Impact of Adopting Topic 606 2 (Details) - USD ($) $ in Millions	Sep. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
Current assets:
Cash and cash equivalents	$ 2,931		$ 3,405
Trade accounts receivable, net	507		793
Contract assets	817		0
Other current assets	107		210
Total current assets	4,362		4,408
Property and equipment, net	213		237
Goodwill	6,790		6,804
Capitalized software and other intangible assets, net	981		1,111
Deferred income taxes	124		346
Contract assets	112		0
Contract costs	400		0
Other noncurrent assets, net	121		154
Total assets	13,103		13,060
Current liabilities:
Current portion of long-term debt	20		269
Accounts payable	81		85
Accrued salaries, wages and commissions	201		242
Accrued expenses and other current liabilities	309		340
Deferred revenue and advanced payments	1,002		2,289
Taxes payable, other than income taxes payable	25		55
Federal, state and foreign income taxes payable	72		41
Total current liabilities	1,710		3,321
Long-term debt, net of current portion	2,506		2,514
Federal, state and foreign income taxes payable	297		311
Deferred income taxes	171		111
Deferred revenue and advanced payments	419		820
Other noncurrent liabilities	98		88
Total liabilities	5,201		7,165
Stockholders' equity:
Preferred stock	0		0
Common stock	59		59
Additional paid-in capital	3,735		3,744
Retained earnings	9,156		6,971
Accumulated other comprehensive loss	(463)		(290)
Treasury stock	(4,585)		(4,589)
Total stockholders' equity	7,902		5,895
Total liabilities and stockholders' equity	13,103		13,060
As Reported under Topic 606
Current assets:
Cash and cash equivalents	2,931	$ 3,405
Trade accounts receivable, net	507	802
Contract assets	817	772
Other current assets	107	172
Total current assets	4,362	5,151
Property and equipment, net	213	237
Goodwill	6,790	6,804
Capitalized software and other intangible assets, net	981	1,111
Deferred income taxes	124	125
Contract assets	112	159
Contract costs	400	427
Other noncurrent assets, net	121	135
Total assets	13,103	14,149
Current liabilities:
Current portion of long-term debt	20	269
Accounts payable	81	85
Accrued salaries, wages and commissions	201	242
Accrued expenses and other current liabilities	309	332
Deferred revenue and advanced payments	1,002	1,222
Taxes payable, other than income taxes payable	25	55
Federal, state and foreign income taxes payable	72	211
Total current liabilities	1,710	2,416
Long-term debt, net of current portion	2,506	2,514
Federal, state and foreign income taxes payable	297	421
Deferred income taxes	171	191
Deferred revenue and advanced payments	419	529
Other noncurrent liabilities	98	88
Total liabilities	5,201	6,159
Stockholders' equity:
Preferred stock	0	0
Common stock	59	59
Additional paid-in capital	3,735	3,744
Retained earnings	9,156	9,075
Accumulated other comprehensive loss	(463)	(299)
Treasury stock	(4,585)	(4,589)
Total stockholders' equity	7,902	7,990
Total liabilities and stockholders' equity	13,103	14,149
Proforma as if the previous accounting of Topic 605 was in effect
Current assets:
Cash and cash equivalents	2,931		3,405
Trade accounts receivable, net	502		793
Contract assets	0		0
Other current assets	183		210
Total current assets	3,616		4,408
Property and equipment, net	213		237
Goodwill	6,790		6,804
Capitalized software and other intangible assets, net	981		1,111
Deferred income taxes	338		346
Contract assets	0		0
Contract costs	0		0
Other noncurrent assets, net	136		154
Total assets	12,074		13,060
Current liabilities:
Current portion of long-term debt	20		269
Accounts payable	81		85
Accrued salaries, wages and commissions	201		242
Accrued expenses and other current liabilities	319		340
Deferred revenue and advanced payments	1,826		2,289
Taxes payable, other than income taxes payable	25		55
Federal, state and foreign income taxes payable	0		41
Total current liabilities	2,472		3,321
Long-term debt, net of current portion	2,506		2,514
Federal, state and foreign income taxes payable	187		311
Deferred income taxes	98		111
Deferred revenue and advanced payments	638		820
Other noncurrent liabilities	98		88
Total liabilities	5,999		7,165
Stockholders' equity:
Preferred stock	0		0
Common stock	59		59
Additional paid-in capital	3,735		3,744
Retained earnings	7,263		6,971
Accumulated other comprehensive loss	(397)		(290)
Treasury stock	(4,585)		(4,589)
Total stockholders' equity	6,075		5,895
Total liabilities and stockholders' equity	12,074		$ 13,060
Effect of Change Higher/(Lower)
Current assets:
Cash and cash equivalents	0	0
Trade accounts receivable, net	5	9
Contract assets	817	772
Other current assets	(76)	(38)
Total current assets	746	743
Property and equipment, net	0	0
Goodwill	0	0
Capitalized software and other intangible assets, net	0	0
Deferred income taxes	(214)	(221)
Contract assets	112	159
Contract costs	400	427
Other noncurrent assets, net	(15)	(19)
Total assets	1,029	1,089
Current liabilities:
Current portion of long-term debt	0	0
Accounts payable	0	0
Accrued salaries, wages and commissions	0	0
Accrued expenses and other current liabilities	(10)	(8)
Deferred revenue and advanced payments	(824)	(1,067)
Taxes payable, other than income taxes payable	0	0
Federal, state and foreign income taxes payable	72	170
Total current liabilities	(762)	(905)
Long-term debt, net of current portion	0	0
Federal, state and foreign income taxes payable	110	110
Deferred income taxes	73	80
Deferred revenue and advanced payments	(219)	(291)
Other noncurrent liabilities	0	0
Total liabilities	(798)	(1,006)
Stockholders' equity:
Preferred stock	0	0
Common stock	0	0
Additional paid-in capital	0	0
Retained earnings	1,893	2,104
Accumulated other comprehensive loss	(66)	(9)
Treasury stock	0	0
Total stockholders' equity	1,827	2,095
Total liabilities and stockholders' equity	$ 1,029	$ 1,089