Employee Benefit Plans - Components of Net Periodic Benefit Cost and Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Other Postretirement Benefits Plan
Components of net periodic benefit cost
Service cost	$ 760	$ 1,388	$ 1,195
Interest cost	829	1,194	943
Amortization of net loss	(630)	(196)	(500)
Net periodic benefit cost	(798)	629	(119)
Other changes recognized in OCI
Net loss	(2,377)	(4,259)
Amortization of net loss	630	196
Amortization of prior service (cost) credit	1,757	1,757
Total recognized in OCI	10	(2,306)
Net periodic benefit cost (credit)	(798)	629	$ (119)
Total recognized in net periodic benefit cost and OCI	(788)	(1,677)
Farmer Brothers Plan
Components of net periodic benefit cost
Service cost	0	0
Interest cost	5,277	5,875
Expected return on plan assets	(6,067)	(6,470)
Amortization of net loss	1,875	1,411
Net periodic benefit cost	1,085	816
Other changes recognized in OCI
Net loss	(9,363)	20,913
Amortization of net loss	(1,875)	(1,411)
Total recognized in OCI	(11,238)	19,502
Net periodic benefit cost (credit)	1,085	816
Total recognized in net periodic benefit cost and OCI	$ (10,153)	$ 20,318
Weighted average assumptions used to determine benefit obligations
Discount rate	3.55%	4.40%
Expected long-term return on plan assets	7.75%	7.50%
Brewmatic Plan
Components of net periodic benefit cost
Service cost	$ 0	$ 0
Interest cost	157	172
Expected return on plan assets	(188)	(219)
Amortization of net loss	102	68
Net periodic benefit cost	71	21
Other changes recognized in OCI
Net loss	(519)	859
Amortization of net loss	(102)	(68)
Total recognized in OCI	(621)	791
Net periodic benefit cost (credit)	71	21
Total recognized in net periodic benefit cost and OCI	$ (550)	$ 812
Weighted average assumptions used to determine benefit obligations
Discount rate	3.55%	4.40%
Expected long-term return on plan assets	7.75%	7.50%
Hourly Employees’ Plan
Components of net periodic benefit cost
Service cost	$ 124	$ 389
Interest cost	152	137
Expected return on plan assets	(172)	(149)
Amortization of net loss	53	0
Net periodic benefit cost	157	377
Other changes recognized in OCI
Net loss	(317)	750
Amortization of net loss	(53)	0
Total recognized in OCI	(370)	750
Net periodic benefit cost (credit)	157	377
Total recognized in net periodic benefit cost and OCI	$ (213)	$ 1,127
Weighted average assumptions used to determine benefit obligations
Discount rate	3.55%	4.40%
Expected long-term return on plan assets	7.75%	7.50%