CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue, Net [Abstract]
Service	$ 6,413	$ 6,880	$ 12,929	$ 13,917
Equipment	1,834	1,095	3,330	2,085
Net operating revenues	8,247	7,975	16,259	16,002
Net operating expenses
Cost of Services (exclusive of depreciation and amortization included below)	2,101	2,453	4,200	4,846
Cost of Products (exclusive of depreciation and amortization included below)	1,693	1,290	3,112	2,655
Selling, general and administrative	1,995	2,224	3,912	4,411
Severance and exit costs	(5)	25	11	38
Depreciation	1,710	1,412	3,390	2,653
Amortization	271	331	558	678
Other, net	(140)	242	93	222
Total costs and expenses	7,625	7,977	15,276	15,503
Operating Income	622	(2)	983	499
Other (expense) income
Interest Expense	(630)	(542)	(1,245)	(1,084)
Other income, net	(15)	5	(7)	9
Nonoperating Expense	(645)	(537)	(1,252)	(1,075)
Loss (income) before income taxes	(23)	(539)	(269)	(576)
Income tax benefit	(119)	(46)	(175)	(29)
Net (loss) income	$ (142)	$ (585)	$ (444)	$ (605)
Basic net (loss) income per common share	$ (0.04)	$ (0.15)	$ (0.11)	$ (0.15)
Diluted net (loss) income per common share	$ (0.04)	$ (0.15)	$ (0.11)	$ (0.15)
Basic weighted average common shares outstanding	3,979	3,969	3,977	3,968
Diluted weighted average common shares outstanding	3,979	3,969	3,977	3,968
Other comprehensive (loss) income, net of tax:
Net unrealized holding gains on securities and other	$ 7	$ (9)	$ 5	$ (7)
Net unrecognized net periodic pension and other postretirement benefits	1	1	2	3
Other comprehensive income	8	(8)	7	(4)
Comprehensive (loss) income	$ (134)	$ (593)	$ (437)	$ (609)