Restructuring - Narrative (Details) - Cost Alignment Plan - USD ($) $ in Millions	3 Months Ended		16 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring charges incurred to-date			$ 246
Pre-tax charges recorded during period		$ 9
Other Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	$ 64		64	$ 71
Noncurrent Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	35		35	$ 35
Severance
Restructuring Cost and Reserve [Line Items]
Payments for severance	14	$ 45
Minimum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	250		250
Maximum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	$ 270		$ 270