Divestitures (Narrative) (Details) - naviHealth [Member] - USD ($) $ in Millions		6 Months Ended
Aug. 01, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	98.00%
Proceeds from Divestiture of Businesses	$ 737
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	44.00%
Partnership Indirect Ownership	100.00%
Pre-Tax Gain on Divestiture		$ 508
Equity Method Investments	$ 358	343
Redeemable Non Controlling Interest Divested	$ 12
Tax Expense From Divestiture of a Business		$ 130

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