Business and Summary of Significant Accounting Policies - Redeemable Noncontrolling Interests and Noncontrolling Interest - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) Facility	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Aug. 31, 2022
Summary Of Business And Significant Accounting Policies [Line Items]
Behavioral health care facilities with outside owners holding non-controlling minority interest | Facility	6
Non-controlling interest balances	$ 83
Redeemable non-controlling interest balances	13
Payments to Acquire Businesses	$ 19	$ 4	$ 20
Texas | Outside Owners | Acute Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	7.00%
Arizona | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	49.00%
Pennsylvania | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	20.00%
Ohio | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	30.00%
Washington | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	20.00%
Missouri | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	25.00%
Lowa | Outside Owners | Behavioral Health Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	48.00%
Michigan
Summary Of Business And Significant Accounting Policies [Line Items]
Behavioral health care facilities with outside owners holding non-controlling minority interest | Facility	2
Michigan | Outside Owners | Behavioral Health Care Facility One
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	26.00%
Michigan | Outside Owners | Behavioral Health Care Facility Two
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	49.00%
Michigan | Outside Owners | Surgery center
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	49.00%
Nevada | Outside Owners | Acute Care Facility
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners	5.00%
DC
Summary Of Business And Significant Accounting Policies [Line Items]
Payments to Acquire Businesses	$ 51
DC | Hospital
Summary Of Business And Significant Accounting Policies [Line Items]
Non-controlling ownership interests	100.00%			20.00%