CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
REVENUES
Questar Gas / Revenues from unaffiliated customers	$ 164.0	$ 148.6	$ 577.9	$ 509.3	$ 970.4	$ 884.0
Questar Pipeline / Revenues from unaffiliated customers	50.5	48.2	98.8	95.9	200.1	184.1
Wexpro	8.4	4.3	16.2	10.5	30.3	22.5
Total Revenues	222.9	201.1	692.9	615.7	1,200.8	1,090.6
OPERATING EXPENSES
Cost of sales (excluding operating expenses shown separately)	31.2	18.4	241.1	176.7	345.3	273.0
Operating and maintenance	39.8	39.3	91.2	91.1	175.9	176.3
General and administrative	26.2	25.0	59.2	51.2	116.5	98.5
Separation costs	0	11.5	0	11.5	0	11.5
Production and other taxes	13.1	13.2	26.7	27.8	49.5	47.5
Depreciation, depletion and amortization	38.9	37.4	78.3	76.3	155.4	151.3
Total Operating Expenses	149.2	144.8	496.5	434.6	842.6	758.1
Net gain (loss) from asset sales	0	0	0.1	0	0.5	(0.1)
OPERATING INCOME	73.7	56.3	196.5	181.1	358.7	332.4
Interest and other income	2.3	2.6	5.2	5.4	11.5	11.7
Income from unconsolidated affiliate	1.0	0.9	1.9	1.9	3.8	3.8
Interest expense	(14.8)	(14.0)	(30.8)	(28.3)	(59.6)	(57.1)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	62.2	45.8	172.8	160.1	314.4	290.8
Income taxes	(21.9)	(17.1)	(62.6)	(59.2)	(112.8)	(107.7)
INCOME FROM CONTINUING OPERATIONS	40.3	28.7	110.2	100.9	201.6	183.1
Discontinued operations, net of income taxes	0	69.5	0	148.2	0	315.7
Discontinued operations, noncontrolling interest	0	(0.7)	0	(1.3)	0	(2.8)
Total Discontinued Operations, Net Of Income Taxes	0	68.8	0	146.9	0	312.9
NET INCOME (LOSS)	40.3	97.5	110.2	247.8	201.6	496.0
Earnings Per Common Share Attributable To Questar
Basic from continuing operations	$ 0.22	$ 0.17	$ 0.62	$ 0.58	$ 1.13	$ 1.05
Basic from discontinued operations	$ 0	$ 0.39	$ 0	$ 0.84	$ 0	$ 1.80
Basic total	$ 0.22	$ 0.56	$ 0.62	$ 1.42	$ 1.13	$ 2.85
Diluted from continuing operations	$ 0.22	$ 0.16	$ 0.62	$ 0.57	$ 1.13	$ 1.03
Diluted from discontinued operations	$ 0	$ 0.39	$ 0	$ 0.83	$ 0	$ 1.77
Diluted total	$ 0.22	$ 0.55	$ 0.62	$ 1.40	$ 1.13	$ 2.80
Weighted-average common shares outstanding
Used in basic calculation	177.5	175.1	177.2	175.0	177.0	174.6
Used in diluted calculation	178.8	177.6	178.7	177.4	179.0	176.9
Dividends per common share	$ 0.1525	$ 0.13	$ 0.305	$ 0.26	$ 0.585	$ 0.515
Questar Pipeline [Member]
REVENUES
Questar Pipeline / Revenues from unaffiliated customers	50.5	48.2	98.8	95.9	200.1	184.1
Revenues from affiliated companies	18.7	18.5	37.3	37.3	74.0	73.4
Total Revenues	69.2	66.7	136.1	133.2	274.1	257.5
OPERATING EXPENSES
Operating and maintenance	10.3	10.3	18.9	18.1	42.2	40.5
General and administrative	11.1	10.4	24.2	21.0	44.2	39.8
Depreciation and amortization	12.8	11.8	25.1	23.6	48.9	46.2
Other taxes	2.3	2.4	5.4	4.8	9.6	9.0
Cost of goods sold (excluding operating expenses shown separately)	1.0	0.5	1.6	1.0	3.0	1.5
Total Operating Expenses	37.5	35.4	75.2	68.5	147.9	137.0
Net gain (loss) from asset sales	0	0	0.1	0.1	0.8	0.3
OPERATING INCOME	31.7	31.3	61.0	64.8	127.0	120.8
Interest and other income	0.1	0.2	1.0	0.3	1.1	2.2
Income from unconsolidated affiliate	1.0	0.9	1.9	1.9	3.8	3.8
Interest expense	(6.8)	(7.3)	(13.9)	(14.7)	(28.0)	(29.4)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	26.0	25.1	50.0	52.3	103.9	97.4
Income taxes	(9.4)	(9.2)	(18.1)	(19.2)	(37.7)	(35.8)
NET INCOME (LOSS)	16.6	15.9	31.9	33.1	66.2	61.6
Questar Gas [Member]
REVENUES
Questar Gas / Revenues from unaffiliated customers	164.0	148.6	577.9	509.3	970.4	884.0
Revenues from affiliated company	1.0	0.1	1.8	0.4	2.5	0.9
Total Revenues	165.0	148.7	579.7	509.7	972.9	884.9
OPERATING EXPENSES
Cost of natural gas sold (excluding operating expenses shown separately)	109.8	96.5	398.5	333.5	657.2	577.4
Operating and maintenance	24.4	24.5	61.8	63.5	112.7	116.9
General and administrative	10.2	11.5	24.8	22.8	51.9	44.9
Depreciation and amortization	10.9	11.2	21.8	22.3	43.2	44.4
Other taxes	4.0	3.9	8.3	7.9	14.5	13.5
Total Operating Expenses	159.3	147.6	515.2	450.0	879.5	797.1
OPERATING INCOME	5.7	1.1	64.5	59.7	93.4	87.8
Interest and other income	1.3	1.7	2.9	3.2	6.4	6.9
Interest expense	(6.5)	(6.5)	(13.1)	(13.3)	(26.0)	(26.9)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	0.5	(3.7)	54.3	49.6	73.8	67.8
Income taxes	(0.1)	1.5	(20.5)	(18.7)	(27.0)	(25.1)
NET INCOME (LOSS)	$ 0.4	$ (2.2)	$ 33.8	$ 30.9	$ 46.8	$ 42.7