Summary of Net Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2015
Finite Lived Intangible Assets [Line Items]
Net Intangible Assets	$ 173	$ 220
Foundations Tradename
Finite Lived Intangible Assets [Line Items]
Net Intangible Assets	75	124	$ 124
Medicare Licenses
Finite Lived Intangible Assets [Line Items]
Net Intangible Assets	57	57
Certificates of Need
Finite Lived Intangible Assets [Line Items]
Net Intangible Assets	21	12
Contract Relationships and Other
Finite Lived Intangible Assets [Line Items]
Net Intangible Assets	$ 20	$ 27