Impact of Adopting Topic 606 5 (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 166	$ 178
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	86	96
Deferred income taxes	(3)	5
Provision for bad debts	0	2
Share-based compensation expense	33	32
Other non-cash items	3	1
Foreign currency transaction (gains) losses	(5)	1
Changes in other operating assets and liabilities, net of effect of acquisitions:
Decrease in trade accounts receivable	262	308
Increase in contract assets	(6)	0
Decrease in contract costs	11	0
Decrease in deferred revenue and advanced payments	(148)	(172)
Decrease in taxes payable, net	(179)	(56)
Increase in accounts payable, accrued expenses and other	44	(5)
Decrease in accrued salaries, wages and commissions	(36)	(102)
Changes in other operating assets and liabilities, net	34	10
Net cash provided by operating activities	262	$ 298
As Reported under Topic 606
Operating activities:
Net income	166
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	86
Deferred income taxes	(3)
Provision for bad debts	0
Share-based compensation expense	33
Other non-cash items	3
Foreign currency transaction (gains) losses	(5)
Changes in other operating assets and liabilities, net of effect of acquisitions:
Decrease in trade accounts receivable	262
Increase in contract assets	(6)
Decrease in contract costs	11
Decrease in deferred revenue and advanced payments	(148)
Decrease in taxes payable, net	(179)
Increase in accounts payable, accrued expenses and other	44
Decrease in accrued salaries, wages and commissions	(36)
Changes in other operating assets and liabilities, net	34
Net cash provided by operating activities	262
Proforma as if the previous accounting of Topic 605 was in effect
Operating activities:
Net income	261
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	86
Deferred income taxes	(1)
Provision for bad debts	(1)
Share-based compensation expense	33
Other non-cash items	3
Foreign currency transaction (gains) losses	1
Changes in other operating assets and liabilities, net of effect of acquisitions:
Decrease in trade accounts receivable	257
Increase in contract assets	0
Decrease in contract costs	0
Decrease in deferred revenue and advanced payments	(260)
Decrease in taxes payable, net	(159)
Increase in accounts payable, accrued expenses and other	45
Decrease in accrued salaries, wages and commissions	(36)
Changes in other operating assets and liabilities, net	33
Net cash provided by operating activities	262
Effect of Change Higher/(Lower)
Operating activities:
Net income	(95)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	0
Deferred income taxes	(2)
Provision for bad debts	1
Share-based compensation expense	0
Other non-cash items	0
Foreign currency transaction (gains) losses	(6)
Changes in other operating assets and liabilities, net of effect of acquisitions:
Decrease in trade accounts receivable	5
Increase in contract assets	(6)
Decrease in contract costs	11
Decrease in deferred revenue and advanced payments	112
Decrease in taxes payable, net	(20)
Increase in accounts payable, accrued expenses and other	(1)
Decrease in accrued salaries, wages and commissions	0
Changes in other operating assets and liabilities, net	1
Net cash provided by operating activities	$ 0