Partners' Capital (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended					3 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Mar. 31, 2013 Class B Units [Member]	Jun. 30, 2013 Class B Units [Member]	Jun. 30, 2013 QRE GP [Member]	Jun. 30, 2013 General Partner [Member] QRE GP [Member]	Jun. 30, 2013 Limited Partner [Member] QRE GP [Member]	Jun. 30, 2013 Limited Partner [Member] Fund [Member]	Mar. 31, 2013 Class B Units [Member]	Jun. 30, 2013 Class B Units [Member] QRE GP [Member]	Jul. 31, 2013 Subsequent Event [Member]	Sep. 30, 2013 Subsequent Event [Member]	Jun. 30, 2013 Subsequent Event [Member]	Jul. 24, 2013 Subsequent Event [Member]
Partners' Capital Activity [Line Items]
Percentage of management fee converted to Class B units										80.00%
Issue of units in lieu of management fee				6,133,558	6,133,558					6,133,558
Management incentive fee incurred	$ 0.7	$ 0.7											$ 1.3
Distribution to General Partner										$ 3.0
General partner, outstanding (in units)		51,036	51,036			51,036
Class B convertible unitholders, outstanding (in units)		6,133,558	0
Ownership percentage							0.10%	7.50%	29.30%		7.50%
Interest in cash distributions						7.60%
Period of time after quarter available cash is distributed to unitholders		45 days
Date distribution was declared												Jul. 24, 2013		Jul. 24, 2013
Cash distribution per unit															$ 0.4875
Date distribution will be paid												Aug. 14, 2013		Aug. 14, 2013
Date unitholders of record												Aug. 07, 2013		Aug. 07, 2013