Consolidated Statements of Operations - USD ($) $ in Thousands	11 Months Ended	12 Months Ended
	Nov. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Revenues	$ 5,009,728	$ 5,048,906	$ 3,848,011
Interest expense	89,249	101,202	95,757
Net revenues	3,764,034	4,077,445	3,035,374
Expenses:
Compensation and benefits	1,862,782	1,950,935	1,688,325
Cost of sales	307,071	280,952	337,039
Floor brokerage and clearing fees	184,210	174,506	167,205
Interest expense	89,249	101,202	95,757
Depreciation and amortization	120,317	110,395	117,111
Selling, general and other expenses	961,328	778,052	797,127
Total expenses	3,524,957	3,396,042	3,202,564
Income (loss) from continuing operations before income taxes and income (loss) related to associated companies	239,077	681,403	(167,190)
Income (loss) related to associated companies	57,023	(74,901)	154,598
Income (loss) from continuing operations before income taxes	296,100	606,502	(12,592)
Income tax provision	19,008	642,286	25,773
Income (loss) from continuing operations	277,092	(35,784)	(38,365)
Income from discontinued operations, net of income tax provision of $47,045, $118,681 and $96,336	130,063	288,631	232,686
Gain on disposal of discontinued operations, net of income tax provision of $229,553, $0 and $0	643,921	0	0
Net income	1,051,076	252,847	194,321
Net loss attributable to the noncontrolling interests	12,975	3,455	1,426
Net income attributable to the redeemable noncontrolling interests	(37,263)	(84,576)	(65,746)
Preferred stock dividends	(4,470)	(4,375)	(4,063)
Net income attributable to Jefferies Financial Group Inc. common shareholders	$ 1,022,318	$ 167,351	$ 125,938
Basic earnings (loss) per common share attributable to Jefferies Financial Group Inc. common shareholders:
Income (loss) from continuing operations (USD per share)	$ 0.82	$ (0.10)	$ (0.10)
Income from discontinued operations (USD per share)	0.27	0.55	0.44
Gain on disposal of discontinued operations (USD per share)	1.84	0.00	0.00
Net income (USD per share)	2.93	0.45	0.34
Diluted earnings (loss) per common share attributable to Jefferies Financial Group Inc. common shareholders:
Income (loss) from continuing operations (USD per share)	0.81	(0.10)	(0.10)
Income from discontinued operations (USD per share)	0.26	0.55	0.44
Gain on disposal of discontinued operations (USD per share)	1.83	0.00	0.00
Net income (USD per share)	$ 2.90	$ 0.45	$ 0.34
Amounts attributable to Jefferies Financial Group Inc. common shareholders:
Income (loss) from continuing operations, net of taxes	$ 285,475	$ (36,003)	$ (37,937)
Income from discontinued operations, net of taxes	92,922	203,354	163,875
Gain on disposal of discontinued operations, net of taxes	643,921	0	0
Net income attributable to Jefferies Financial Group Inc. common shareholders	1,022,318	167,351	125,938
Commissions and other fees
Revenues:
Revenues	634,271	593,257	611,574
Principal transactions
Revenues:
Revenues	232,224	923,418	534,784
Investment banking
Revenues:
Revenues	1,904,870	1,764,285	1,193,973
Interest income
Revenues:
Revenues	1,294,325	993,198	926,089
Manufacturing revenues
Revenues:
Revenues	357,427	326,197	412,826
Other
Revenues:
Revenues	586,611	448,551	168,765
Jefferies Group
Revenues:
Interest expense	1,245,694	971,461	812,637
Net revenues	3,183,376	3,198,109	2,414,614
Expenses:
Interest expense	$ 1,245,694	$ 971,461	$ 812,637