Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Statement of Shareholders' Equity
Tax effect of unrealized loss on cash flow hedge	$ 1,875	$ 3,215

The tax effect of the fair value of derivatives as of the balance sheet date.

No definition available.

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