Fair Value Measures Significant Quantitative Unobservable Inputs for Embedded Derivative Fair Value (Details)	Dec. 31, 2012
Fair Value Disclosures [Abstract]
Fair Value, Embedded Derivatives Significant Unobservable Input, Credit Spread	6.49%
Fair Value, Embedded Derivatives Significant Unobservable Input, Volatility	21.38%

The estimated midpoint between the option adjusted spreads (OAS) of the Company's traded bonds and the Company's cost of equity after subtracting the risk free rate.

No definition available.

Name:	rgp_FairValueEmbeddedDerivativesSignificantUnobservableInputCreditSprea
Namespace Prefix:	rgp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant