Share-Based Compensation - Stock Option Activity (Details) - USD ($) | 3 Months Ended | 6 Months Ended | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Jun. 30, 2017 | Dec. 31, 2017 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Proceeds from stock option exercises | | | $ 625,000 | $ 405,000 | | |
NQOs | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | | | 12,000 | | | |
Proceeds from stock option exercises | | | $ 500,000 | 400,000 | | |
NQOs | Vested | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] | | | | | | |
Number of options - Beginning balance (in shares) | | | 133,464 | | | |
Number of options - Ending balance (in shares) | | | | | 133,464 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] | | | | | | |
Weighted Average Exercise Price, Beginning balance (in US$ per share) | | | $ 13.05 | | | |
Weighted Average Exercise Price, Ending balance (in US$ per share) | | | | | $ 13.05 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] | | | | | | |
Weighted Average Grant Date Fair Value, Beginning balance (in US$ per share) | | | 5.99 | | | |
Weighted Average Grant Date Fair Value, Ending balance (in US$ per share) | | | | | $ 5.99 | |
Weighted Average Remaining Life, Beginning balance | | | | | 2 years 7 months 6 days | |
Weighted Average Remaining Life, Ending balance | | | | | 2 years 7 months 6 days | |
Aggregate Intrinsic Value, Beginning balance | | | | | $ 2,299,000 | |
Aggregate Intrinsic Value, Ending balance | | | | | $ 2,299,000 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] | | | | | | |
Options, Vested and exercisable, Outstanding (in shares) | | | | | | 89,055 |
Options, Vested and exercisable, Weighted Average Exercise Price (in US$ per share) | | | | | | $ 12.33 |
Options, Vested and exercisable, Weighted Average Grant Date Fair Value (in US$ per share) | | | $ 5.74 | | | |
Options, Vested and exercisable, Weighted Average Remaining Contractual Term | | | 2 years | | | |
Options, Vested and exercisable, Aggregate Intrinsic Value | | | | | | $ 1,765,000 |
Options, Vested and expected to vest, Outstanding (in shares) | | | | | | 205,308 |
Options, Vested and expected to vest, Weighted Average Exercise Price (in US$ per share) | | | | | | $ 23.28 |
Options, Vested and expected to vest, Weighted Average Grant Date Fair Value (in US$ per share) | | | $ 8.41 | | | |
Options, Vested and expected to vest, Exercisable, Weighted Average Remaining Life | | | 4 years 8 months 12 days | | | |
Options, Vested and expected to vest, Aggregate Intrinsic Value | | | | | | $ 1,820,000 |
NQOs | 2017 Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] | | | | | | |
Number of options granted (shares) | | | 124,278 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] | | | | | | |
Weighted average purchase price (in US$ per share) | | | $ 31.70 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] | | | | | | |
Weighted average fair value (in US$ per share) | | | $ 10.41 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Remaining Contractual Term | | | 6 years 10 months 24 days | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value | | | $ 0 | | | |
NQOs | Farmer Bros. Co. Amended and Restated 2007 Long-term Incentive Plan | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares | | | (945) | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] | | | | | | |
Number of options exercised (shares) | | | (37,266) | | | |
Number of options cancelled/forfeited (shares) | | | (4,194) | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] | | | | | | |
Weighted Average Exercise Price, Exercised (in US$ per share) | | | $ 12.09 | | | |
Weighted Average Exercise Price, Cancelled/Forfeited (in US$ per share) | | | 24.41 | | | |
Weighted Average Exercise Price, Ending balance (in US$ per share) | $ 23.71 | | 23.71 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] | | | | | | |
Weighted average fair value (in US$ per share) | | | 31.70 | | | |
Weighted Average Grant Date Fair Value, Exercised (in US$ per share) | | | 5.57 | | | |
Weighted Average Grant Date Fair Value, Cancelled/Forfeited (in US$ per share) | | | 10.60 | | | |
Weighted Average Grant Date Fair Value, Ending balance (in US$ per share) | $ 8.51 | | $ 8.51 | | | |
Weighted Average Remaining Life, Beginning balance | | | 4 years 9 months 18 days | | | |
Weighted Average Remaining Life, Ending balance | | | 4 years 9 months 18 days | | | |
Aggregate Intrinsic Value, Beginning balance | $ 1,825,000 | | $ 1,825,000 | | | $ 1,825,000 |
Aggregate intrinsic value, exercised | | | 752,000 | | | |
Aggregate Intrinsic Value, Cancelled/Forfeited | | | 0 | | | |
Aggregate Intrinsic Value, Ending balance | 1,825,000 | | 1,825,000 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] | | | | | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | | | | | | 216,282 |
PNQs | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | | | 600,000 | | | |
Proceeds from stock option exercises | | | $ 200,000 | 100,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] | | | | | | |
Weighted Average Remaining Life, Beginning balance | | | 4 years 6 months 22 days | | | |
Weighted Average Remaining Life, Ending balance | | | 4 years 6 months 22 days | | | |
PNQs | Farmer Bros. Co. Amended and Restated 2007 Long-term Incentive Plan | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Compensation expense recognized | $ 200,000 | $ 400,000 | $ 400,000 | 600,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares | | | (56,822) | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] | | | | | | |
Number of options - Beginning balance (in shares) | | | 358,786 | | | |
Number of options granted (shares) | | | 0 | | | |
Number of options exercised (shares) | | | (6,679) | | | |
Number of options cancelled/forfeited (shares) | | | (43,330) | | | |
Number of options - Ending balance (in shares) | 308,777 | | 308,777 | | 358,786 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] | | | | | | |
Weighted Average Exercise Price, Beginning balance (in US$ per share) | | | $ 27.75 | | | |
Weighted average purchase price (in US$ per share) | | | 0 | | | |
Weighted Average Exercise Price, Exercised (in US$ per share) | | | 26.10 | | | |
Weighted Average Exercise Price, Cancelled/Forfeited (in US$ per share) | | | 32.10 | | | |
Weighted Average Exercise Price, Ending balance (in US$ per share) | $ 27.17 | | 27.17 | | $ 27.75 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] | | | | | | |
Weighted Average Grant Date Fair Value, Beginning balance (in US$ per share) | | | 10.96 | | | |
Weighted average fair value (in US$ per share) | | | 0 | | | |
Weighted Average Grant Date Fair Value, Exercised (in US$ per share) | | | 10.87 | | | |
Weighted Average Grant Date Fair Value, Cancelled/Forfeited (in US$ per share) | | | 11.43 | | | |
Weighted Average Grant Date Fair Value, Ending balance (in US$ per share) | $ 10.90 | | $ 10.90 | | $ 10.96 | |
Weighted Average Remaining Life, Beginning balance | | | | | 5 years 2 months 9 days | |
Weighted Average Remaining Life, Ending balance | | | | | 5 years 2 months 9 days | |
Aggregate Intrinsic Value, Beginning balance | $ 1,590,000 | | $ 1,590,000 | | $ 1,181,000 | $ 1,590,000 |
Aggregate intrinsic value, exercised | | | 45,000 | | | |
Aggregate Intrinsic Value, Cancelled/Forfeited | | | 0 | | | |
Aggregate Intrinsic Value, Ending balance | 1,590,000 | | $ 1,590,000 | | $ 1,181,000 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] | | | | | | |
Options, Vested and exercisable, Outstanding (in shares) | | | | | | 200,904 |
Options, Vested and exercisable, Weighted Average Exercise Price (in US$ per share) | | | | | | $ 25.87 |
Options, Vested and exercisable, Weighted Average Grant Date Fair Value (in US$ per share) | | | $ 10.80 | | | |
Options, Vested and exercisable, Weighted Average Remaining Contractual Term | | | 4 years 2 months 23 days | | | |
Options, Vested and exercisable, Aggregate Intrinsic Value | | | | | | $ 1,278,000 |
Options, Vested and expected to vest, Outstanding (in shares) | | | | | | 303,990 |
Options, Vested and expected to vest, Weighted Average Exercise Price (in US$ per share) | | | | | | $ 27.10 |
Options, Vested and expected to vest, Weighted Average Grant Date Fair Value (in US$ per share) | | | $ 10.89 | | | |
Options, Vested and expected to vest, Exercisable, Weighted Average Remaining Life | | | 4 years 6 months 15 days | | | |
Options, Vested and expected to vest, Aggregate Intrinsic Value | | | | | | $ 1,585,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value | | | $ 0 | | | |
General and Administrative Expense | Stock Options | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Compensation expense recognized | $ 62,000 | $ 0 | $ 64,000 | $ 89,000 | | |