Income Taxes (Deferred Income Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Mar. 31, 2015
Deferred tax assets
Net operating loss carryforwards, long-term	$ 8,057	$ 8,155
Tax credit carryforwards, long-term	384	381
Capital loss carryforwards, long-term	83	84
Property, plant and equipment, long-term	1,230	261
Debt obligations, long-term	0	419
Deferred rent, long-term	438	470
Pension and other postretirement benefits, long-term	378	385
Accruals and other liabilities, current		637
Accruals and other liabilities, long-term	1,376	561
Deferred tax assets, gross, current		637
Deferred tax assets, gross, noncurrent	11,946	10,716
Valuation allowance, current		(509)
Valuation allowance, noncurrent	(9,793)	(8,371)
Deferred tax assets, net of valuation allowance, current		128
Deferred tax assets, net of valuation allowance, noncurrent	2,153	2,345
Deferred tax liabilities
FCC Licenses	12,738	12,558
Trademarks	1,718	1,725
Intangibles	1,166	1,658
Deferred Tax Liabilities, Deferred Expense, Debt Issuance Costs	58	0
Other, current		66
Other, long-term	432	302
Deferred tax liabilities, current		66
Deferred tax liabilities, long-term	16,112	16,243
Current deferred tax asset	0	62
Long-term deferred tax liability	$ 13,959	13,898
Successor [Member]
Deferred tax liabilities
Current deferred tax asset		$ 62