Note 6 - Financial Instruments and Fair Value - Pre-tax Effect of Interest Rate Swaps (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Long-lived assets held for sale, fair value	$ 7,645
Long-lived assets held for sale, gain (loss) included in earnings	$ (56)

Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

No definition available.

Name:	rusha_FairValueMeasurementWithUnobservableInputsReconciliationNonrecurringBasisAssetGainLossIncludedInEarnings
Namespace Prefix:	rusha_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration