CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Revenue, Net [Abstract]
Sales Revenue, Services, Net	$ 5,740	$ 6,071
Revenue, equipment sales, net	1,173	1,187
Revenue, equipment rentals, net	1,212	899
Net operating revenues	8,125	8,157
Net operating expenses
Cost of Services (exclusive of depreciation and amortization included below)	1,677	1,709
Cost of equipment sales	1,270	1,545
Cost of equipment rentals	124	112
Selling, general and administrative	1,867	1,938
Depreciation, network and other	1,023	977
Depreciation, equipment rentals	1,136	854
Amortization	171	223
Other, net	42	(364)
Total costs and expenses	7,310	6,994
Operating Income	815	1,163
Other (expense) income
Interest Expense	(637)	(613)
Other income, net	42	(52)
Nonoperating Expense	(595)	(665)
Loss (income) before income taxes	220	498
Income tax benefit	(47)	(292)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	173	206
Net Income (Loss) Attributable to Noncontrolling Interest	3	0
Net Income (Loss) Attributable to Parent	$ 176	$ 206
Basic net (loss) income per common share	$ 0.04	$ 0.05
Diluted net (loss) income per common share	$ 0.04	$ 0.05
Basic weighted average common shares outstanding	4,010	3,993
Diluted weighted average common shares outstanding	4,061	4,076
Other comprehensive (loss) income, net of tax:
Net unrealized holding gains on securities and other	$ (8)	$ 5
Net unrealized holding gains (losses) on derivatives	10	(9)
Net unrecognized net periodic pension and other postretirement benefits	2	0
Cumulative Effect of New Accounting Pronouncement	(8)
Other comprehensive income	(4)	(4)
Comprehensive (loss) income	$ 169	$ 202