Divestiture of Businesses (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Discontinued Operations Disclosures
Pre-tax gain on sale of business			$ (94)	$ 103	$ 0
Distribution Solutions | ZEE Medical Business | Operating Segments
Discontinued Operations Disclosures
Proceeds from divestiture of businesses	$ 134
Pre-tax gain on sale of business	52			52
Gain from sale of business, after tax	$ 29
Technology Solutions | Nurse Triage | Operating Segments
Discontinued Operations Disclosures
Proceeds from divestiture of businesses		$ 84
Pre-tax gain on sale of business		51		$ 51
Gain from sale of business, after tax		$ 38