Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Statement of Stockholders' Equity [Abstract]
Tax effect of unrealized loss on cash flow hedge	$ 1,875

The tax effect of unrealized losses on cash flow hedge derivatives.

No definition available.

Name:	orly_DerivativeFairValueTaxEffect
Namespace Prefix:	orly_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant