Restructuring - Summary of Activity Related to Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
2016 Cost Alignment Plan
Beginning balance		$ 222	$ 0
Net restructuring charges recognized	$ 229	14	229
Non-cash charges		(9)	(2)
Cash Payments		(106)	(1)
Other		(15)	(4)
Ending balance	222	106	222
Operating Segments | Distribution Solutions
2016 Cost Alignment Plan
Beginning balance		156	0
Net restructuring charges recognized	161	19	161
Non-cash charges		(10)	(4)
Cash Payments		(67)	(1)
Other		(8)	0
Ending balance	156	90	156
Operating Segments | Technology Solutions
2016 Cost Alignment Plan
Beginning balance		45	0
Net restructuring charges recognized	51	(10)	51
Non-cash charges		0	(3)
Cash Payments		(20)	0
Other		(5)	(3)
Ending balance	45	10	45
Corporate
2016 Cost Alignment Plan
Beginning balance		21	0
Net restructuring charges recognized	17	5	17
Non-cash charges		1	5
Cash Payments		(19)	0
Other		(2)	(1)
Ending balance	$ 21	$ 6	$ 21