The amount of previously capitalized costs were charged to depreciation expense.

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The amount of previously capitalized costs were charged to depreciation expense net of tax.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee, net of tax.

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Represents the number of motorsports events promoted by the entity.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of expense to remove long-lived assets related to the removal and disposal.

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After tax amount of expense to remove long-lived assets related to the removal and disposal.

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Increase (decrease) in net earnings per share basic and diluted for measurement period adjustment from accounting for tax effect pursuant to Tax Cuts and Jobs Act of 2017.

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Net Income (loss) for measurement period adjustment from accounting for tax effect pursuant to Tax Cuts and Jobs Act of 2017.

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Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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The net result for the period of deducting operating expenses from operating revenues.

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Quarterly Results (unaudited) (Details)		3 Months Ended									12 Months Ended
Quarterly Results (unaudited) (Details)	Jan. 01, 2018	Dec. 31, 2018 USD ($) item $ / shares	Sep. 30, 2018 USD ($) $ / shares	Jun. 30, 2018 USD ($) item $ / shares	Mar. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) item $ / shares	Sep. 30, 2017 USD ($) item $ / shares	Jun. 30, 2017 USD ($) item $ / shares	Mar. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($)	Dec. 31, 2019 item	Dec. 31, 2018 USD ($) item $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares
Quarterly Results (unaudited)
Revenues		$ 20,751,000	$ 227,000	$ 25,812,000	$ 226,000	$ 18,305,000	$ 2,740,000	$ 25,587,000	$ 110,000
Operating (loss) earnings		5,911,000	(4,062,000)	8,954,000	(1,246,000)	5,364,000	(3,382,000)	8,868,000	(4,071,000)			$ 9,557,000	$ 6,779,000	$ 6,607,000
Net (loss) earnings		$ 4,072,000	$ (2,699,000)	$ 6,508,000	$ (992,000)	$ 7,643,000	$ (2,015,000)	$ 5,203,000	$ (2,405,000)
Net (loss) earnings per share - basic and diluted \| $ / shares		$ 0.11	$ (0.07)	$ 0.18	$ (0.03)	$ 0.21	$ (0.06)	$ 0.14	$ (0.07)			$ 0.19	$ 0.23	$ 0.10
Costs to remove long-lived assets									$ 286,000	$ 203,000			$ 286,000	$ 203,000
Costs to remove long-lived assets, after income taxes									$ 167,000
Capitalized costs charged to depreciation						$ 186,000
Capitalized costs charged to depreciation, after income taxes						$ 110,000
Federal income tax rate (as a percent)	21.00%					21.00%						21.00%	35.00%	35.00%
Net earnings due to revalue of net deferred federal tax liabilities						$ 4,531,000
Net earnings per share - basic and diluted due to revalue of net deferred federal tax liabilities \| $ / shares						$ 0.13
Gain (loss) on sale of land												$ 2,413,000
Number of events promoted \| item		3		3		1	2	3				6
Scheduled for 2019
Quarterly Results (unaudited)
Number of events promoted \| item											6
Assets held for sale \| Nashville Superspeedway
Quarterly Results (unaudited)
Gain (loss) on sale of land					$ 2,512,000
Gain (loss) on sale of land after income taxes					$ 1,984,000
Assets held for sale \| Parcel of land near St. Louis
Quarterly Results (unaudited)
Gain (loss) on sale of land			$ (99,000)									$ (99,000)
Gain (loss) on sale of land after income taxes			$ (76,000)