Quarterly Results - (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Results - (unaudited)
Revenues	$ 157,000	$ 21,061,000	$ 24,273,000	$ 183,000	$ 129,000	$ 21,470,000	$ 24,465,000	$ 116,000
Operating (loss) earnings	(3,433,000)	4,251,000	8,411,000	(3,537,000)	(7,645,000)	7,300,000	8,679,000	(3,674,000)	5,692,000	4,660,000	9,185,000
Net (loss) earnings	(2,182,000)	2,601,000	4,844,000	(2,118,000)	(4,758,000)	4,158,000	4,903,000	(2,279,000)	3,095,000	1,991,000	4,504,000
Net earnings (loss) per common share - basic (in dollars per share)	$ (0.06)	$ 0.07	$ 0.13	$ (0.06)	$ (0.13)	$ 0.11	$ 0.13	$ (0.06)	$ 0.09	$ 0.05	$ 0.12
Net earnings (loss) per common share - diluted (in dollars per share)	$ (0.06)	$ 0.07	$ 0.13	$ (0.06)	$ (0.13)	$ 0.11	$ 0.13	$ (0.06)	$ 0.09	$ 0.05	$ 0.12
Quarterly Financial Information [Line Items]
Loss on disposal of long-lived assets		2,403,000							(2,403,000)
Loss on disposal of long-lived assets after income taxes		1,447,000
Non-cash pre-tax impairment charge										4,329,000
Nashville Superspeedway
Quarterly Financial Information [Line Items]
Non-cash pre-tax impairment charge					4,329,000
Non-cash pre-tax impairment charges after income taxes					$ 2,814,000