Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended		9 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2011 QCII	Dec. 31, 2012 QCII	Mar. 31, 2011 QCII Predecessor	Dec. 31, 2010 QCII Predecessor	Dec. 31, 2011 Pension Plan QCII	Dec. 31, 2012 Pension Plan QCII	Mar. 31, 2011 Pension Plan QCII Predecessor	Dec. 31, 2010 Pension Plan QCII Predecessor	Dec. 31, 2012 Post-Retirement Benefit Plan	Dec. 31, 2011 Post-Retirement Benefit Plan QCII	Dec. 31, 2012 Post-Retirement Benefit Plan QCII	Mar. 31, 2011 Post-Retirement Benefit Plan QCII Predecessor	Dec. 31, 2010 Post-Retirement Benefit Plan QCII Predecessor
Employee Benefits
Unfunded status					$ 627	$ 948				$ 2,706	$ 2,866
Pension (income) expense					(51)	(117)	11	53
Other postretirement benefit expense										$ 84	$ 106	$ 16	$ 72
Percentage of allocated portion of QCII's total pension and post-retirement benefit expenses	96.00%	91.00%	102.00%	101.00%
Collective bargaining agreements, term									4 years
Percentage of unionized employees covered under the collective bargaining agreements									1.00