Supplemental Financial Information (Details) (Successor [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Successor [Member]
Accounts and notes receivable, net
Trade	$ 1,037		$ 3,271
Unbilled trade and other	1,457		533
Less allowance for doubtful accounts	(204)		(197)
Accounts and notes receivable, net	2,290		3,607
Prepaid expenses and other current assets
Prepaid expenses	401		451
Due from conduits for receivables sold	1,198		0
Deferred charges and other	291		221
Prepaid expense and other assets, current	1,890		672
Other assets
Unbilled trade installment receivables, net	361		317
Investments	151		146
Other	565		429
Other assets	1,077		892
Accounts payable
Trade	3,786	[1]	2,492	[1]
Accrued interconnection costs	198	[1]	316	[1]
Capital expenditures and other	363	[1]	355	[1]
Accounts payable	4,347	[1]	3,163	[1]
Accrued expenses and other current liabilities
Deferred revenues	1,385		1,286
Accrued taxes	238		306
Payroll and related	589		290
Severance, lease and other exit costs	223		555
Accrued interest	525		515
Accrued capital expenditures	705		1,247
Other	1,628		1,345
Accrued expenses and other current liabilites	5,293		5,544
Other liabilities
Deferred rental income-communications towers	229		240
Deferred rent	366		179
Asset retirement obligations	584		651
Unfavorable lease liabilities	856		1,068
Post-retirement benefits and other non-current employee related liabilities	987		647
Other	929		900
Other liabilities	3,951		3,685
Checks issued in excess of associated bank balances but not yet presented for collection	$ 90		$ 91

[1] Includes liabilities in the amounts of $90 million and $91 million as of March 31, 2015 and 2014, respectively, for checks issued in excess of associated bank balances but not yet presented for collection.