Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Sep. 12, 2018	Dec. 29, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2018
Trading Symbol	FARM
Entity Registrant Name	FARMER BROTHERS CO
Entity Central Index Key	0000034563
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		16,954,368
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 337.6