Employee Benefits (Details) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended																			1 Months Ended	12 Months Ended		12 Months Ended								12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Mar. 31, 2013 Pension Plans	Dec. 31, 2012 Pension Plans	Dec. 31, 2011 Pension Plans	Dec. 31, 2010 Pension Plans	Dec. 31, 2012 Pension Plans Interest rate sensitive investments	Dec. 31, 2012 Pension Plans Investment grade bonds	Dec. 31, 2012 Pension Plans High yield and emerging market bonds	Dec. 31, 2012 Pension Plans Convertible bonds	Dec. 31, 2012 Pension Plans Diversified strategies	Dec. 31, 2012 Pension Plans Interest rate investments with higher returns	Dec. 31, 2012 Pension Plans U.S. stocks	Dec. 31, 2012 Pension Plans Developed market Non-U.S. stocks	Dec. 31, 2012 Pension Plans Other	Dec. 31, 2012 Pension Plans Real estate	Dec. 31, 2012 Pension Plans Minimum	Dec. 31, 2011 Pension Plans Minimum	Dec. 31, 2010 Pension Plans Minimum	Dec. 31, 2012 Pension Plans Maximum	Dec. 31, 2011 Pension Plans Maximum	Dec. 31, 2010 Pension Plans Maximum	Apr. 30, 2011 Pension Plans Qwest sponsored defined benefit plans	Dec. 31, 2011 Pension Plans Qwest sponsored defined benefit plans	Apr. 02, 2011 Pension Plans Qwest sponsored defined benefit plans	Dec. 31, 2012 Post-Retirement Plans	Dec. 31, 2011 Post-Retirement Plans	Dec. 31, 2010 Post-Retirement Plans	Dec. 31, 2012 Post-Retirement Plans Equity Securities	Dec. 31, 2012 Post-Retirement Plans Non-equity investments	Dec. 31, 2012 Post-Retirement Plans Minimum	Dec. 31, 2010 Post-Retirement Plans Minimum	Dec. 31, 2011 Post-Retirement Plans Minimum	Dec. 31, 2012 Post-Retirement Plans Maximum	Dec. 31, 2011 Post-Retirement Plans Maximum	Dec. 31, 2010 Post-Retirement Plans Maximum	Apr. 30, 2011 Post-Retirement Plans Qwest sponsored defined benefit plans	Dec. 31, 2011 Post-Retirement Plans Qwest sponsored defined benefit plans	Apr. 02, 2011 Post-Retirement Plans Qwest sponsored defined benefit plans
Employee Benefits
Amortization period of the plan shortfall					7 years
Unfunded status					$ (2,500,000,000)
Liability for the unfunded status of the defined benefit plans					2,554,000,000	1,782,000,000																				490,000,000	3,289,000,000	3,073,000,000												2,500,000,000
Estimated projected benefit obligations					14,881,000,000	13,596,000,000	4,534,000,000																			8,300,000,000	4,075,000,000	3,930,000,000	558,000,000											3,300,000,000
Estimated fair value of plan assets					12,321,000,000	11,814,000,000	3,732,000,000																			7,800,000,000	626,000,000	693,000,000	54,000,000											762,000,000
Reduction of benefit obligation							110,000,000
Curtailment gain							(21,000,000)
Effect of change of 100 basis points in the assumed initial health care cost trend rate
Effect on the aggregate of the service and interest cost components of net periodic post-retirement benefit expense (statements of operations) - Increase																											3,000,000
Effect on the aggregate of the service and interest cost components of net periodic post-retirement benefit expense (statements of operations) - Decrease																											(3,000,000)
Effect of one-percentage point increase on postretirement benefit obligation																											77,000,000
Effect on benefit obligation (balance sheets) - Decrease																											(70,000,000)
Healthcare cost increase trend rates (as a percent)
Annual decrease in health care cost trend rate (as a percent)																											(0.25%)
Health care cost trend rate (as a percent)																											6.75%
Ultimate health care cost trend rate (as a percent)																											4.50%	5.00%	5.00%									5.00%
Estimated future projected benefit payments
2013					1,051,000,000																						377,000,000
2014					1,006,000,000																						370,000,000
2015					996,000,000																						358,000,000
2016					985,000,000																						348,000,000
2017					972,000,000																						338,000,000
2018-2022					4,626,000,000																						1,511,000,000
Medicare Part D Subsidy Receipts
2013																											(25,000,000)
2014																											(26,000,000)
2015																											(28,000,000)
2016																											(29,000,000)
2017																											(31,000,000)
2018-2022																											(173,000,000)
Actuarial assumptions at beginning of year:
Discount rate (as a percent)																		4.25%	5.00%	5.50%	5.10%	5.50%	6.00%	5.40%				5.30%				4.60%	5.70%		4.80%		5.80%	5.30%
Rate of compensation increase (as a percent)					3.25%	3.25%														3.50%			4.00%	3.50%
Expected long-term rate of return on plan assets (as a percent)					7.50%														7.50%	8.25%		8.00%	8.50%	7.50%			7.50%	7.25%	7.25%			6.00%			7.50%			7.50%
Initial health care cost trend rate (as a percent)																											8.00%	8.50%	8.00%						7.50%	8.00%		7.50%
Ultimate health care cost trend rate (as a percent)																											4.50%	5.00%	5.00%									5.00%
Components of net periodic benefit (income) expense
Service cost					87,000,000	70,000,000	61,000,000																				22,000,000	18,000,000	15,000,000
Interest cost					625,000,000	560,000,000	246,000,000																				173,000,000	152,000,000	32,000,000
Expected return on plan assets	(892,000,000)	(750,000,000)			(847,000,000)	(709,000,000)	(283,000,000)																				(45,000,000)	(41,000,000)	(4,000,000)
Curtailment gain							(21,000,000)
Settlements						1,000,000
Amortization of unrecognized prior service cost					4,000,000	2,000,000	2,000,000																					(2,000,000)	(3,000,000)
Amortization of unrecognized acturial loss					35,000,000	13,000,000	17,000,000																						1,000,000
Net periodic benefits (income) expense					(96,000,000)	(63,000,000)	22,000,000																		(58,000,000)		150,000,000	127,000,000	41,000,000										92,000,000
Actuarial assumptions at end of year:
Discount rate (as a percent)																		3.25%	4.25%		4.20%	5.10%					3.60%							4.60%		4.80%
Rate of compensation increase (as a percent)					3.25%	3.25%
Initial health care cost trend rate (as a percent)																											8.00%	8.50%	8.00%						7.50%	8.00%		7.50%
Ultimate health care cost trend rate (as a percent)																											4.50%	5.00%	5.00%									5.00%
Change in benefit obligation
Benefit obligation at beginning of year				14,881,000,000	13,596,000,000	4,534,000,000	4,182,000,000																			8,300,000,000	3,930,000,000	558,000,000	582,000,000											3,300,000,000
Service cost					87,000,000	70,000,000	61,000,000																				22,000,000	18,000,000	15,000,000
Interest cost					625,000,000	560,000,000	246,000,000																				173,000,000	152,000,000	32,000,000
Participant contributions																											86,000,000	64,000,000	14,000,000
Plan amendments					14,000,000	12,000,000	4,000,000																					31,000,000
Acquisitions						8,267,000,000																						(3,284,000,000)
Direct subsidy receipts																											19,000,000	22,000,000	1,000,000
Actuarial (gain) loss					1,565,000,000	930,000,000	427,000,000																				260,000,000	153,000,000	(32,000,000)
Curtailment gain							(110,000,000)
Benefits paid by company					(5,000,000)	(16,000,000)	(5,000,000)																				(268,000,000)	(219,000,000)	(45,000,000)
Benefits paid from plan assets					(1,001,000,000)	(761,000,000)	(271,000,000)																				(147,000,000)	(133,000,000)	(9,000,000)
Benefit obligation at end of year					14,881,000,000	13,596,000,000	4,534,000,000																			8,300,000,000	4,075,000,000	3,930,000,000	558,000,000											3,300,000,000
Aggregate accumulated benefit obligation	18,956,000,000	17,499,000,000	4,509,000,000
Change in plan assets
Fair value of plan assets at the beginning of the period				12,321,000,000	11,814,000,000	3,732,000,000	3,220,000,000																			7,800,000,000	693,000,000	54,000,000	57,000,000											762,000,000
Return (loss) on plan assets	1,555,000,000,000	483,000,000			1,476,000,000	479,000,000	483,000,000																				80,000,000	4,000,000	6,000,000
Acquisitions						7,777,000,000																						768,000,000
Employer contributions				147,000,000	32,000,000	587,000,000	300,000,000
Benefits paid from plan assets					(1,001,000,000)	(761,000,000)	(271,000,000)																				(147,000,000)	(133,000,000)	(9,000,000)
Fair value of plan assets at the end of the period					$ 12,321,000,000	$ 11,814,000,000	$ 3,732,000,000																			$ 7,800,000,000	$ 626,000,000	$ 693,000,000	$ 54,000,000											$ 762,000,000
Target allocation of plan assets
Target asset allocation percentage								55.00%	35.00%	13.50%	13.50%	6.50%	45.00%	14.00%	14.00%	12.00%	5.00%													35.00%	65.00%
Expected long-term rate of return on plan assets (as a percent)					7.50%														7.50%	8.25%		8.00%	8.50%	7.50%			7.50%	7.25%	7.25%			6.00%			7.50%			7.50%
Permitted investment in securities issued by the sponsor company (as a percent)	10.00%