CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Cash Flows [Abstract]
Proceeds from Life Insurance Policy	$ 5	$ 110
Cash flows from operating activities
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(514)	235
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Impairments	231	0
Depreciation and amortization	7,050	7,061
Bad debt expense	435	278
Share-based and long-term incentive compensation expense	90	101
Deferred income tax benefit	(532)	25
Gain Loss from asset dispositions and exchanges	4	12
Amortization and accretion of long-term debt premiums and discounts	(47)	(94)
Loss on disposition of property, plant, and equipment	692	642
Other changes in assets and liabilities:
Accounts and notes receivable	(754)	65
Deferred purchase price from sale of receivables	0	(223)
Inventories and other current assets	650	248
Operating lease, right-of-use asset (cash flow)	1,280
Accounts payable and other current liabilities	(436)	(530)
Current and long-term operating lease liabilities (cash flow)	(1,433)
Non-current assets and liabilities, net	(172)	(601)
Other, net	225	375
Net cash provided by operating activities	6,765	7,582
Cash flows from investing activities
Capital expenditures - network and other	(3,360)	(3,814)
Capital expenditures - leased devices	(5,449)	(5,739)
Expenditures relating to FCC licenses	(24)	(145)
Proceeds from sales and maturities of short-term investments	79	6,619
Purchases of short-term investments	(74)	(5,152)
Proceeds from sales of assets and FCC Licenses	819	416
Proceeds from Sale and Collection of Receivables	0	223
Other, net	(27)	52
Net Cash Used in Investing Activities	(8,031)	(7,430)
Cash flows from financing activities
Proceeds from debt and financings	4,731	6,416
Repayments of debt and capital lease obligations	(7,188)	(6,937)
Debt financing costs	12	286
Proceeds from issuance of common stock, net	(29)	281
Net cash provided by (used in) financing activities	(2,530)	(526)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(3,796)	(374)
Cash and cash equivalents, end of period	3,179	6,285
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	3,267	6,285
Acquisition of noncontrolling interest	(33)
Other, net	$ 1	$ 0