Commitments and Contingencies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Physician Recruiting Commitments [Abstract]
Physician recruiting commitment, physician income guarantee period	12 months
Physician recruiting commitment, period of recoverability of physician income guarantee for noncommitment	3 years
Physician recruiting commitment, maximum potential future payments in excess of liability recorded	$ 26
La Porte, Indiana hospital [Member]
Construction and Other Capital Commitments [Abstract]
Capital commitment, post-acquisition estimated cost of replacement hospital	128
Construction and other capital commitments incurred	6
Knox, Indiana hospital [Member]
Construction and Other Capital Commitments [Abstract]
Capital commitment, post-acquisition estimated cost of replacement hospital	15
All other purchase commitments [Member]
Construction and Other Capital Commitments [Abstract]
Capital commitment, post-acquisition estimated cost of replacement hospital	64
Construction and other capital commitments incurred	$ 50
Minimum [Member] | All other purchase commitments [Member]
Construction and Other Capital Commitments [Abstract]
Capital commitment, future period after acquisition for completing open capital improvement projects	5 years
Maximum [Member] | All other purchase commitments [Member]
Construction and Other Capital Commitments [Abstract]
Capital commitment, future period after acquisition for completing open capital improvement projects	7 years