share-based compensation, holding period	3 years	3 years
Stock price (USD per share)						$ 23.25	$ 17.39
Performance measurement benchmark, percentage			8.00%
Senior Executives | Senior Executive Compensation Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement benchmark, percentage			4.00%
Senior Executives | Senior Executive Compensation Plan | Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement benchmark, percentage			12.00%
Senior Executives | 2016 Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards eligible			846,882
Senior Executives | 2017 Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards eligible			537,634
Benchmark Two | Senior Executives | 2016 Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards eligible			1,693,766
Benchmark Two | Senior Executives | 2017 Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards eligible			1,075,268
Benchmark Three | Senior Executives | Senior Executive Compensation Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional incentive compensation, percentage			50.00%
Dividend Equivalents | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend equivalents declared on restricted stock units			89,000	108,000
Grants, weighted average grant date fair value (USD per share)			$ 21.03	$ 13.53
Dividend Equivalents | Senior Executive Compensation Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend equivalents declared on restricted stock units			70,000	47,000
Grants, weighted average grant date fair value (USD per share)			$ 21.04	$ 13.63
Forecast | Subsequent Event | Senior Executives | 2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award performance measurement period					3 years
Employee Service Share-based Compensation, Performance Measurement, Targeted Long-Term Compensation					$ 25,000,000
Forecast | Subsequent Event | Senior Executives | 2018 Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement benchmark, percentage					8.00%
Additional incentive compensation, percentage					50.00%
Employee Service Share-based Compensation, Performance Measurement, Targeted Long-Term Compensation					$ 16,000,000
Forecast | Subsequent Event | Senior Executives | 2018 Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement benchmark, percentage					5.00%
Forecast | Subsequent Event | Senior Executives | 2018 Plan | Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement benchmark, percentage					12.00%
Forecast | Subsequent Event | Senior Executives | 2018 Plan | Long-term Cash
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Performance Measurement, Targeted Long-Term Compensation					$ 9,000,000

Compensation Plans - Directors'

Compensation Plans - Directors' Plan (Details) - Directors' Plan	12 Months Ended
	Dec. 31, 2017USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares to be granted to each non employee director | $	$ 120,000
Vesting period for award granted	3 years
Shares issuable upon settlement of deferred shares	321,026
Stock available for grant	297,926

Compensation Plans - Other Comp

Compensation Plans - Other Compensation Plan (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Installmentshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)	Mar. 01, 2013plan	Dec. 31, 2011shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of award plans | plan				2
Share-based compensation | $	$ 48,384	$ 33,597	$ 74,087
Shares reserved for stock options and warrants	331,312	641,478
Unamortized portion of compensation expense for restricted cash awards | $	$ 481,600
1999 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock available for grant	0
1999 Stock Option Plan | Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (shares)	0
Senior Executive Warrant Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock available for grant	0
Number of securities called by warrants (shares)					2,000,000
Share-based compensation | $			$ 1,000
Employee | 1999 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of annual installments | Installment	5
Director | 1999 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of annual installments | Installment	4

Compensation Plans - Summary of

Compensation Plans - Summary of stock options activities (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Shares Subject to Option
Beginning balance (shares)	641	661	1,640
Granted (shares)	0	0	0
Exercised (shares)	(20)	0	(2)
Cancelled (shares)	(290)	(20)	(977)
Ending balance (shares)	331	641	661
Exercisable (shares)	264
Weighted- Average Exercise Prices
Weighted-Average Exercise Prices, Beginning balance (USD per share)	$ 24.80	$ 24.97	$ 24.91
Weighted-Average Exercise Prices, Granted (USD per share)	0	0	0
Weighted-Average Exercise Prices, Exercised (USD per share)	22.75	0	21.66
Weighted-Average Exercise Prices, Cancelled (USD per share)	26.98	30.49	24.88
Weighted-Average Exercise Prices, Ending balance (USD per share)	23.03	$ 24.80	$ 24.97
Weighted-Average Exercise Prices, Exercisable (USD per share)	$ 23.07
Weighted-Average Remaining Contractual Term	1 year
Weighted-Average Remaining Contractual Term, Exercisable	1 year
Aggregate Intrinsic Value, Exercised	$ 65	$ 0	$ 6
Aggregate Intrinsic Value, Outstanding	1,156
Aggregate Intrinsic Value, Exercisable	$ 911

Compensation Plans - Stock-Base

Compensation Plans - Stock-Based Compensation Expense (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 48,384	$ 33,597	$ 74,087
Tax benefit for issuance of share-based awards	17,300	12,400	27,300
Total unrecognized compensation costs related to nonvested share-based compensation plans	$ 68,000
Total unrecognized compensation costs related to nonvested share-based compensation plans, period for recognition	1 year 7 months 28 days
Net tax benefit related to share-based compensation plans recognized as additional paid in capital		$ (4,200)	$ (5,900)
Potential maximum increase to common shares outstanding from restricted stock and other shares	16,887
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, future service required	1,142	1,362	2,004	3,383
Other Shares Issuable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other shares issuable	887
Future Service Required | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, future service required	1,142
Future Service Required | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, future service required	32	68	3,388	4,238
Future Service Required | Incentive Plan and Senior Executive Compensation Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, future service required	5,687
No Future Service Required | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, no future service required	10,313	10,348	8,583	8,467

Accumulated Other Comprehens130

Accumulated Other Comprehensive Income - Summary of Accumulated Other Comprehensive Income, Net of Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ 10,138,979	$ 10,303,649	$ 10,465,890	$ 10,370,022
Net unrealized gains on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	572,085	561,497	557,601
Net unrealized foreign exchange losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(101,400)	(184,829)	(63,248)
Net unrealized losses in instrument specific credit risk
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(34,432)	(6,494)	0
Net unrealized losses on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(1,138)	0	0
Net minimum pension liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(62,391)	(59,477)	(55,560)
AOCI attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ 372,724	$ 310,697	$ 438,793	$ 447,082

Accumulated Other Comprehens131

Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income Reclassifications (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized securities gains	$ 23,028	$ 29,542	$ 62,957
Reclassifications for the period, net of tax	(5,615)	(1,530)
Net unrealized gains on available for sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications for the period, tax	124	2
Net unrealized foreign exchange losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications for the period, tax	(1,086)	0
Net minimum pension liability
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications for the period, net of tax	(1,748)	(1,534)
Reclassifications for the period, tax	(811)	(700)
Other pension
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications for the period, tax	1,231	0
Reclassification out of Accumulated Other Comprehensive Income | Net unrealized gains on available for sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized securities gains	212	4
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	$ (5,310)	$ 0

Pension Plans and Postretire132

Pension Plans and Postretirement Benefits - Additional Information (Details) $ in Thousands, € in Millions	12 Months Ended
	Dec. 31, 2017USD ($)portfolio	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)participant	Dec. 28, 2017USD ($)	Dec. 28, 2017EUR (€)
Pension Plan Disclosure [Line Items]
Number of portfolios | portfolio	2
Pension expense	$ 8,900	$ 9,600	$ 9,600
U.S. Pension Plans
Pension Plan Disclosure [Line Items]
Settlement charge	0	0	$ 40,973
Charge to accumulated other comprehensive income (loss)	51,300	58,900
Accrued pension cost	60,500	$ 77,900
Estimated net loss that will be amortized from AOCI next year	2,500
Estimated employer contributions in next fiscal year	$ 8,900
U.S. Pension Plans | WilTel Plan
Pension Plan Disclosure [Line Items]
Number of participants offered | participant			4,000
Number of participants accepted | participant			2,400
Distributions paid			$ 110,700
Settlement charge			$ 40,700
Current expected inflation rate	2.25%
Equity risk premium over cash	4.00%
Expected long-term rate of return assumption	7.00%	7.00%
U.S. Pension Plans | WilTel Plan | Minimum
Pension Plan Disclosure [Line Items]
Long duration risk free real rate of return	1.00%
Return premium for corporate credit risk	1.00%
U.S. Pension Plans | WilTel Plan | Maximum
Pension Plan Disclosure [Line Items]
Long duration risk free real rate of return	1.50%
Return premium for corporate credit risk	1.50%
U.S. Pension Plans | Jefferies Plan
Pension Plan Disclosure [Line Items]
Expected long-term rate of return assumption	6.25%	6.25%
German Pension Plan
Pension Plan Disclosure [Line Items]
Charge to accumulated other comprehensive income (loss)	$ 5,300	$ 5,700
Investment in Insurance contract	$ 16,000	$ 15,200
German Pension Plan | Jefferies Plan
Pension Plan Disclosure [Line Items]
Consideration for release indemnity relating to pension obligation				$ 3,250
German Pension Plan | Jefferies Bache Limited
Pension Plan Disclosure [Line Items]
Payment to transfer defined benefit pension obligations and insurance contracts | €					€ 6.5

Pension Plans and Postretire133

Pension Plans and Postretirement Benefits - Components of Defined Benefit Pension Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. Pension Plans
Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	$ 205,405	$ 207,025
Interest cost	8,119	8,464	$ 12,958
Actuarial (gains) losses	6,644	(544)
Benefits paid	(8,911)	(9,540)
Projected benefit obligation at end of year	211,257	205,405	207,025
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	127,514	117,719
Actual return on plan assets	22,192	2,947
Employer contributions	12,417	19,100
Administrative expenses	(2,406)	(2,712)
Benefits paid	(8,911)	(9,540)
Fair value of plan assets at end of year	150,806	127,514	117,719
Funded status at end of year	(60,451)	(77,891)
German Pension Plan
Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	24,166	23,545
Interest cost	426	529	523
Actuarial (gains) losses	91	(1,157)
Currency adjustment	2,976	39
Benefits paid	(1,233)	(1,104)
Projected benefit obligation at end of year	26,244	24,166	$ 23,545
Change in Fair Value of Plan Assets [Roll Forward]
Benefits paid	$ (1,233)	$ (1,104)

Pension Plans and Postretire134

Pension Plans and Postretirement Benefits - Components of Pension Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 8,119	$ 8,464	$ 12,958
Expected return on plan assets	(7,689)	(7,589)	(10,581)
Settlement charge	0	0	(40,973)
Actuarial losses	2,207	1,908	6,963
Net periodic pension cost	2,637	2,783	50,313
Net (gain) loss arising during the period	(5,453)	6,811	(24,186)
Amortization of net loss	(2,207)	(1,908)	(6,963)
Total recognized in other comprehensive income (loss)	(7,660)	4,903	(72,122)
Net amount recognized in net periodic benefit cost and other comprehensive income (loss)	(5,023)	7,686	(21,809)
German Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	426	529	523
Net amortization	353	326	325
Net periodic pension cost	$ 779	$ 855	$ 848

Pension Plans and Postretire135

Pension Plans and Postretirement Benefits - Schedule of Assumptions for Pensions Plan (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
U.S. Pension Plans | WilTel Plan
Projected benefit obligation
Discount rate	3.51%	3.85%
Net periodic pension benefit cost
Discount rate	3.85%	4.00%
Discount rate	7.00%	7.00%
U.S. Pension Plans | Jefferies Plan
Projected benefit obligation
Discount rate	3.60%	3.90%
Net periodic pension benefit cost
Discount rate	3.90%	4.10%
Discount rate	6.25%	6.25%
German Pension Plan
Projected benefit obligation
Discount rate	1.80%	1.70%
Net periodic pension benefit cost
Discount rate	1.70%	2.20%

Pension Plans and Postretire136

Pension Plans and Postretirement Benefits - Schedule of Expected Pension Benefit Payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 9,943
2,019	9,915
2,020	9,666
2,021	9,577
2,022	10,233
2023 - 2027	67,493
German Pension Plan
Defined Benefit Plan Disclosure [Line Items]
2,018	1,303
2,019	1,275
2,020	1,329
2,021	1,339
2,022	1,320
2023 - 2027	$ 6,571

Pension Plans and Postretire137

Pension Plans and Postretirement Benefits - Schedule of Plan's Assets at Fair Value (Details) - U.S. Pension Plans - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 150,806	$ 127,514	$ 117,719
WilTel Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	97,857	77,522
WilTel Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	539	919
WilTel Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	97,318	76,603
WilTel Plan | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	539	919
WilTel Plan | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	539	919
WilTel Plan | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
WilTel Plan | Growth Portfolio
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	65,625	51,852
WilTel Plan | Growth Portfolio | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
WilTel Plan | Growth Portfolio | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	65,625	51,852
WilTel Plan | Liability-Driven Investing Portfolio
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	31,693	24,751
WilTel Plan | Liability-Driven Investing Portfolio | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
WilTel Plan | Liability-Driven Investing Portfolio | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	31,693	24,751
Jefferies Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	52,949	49,992
Jefferies Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	38,847
Jefferies Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	52,949	11,145
Jefferies Plan | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		1,135
Jefferies Plan | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		1,135
Jefferies Plan | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Common collective trusts
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	52,949
Jefferies Plan | Common collective trusts | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0
Jefferies Plan | Common collective trusts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 52,949
Jefferies Plan | Listed equity securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		32,342
Jefferies Plan | Listed equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		32,342
Jefferies Plan | Listed equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		4,906
Jefferies Plan | Corporate debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Corporate debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		4,906
Jefferies Plan | Foreign corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		1,835
Jefferies Plan | Foreign corporate debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Foreign corporate debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		1,835
Jefferies Plan | U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		5,370
Jefferies Plan | U.S. government securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		5,370
Jefferies Plan | U.S. government securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Agency mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		3,330
Jefferies Plan | Agency mortgage-backed securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Agency mortgage-backed securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		3,330
Jefferies Plan | Commercial mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		591
Jefferies Plan | Commercial mortgage-backed securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Commercial mortgage-backed securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		591
Jefferies Plan | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		483
Jefferies Plan | Asset-backed securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		0
Jefferies Plan | Asset-backed securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		$ 483

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current taxes:
Federal	$ 413	$ (574)	$ 709
State and local	33,845	8,672	(25,308)
Foreign	14,654	(4,620)	3,504
Total current income taxes	48,912	3,478	(21,095)
Deferred taxes:
Federal	694,207	108,241	134,590
State and local	9,697	8,335	4,552
Foreign	8,151	2,055	(8,100)
Total deferred income taxes	712,055	118,631	131,042
Total income tax provision	$ 760,967	$ 122,109	$ 109,947

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Discrete tax expense related to Tax Cuts and Jobs Act of 2017	$ 450,500	$ 450,500
Increase of effective income tax rate		44.40%
Effective income tax rate		75.10%	38.60%	30.80%
Discrete tax expense related to revaluation of deferred tax asset	415,000	$ 415,000	$ 0	$ 0
Discrete tax expense related to deemed repatriation of foreign earnings	35,500	35,500	0	0
Tax benefit from repatriation of foreign earnings		31,900
Increase of income taxes provision		161	24,907	0
Net interest expense related to unrecognized tax benefits		9,700	8,600	$ 4,200
Interest accrued related to unrecognized tax benefits	57,400	57,400	47,700
Expected decrease in unrecognized tax benefit related to uncertain tax position over next 12 months		14,000
Valuation allowance	93,758	93,758	106,042
Undistributed earnings of foreign subsidiaries			157,000
Deferred tax liability not recorded on earnings of foreign subsidiaries permanently invested abroad			$ 55,000
Subsidiary [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,200,000	1,200,000
Consolidated Tax Group [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,200,000	1,200,000
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	68,600	68,600
Valuation allowance	$ 10,000	$ 10,000

Income Taxes - Components of In

Income Taxes - Components of Income from Continuing Operations before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S.	$ 944,014	$ 337,374	$ 336,856
Non-U.S.	69,800	(20,944)	19,680
Income from continuing operations before income taxes	$ 1,013,814	$ 316,430	$ 356,536

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Expected Statutory Federal Income Tax To Actual Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed expected federal income tax, Amount		$ 354,835	$ 110,751	$ 124,788
State and local income taxes, net of federal income tax benefit, Amount		19,938	1,045	(6,928)
International operations (including foreign rate differential), Amount		(11,577)	(3,137)	(11,474)
Increase (decrease) in valuation allowance, Amount		0	2,825	(13,227)
Permanent differences, Amount		7,474	7,523	13,892
Tax exempt income, Amount		(3,850)	(4,640)	(6,789)
Foreign tax credits, Amount		(32,974)	0	(7,240)
Income allocated to noncontrolling interest, not subject to tax, Amount		(28,392)	(22,512)	11,039
Excess stock detriment, Amount		161	24,907	0
Revaluation of deferred tax asset, Amount	$ 415,000	415,000	0	0
Transition tax, Amount	$ 35,500	35,500	0	0
Other, Amount		4,852	5,347	5,886
Total income tax provision		$ 760,967	$ 122,109	$ 109,947
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Computed expected federal income tax, Percent		35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefit, Percent		2.00%	0.30%	(1.90%)
International operations (including foreign rate differential), Percent		(1.10%)	(1.00%)	(3.20%)
Increase (decrease) in valuation allowance, Percent		0.00%	0.90%	(3.70%)
Permanent differences, Percent		0.70%	2.40%	3.90%
Tax exempt income, Percent		(0.40%)	(1.50%)	(1.90%)
Foreign tax credits, Percent		(3.20%)	0.00%	(2.00%)
Income allocated to noncontrolling interest, not subject to tax, Percent		(2.80%)	(7.10%)	3.10%
Excess stock detriment, Percent		0.00%	7.90%	0.00%
Revaluation of deferred tax asset, Amount, Percent		40.90%	0.00%	0.00%
Transition tax, Percent		3.50%	0.00%	0.00%
Other, Percent		0.50%	1.70%	1.50%
Actual income tax provision, Percent		75.10%	38.60%	30.80%

Income Taxes - Schedule of R142

Income Taxes - Schedule of Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 148,848	$ 150,867	$ 148,590
Increases based on tax positions related to current period	18,619	5,045	3,475
Increases based on tax positions related to prior periods	10,358	3,697	22,030
Decreases based on tax positions related to prior periods	(8,805)	(9,414)	(15,349)
Decreases related to settlements with taxing authorities	0	(1,347)	(7,879)
Balance at end of period	$ 169,020	$ 148,848	$ 150,867

Income Taxes - Schedule of Prin

Income Taxes - Schedule of Principal Components of Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss carryover	$ 599,839	$ 1,262,584
Compensation and benefits	213,340	309,100
Long-term debt	11,799	54,102
Other assets	97,061	155,028
Tax credits	93,026	10,749
Securities valuation reserves	3,012	12,345
Intangible assets, net and goodwill	270	311
Other liabilities	21,605	39,188
Gross tax assets	1,039,952	1,843,407
Valuation allowance	(93,758)	(106,042)
Total deferred tax assets, net	946,194	1,737,365
Unrealized gains on investments	(8,060)	(998)
Amortization of intangible assets	(71,583)	(107,437)
Property and equipment	(8,209)	(14,228)
Investment in FXCM	(37,942)	(117,594)
Transition tax	(35,165)	0
Other	(41,424)	(35,293)
Gross tax liability	(202,383)	(275,550)
Net deferred tax asset	$ 743,811	$ 1,461,815

Net Realized Securities Gain144

Net Realized Securities Gains (Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Investments [Abstract]
Net realized gains (losses) on securities	$ 13	$ (286)	$ 14,112
Other	23,015	29,828	48,845
Net securities gains (losses)	23,028	29,542	62,957
Gain on investment in non-public security	19,700
Investment recovery			35,000
Proceeds from sales of investments	$ 400,000	$ 500,000	1,900,000
Gross gains			16,900
Gross losses			$ 2,800

Other Results of Operations 145

Other Results of Operations Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Manufacturing revenues		$ 326,197	$ 412,826	$ 391,920
Losses from managed funds		(8,118)	(69,038)	(37,237)
Asset management fees		28,831	29,492	34,777
Dividend income		(452)	3,856	5,482
Income from associated companies classified as other revenues		75,889	17,184	75,717
Revenues of oil and gas production and development businesses		61,541	49,890	45,939
Gain on sale of subsidiaries		179,605	0	0
Other		86,384	43,976	32,630
Total other income		748,508	488,186	549,228
Taxes other than income or payroll		39,600	35,400	21,900
Advertising costs		21,600	$ 20,000	$ 18,100
Disposed of by Sale | Conwed
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of subsidiaries	$ 179,900	$ 178,236

Common Shares and Earnings P146

Common Shares and Earnings Per Common Share - Earnings Per Share Computation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator for earnings per share:
Net income attributable to Leucadia National Corporation common shareholders	$ (271,601)	$ 99,351	$ 58,193	$ 281,408	$ 137,171	$ 154,358	$ 57,289	$ (222,880)	$ 167,351	$ 125,938	$ 279,587
Allocation of earnings to participating securities									(610)	(574)	(4,711)
Net income attributable to Leucadia National Corporation common shareholders for basic earnings per share									166,741	125,364	274,876
Adjustment to allocation of earnings to participating securities related to diluted shares									(14)	(19)	(34)
Mandatorily redeemable convertible preferred share dividends									0	0	0
Net income attributable to Leucadia National Corporation common shareholders for diluted earnings per share									$ 166,727	$ 125,345	$ 274,842
Denominator for earnings per share:
Denominator for basic earnings per share – weighted average shares (shares)	366,000,000	367,828,000	369,212,000	369,267,000	369,299,000	370,404,000	372,556,000	372,367,000	368,197,000	371,211,000	372,430,000
Mandatorily redeemable convertible preferred shares (shares)									0	0	0
Denominator for diluted earnings per share (shares)	366,000,000	370,198,000	371,552,000	375,721,000	374,693,000	374,567,000	372,556,000	372,367,000	370,701,000	371,518,000	372,431,000
Weighted average shares of participating securities									1,401,000	1,986,800	6,500,000
Dividends declared on participating securities									$ 400	$ 400	$ 1,500
Stock options
Denominator for earnings per share:
Dilutive effect of share-based payment arrangements (shares)									24,000	0	1,000
Restricted Stock Units (RSUs)
Denominator for earnings per share:
Dilutive effect of share-based payment arrangements (shares)									2,480,000	307,000	0

Common Shares and Earnings P147

Common Shares and Earnings Per Common Share - Additional Information (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of common shares authorized to repurchase	12,500,000
3.875% Convertible Senior Debentures, due November 1, 2029
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible notes interest rate	3.875%	3.875%	3.875%
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computation of earnings per share amount		923,077	4,000,000
Exercise price (USD per share)		$ 33.33	$ 33.33
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computation of earnings per share amount		656,894	1,000,137
Redeemable Convertible Preferred Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computation of earnings per share amount	4,162,200	4,162,200	4,162,200

Commitments, Contingencies a148

Commitments, Contingencies and Guarantees - Additional Information (Details)	Dec. 30, 2004USD ($)	Aug. 31, 2014USD ($)	Sep. 30, 2017	Dec. 31, 2017USD ($)Seat	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Loss Contingencies [Line Items]
Rental expense (net of sublease rental income)				$ 80,800,000	$ 80,400,000	$ 84,000,000
Loan commitments outstanding to clients				68,300,000
Fair value of derivative contracts meeting the definition of a guarantee				243,600,000
Fair value of mortgage-related and other purchase commitments				37,600,000
Lease obligations				$ 7,413,100,000
Standby letters of credit
Loss Contingencies [Line Items]
Debt instrument, term				1 year
Jefferies Capital Partners LLC and Its Private Equity Funds
Loss Contingencies [Line Items]
Equity commitments				$ 22,000,000
Other Various Investments
Loss Contingencies [Line Items]
Equity commitments				14,400,000
Folger Hill
Loss Contingencies [Line Items]
Entity line of credit facility, Original Term		3 years
Entity line of credit facility		$ 20,000,000
Amount funded under credit facility				10,200,000
National Beef
Loss Contingencies [Line Items]
Service charge commitment for city improvements	$ 19,300,000
Service charge commitment for city improvements, duration of payments	20 years
Service charge commitment for city improvements, remaining amount				4,900,000
Service charge commitment for city improvements future payment in 2018				800,000
Service charge commitment for city improvements future payment in 2019				800,000
Service charge commitment for city improvements future payment in subsequent years				3,300,000
Letters of credit				13,900,000
54 Madison
Loss Contingencies [Line Items]
Maximum amount committed to invest as per agreement				202,500,000
Amount of contributed commitment				144,800,000
Approved unfunded commitment				$ 28,000,000
Number of seats in investment committee retained by Company | Seat				2
Number of seats in investment committee | Seat				4
Jefferies Finance
Loss Contingencies [Line Items]
Line of credit commitment to associated companies, funded portion				$ 0
Line of credit facility commitment of Jefferies				250,000,000
Folger Hill
Loss Contingencies [Line Items]
Number of days prior written notice for optional termination right			10 days
Jefferies Plan | Standby letters of credit
Loss Contingencies [Line Items]
Letters of credit				$ 51,800,000
Berkadia
Loss Contingencies [Line Items]
Reimbursement of losses incurred, maximum percentage				50.00%
Surety policy issued				$ 1,500,000,000
Aggregate amount of commercial paper outstanding				1,470,000,000
Other subsidiaries
Loss Contingencies [Line Items]
Letters of credit				$ 15,000,000
Minimum
Loss Contingencies [Line Items]
Noncancellable operating lease terms				1 year
Maximum
Loss Contingencies [Line Items]
Noncancellable operating lease terms				22 years
Empire Insurance Company
Loss Contingencies [Line Items]
Lease obligations				$ 9,800,000

Commitments, Contingencies a149

Commitments, Contingencies and Guarantees - Schedule of Future Minimum Annual Rentals (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 94,734
2,019	84,110
2,020	68,195
2,021	62,507
2,022	59,844
Thereafter	638,441
Future minimum annual rentals	1,007,831
Less: sublease income	(29,633)
Future minimum annual rentals net of sublease income	$ 978,198

Commitments, Contingencies a150

Commitments, Contingencies and Guarantees - Schedule of Commitments (Details) $ in Millions	Dec. 31, 2017USD ($)
Guarantor Obligations [Line Items]
2,018	$ 6,740
2,019	300.8
2020 and 2021	93.5
2022 and 2023	153
2024 and Later	125.8
Maximum Payout	7,413.1
Equity commitments
Guarantor Obligations [Line Items]
2,018	33.5
2,019	0.2
2020 and 2021	18.7
2022 and 2023	0
2024 and Later	125.8
Maximum Payout	178.2
Loan commitments
Guarantor Obligations [Line Items]
2,018	277.7
2,019	0
2020 and 2021	56.5
2022 and 2023	0
2024 and Later	0
Maximum Payout	334.2
Mortgage-related and other purchase commitments
Guarantor Obligations [Line Items]
2,018	0
2,019	177.7
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	177.7
Underwriting commitments
Guarantor Obligations [Line Items]
2,018	11
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	11
Forward starting reverse repos
Guarantor Obligations [Line Items]
2,018	3,211.1
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	3,211.1
Other commitment settled within three business days	3,207.4
Forward starting repos
Guarantor Obligations [Line Items]
2,018	2,987.9
2,019	0
2020 and 2021	0
2022 and 2023	0
2024 and Later	0
Maximum Payout	2,987.9
Other commitment settled within three business days	2,982.8
Other unfunded commitments
Guarantor Obligations [Line Items]
2,018	218.8
2,019	122.9
2020 and 2021	18.3
2022 and 2023	153
2024 and Later	0
Maximum Payout	$ 513

Commitments, Contingencies a151

Commitments, Contingencies and Guarantees - Summary of Notional Amounts Associated with Derivative Contracts (Details) $ in Millions	Dec. 31, 2017USD ($)
Derivative contracts – non-credit related
Guarantor Obligations [Line Items]
2,018	$ 24,454.8
2,019	2,420.2
2020 and 2021	150.5
2022 and 2023	45.9
2024 and Later	466.3
Maximum Payout	27,537.7
Written derivative contracts – credit related
Guarantor Obligations [Line Items]
2,018	0
2,019	42
2020 and 2021	20.5
2022 and 2023	155.7
2024 and Later	0
Maximum Payout	218.2
Derivatives
Guarantor Obligations [Line Items]
2,018	24,454.8
2,019	2,462.2
2020 and 2021	171
2022 and 2023	201.6
2024 and Later	466.3
Maximum Payout	$ 27,755.9

Net Capital Requirements (Detai

Net Capital Requirements (Details) - Jefferies LLC $ in Millions	Dec. 31, 2017USD ($)
Net Capital Requirements [Line Items]
Net Capital	$ 1,418.9
Excess Net Capital	$ 1,330.2

Other Fair Value Information (D

Other Fair Value Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term borrowings	$ 436,215	$ 525,842
Long-term debt	7,885,783	7,380,443
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	579,071	962,938
Short-term borrowings	412,891	525,842
Long-term debt	7,278,827	7,131,587
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	565,285	958,377
Short-term borrowings	412,891	525,842
Long-term debt	$ 7,678,210	$ 7,221,459

Related Party Transactions (Det

Related Party Transactions (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)directorcattle	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)shares
Related Party Transaction [Line Items]
Head of cattle to be purchased per year from members of USPB, actual number | cattle		735,385
Percentage of cattle requirements obtained through USPB		24.00%	27.00%
Sales to related party		$ 31,700	$ 30,900
Purchases from related party		13,400	14,800
Long term debt		$ 7,885,783	7,380,443
HomeFed Corporation
Related Party Transaction [Line Items]
Cash paid on acquisition of common shares					$ 14,000
Common shares acquired | shares					7,500,000
Number of executives from the Company | director		3
54 Madison
Related Party Transaction [Line Items]
Related party transaction amount	$ 86,500
Jefferies Capital Partners Related Funds
Related Party Transaction [Line Items]
Loans to and/or equity investments in related funds		$ 23,700	37,700
Net income (losses) from private equity related funds		(11,700)	(2,300)	$ (26,200)
Berkadia Commercial Mortgage, LLC
Related Party Transaction [Line Items]
Purchase Commitments Outstanding		864,100	817,000
Officers and Employees
Related Party Transaction [Line Items]
Loans outstanding to related party		$ 45,600	41,200
Company Chairman | HomeFed Corporation
Related Party Transaction [Line Items]
Ownership percentage of company		4.80%
Term Loan | Minority owners of 54 Madison
Related Party Transaction [Line Items]
Long term debt			230,200
Term Loan | 54 Madison
Related Party Transaction [Line Items]
Long term debt		$ 0	$ 406,028
Minimum | Term Loan | 54 Madison
Related Party Transaction [Line Items]
Interest rate			4.20%
Maximum | Term Loan | 54 Madison
Related Party Transaction [Line Items]
Interest rate			6.00%

Discontinued Operations and 155

Discontinued Operations and Assets Held for Sale - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain on disposal			$ 179,605	$ 0	$ 0
Disposed of by Sale | Conwed
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage	100.00%
Cash consideration from sale of business	$ 295,000
Net book value				100,600
Pre-tax gain on disposal		$ 179,900	$ 178,236
Held-for-sale | Conwed
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities held for sale				$ 14,700
Maximum | Disposed of by Sale | Conwed
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Potential earn-out payment to be received from sale of subsidiary	$ 40,000

Discontinued Operations and 156

Discontinued Operations and Assets Held for Sale - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0	$ 128,083
Conwed | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash		5,206
Receivables		15,297
Property, equipment and leasehold improvements, net		18,664
Intangible assets, net and goodwill		56,854
Inventory		19,069
Other assets		12,993
Assets held for sale		$ 128,083

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information By Segment (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Net Revenues	$ 2,939,509		$ 2,896,522	$ 2,732,380	$ 2,867,982	$ 2,745,778		$ 2,676,375	$ 2,625,358	$ 2,015,106	$ 11,436,393		$ 10,062,617		$ 10,886,458
Income (loss) from continuing operations before income taxes											1,013,814		316,430		356,536
Depreciation and amortization expenses											208,910		211,593		224,133
Identifiable assets employed	47,169,108	[1]				45,071,307	[1]				47,169,108	[1]	45,071,307	[1]	46,331,184
Principal transactions											931,576		603,822		642,824
Deferred tax asset, net	743,811					1,461,815					743,811		1,461,815
Parent Company interest
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes											(58,943)		(58,881)		(87,181)
Identifiable assets employed	19,891,264					19,626,186					19,891,264		19,626,186
Principal transactions											(9,754)		16,735		491,341
Deferred tax asset, net	205,773					346,684					205,773		346,684
FXCM
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes											(154,500)		(54,600)		491,300
Principal transactions											23,200		(54,600)		491,300
Jefferies Plan
Segment Reporting Information [Line Items]
Deferred tax asset, net	213,000					337,600					213,000		337,600		320,200
Operating Segments
Segment Reporting Information [Line Items]
Net Revenues											10,628,892		9,536,888		9,956,674
Income (loss) from continuing operations before income taxes											856,190		390,916		(49,045)
Depreciation and amortization expenses											166,361		158,307		185,226
Identifiable assets employed	43,042,807					40,425,531					43,042,807		40,425,531		41,899,234
All other
Segment Reporting Information [Line Items]
Net Revenues											807,501		525,729		950,784
Income (loss) from continuing operations before income taxes											216,567		(15,605)		492,762
Depreciation and amortization expenses											42,549		53,286		38,907
Identifiable assets employed	4,196,622					4,728,457					4,196,622		4,728,457		4,581,673
Intercompany eliminations
Segment Reporting Information [Line Items]
Net Revenues											0		0		(21,000)
Identifiable assets employed	(70,321)					(82,681)					(70,321)		(82,681)		(149,723)
Jefferies Plan | Operating Segments
Segment Reporting Information [Line Items]
Net Revenues											3,207,097		2,421,055		2,476,133
Income (loss) from continuing operations before income taxes											527,804		43,508		119,165
Depreciation and amortization expenses											62,668		60,206		92,165
Identifiable assets employed	39,575,732					36,992,096					39,575,732		36,992,096		38,607,786
National Beef | Operating Segments
Segment Reporting Information [Line Items]
Net Revenues											7,358,948		7,027,243		7,402,419
Income (loss) from continuing operations before income taxes											407,312		329,022		(123,915)
Depreciation and amortization expenses											98,515		94,482		89,317
Identifiable assets employed	1,460,539					1,498,317					1,460,539		1,498,317		1,514,249
Corporate and other | Operating Segments
Segment Reporting Information [Line Items]
Net Revenues											62,847		88,590		78,122
Income (loss) from continuing operations before income taxes											(78,926)		18,386		(44,295)
Depreciation and amortization expenses											5,178		3,619		3,744
Identifiable assets employed	$ 2,006,536					$ 1,935,118					$ 2,006,536		$ 1,935,118		$ 1,777,199
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Segment Information - Schedu158

Segment Information - Schedule of Net Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 2,939,509	$ 2,896,522	$ 2,732,380	$ 2,867,982	$ 2,745,778	$ 2,676,375	$ 2,625,358	$ 2,015,106	$ 11,436,393	$ 10,062,617	$ 10,886,458
Jefferies
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									3,207,097	2,421,055	2,476,133
Americas | Jefferies
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									2,611,729	1,876,796	1,887,899
Europe | Jefferies
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									489,583	458,046	510,044
Asia | Jefferies
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									$ 105,785	$ 86,213	$ 78,190

Segment Information - Additiona

Segment Information - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net realized securities gains	$ 23,028	$ 29,542	$ 62,957
Interest	107,859	108,703	115,804
Corporate and other
Segment Reporting Information [Line Items]
Net realized securities gains	23,000	16,400	63,000
National Beef
Segment Reporting Information [Line Items]
Interest	6,700	12,900	16,600
Parent Company
Segment Reporting Information [Line Items]
Interest	58,943	58,881	87,181
All other
Segment Reporting Information [Line Items]
Interest	$ 42,200	$ 36,900	$ 12,000
U.S. | Geographic Concentration Risk | Revenue | National Beef
Segment Reporting Information [Line Items]
Concentration risk, percentage	88.80%	89.20%	89.50%

Exit Costs - Additional Informa

Exit Costs - Additional Information (Details) - Jefferies Plan - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Jul. 31, 2015
Restructuring Cost and Reserve [Line Items]
Non-cash restructuring costs	$ 300,000	$ 28,700,000
Jefferies Senior Secured Revolving Credit Facility
Restructuring Cost and Reserve [Line Items]
Credit facility term loan, maximum amount			$ 750,000,000
Recognized costs related to credit facility termination		$ 3,800,000

Exit Costs - Schedule of Restru

Exit Costs - Schedule of Restructuring and Impairment Costs (Details) - Jefferies Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Impairment costs	$ 1,854	$ 73,094
Severance costs
Restructuring Cost and Reserve [Line Items]
Impairment costs	279	30,327
Accelerated amortization of restricted stock and restricted cash awards
Restructuring Cost and Reserve [Line Items]
Impairment costs	41	7,922
Accelerated amortization of capitalized software
Restructuring Cost and Reserve [Line Items]
Impairment costs	0	19,745
Contract termination costs
Restructuring Cost and Reserve [Line Items]
Impairment costs	1,234	11,247
Selling, general and other expenses
Restructuring Cost and Reserve [Line Items]
Impairment costs	$ 300	$ 3,853

Selected Quarterly Financial162

Selected Quarterly Financial Data (Schedule of Selected Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Net revenues	$ 2,939,509	$ 2,896,522	$ 2,732,380	$ 2,867,982	$ 2,745,778	$ 2,676,375	$ 2,625,358	$ 2,015,106	$ 11,436,393	$ 10,062,617	$ 10,886,458
Income (loss) from continuing operations	(251,905)	136,767	74,062	293,923	166,105	176,206	70,612	(218,602)	252,847	194,321	246,589
Income from discontinued operations, net of taxes									0	0	429
Gain on disposal of discontinued operations, net of taxes									0	0	5,093
Net (income) loss attributable to the noncontrolling interest	1,514	(28)	1,446	523	(2,256)	1,870	760	1,052	3,455	1,426	4,996
Net income attributable to the redeemable noncontrolling interests	(20,038)	(36,216)	(16,300)	(12,022)	(25,662)	(22,702)	(13,068)	(4,314)	(84,576)	(65,746)	26,543
Preferred stock dividends	(1,172)	(1,172)	(1,015)	(1,016)	(1,016)	(1,016)	(1,015)	(1,016)	(4,375)	(4,063)	(4,063)
Net income attributable to Leucadia National Corporation common shareholders	$ (271,601)	$ 99,351	$ 58,193	$ 281,408	$ 137,171	$ 154,358	$ 57,289	$ (222,880)	$ 167,351	$ 125,938	$ 279,587
Income (loss) from continuing operations (USD per share)									$ 0.45	$ 0.34	$ 0.73
Income (loss) from discontinued operations (USD per share)									0	0	0
Gain (loss) on disposal of discontinued operations (USD per share)									0	0	0.01
Net income (loss) (USD per share)	$ (0.74)	$ 0.27	$ 0.16	$ 0.76	$ 0.37	$ 0.41	$ 0.15	$ (0.60)	$ 0.45	$ 0.34	$ 0.74
Number of shares used in calculation - basic (shares)	366,000	367,828	369,212	369,267	369,299	370,404	372,556	372,367	368,197	371,211	372,430
Income (loss) from continuing operations (USD per share)									$ 0.45	$ 0.34	$ 0.73
Income (loss) from discontinued operations (USD per share)									0	0	0
Gain (loss) on disposal of discontinued operations - diluted (USD per share)									0	0	0.01
Net income (USD per share)	$ (0.74)	$ 0.27	$ 0.16	$ 0.75	$ 0.37	$ 0.41	$ 0.15	$ (0.60)	$ 0.45	$ 0.34	$ 0.74
Number of shares used in calculation (shares)	366,000	370,198	371,552	375,721	374,693	374,567	372,556	372,367	370,701	371,518	372,431
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of subsidiaries									$ 179,605	$ 0	$ 0
Discrete tax expense related to Tax Cuts and Jobs Act of 2017	$ 450,500								450,500
Discrete tax expense related to revaluation of deferred tax asset	415,000								415,000	0	0
Discrete tax expense related to deemed repatriation of foreign earnings	$ 35,500								35,500	$ 0	$ 0
Conwed | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of subsidiaries				$ 179,900					$ 178,236
Investment in HRG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Changes in fair value of investments reflected as principal transactions		$ (97,900)	$ (75,000)	175,200		$ 91,800
Investment in FXCM
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Changes in fair value of investments reflected as principal transactions						42,700	$ (47,900)	$ (53,200)
Equity method investment impairment				$ 130,200
Corporate trading assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Changes in fair value of investments reflected as principal transactions								65,600
Jefferies | Investment in equity block positions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Changes in fair value of investments reflected as principal transactions								$ (82,200)
Jefferies | Investment in KCG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Changes in fair value of investments reflected as principal transactions			$ 95,800				$ 55,800
JETX Energy, LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of oil and gas properties						$ 55,000

Schedule I - Condensed Finan163

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents		$ 5,275,480		$ 3,807,558		$ 3,638,648	$ 4,276,775
Financial instruments owned, including securities pledged of $10,842,051 and $9,706,881:
Trading assets, at fair value		15,512,730		14,985,237
Available for sale securities		716,561		301,049
Total financial instruments owned		16,229,291		15,286,286
Loans to and investments in associated companies		2,066,829		2,125,098
Deferred tax asset, net		743,811		1,461,815
Other assets		1,661,777		1,635,664
Total assets		47,169,108	[1]	45,071,307	[1]	46,331,184
LIABILITIES
Payables, expense accruals and other liabilities		7,167,666		7,373,708
Long-term debt		7,885,783		7,380,443
Total liabilities	[1]	36,478,536		34,305,849
Commitments and contingencies
MEZZANINE EQUITY
Mandatorily redeemable convertible preferred shares		125,000		125,000
EQUITY
Common shares, par value $1 per share, authorized 600,000,000 shares; 356,227,038 and 359,425,061 shares issued and outstanding, after deducting 60,165,980 and 56,947,654 shares held in treasury		356,227		359,425
Additional paid-in capital		4,676,038		4,812,587
Accumulated other comprehensive income		372,724		310,697
Retained earnings		4,700,968		4,645,391
Total Leucadia National Corporation shareholders’ equity		10,105,957		10,128,100
Total		47,169,108		45,071,307
Parent Company
ASSETS
Cash and cash equivalents		12,317		105,222		$ 353	$ 81
Financial instruments owned, including securities pledged of $10,842,051 and $9,706,881:
Trading assets, at fair value		200,804		223,218
Available for sale securities		16,378		15,635
Total financial instruments owned		217,182		238,853
Investments in subsidiaries		18,615,819		18,412,037
Advances to subsidiaries		542,976		235,879
Loans to and investments in associated companies		288,382		273,518
Deferred tax asset, net		205,773		346,684
Other assets		8,815		13,993
Total assets		19,891,264		19,626,186
LIABILITIES
Accrued interest payable		11,447		11,447
Pension liabilities		52,841		69,152
Payables, expense accruals and other liabilities		31,919		39,284
Advances from subsidiaries		8,575,079		8,265,312
Long-term debt		989,021		987,891
Total liabilities		9,660,307		9,373,086
Commitments and contingencies
MEZZANINE EQUITY
Mandatorily redeemable convertible preferred shares		125,000		125,000
EQUITY
Common shares, par value $1 per share, authorized 600,000,000 shares; 356,227,038 and 359,425,061 shares issued and outstanding, after deducting 60,165,980 and 56,947,654 shares held in treasury		356,227		359,425
Additional paid-in capital		4,676,038		4,812,587
Accumulated other comprehensive income		372,724		310,697
Retained earnings		4,700,968		4,645,391
Total Leucadia National Corporation shareholders’ equity		10,105,957		10,128,100
Total		$ 19,891,264		$ 19,626,186
[1]	Total assets include assets related to variable interest entities of $382.9 million and $815.8 million at December 31, 2017 and 2016, respectively, and Total liabilities include liabilities related to variable interest entities of $1,031.0 million and $1,284.7 million at December 31, 2017 and 2016, respectively. See Note 9 for additional information related to variable interest entities.

Schedule I - Condensed Finan164

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Financial Condition, Additional Information (Details) - $ / shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Common shares, par value (USD per share)	$ 1	$ 1	$ 1
Common shares, authorized	600,000,000	600,000,000
Common shares, issued and outstanding after deducting shares held in treasury	356,227,038	359,425,061
Treasury stock, shares	60,165,980	56,947,654
Parent Company
Condensed Balance Sheet Statements, Captions [Line Items]
Common shares, par value (USD per share)	$ 1	$ 1
Common shares, authorized	600,000,000	600,000,000
Common shares, issued and outstanding after deducting shares held in treasury	356,227,038	359,425,061
Treasury stock, shares	60,165,980	56,947,654

Schedule I - Condensed Finan165

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Principal transactions									$ 931,576	$ 603,822	$ 642,824
Other									748,508	488,186	549,228
Total revenues									12,407,854	10,875,254	11,683,927
Expenses:
Compensation and benefits									1,993,776	1,730,585	1,665,465
Interest									107,859	108,703	115,804
Selling, general and other expenses									817,620	831,892	757,788
Total expenses									10,347,678	9,900,785	10,640,203
Income (loss) related to associated companies									(74,901)	154,598	110,281
Income tax provision (benefit)									760,967	122,109	109,947
Income from continuing operations									167,351	125,938	274,065
Preferred stock dividends	$ (1,172)	$ (1,172)	$ (1,015)	$ (1,016)	$ (1,016)	$ (1,016)	$ (1,015)	$ (1,016)	(4,375)	(4,063)	(4,063)
Net income attributable to Leucadia National Corporation common shareholders	$ (271,601)	$ 99,351	$ 58,193	$ 281,408	$ 137,171	$ 154,358	$ 57,289	$ (222,880)	$ 167,351	$ 125,938	$ 279,587
Basic earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)									$ 0.45	$ 0.34	$ 0.73
Income from discontinued operations (USD per share)									0	0	0
Gain on disposal of discontinued operations (USD per share)									0	0	0.01
Net income (USD per share)	$ (0.74)	$ 0.27	$ 0.16	$ 0.76	$ 0.37	$ 0.41	$ 0.15	$ (0.60)	0.45	0.34	0.74
Diluted earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)									0.45	0.34	0.73
Income from discontinued operations (USD per share)									0	0	0
Gain on disposal of discontinued operations (USD per share)									0	0	0.01
Net income (USD per share)	$ (0.74)	$ 0.27	$ 0.16	$ 0.75	$ 0.37	$ 0.41	$ 0.15	$ (0.60)	0.45	0.34	0.74
Dividends per common share (USD per share)									$ 0.3250	$ 0.25	$ 0.25
Parent Company
Revenues:
Principal transactions									$ (9,754)	$ 16,735	$ 491,341
Other									277	2,300	1,477
Total revenues									(9,477)	19,035	492,818
Expenses:
Compensation and benefits									47,462	39,693	58,899
WilTel pension									2,957	2,989	50,836
Interest									58,943	58,881	87,181
Intercompany interest expense									361,446	293,527	241,906
Selling, general and other expenses									20,821	19,244	26,784
Total expenses									491,629	414,334	465,606
Income (loss) from continuing operations before income taxes, income related to associated companies and equity in earnings of subsidiaries									(501,106)	(395,299)	27,212
Income (loss) related to associated companies									3,183	21,195	3,479
Income (loss) from continuing operations before income taxes and equity in earnings of subsidiaries									(497,923)	(374,104)	30,691
Income tax provision (benefit)									(47,329)	(117,699)	267
Income (loss) from continuing operations before equity in earnings of subsidiaries									(450,594)	(256,405)	30,424
Equity in earnings of subsidiaries, net of taxes									622,320	386,406	247,704
Income from continuing operations									171,726	130,001	278,128
Equity in income from discontinued operations, net of taxes									0	0	429
Equity in gain on disposal of discontinued operations, net of taxes									0	0	5,093
Net income									171,726	130,001	283,650
Preferred stock dividends									(4,375)	(4,063)	(4,063)
Net income attributable to Leucadia National Corporation common shareholders									$ 167,351	$ 125,938	$ 279,587
Basic earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)									$ 0.45	$ 0.34	$ 0.73
Income from discontinued operations (USD per share)									0	0	0
Gain on disposal of discontinued operations (USD per share)									0	0	0.01
Net income (USD per share)									0.45	0.34	0.74
Diluted earnings per common share attributable to Leucadia National Corporation common shareholders:
Income from continuing operations (USD per share)									0.45	0.34	0.73
Income from discontinued operations (USD per share)									0	0	0
Gain on disposal of discontinued operations (USD per share)									0	0	0.01
Net income (USD per share)									0.45	0.34	0.74
Dividends per common share (USD per share)									$ 0.325	$ 0.250	$ 0.250

Schedule I - Condensed Finan166

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other comprehensive income (loss):
Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $3,450, $2,262 and $(5,029)									$ 5,923	$ 3,900	$ (9,057)
Less: reclassification adjustment for net (gains) losses included in net income, net of income tax provision (benefit) of $124, $2 and $6,068									(212)	(4)	(10,930)
Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $3,326, $2,260 and $(11,097)									5,711	3,896	(19,987)
Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $14,616, $(3,530) and $(5,174)									78,493	(121,581)	(36,477)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income, net of income tax provision (benefit) of $1,086, $0 and $0									5,310	0	0
Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $13,530, $(3,530) and $(5,174)									83,803	(121,581)	(36,477)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, net of income tax provision (benefit) of $(13,215), $(4,251) and $0									(21,394)	(6,494)	0
Net change in unrealized instrument specific credit risk gains (losses), net of income tax provision (benefit) of $(13,215), $(4,251) and $0									(21,394)	(6,494)	0
Net unrealized gains (losses) on cash flow hedges arising during the period, net of income tax provision (benefit) of $(593), $0 and $0									(936)	0	0
Net change in unrealized cash flow hedges gains (losses), net of income tax provision (benefit) of $(593), $0 and $0									(936)	0	0
Net pension gains (losses) arising during the period, net of income tax provision (benefit) of $2,018, $(2,516) and $7,152									3,526	(5,451)	17,073
Less: reclassification adjustment for pension (gains) losses included in net income, net of income tax provision (benefit) of $(2,042), $(700) and $(17,159)									517	1,534	31,102
Net change in pension liability benefits, net of income tax provision (benefit) of $4,060, $(1,816) and $24,311									4,043	(3,917)	48,175
Other comprehensive income (loss), net of income taxes									71,227	(128,096)	(8,289)
Preferred stock dividends	$ (1,172)	$ (1,172)	$ (1,015)	$ (1,016)	$ (1,016)	$ (1,016)	$ (1,015)	$ (1,016)	(4,375)	(4,063)	(4,063)
Comprehensive income (loss) attributable to Leucadia National Corporation common shareholders									238,578	(2,158)	271,298
Parent Company
Condensed Statement of Income Captions [Line Items]
Net income									171,726	130,001	283,650
Other comprehensive income (loss):
Net unrealized holding gains (losses) on investments arising during the period, net of income tax provision (benefit) of $3,450, $2,262 and $(5,029)									5,923	3,900	(9,057)
Less: reclassification adjustment for net (gains) losses included in net income, net of income tax provision (benefit) of $124, $2 and $6,068									(212)	(4)	(10,930)
Net change in unrealized holding gains (losses) on investments, net of income tax provision (benefit) of $3,326, $2,260 and $(11,097)									5,711	3,896	(19,987)
Net unrealized foreign exchange gains (losses) arising during the period, net of income tax provision (benefit) of $14,616, $(3,530) and $(5,174)									78,493	(121,581)	(36,477)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income, net of income tax provision (benefit) of $1,086, $0 and $0									5,310	0	0
Net change in unrealized foreign exchange gains (losses), net of income tax provision (benefit) of $13,530, $(3,530) and $(5,174)									83,803	(121,581)	(36,477)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, net of income tax provision (benefit) of $(13,215), $(4,251) and $0									(21,394)	(6,494)	0
Net change in unrealized instrument specific credit risk gains (losses), net of income tax provision (benefit) of $(13,215), $(4,251) and $0									(21,394)	(6,494)	0
Net unrealized gains (losses) on cash flow hedges arising during the period, net of income tax provision (benefit) of $(593), $0 and $0									(936)	0	0
Net change in unrealized cash flow hedges gains (losses), net of income tax provision (benefit) of $(593), $0 and $0									(936)	0	0
Net pension gains (losses) arising during the period, net of income tax provision (benefit) of $2,018, $(2,516) and $7,152									3,526	(5,451)	17,073
Less: reclassification adjustment for pension (gains) losses included in net income, net of income tax provision (benefit) of $(2,042), $(700) and $(17,159)									517	1,534	31,102
Net change in pension liability benefits, net of income tax provision (benefit) of $4,060, $(1,816) and $24,311									4,043	(3,917)	48,175
Other comprehensive income (loss), net of income taxes									71,227	(128,096)	(8,289)
Comprehensive income									242,953	1,905	275,361
Preferred stock dividends									(4,375)	(4,063)	(4,063)
Comprehensive income (loss) attributable to Leucadia National Corporation common shareholders									$ 238,578	$ (2,158)	$ 271,298

Schedule I - Condensed Finan167

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Comprehensive Income (Loss), Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Statement of Income Captions [Line Items]
Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit)	$ 3,450	$ 2,262	$ (5,029)
Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit)	(124)	(2)	(6,068)
Net change in unrealized holding gains (losses) on investments, tax provision (benefit)	3,326	2,260	(11,097)
Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit)	14,616	(3,530)	(5,174)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit)	(1,086)	0	0
Net change in unrealized foreign exchange gains (losses), tax provision (benefit)	13,530	(3,530)	(5,174)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, income tax provision (benefit)	(13,215)	(4,251)	0
Net change in unrealized instrument specific credit risk gains (losses), income tax provision (benefit)	(13,215)	(4,251)	0
Net unrealized gains (losses) on derivatives arising during the period, tax provision (benefit)	(593)	0	0
Net change in unrealized derivative gains (losses), tax provision (benefit)	(593)	0	0
Net pension and postretirement gains (losses) arising during the period, tax provision (benefit)	2,018	(2,516)	7,152
Less: reclassification adjustment for pension and postretirement (gains) losses included in net income (loss), tax provision (benefit)	(2,042)	(700)	(17,159)
Net change in pension liability and postretirement benefits, tax provision (benefit)	4,060	(1,816)	24,311
Parent Company
Condensed Statement of Income Captions [Line Items]
Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit)	3,450	2,262	(5,029)
Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit)	(124)	(2)	(6,068)
Net change in unrealized holding gains (losses) on investments, tax provision (benefit)	3,326	2,260	(11,097)
Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit)	14,616	(3,530)	(5,174)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit)	(1,086)	0	0
Net change in unrealized foreign exchange gains (losses), tax provision (benefit)	13,530	(3,530)	(5,174)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, income tax provision (benefit)	(13,215)	(4,251)	0
Net change in unrealized instrument specific credit risk gains (losses), income tax provision (benefit)	(13,215)	(4,251)	0
Net unrealized gains (losses) on derivatives arising during the period, tax provision (benefit)	(593)	0	0
Net change in unrealized derivative gains (losses), tax provision (benefit)	(593)	0	0
Net pension and postretirement gains (losses) arising during the period, tax provision (benefit)	2,018	(2,516)	7,152
Less: reclassification adjustment for pension and postretirement (gains) losses included in net income (loss), tax provision (benefit)	(2,042)	(700)	(17,159)
Net change in pension liability and postretirement benefits, tax provision (benefit)	$ 4,060	$ (1,816)	$ 24,311

Schedule I - Condensed Finan168

Schedule I - Condensed Financial Information of Registrant - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adjustments to reconcile net income to net cash provided by (used for) operations:
Deferred income tax provision (benefit)	$ 712,055	$ 118,631	$ 131,042
Share-based compensation	48,384	33,597	74,087
Income related to associated companies	74,901	(154,598)	(110,281)
Distributions from associated companies	143,286	191,455	223,658
Change in estimated litigation reserve	0	0	(96,500)
Net change in:
Trading assets	(596,780)	2,687,399	1,380,230
Other assets	2,987	(283,234)	83,414
Trade payables, expense accruals and other liabilities	427,115	361,295	(225,711)
Other	236	(61,900)	(93,967)
Net cash provided by (used for) operating activities	1,072,832	608,847	(761,755)
Net cash flows from investing activities:
Advances on notes, loans and other receivables	(39,953)	(342,281)	(420,219)
Collections on notes, loans and other receivables	270,689	121,825	153,004
Loans to and investments in associated companies	(3,305,791)	(763,528)	(1,492,060)
Purchases of investments (other than short-term)	(1,146,595)	(739,298)	(873,831)
Other	1,339	978	(2,532)
Net cash provided by (used for) investing activities	(47,262)	(639,657)	781,165
Net cash flows from financing activities:
Repayment of debt	(1,401,104)	(962,515)	(1,316,494)
Issuance of common shares	1,501	1,062	1,223
Purchase of common shares for treasury	(100,477)	(95,020)	(125,754)
Dividends paid	(117,407)	(91,296)	(92,550)
Net cash provided by (used for) financing activities	434,801	230,906	(651,983)
Net increase (decrease) in cash and cash equivalents	1,467,922	168,910	(638,127)
Cash and cash equivalents at January 1,	3,807,558	3,638,648	4,276,775
Cash and cash equivalents at December 31,	5,275,480	3,807,558	3,638,648
Parent Company
Net cash flows from operating activities:
Net income	171,726	130,001	283,650
Adjustments to reconcile net income to net cash provided by (used for) operations:
Deferred income tax provision (benefit)	116,942	(12,220)	(2,457)
Accretion of interest	975	921	1,788
Share-based compensation	48,384	33,597	74,087
Equity in earnings of subsidiaries	(622,320)	(386,406)	(253,226)
Income related to associated companies	(3,183)	(21,195)	(3,479)
Distributions from associated companies	5,641	1,861	312
Change in estimated litigation reserve	0	0	(88,500)
Net change in:
Trading assets	22,415	(40,235)	(615,768)
Other assets	1,250	(708)	(49,006)
Accrued interest payable	0	0	(10,982)
Pension liabilities	(8,461)	(13,111)	49,835
Trade payables, expense accruals and other liabilities	(7,763)	(23,218)	558
Income taxes receivable/payable, net	(164,684)	(90,898)	6,640
Other	2,316	1,262	5,110
Net cash provided by (used for) operating activities	(436,762)	(420,349)	(601,438)
Net cash flows from investing activities:
Investments in subsidiaries	(365,381)	(427,933)	(637,400)
Distributions from subsidiaries	753,193	868,612	119,695
Advances on notes, loans and other receivables	0	0	(279,000)
Collections on notes, loans and other receivables	0	16,233	144,652
Loans to and investments in associated companies	(45,457)	(11,611)	(8,101)
Capital distributions from associated companies	2,796	1,501	1,317
Purchases of investments (other than short-term)	(1,316)	(2,242)	(7,968)
Other	1,886	150	276
Net cash provided by (used for) investing activities	345,721	444,710	(666,529)
Net cash flows from financing activities:
Repayment of debt	0	0	(458,641)
Advances from (to) subsidiaries, net	214,519	265,762	1,943,961
Issuance of common shares	1,501	1,062	1,223
Purchase of common shares for treasury	(100,477)	(95,020)	(125,754)
Dividends paid	(117,407)	(91,296)	(92,550)
Net cash provided by (used for) financing activities	(1,864)	80,508	1,268,239
Net increase (decrease) in cash and cash equivalents	(92,905)	104,869	272
Cash and cash equivalents at January 1,	105,222	353	81
Cash and cash equivalents at December 31,	$ 12,317	$ 105,222	$ 353

Schedule I - Condensed Finan169

Schedule I - Condensed Financial Information of Registrant - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash paid during the year for:
Interest	$ 1,120,191	$ 957,140	$ 980,266
Income tax payments (refunds), net	15,361	(13,738)	510
Parent Company
Cash paid during the year for:
Interest	57,813	57,813	95,074
Income tax payments (refunds), net	1,440	(10,199)	(2,332)
Non-cash investing activities:
Investments contributed to subsidiary	25,328	423,009	0
Investments contributed to subsidiary	0	2,022	0
Dividends received from subsidiaries	$ 32,792	$ 0	$ 0

Schedule I - Condensed Finan170

Schedule I - Condensed Financial Information of Registrant - Transactions with Subsidiaries (Details) - Parent Company - USD ($)	2 Months Ended	12 Months Ended
	Feb. 15, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Intercompany loans		$ 0
Dividends received from subsidiaries		$ 32,792,000	$ 0	$ 0
Prime Rate
Schedule of Equity Method Investments [Line Items]
Basis spread on variable rate		0.125%
Subsequent Event
Schedule of Equity Method Investments [Line Items]
Dividends received from subsidiaries	$ 7,900,000,000
Decrease of investments in subsidiaries	7,900,000,000
Decrease of advances to subsidiaries	200,000,000
Decrease of advances from subsidiaries	$ 8,100,000,000

Schedule I - Condensed Finan171

Schedule I - Condensed Financial Information of Registrant - Restricted Net Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Registration Payment Arrangement [Line Items]
Undistributed earnings of unconsolidated subsidiaries	$ 202.9
Parent Company
Registration Payment Arrangement [Line Items]
Assets that may be restricted to the payment of cash dividends and advances	6,100	$ 6,000
Undistributed earnings of unconsolidated subsidiaries	202.9
Restricted Assets due to regulatory requirements or regulatory approvals [Member] | Parent Company
Registration Payment Arrangement [Line Items]
Assets that may be restricted to the payment of cash dividends and advances	$ 5,100	$ 4,800