Healthcare Technology Net Asset Exchange (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Mar. 01, 2017
Schedule of Equity Method Investments [Line Items]
Gain on Healthcare Technology Net Asset Exchange	$ 37		$ 0
Net losses from Change Healthcare	120		$ 0
Carrying value of investment	3,855	$ 4,063
Tax Receivable Agreement (“TRA”) | Change Healthcare, LLC (“Change Healthcare”)
Schedule of Equity Method Investments [Line Items]
Noncurrent liability	136	136
Joint Venture | Transition Services Agreements (“TSA”)
Schedule of Equity Method Investments [Line Items]
Reimbursements for transition services fees	37
Change Healthcare, LLC (“Change Healthcare”)
Schedule of Equity Method Investments [Line Items]
Proportionate share of net loss reported by joint venture	59
Change Healthcare, LLC (“Change Healthcare”) | Core MTS Businesses | Operating Segments | Technology Solutions
Schedule of Equity Method Investments [Line Items]
Gain on Healthcare Technology Net Asset Exchange	37	3,947
Gain from sale of business, after tax	22	$ 3,018
Change Healthcare, LLC (“Change Healthcare”) | Joint Venture
Schedule of Equity Method Investments [Line Items]
Expected ownership interest in the joint venture (percent)				70.00%
Receivable from Change Healthcare	126
Net losses from Change Healthcare	120
Carrying value of investment	3,855
Excess of carrying value of investment over proportional share of book value	4,768
Proportionate share of net loss reported by joint venture	$ 84