Comprehensive Income (Details) - USD ($) $ in Thousands	Aug. 31, 2017	Nov. 30, 2016
Statement of Comprehensive Income [Abstract]
Terminated interest rate swap, net of tax benefit of $1,758 and $1,448, respectively	$ (2,158)	$ (2,659)
Accumulated other comprehensive income (loss), terminated interest rate swap, tax	$ 1,448	$ 1,758

Accumulated Other Comprehensive Income (Loss), Terminated Interest Rate Swap, Net of Tax

No definition available.

Name:	isca_AccumulatedOtherComprehensiveIncomeLossTerminatedInterestRateSwapNetOfTax
Namespace Prefix:	isca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant