Income Taxes (Deferred Income Tax Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Deferred tax assets
Capital loss carryforwards, long-term	$ 84
Successor [Member]
Deferred tax assets
Net operating loss carryforwards, long-term	8,155	7,264
Tax credit carryforwards, long-term	381	374
Capital loss carryforwards, long-term	84	82
Property, plant and equipment, long-term	261	500
Debt obligations, long-term	419	598
Deferred rent, long-term	470	474
Pension and other postretirement benefits, long-term	385	252
Accruals and other liabilities, current	637	738
Accruals and other liabilities, long-term	561	601
Deferred tax assets, gross, current	637	738
Deferred tax assets, gross, noncurrent	10,716	10,145
Valuation allowance, current	(509)	(522)
Valuation allowance, noncurrent	(8,371)	(7,175)
Deferred tax assets, net of valuation allowance, current	128	216
Deferred tax assets, net of valuation allowance, noncurrent	2,345	2,970
Deferred tax liabilities
FCC Licenses	12,558	12,158
Trademarks	1,725	2,461
Intangibles	1,658	2,248
Other, current	66	88
Other, long-term	302	310
Deferred tax liabilities, current	66	88
Deferred tax liabilities, long-term	16,243	17,177
Current deferred tax asset	62	128
Long-term deferred tax liability	$ 13,898	$ 14,207