QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

A summary of Questar Gas’ quarterly results of operations for the years ended December 31, 2017 and 2016 follows. Amounts reflect all adjustments necessary in the opinion of management for a fair statement of the results for the interim periods. Results for interim periods may fluctuate as a result of weather conditions, changes in rates and other factors.

	First Quarter		Second Quarter			Third Quarter			Fourth Quarter		Year
(millions)
2017
Operating revenue	$	396.9	$	139.7		$	90.9		$	319.5	$	947.0
Income (loss) from operations		91.9		(2.5	)		(6.6	)		61.5		144.3
Net income (loss)		52.2		(6.2	)		(8.5	)		30.0		67.5
2016
Operating revenue	$	407.9	$	128.2		$	87.9		$	297.3	$	921.3
Income (loss) from operations		83.4		3.8			(19.8	)		53.3		120.7
Net income (loss)		47.6		(1.6	)		(17.7	)		28.9		57.2