Note 10 - Segment Disclosures - Segment Information on Continuing Operations (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues	$ 137,608,000		$ 170,661,000	$ 397,186,000	$ 429,525,000
Depreciation and amortization	13,834,000		14,016,000	44,808,000	40,957,000
Total segment operating income	17,548,000		22,781,000	62,436,000	70,208,000
Impairment of goodwill (Note 4)				1,117,000
Capital expenditures				21,960,000	33,440,000
Motorsports Event Segment [Member]
Revenues	133,041,000		134,686,000	382,283,000	382,656,000
Depreciation and amortization	13,799,000		13,976,000	44,700,000	40,833,000
Total segment operating income	16,609,000		14,938,000	59,037,000	59,715,000
Impairment of goodwill (Note 4)		$ 1,117,000		1,117,000
Capital expenditures				21,931,000	33,387,000
Other Segments [Member]
Revenues	4,567,000		35,975,000	14,903,000	46,869,000
Depreciation and amortization	35,000		40,000	108,000	124,000
Total segment operating income	$ 939,000		$ 7,843,000	3,399,000	10,493,000
Impairment of goodwill (Note 4)
Capital expenditures				$ 29,000	$ 53,000