Employee Benefit Plans - Components of Net Periodic Benefit Cost and Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Other changes recognized in OCI
Amortization of net gain (loss)				$ (600)
Postretirement Benefits Other Than Pension
Components of net periodic benefit cost
Service cost	$ 1,388	$ 1,195	$ 1,388	1,195	$ 936
Interest cost	$ 1,194	$ 943	1,194	943	810
Amortization of net loss (gain)			(196)	(500)	(880)
Net periodic benefit (credit) cost			629	(119)	$ (891)
Other changes recognized in OCI
Total recognized in OCI			(2,306)	5,008
Total recognized in net periodic benefit cost and OCI			(1,677)	4,889
Farmer Brothers Plan
Components of net periodic benefit cost
Service cost			0	0
Interest cost			5,875	5,393
Expected return on plan assets			(6,470)	(6,938)
Amortization of net loss (gain)			1,411	1,153
Net periodic benefit (credit) cost			816	(392)
Other changes recognized in OCI
Net (gain)/loss			20,913	9,803
Amortization of net gain (loss)			(1,411)	(1,153)
Total recognized in OCI			19,502	8,650
Total recognized in net periodic benefit cost and OCI			$ 20,318	$ 8,258
Weighted average assumptions used to determine benefit obligations
Discount rate			4.40%	4.15%
Expected long-term return on plan assets			7.50%	7.50%
Brewmatic Plan
Components of net periodic benefit cost
Service cost			$ 0	$ 0
Interest cost			172	160
Expected return on plan assets			(219)	(234)
Amortization of net loss (gain)			68	57
Net periodic benefit (credit) cost			21	(17)
Other changes recognized in OCI
Net (gain)/loss			859	356
Amortization of net gain (loss)			(68)	(57)
Total recognized in OCI			791	299
Total recognized in net periodic benefit cost and OCI			$ 812	$ 282
Weighted average assumptions used to determine benefit obligations
Discount rate			4.40%	4.15%
Expected long-term return on plan assets			7.50%	7.50%
Hourly Employees’ Plan
Components of net periodic benefit cost
Service cost			$ 389	$ 386
Interest cost			137	108
Expected return on plan assets			(149)	(119)
Amortization of net loss (gain)			0	0
Net periodic benefit (credit) cost			377	375
Other changes recognized in OCI
Net (gain)/loss			750	165
Amortization of net gain (loss)			0	0
Total recognized in OCI			750	165
Total recognized in net periodic benefit cost and OCI			$ 1,127	$ 540
Weighted average assumptions used to determine benefit obligations
Discount rate			4.40%	4.15%
Expected long-term return on plan assets			7.50%	7.50%