Employee Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Farmer Brothers Plan
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	$ 97,211	$ 97,304	$ 91,201
Farmer Brothers Plan | Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Farmer Brothers Plan | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Farmer Brothers Plan | Level 3
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Farmer Brothers Plan | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	97,211	97,304
Brewmatic Plan
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	3,719	3,115	2,989
Brewmatic Plan | Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Brewmatic Plan | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Brewmatic Plan | Level 3
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Brewmatic Plan | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	3,719	3,115
Hourly Employees’ Plan
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	3,629	2,999	$ 2,447
Hourly Employees’ Plan | Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Hourly Employees’ Plan | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Hourly Employees’ Plan | Level 3
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	0	0
Hourly Employees’ Plan | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure
Fair value of plan assets at measurement date	$ 3,629	$ 2,999