Debt (Schedule of Lines of Credit Outstanding) (Details) - USD ($) $ in Thousands	May 03, 2016	Dec. 15, 2015	Dec. 31, 2018	Dec. 31, 2017	Jul. 30, 2015
Line of Credit Facility [Line Items]
Long-term Line of Credit			$ 200,386	$ 105,773
Debt Issuance Costs, Net			(1,614)	(1,227)
Inwood National Bank
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 75,000		$ 50,000
Line of Credit Facility, Interest Rate at Period End			5.25%
Inwood National Bank | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit			$ 46,500	32,000
BorrowingBaseLimitationTotalValueOfland	50.00%
BorrowingBaseLimitationTotalValueOfLotsOwned	65.00%
MaximumValueOfLandUsedWhenCalculatingBorrowingBase	65.00%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Citibank, N.A., Credit Suisse AG, Cayman Islands Branch, Flagstar Bank, JP Morgan Chase and Chemical Bank [Member] | Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit			$ 155,500	$ 75,000
Minimum | Citibank, N.A., Credit Suisse AG, Cayman Islands Branch, Flagstar Bank, JP Morgan Chase and Chemical Bank [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End			4.89%
Minimum | Subsidiary of JBGL | Inwood National Bank | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Stated interest rate					4.00%
Maximum | Citibank, N.A., Credit Suisse AG, Cayman Islands Branch, Flagstar Bank, JP Morgan Chase and Chemical Bank [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End			5.01%
Maximum | Subsidiary of JBGL | Inwood National Bank | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Stated interest rate					18.00%
Unsecured Debt [Member] | Citibank, N.A., Credit Suisse AG, Cayman Islands Branch, Flagstar Bank, JP Morgan Chase and Chemical Bank [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.45%
Unrestricted Cash Borrowing Base Limitation		100.00%
Borrowing Base Limitation for Unrestricted Cash		$ 15,000
Book Value of Model Homes Borrowing Base		85.00%
Book Value of Finished Lots and Land Under Development		65.00%
Book Value of Entitled Land		50.00%