(Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accrued Liabilities, Fair Value Disclosure	$ 136
Payments	(32)	$ 0
Accrued Liabilities, Fair Value Disclosure	102
Other liabilities | Fair Value, Inputs, Level 3 [Member] | Contingent consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accrued Liabilities, Fair Value Disclosure	136
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	1
Payments		$ (35)
Accrued Liabilities, Fair Value Disclosure	$ 102