Operations by Line of Business (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 14, 2013
Segment Reporting Information [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	57.80%								57.80%			63.30%
Revenues
Total Revenues	$ 715.5	$ 772.8	$ 751.0	$ 696.5	$ 704.9	$ 542.4	$ 499.3	$ 603.2	$ 2,935.8	$ 2,349.8	$ 3,159.2
Operating expenses
Purchased gas, oil and NGL expense									765.9	655.6	1,077.1
Lease operating expense									177.8	172.3	145.2
Natural gas, oil and NGL transportation and other handling costs									141.4	148.9	102.2
Gathering, processing and other									90.6	88.0	107.3
General and administrative									191.1	266.6	123.2
Production and property taxes									166.5	103.4	105.4
Results of Operations, Depreciation, Depletion, Amortization and Accretion									1,016.0	905.3	765.6
Other Expenses									104.9	144.2	228.7
Operating Expenses									2,654.2	2,484.3	2,654.7
Gain (Loss) on Sale of Property Plant Equipment									103.0	1.2	1.4
OPERATING (LOSS) INCOME	(15.7)	128.2	207.3	64.8	(114.7)	(12.6)	(55.5)	49.5	384.6	(133.3)	505.9
Realized and unrealized gains (losses) on derivative contracts									58.9	441.9	0
Interest and other income									5.2	6.6	4.1
Income from unconsolidated affiliates									5.8	6.8	5.5
Loss from early extinguishment of debt									0	(0.6)	(0.7)
Interest expense									(163.3)	(122.9)	(90.0)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	(51.0)	63.5	284.6	(5.9)	(42.1)	(4.4)	0.3	244.7	291.2	198.5	424.8
Income taxes									(119.8)	(66.5)	(154.4)
NET INCOME									171.4	132.0	270.4
Net income attributable to noncontrolling interest									(12.0)	(3.7)	(3.2)
NET INCOME ATTRIBUTABLE TO QEP	(52.0)	37.3	178.4	(4.3)	(23.1)	(3.1)	(0.7)	155.2	159.4	128.3	267.2
Assets	9,376.8				9,108.5				9,376.8	9,108.5	7,442.7
Equity Method Investments	39.0				41.2				39.0	41.2	42.2
Cash capital expenditures									1,602.6	2,799.7	1,431.1
Accrued capital expenditures									1,577.4	2,888.2	1,445.9
Goodwill	0				59.5				0	59.5	59.5
Unaffiliated customers [Member]
Revenues
Total Revenues									2,935.8	2,349.8	3,159.2
Affiliated customers [Member]
Revenues
Total Revenues									0	0	0
QEP Energy [Member]
Revenues
Total Revenues									2,092.8	1,615.4	2,213.2
Operating expenses
Purchased gas, oil and NGL expense									197.1	224.7	506.4
Lease operating expense									181.3	175.8	148.2
Natural gas, oil and NGL transportation and other handling costs									242.2	228.1	186.0
Gathering, processing and other									0	0	0
General and administrative									139.7	236.3	98.4
Production and property taxes									159.8	97.2	99.1
Results of Operations, Depreciation, Depletion, Amortization and Accretion									954.2	838.4	707.4
Other Expenses									104.9	144.2	228.7
Operating Expenses									1,979.2	1,944.7	1,974.2
Gain (Loss) on Sale of Property Plant Equipment									104.1	1.2	1.4
OPERATING (LOSS) INCOME									217.7	(328.1)	240.4
Realized and unrealized gains (losses) on derivative contracts									59.1	434.9
Interest and other income									3.6	6.2	4.0
Income from unconsolidated affiliates									0.2	0.1	0.1
Loss from early extinguishment of debt									0	0	0
Interest expense									(192.6)	(116.8)	(81.9)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									88.0	(3.7)	162.6
Income taxes									(49.1)	4.3	(57.9)
NET INCOME									38.9	0.6	104.7
Net income attributable to noncontrolling interest									0	0	0
NET INCOME ATTRIBUTABLE TO QEP									38.9	0.6	104.7
Assets	7,930.6				7,436.5				7,930.6	7,436.5	5,815.7
Equity Method Investments					0					0	0
Cash capital expenditures									1,488.6	2,621.1	1,295.5
Accrued capital expenditures									1,467.2	2,702.4	1,338.8
Goodwill					59.5					59.5	59.5
QEP Energy [Member] | Unaffiliated customers [Member]
Revenues
Total Revenues									2,092.8	1,615.4	2,213.2
QEP Energy [Member] | Affiliated customers [Member]
Revenues
Total Revenues									0	0	0
QEP Field Services [Member]
Revenues
Total Revenues									403.4	439.2	465.5
Operating expenses
Purchased gas, oil and NGL expense									8.9	12.1	0
Lease operating expense									0	0	0
Natural gas, oil and NGL transportation and other handling costs									13.9	33.6	9.3
Gathering, processing and other									88.9	86.8	106.0
General and administrative									51.6	34.4	29.2
Production and property taxes									6.6	6.0	6.1
Results of Operations, Depreciation, Depletion, Amortization and Accretion									60.9	63.2	55.7
Other Expenses									0	0	0
Operating Expenses									230.8	236.1	206.3
Gain (Loss) on Sale of Property Plant Equipment									(0.5)	0	0
OPERATING (LOSS) INCOME									172.1	203.1	259.2
Realized and unrealized gains (losses) on derivative contracts									0	8.4
Interest and other income									1.2	0.2	0.1
Income from unconsolidated affiliates									5.6	6.7	5.4
Loss from early extinguishment of debt									0	0	0
Interest expense									(13.1)	(13.6)	(13.6)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									165.8	204.8	251.1
Income taxes									(55.4)	(71.8)	(93.4)
NET INCOME									110.4	133.0	157.7
Net income attributable to noncontrolling interest									(12.0)	(3.7)	(3.2)
NET INCOME ATTRIBUTABLE TO QEP									98.4	129.3	154.5
Assets	1,455.1				1,399.7				1,455.1	1,399.7	1,312.7
Equity Method Investments	39.0				41.2				39.0	41.2	42.2
Cash capital expenditures									89.8	164.0	130.1
Accrued capital expenditures									86.0	171.2	101.6
Goodwill					0					0	0
QEP Field Services [Member] | Unaffiliated customers [Member]
Revenues
Total Revenues									282.4	320.2	369.3
QEP Field Services [Member] | Affiliated customers [Member]
Revenues
Total Revenues									121.0	119.0	96.2
QEP Marketing and Other [Member]
Revenues
Total Revenues									1,573.2	1,019.9	1,156.9
Operating expenses
Purchased gas, oil and NGL expense									1,570.5	1,021.1	1,144.5
Lease operating expense									0	0	0
Natural gas, oil and NGL transportation and other handling costs									0	0	0
Gathering, processing and other									1.7	1.2	1.3
General and administrative									4.6	2.0	2.1
Production and property taxes									0.1	0.2	0.2
Results of Operations, Depreciation, Depletion, Amortization and Accretion									0.9	3.7	2.5
Other Expenses									0	0	0
Operating Expenses									1,577.8	1,028.2	1,150.6
Gain (Loss) on Sale of Property Plant Equipment									(0.6)	0	0
OPERATING (LOSS) INCOME									(5.2)	(8.3)	6.3
Realized and unrealized gains (losses) on derivative contracts									(0.2)	(1.4)
Interest and other income									206.9	132.1	98.7
Income from unconsolidated affiliates									0	0	0
Loss from early extinguishment of debt									0	(0.6)	(0.7)
Interest expense									(164.1)	(124.4)	(93.2)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									37.4	(2.6)	11.1
Income taxes									(15.3)	1.0	(3.1)
NET INCOME									22.1	(1.6)	8.0
Net income attributable to noncontrolling interest									0	0	0
NET INCOME ATTRIBUTABLE TO QEP									22.1	(1.6)	8.0
Assets	250.7				272.3				250.7	272.3	314.3
Equity Method Investments	0				0				0	0	0
Cash capital expenditures									24.2	14.6	5.5
Accrued capital expenditures									24.2	14.6	5.5
Goodwill					0					0	0
QEP Marketing and Other [Member] | Unaffiliated customers [Member]
Revenues
Total Revenues									560.6	414.2	576.7
QEP Marketing and Other [Member] | Affiliated customers [Member]
Revenues
Total Revenues									1,012.6	605.7	580.2
Elimination [Member]
Revenues
Total Revenues									(1,133.6)	(724.7)	(676.4)
Operating expenses
Purchased gas, oil and NGL expense									(1,010.6)	(602.3)	(573.8)
Lease operating expense									(3.5)	(3.5)	(3.0)
Natural gas, oil and NGL transportation and other handling costs									(114.7)	(112.8)	(93.1)
Gathering, processing and other									0	0	0
General and administrative									(4.8)	(6.1)	(6.5)
Production and property taxes									0	0	0
Results of Operations, Depreciation, Depletion, Amortization and Accretion									0	0	0
Other Expenses									0	0	0
Operating Expenses									(1,133.6)	(724.7)	(676.4)
Gain (Loss) on Sale of Property Plant Equipment									0	0	0
OPERATING (LOSS) INCOME									0	0	0
Realized and unrealized gains (losses) on derivative contracts									0	0
Interest and other income									(206.5)	(131.9)	(98.7)
Income from unconsolidated affiliates									0	0	0
Loss from early extinguishment of debt									0	0	0
Interest expense									206.5	131.9	98.7
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									0	0	0
Income taxes									0	0	0
NET INCOME									0	0	0
Net income attributable to noncontrolling interest										0	0
NET INCOME ATTRIBUTABLE TO QEP									0	0	0
Assets	(259.6)				0				(259.6)	0	0
Equity Method Investments	0				0				0	0	0
Cash capital expenditures									0	0	0
Accrued capital expenditures									0	0	0
Goodwill					0					0	0
Elimination [Member] | Unaffiliated customers [Member]
Revenues
Total Revenues									0	0	0
Elimination [Member] | Affiliated customers [Member]
Revenues
Total Revenues									$ (1,133.6)	$ (724.7)	$ (676.4)