Segment Information (Operating Revenues by Service and Products) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended		0 Months Ended		3 Months Ended
	Sep. 30, 2014 Successor [Member]	Sep. 30, 2013 Successor [Member]	Sep. 30, 2014 Successor [Member]	Sep. 30, 2013 Successor [Member]	Sep. 30, 2014 Successor [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Wireless [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Wireless [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Services [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Services [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Equipment [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Equipment [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Voice [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Voice [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Data [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Data [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Internet [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Internet [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Wireline [Member] Other Products or Services [Member]	Sep. 30, 2013 Successor [Member] Wireline [Member] Other Products or Services [Member]	Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]		Sep. 30, 2014 Successor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]		Sep. 30, 2013 Successor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]		Jul. 10, 2013 Predecessor [Member]	Jul. 10, 2013 Predecessor [Member]	Jul. 10, 2013 Predecessor [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireless [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Equipment [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Voice [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Data [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Internet [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Wireline [Member] Other Products or Services [Member]	Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Services [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Equipment [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Voice [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Data [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Internet [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]		Jul. 10, 2013 Predecessor [Member] Corporate, Other And Eliminations [Member] Other Products or Services [Member]
Segment Reporting Information [Line Items]
Net operating revenues	$ 8,488	$ 7,749	$ 17,277	$ 7,749																									$ 7,929	$ 7,159	$ 16,122	$ 7,159	$ 6,693	$ 6,399	$ 13,601	$ 6,399	$ 1,039	$ 636	$ 2,145	$ 636	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 197	$ 124	$ 376	$ 124	$ 708	$ 777	$ 1,454	$ 777	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 294	$ 333	$ 621	$ 333	$ 53	$ 57	$ 109	$ 57	$ 340	$ 373	$ 685	$ 373	$ 21	$ 14	$ 39	$ 14	$ (149)	[1]	$ (187)	[1]	$ (299)	[1]	$ (187)	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ (86)	[1]	$ (120)	[1]	$ (177)	[1]	$ (120)	[1]	$ (22)	[1]	$ (23)	[1]	$ (46)	[1]	$ (23)	[1]	$ (41)	[1]	$ (46)	[1]	$ (79)	[1]	$ (46)	[1]	$ 0	[1]	$ 2	[1]	$ 3	[1]	$ 2	[1]	$ 932	$ 9,809													$ 858	$ 9,036	$ 769	$ 7,996	$ 74	$ 894	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 15	$ 146	$ 98	$ 1,008	$ 0	$ 0	$ 0	$ 0	$ 42	$ 419	$ 7	$ 94	$ 47	$ 479	$ 2	$ 16	$ (24)	[1]	$ (235)	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ (15)	[1]	$ (137)	[1]	$ (3)	[1]	$ (47)	[1]	$ (5)	[1]	$ (53)	[1]	$ (1)	[1]	$ 2	[1]
Segment Reporting Information, Total Net Operating Revenues	$ 8,488	$ 7,749	$ 17,277	$ 7,749	$ 6,693	$ 6,399	$ 13,601	$ 6,399	$ 1,039	$ 636	$ 2,145	$ 636	$ 208	$ 213	$ 444	$ 213	$ 31	$ 34	$ 63	$ 34	$ 299	$ 327	$ 606	$ 327	$ 218	$ 140	$ 418	$ 140	$ 7,929	$ 7,159	$ 16,122	$ 7,159																									$ 555	$ 586	$ 1,148	$ 586																									$ 4		$ 4		$ 7		$ 4																																																		$ 932	$ 9,809	$ 769	$ 7,996	$ 74	$ 894	$ 27	$ 282	$ 4	$ 47	$ 42	$ 426	$ 16	$ 164	$ 858	$ 9,036													$ 74	$ 769													$ 0		$ 4

[1] Revenues eliminated in consolidation consist primarily of wireline services provided to the Wireless segment for resale to or use by wireless subscribers.