Basis of Presentation and Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jan. 01, 2016
Allowance for Doubtful Accounts, Policy [Abstract]
Number of days from the date of discharge over which all accounts are reserved 100%	365 days
Electronic Health Records Reimbursement, Policy [Abstract]
Electronic health records incentive reimbursement under HITECH	$ 18	$ 26
Electronic Health Records Incentive Reimbursement, Cash Received	85	54
Reclassification of debt issuance costs			$ 266
Electronic Health Records Incentive Reimbursements [Member]
Electronic Health Records Reimbursement, Policy [Abstract]
Deferred Revenue	$ 34	$ 75