Business Operations (Details) (USD $)	3 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	May 29, 2014	Dec. 31, 2013	Dec. 31, 2011	Jun. 30, 2014 item	Jun. 30, 2013 item	Jul. 31, 2012 item
Business Operations
Number of days the Firefly Music Festival is held	3 days
Non-refundable deposit received on expected sale of facility		$ 1,700,000
Assets held for sale	26,000,000	26,000,000
Non-cash pre-tax impairment charge			4,329,000
Benefit for contingent obligation		(30,000)	(91,000)	(321,000)
Provision for contingent obligation	1,813,000	1,813,000	1,843,000			1,843,000
Nashville Superspeedway
Business Operations
Proceeds from sale of facility					27,000,000
Non-refundable deposit received on expected sale of facility		1,700,000
Additional consideration received		400,000
Assets held for sale	26,000,000	26,000,000
Non-cash pre-tax impairment charge						4,329,000
Nashville Superspeedway | Scenario Forecast | Minimum
Business Operations
Income tax on expected gains (losses) on sale of facility	4,500,000	4,500,000
Nashville Superspeedway | Scenario Forecast | Maximum
Business Operations
Income tax on expected gains (losses) on sale of facility	5,000,000	5,000,000
Nashville Superspeedway | Nontaxable Municipal Bonds
Business Operations
Benefit for contingent obligation							2,250,000
Decrease in the provision for contingent obligation due to changing interest rates		(30,000)	(91,000)	(316,000)
Provision for contingent obligation	$ 1,813,000	$ 1,813,000
Dover International Speedway
Business Operations
Number of events scheduled to be promoted		6
Dover Facility
Business Operations
Number of years Firefly Music Festival hosted		3 years						4 days	3 days
Number of events promoted		6
Number of days the Firefly Music Festival is held										3 days
Number of music acts featured in Firefly Music Festival	50							100	70	40
Percentage of total revenues		97.00%	97.00%	96.00%
Number of options granted to extend rent agreement		2
Number of years each agreement permits to use our facility		5 years
Dover Facility | NASCAR Sprint Cup Series Events
Business Operations
Number of events promoted		2
Dover Facility | NASCAR Nationwide Series Events
Business Operations
Number of events promoted		2
Dover Facility | NASCAR Camping World Truck Series Events
Business Operations
Number of events promoted		1
Dover Facility | NASCAR K and N Pro Series East Event
Business Operations
Number of events promoted		1