Commitments and Contingencies (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Other Commitments [Line Items]
Accrued Liabilities and Other Liabilities	$ 1,994	$ 2,191
Insurance receivable for malpractice	$ 15
India Defined Contribution Obligation [Member]
Other Commitments [Line Items]
Accrued Liabilities and Other Liabilities			$ 117