Restructuring - Narrative (Details) - Cost Alignment Plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended	7 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Pre-tax charges recorded during period	$ (10)	$ 229	$ (1)
Restructuring liabilities	130	$ 222	130	$ 130
Pre-tax restructuring charges incurred to-date				228
Other Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	89		89	89
Other Noncurrent Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	41		41	41
Minimum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	260		260	260
Maximum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	280		280	$ 280
Severance
Restructuring Cost and Reserve [Line Items]
Payments for severance	$ 26		$ 71