Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Floor Plan Notes Payable	$ 845,977,000rusha_FloorPlanNotesPayable	$ 593,649,000rusha_FloorPlanNotesPayable
Debt, Weighted Average Interest Rate	1.16%us-gaap_DebtWeightedAverageInterestRate	1.26%us-gaap_DebtWeightedAverageInterestRate
If Terminated after January 11, 2015 and On or Prior to July 11, 2015 [Member] \| GE Capital Credit Agreement [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Debt Instrument, Prepayment Processing Fee, Amount	7,500,000
If Terminated After July 11, 2015[Member] \| GE Capital Credit Agreement [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Debt Instrument, Prepayment Processing Fee, Amount	300,000
GE Capital Credit Agreement [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.03%
GE Capital Credit Agreement [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	750,000,000
Debt Instrument, Interest Rate, Effective Percentage	2.28%
Debt Instrument, Working Capital Fee, Percentage	0.35%
Floor Plan Notes Payable	677,800,000
Ford Motor Financing Agreement [Member] \| Prime Rate [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	3.75%
Ford Motor Financing Agreement [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	5.25%
Floor Plan Notes Payable	79,400,000
Line of Credit [Member]
Note 7 - Floor Plan Notes Payable and Lines of Credit (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	17,500,000
Long-term Line of Credit	0
Line of Credit, Amount Pledged to Secure Letters of Credit	15,300,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 2,200,000

Amount of prepayment processing fee payable to lenders.

No definition available.

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- Definition

Working capital fee.

+ References

No definition available.

+ Details

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Namespace Prefix:	rusha_
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- Definition

Amounts borrowed to finance the purchase of new and used commercial vehicle inventory.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit, Amount Pledged to Secure Letters of Credit.

+ References

No definition available.

+ Details

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Namespace Prefix:	rusha_
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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Minimum contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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