XML 53 R39.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] |  |
Increase in fair value of marketable securities | $ 3,600 | $ 1,900
Non-financial assets and liabilities measured at fair value on a nonrecurring basis | $ 0 | $ 0

X
- Definition Represents the aggregate of the non-financial assets and/or liabilities reported on the balance sheet at period end measured at fair value on a nonrecurring basis. Non-financial assets and liabilities may include assets acquired in a business combination or property and equipment that are determined to be impaired. + References No definition available. + Details
Name: | orly_NonFinancialAssetsAndLiabilitiesFairValueNonrecurring
Namespace Prefix: | orly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of equity or debt securities classified as trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3444-108585 + Details
Name: | us-gaap_IncreaseDecreaseInTradingSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration