Restructuring Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			$ 8.0
Restructuring and Related Cost, Cost Incurred to Date			7.7
Restructuring Charges	0.2	2.3	0.6	5.0
Increase (Decrease) in Restructuring Liability [Roll Forward]
Balance at Beginning of Period			1.0
Restructuring Reserve, Accrual Adjustment			0.6
Costs paid or otherwise settled			(1.3)
Balance at End of Period	0.3		0.3
Number of regional offices created			1
One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			3.6
Restructuring and Related Cost, Cost Incurred to Date			3.5
Restructuring Charges	0.1	0.8	0.4	1.9
Employee Relocation [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			3.8
Restructuring and Related Cost, Cost Incurred to Date			3.6
Restructuring Charges	0.1	1.5	0.2	3.1
Termination of Lease [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.6
Restructuring and Related Cost, Cost Incurred to Date			0.6
Restructuring Charges	0	0	0	0
QEP Energy [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			7.6
Restructuring and Related Cost, Cost Incurred to Date			7.4
Restructuring Charges	0.2	2.3	0.5	5.0
Increase (Decrease) in Restructuring Liability [Roll Forward]
Balance at Beginning of Period			1.0
Restructuring Reserve, Accrual Adjustment			0.5
Costs paid or otherwise settled			(1.2)
Balance at End of Period	0.3		0.3
QEP Energy [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			3.3
Restructuring and Related Cost, Cost Incurred to Date			3.3
Restructuring Charges	0.1	0.8	0.3	1.9
QEP Energy [Member] | Employee Relocation [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			3.7
Restructuring and Related Cost, Cost Incurred to Date			3.5
Restructuring Charges	0.1	1.5	0.2	3.1
QEP Energy [Member] | Termination of Lease [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.6
Restructuring and Related Cost, Cost Incurred to Date			0.6
Restructuring Charges	0	0		0
QEP Field Services [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.1
Restructuring and Related Cost, Cost Incurred to Date			0.1
Restructuring Charges	0	0	0	0
Increase (Decrease) in Restructuring Liability [Roll Forward]
Balance at Beginning of Period			0
Restructuring Reserve, Accrual Adjustment			0
Costs paid or otherwise settled			0
Balance at End of Period	0		0
QEP Field Services [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0
Restructuring and Related Cost, Cost Incurred to Date			0
Restructuring Charges	0	0	0	0
QEP Field Services [Member] | Employee Relocation [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.1
Restructuring and Related Cost, Cost Incurred to Date			0.1
Restructuring Charges	0	0	0	0
QEP Field Services [Member] | Termination of Lease [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0
Restructuring and Related Cost, Cost Incurred to Date			0
Restructuring Charges	0	0	0	0
QEP Marketing [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.3
Restructuring and Related Cost, Cost Incurred to Date			0.2
Restructuring Charges	0	0	0.1	0
Increase (Decrease) in Restructuring Liability [Roll Forward]
Balance at Beginning of Period			0
Restructuring Reserve, Accrual Adjustment			0.1
Costs paid or otherwise settled			(0.1)
Balance at End of Period	0		0
QEP Marketing [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0.3
Restructuring and Related Cost, Cost Incurred to Date			0.2
Restructuring Charges	0	0	0.1	0
QEP Marketing [Member] | Employee Relocation [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0
Restructuring and Related Cost, Cost Incurred to Date			0
Restructuring Charges	0	0	0	0
QEP Marketing [Member] | Termination of Lease [Member]
Restructuring Cost and Reserve [Line Items]
Estimated restructuring costs			0
Restructuring and Related Cost, Cost Incurred to Date			0
Restructuring Charges	$ 0	$ 0	$ 0	$ 0