Nature Of Operations (Details) $ / shares in Units, $ in Millions	Sep. 01, 2016 director	Sep. 30, 2016 USD ($) Dealership facility	Dec. 31, 2015	Nov. 08, 2015 $ / shares	Jan. 31, 2015 USD ($)
HomeFed Corporation [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		65.00%
Foursight Capital [Member]
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		100.00%
Chrome Capital [Member]
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		85.00%
National Beef [Member]
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		78.90%
HRG [Member]
Nature Of Operations [Line Items]
Percentage of outstanding common stock owned		23.00%	23.00%
Garcadia [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		75.00%
Number of automobile dealerships | Dealership		29
Vitesse Energy, LLC [Member]
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		96.00%
Juneau Energy, LLC [Member]
Nature Of Operations [Line Items]
Percentage interest owned in subsidiary		98.00%
Jefferies LoanCore [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		48.50%
Jefferies Finance [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		50.00%
FXCM [Member]
Nature Of Operations [Line Items]
Senior secured term loan receivable | $		$ 192.5			$ 300.0
Berkadia [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		50.00%
Linkem [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		42.00%
Percentage of ownership upon conversion of note		56.00%
Golden Queen Mining Company, LLC [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned		35.00%
Tanning Facility [Member] | National Beef [Member]
Nature Of Operations [Line Items]
Domestic facilities | facility		1
Beef Processing Facility [Member] | National Beef [Member]
Nature Of Operations [Line Items]
Domestic facilities | facility		2
Consumer-Ready Facility [Member] | National Beef [Member]
Nature Of Operations [Line Items]
Domestic facilities | facility		3
Product Segment [Member] | Spectrum Brands [Member]
Nature Of Operations [Line Items]
Percentage of outstanding common stock owned		58.00%
Insurance Segment [Member] | Fidelity & Guaranty Life [Member]
Nature Of Operations [Line Items]
Percentage of outstanding common stock owned		81.00%
Anbang Insurance Group Co Ltd [Member] | Fidelity & Guaranty Life [Member]
Nature Of Operations [Line Items]
Business acquisition, share price (in USD per share) | $ / shares				$ 26.80
FXCM Term Loan Receivable [Member]
Nature Of Operations [Line Items]
Senior secured loan, extension term	1 year
Investment in FXCM [Member]
Nature Of Operations [Line Items]
Percentage of ownership owned	49.90%	49.90%
Number of directors appointed	8
Number of directors appointed by Company	3
Number of directors appointed by Co-Investee	3
Number of independent directors	2