Alico, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Narrative (Details)

Stockholders' Equity - Narrative (Details)								1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
Stockholders' Equity - Narrative (Details)	Oct. 25, 2018 $ / shares shares	Oct. 03, 2018 USD ($) $ / shares shares	Sep. 07, 2018 $ / shares shares	Sep. 05, 2018 shares	Apr. 27, 2018 USD ($)	Apr. 16, 2018 USD ($)	Dec. 31, 2016 $ / shares shares	Nov. 30, 2017 $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2018 USD ($)	Mar. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) $ / shares	Sep. 30, 2016 $ / shares	Sep. 30, 2015 executive $ / shares shares	Sep. 30, 2017 shares	May 31, 2017 shares	Mar. 31, 2017 shares
Class of Stock [Line Items]
Shares issued (in dollars per share)		$ 34.00
Shares of common stock authorized to be repurchased (up to) (in shares) \| shares																7,000,000	2,000,000	5,000,000
Shares issued (in shares) \| shares		752,234
Cost of shares \| $		$ 25,575,956
Cash capital contribution required, due to catastrophe \| $						$ 2,041,000
Capital contribution received from parent \| $					$ 1,041,000
Capital contribution received from noncontrolling interest \| $											$ 1,000,000
Corporate, General and Administrative Expense
Class of Stock [Line Items]
Stock-based compensation expense \| $									$ (238,000)	$ (192,000)	(476,000)	$ (382,000)
Restricted Stock
Class of Stock [Line Items]
Restricted shares awarded (in shares) \| shares								5,000							12,500
Number of senior executives \| executive															2
Weighted average fair value (in dollars per share)								$ 31.95							$ 49.49
Award vesting period								3 years
Unrecognized expense \| $									120,000		120,000		$ 172,000
Stock-based compensation expense \| $									(26,000)	(37,000)	(52,000)	(63,000)
Employee Stock Option
Class of Stock [Line Items]
Unrecognized expense \| $									658,000		658,000		$ 2,842,000
Stock option credit \| $									594,000		305,000
Stock-based compensation expense \| $									(229,000)	$ (205,000)	$ (518,000)	$ (411,000)
Weighted average remaining contractual term											1 year 8 months 19 days
2017 Authorization Program
Class of Stock [Line Items]
Authorized amount \| $									$ 1,676,443		$ 1,676,443
Minimum \| Restricted Stock
Class of Stock [Line Items]
Award vesting period															3 years
Maximum \| Restricted Stock
Class of Stock [Line Items]
Award vesting period															5 years
2019 Modified Option Grants \| Employee Stock Option
Class of Stock [Line Items]
Grants in period, weighted average (in dollars per share)											$ 1.40
2019 Option Grants
Class of Stock [Line Items]
Shares issued (in dollars per share)	$ 33.34
Period following an executive's termination of employment for a number of reasons	18 months
Period following an executive's termination of employment without cause	12 months
Share price (in dollars per share)									$ 27.21		27.21
2019 Option Grants \| Mr. Kiernan
Class of Stock [Line Items]
Options granted in period (in shares) \| shares	10,000
2019 Option Grants \| Tranche One
Class of Stock [Line Items]
Number of awards vesting (in shares) \| shares	3,333
Period of consecutive trading days	20 days
Amount per share (in dollars per share)	$ 40.00
2019 Option Grants \| Tranche Two
Class of Stock [Line Items]
Number of awards vesting (in shares) \| shares	3,333
Period of consecutive trading days	20 days
Amount per share (in dollars per share)	$ 45.00
2019 Option Grants \| Tranche Three
Class of Stock [Line Items]
Number of awards vesting (in shares) \| shares	3,334
Period of consecutive trading days	20 days
Amount per share (in dollars per share)	$ 50.00
2019 Option Grants \| Employee Stock Option
Class of Stock [Line Items]
Grants in period, weighted average (in dollars per share)											7.10
2019 Option Grants \| Maximum
Class of Stock [Line Items]
Share price (in dollars per share)									$ 40.00		40.00
2018 Option Grants
Class of Stock [Line Items]
Shares issued (in dollars per share)			$ 33.60
Period following an executive's termination of employment for a number of reasons			18 months
Stock-based compensation expense \| $									$ 823,000
Period following an executive's termination of employment without cause			12 months
Share price (in dollars per share)									$ 27.21		$ 27.21
2018 Option Grants \| Mr. Kiernan
Class of Stock [Line Items]
Options granted in period (in shares) \| shares			90,000
2018 Option Grants \| Remy W. Trafelet
Class of Stock [Line Items]
Options granted in period (in shares) \| shares			210,000
2018 Option Grants \| Tranche One
Class of Stock [Line Items]
Period of consecutive trading days			20 years
Amount per share (in dollars per share)			$ 35.00
Percentage of options			25.00%
2018 Option Grants \| Tranche One \| Henry R. Slack
Class of Stock [Line Items]
Period of consecutive trading days											20 days
Amount per share (in dollars per share)											$ 35.00
Number of shares expected to vest (in shares) \| shares											26,250
2018 Option Grants \| Tranche Two
Class of Stock [Line Items]
Period of consecutive trading days			20 years
Amount per share (in dollars per share)			$ 40.00
Percentage of options			25.00%
2018 Option Grants \| Tranche Two \| Henry R. Slack
Class of Stock [Line Items]
Period of consecutive trading days											20 days
Amount per share (in dollars per share)											$ 40.00
Number of shares expected to vest (in shares) \| shares											26,250
2018 Option Grants \| Tranche Three
Class of Stock [Line Items]
Period of consecutive trading days			20 years
Amount per share (in dollars per share)			$ 45.00
Percentage of options			25.00%
2018 Option Grants \| Tranche Four
Class of Stock [Line Items]
Period of consecutive trading days			20 years
Amount per share (in dollars per share)			$ 50.00
Percentage of options			25.00%
2018 Option Grants \| Employee Stock Option
Class of Stock [Line Items]
Grants in period, weighted average (in dollars per share)													$ 7.40
2018 Option Grants \| Maximum
Class of Stock [Line Items]
Share price (in dollars per share)									35.00		$ 35.00
2016 Option Grants
Class of Stock [Line Items]
Shares issued (in dollars per share)							$ 27.15
Period of consecutive trading days							20 days
Period following an executive's termination of employment for a number of reasons							18 months
Share price (in dollars per share)									27.21		27.21
2016 Option Grants \| Remy W. Trafelet
Class of Stock [Line Items]
Options granted in period (in shares) \| shares							300,000
2016 Option Grants \| Henry R. Slack
Class of Stock [Line Items]
Unrecognized expense \| $													$ 783,000
Options granted in period (in shares) \| shares							225,000
Shares forfeited (in shares) \| shares				187,500
2016 Option Grants \| George R. Brokaw
Class of Stock [Line Items]
Options granted in period (in shares) \| shares							225,000
Shares forfeited (in shares) \| shares				187,500
2016 Option Grants \| Tranche One
Class of Stock [Line Items]
Amount per share (in dollars per share)							$ 60.00
Percentage of options							25.00%
2016 Option Grants \| Tranche Two
Class of Stock [Line Items]
Amount per share (in dollars per share)							$ 75.00
Percentage of options							25.00%
2016 Option Grants \| Tranche Three
Class of Stock [Line Items]
Amount per share (in dollars per share)							$ 90.00
Percentage of options							25.00%
2016 Option Grants \| Tranche Four
Class of Stock [Line Items]
Amount per share (in dollars per share)							$ 105.00
Percentage of options							25.00%
2016 Option Grants \| Employee Stock Option
Class of Stock [Line Items]
Grants in period, weighted average (in dollars per share)														$ 3.53
2016 Option Grants \| Maximum
Class of Stock [Line Items]
Share price (in dollars per share)									$ 60.00		$ 60.00
2015 Option Grants \| Employee Stock Option
Class of Stock [Line Items]
Common shares available (in shares) \| shares									1,005,000		1,005,000