Guarantor Financial Information (CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS)) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Net operating revenues	$ 8,107	$ 8,973		$ 24,109	$ 26,250
Cost of Services (exclusive of depreciation and amortization included below)	2,348	2,330		7,194	7,279
Cost of Products (exclusive of depreciation and amortization included below)	1,589	2,952		4,244	7,482
Net operating expenses
Selling, general and administrative	2,129	2,647		6,540	7,232
Impairments	0	2,133	[1]	0	2,133	[1]
Severance and exit costs	209	22		247	333
Depreciation	1,549	940		4,202	2,706
Amortization	316	380		994	1,189
Other, net	164	109		386	109
Total costs and expenses	8,304	11,513		23,807	28,463
Operating Income	(197)	(2,540)		302	(2,213)
Other (expense) income
Interest Income	3	3		7	10
Interest Expense	(546)	(506)		(1,630)	(1,528)
(Losses) earnings of Subsidiaries	0	0		0	0
Other income, net	1	7		6	9
Nonoperating Expense	(542)	(496)		(1,617)	(1,509)
Loss (income) before income taxes	(739)	(3,036)		(1,315)	(3,722)
Income tax benefit	(97)	657		(126)	601
Net (loss) income	(836)	(2,379)		(1,441)	(3,121)
Other Comprehensive Income (Loss), Net of Tax	(7)	(220)		(11)	(227)
Comprehensive (loss) income	(843)	(2,599)		(1,452)	(3,348)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net operating revenues	0	0		0	0
Cost of Services (exclusive of depreciation and amortization included below)	0	0		0	0
Cost of Products (exclusive of depreciation and amortization included below)	0	0		0	0
Net operating expenses
Selling, general and administrative	0	0		0	0
Impairments		0			0
Severance and exit costs	0	0		0	0
Depreciation	0	0		0	0
Amortization	0	0		0	0
Other, net	0	1		0	1
Total costs and expenses	0	1		0	1
Operating Income	0	(1)		0	(1)
Other (expense) income
Interest Income	39	22		118	68
Interest Expense	(406)	(360)		(1,220)	(1,092)
(Losses) earnings of Subsidiaries	(471)	(2,041)		(341)	(2,097)
Other income, net	0	1		0	1
Nonoperating Expense	(838)	(2,378)		(1,443)	(3,120)
Loss (income) before income taxes	(838)	(2,379)		(1,443)	(3,121)
Income tax benefit	0	0		0	0
Net (loss) income	(838)	(2,379)		(1,443)	(3,121)
Other Comprehensive Income (Loss), Net of Tax	(7)	(220)		(11)	(227)
Comprehensive (loss) income	(845)	(2,599)		(1,454)	(3,348)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net operating revenues	8,107	8,973		24,109	26,250
Cost of Services (exclusive of depreciation and amortization included below)	2,348	2,330		7,194	7,279
Cost of Products (exclusive of depreciation and amortization included below)	1,589	2,952		4,244	7,482
Net operating expenses
Selling, general and administrative	2,129	2,647		6,540	7,232
Impairments		2,133			2,133
Severance and exit costs	209	22		247	333
Depreciation	1,549	940		4,202	2,706
Amortization	316	380		994	1,189
Other, net	164	108		386	108
Total costs and expenses	8,304	11,512		23,807	28,462
Operating Income	(197)	(2,539)		302	(2,212)
Other (expense) income
Interest Income	2	1		3	2
Interest Expense	(178)	(166)		(524)	(496)
(Losses) earnings of Subsidiaries	0	0		0	0
Other income, net	1	6		6	8
Nonoperating Expense	(175)	(159)		(515)	(486)
Loss (income) before income taxes	(372)	(2,698)		(213)	(2,698)
Income tax benefit	(99)	657		(128)	601
Net (loss) income	(471)	(2,041)		(341)	(2,097)
Other Comprehensive Income (Loss), Net of Tax	(4)	(208)		(6)	(209)
Comprehensive (loss) income	(475)	(2,249)		(347)	(2,306)
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net operating revenues	0	0		0	0
Cost of Services (exclusive of depreciation and amortization included below)	0	0		0	0
Cost of Products (exclusive of depreciation and amortization included below)	0	0		0	0
Net operating expenses
Selling, general and administrative	0	0		0	0
Impairments		0			0
Severance and exit costs	0	0		0	0
Depreciation	0	0		0	0
Amortization	0	0		0	0
Other, net	0	0		0	0
Total costs and expenses	0	0		0	0
Operating Income	0	0		0	0
Other (expense) income
Interest Income	(236)	(189)		(707)	(567)
Interest Expense	236	189		707	567
(Losses) earnings of Subsidiaries	1,309	4,420		1,784	5,218
Other income, net	0	0		0	0
Nonoperating Expense	1,309	4,420		1,784	5,218
Loss (income) before income taxes	1,309	4,420		1,784	5,218
Income tax benefit	0	0		0	0
Net (loss) income	1,309	4,420		1,784	5,218
Other Comprehensive Income (Loss), Net of Tax	11	428		17	436
Comprehensive (loss) income	1,320	4,848		1,801	5,654
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Net operating revenues	0	0		0	0
Cost of Services (exclusive of depreciation and amortization included below)	0	0		0	0
Cost of Products (exclusive of depreciation and amortization included below)	0	0		0	0
Net operating expenses
Selling, general and administrative	0	0		0	0
Impairments		0			0
Severance and exit costs	0	0		0	0
Depreciation	0	0		0	0
Amortization	0	0		0	0
Other, net	0	0		0	0
Total costs and expenses	0	0		0	0
Operating Income	0	0		0	0
Other (expense) income
Interest Income	198	169		593	507
Interest Expense	(198)	(169)		(593)	(507)
(Losses) earnings of Subsidiaries	(838)	(2,379)		(1,443)	(3,121)
Other income, net	0	0		0	0
Nonoperating Expense	(838)	(2,379)		(1,443)	(3,121)
Loss (income) before income taxes	(838)	(2,379)		(1,443)	(3,121)
Income tax benefit	2	0		2	0
Net (loss) income	(836)	(2,379)		(1,441)	(3,121)
Other Comprehensive Income (Loss), Net of Tax	(7)	(220)		(11)	(227)
Comprehensive (loss) income	$ (843)	$ (2,599)		$ (1,452)	$ (3,348)

[1] Impairments for the three and nine-month periods ended December 31, 2014 consist of a $1.9 billion Sprint trade name impairment related to the Wireless segment and a $233 million impairment related to Wireline long-lived assets.