Debt	9 Months Ended
Sep. 30, 2013
Debt Disclosure [Abstract]
Debt	Note 11 - Debt The Company has a revolving credit facility with various lenders to provide back-up credit liquidity support for its commercial paper program. Credit commitments under this revolving credit facility totaled $750.0 million at September 30, 2013, with no amounts borrowed. This revolving credit facility has interest-rate options generally below the prime interest rate and carries commitment fees on the unused balance. In April 2013, Questar amended and restated its revolving credit facility to increase its size from $500.0 million to $750.0 million and extend its maturity from August 31, 2016 to April 19, 2018. Under the facility, consolidated funded debt cannot exceed 70% of consolidated capitalization. Commercial paper outstanding amounted to $355.0 million at September 30, 2013, $263.0 million at September 30, 2012 and $263.0 million at December 31, 2012. During the third quarter of 2013, Questar Gas entered into a commitment to borrow $150 million of long-term debt in the private placement market to be funded in December 2013. Questar Gas will issue $90 million of 30-year notes with an interest rate of 4.78% and $60 million of 35-year notes with an interest rate of 4.83%. Proceeds from the debt issuance will be used to repay existing indebtedness and for general corporate purposes. Except for the amendment and restatement to the Company's revolving credit facility and the Questar Gas borrowing commitment, there have not been any significant new borrowings or modifications of existing financing arrangements at Questar, Questar Gas or Questar Pipeline since December 31, 2012.

Debt

9 Months Ended

Sep. 30, 2013

Note 11 - Debt

The Company has a revolving credit facility with various lenders to provide back-up credit liquidity support for its commercial paper program. Credit commitments under this revolving credit facility totaled $750.0 million at September 30, 2013, with no amounts borrowed. This revolving credit facility has interest-rate options generally below the prime interest rate and carries commitment fees on the unused balance. In April 2013, Questar amended and restated its revolving credit facility to increase its size from $500.0 million to $750.0 million and extend its maturity from August 31, 2016 to April 19, 2018. Under the facility, consolidated funded debt cannot exceed 70% of consolidated capitalization. Commercial paper outstanding amounted to $355.0 million at September 30, 2013, $263.0 million at September 30, 2012 and $263.0 million at December 31, 2012.

During the third quarter of 2013, Questar Gas entered into a commitment to borrow $150 million of long-term debt in the private placement market to be funded in December 2013. Questar Gas will issue $90 million of 30-year notes with an interest rate of 4.78% and $60 million of 35-year notes with an interest rate of 4.83%. Proceeds from the debt issuance will be used to repay existing indebtedness and for general corporate purposes.

Except for the amendment and restatement to the Company's revolving credit facility and the Questar Gas borrowing commitment, there have not been any significant new borrowings or modifications of existing financing arrangements at Questar, Questar Gas or Questar Pipeline since December 31, 2012.