SHORT-TERM DEBT AND CREDIT AGREEMENTS (Tables)

12 Months Ended

Dec. 31, 2017

Short Term Debt Other Disclosures [Abstract]

Questar Gas' share of commercial paper and letters of credit outstanding under its joint credit facilities with Dominion Energy, Virginia Power and Dominion Energy Gas were as follows:

	Facility Limit		Outstanding Commercial Paper⁽²⁾		Outstanding Letters of Credit
(millions)
At December 31, 2017
Joint revolving credit facility⁽¹⁾	$	500.0	$	165.0	$	—
Joint revolving credit facility⁽¹⁾		500.0		—		—
Total	$	1,000.0	$	165.0	$	—
At December 31, 2016
Joint revolving credit facility⁽¹⁾	$	500.0	$	200.0	$	—
Joint revolving credit facility⁽¹⁾		500.0		—		—
Total	$	1,000.0	$	200.0	$	—

(1)

A maximum of $1.0 billion of the facilities is available to Questar Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Dominion Energy Gas. Sub-limits for Questar Gas are set within the facility limit but can be changed at the option of the borrowers multiple times per year. At December 31, 2017, the sub-limit for Questar Gas was $250.0 million. If Questar Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. The maturity date for these facilities is April 2020. These credit facilities can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

(2)	The weighted-average interest rate of the outstanding commercial paper supported by these credit facilities was 1.56% and 1.10% at December 31, 2017 and 2016, respectively.