Stock-Based Compensation Plans (Details Narrative) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018 USD ($) Years shares	Dec. 31, 2017 USD ($)	Sep. 28, 2018 $ / shares
Number of stock option plans	2
Options expire from date of grant	10 years
Exercisable installments	Immediate or 20% or 25%
Shares available for future issuance \| shares	527,662
Aggregate intrinsic value of exercisable in-the-money options	$ 3,436
Aggregate intrinsic value of outstanding in-the-money options	3,963
Market close price \| $ / shares			$ 62.10
Total unrecognized compensation cost of options granted but not yet vested	$ 97
Weighted average period for compensation to be recognized \| Years	2.2
Gains realized by option holders	$ 1,866
Expected minimum volatility	32.00%
Expected maximum volatility	43.00%
Risk-free interest rate minimum	0.60%
Risk-free interest rate maximum	4.20%
Expected life minimum \| Years	3
Expecited life maximum \| Years	7
Dividend yield	0.00%
Modification stock compensation expense		$ 41
Stock compensation expense for the vesting of option grants due to asset disposition	$ 402
Patriot Transportation
Gains realized by option holders	$ 646
Modification stock compensation expense		$ 150

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Unrecognized cost of unvested share-based compensation awards.

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Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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Price of a single share of a number of saleable stocks of a company.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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