Other Noncurrent Liabilities and Redeemable/Noncontrolling Interests - Additional Information (Detail) $ in Millions	1 Months Ended
	May 31, 2016 USD ($) Hospital	Jun. 30, 2017 USD ($) Facility
Minority Interest [Line Items]
Behavioral health care facilities with outside owners holding non-controlling minority interest | Facility		2
Non-controlling interest balances		$ 65
Redeemable non-controlling interest balances		$ 7
Acute Care Facilities | Washington, District of Columbia
Minority Interest [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners		20.00%
Acute Care Facilities | Texas
Minority Interest [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners		11.00%
Acute Care Facilities | Nevada
Minority Interest [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners		5.00%
Behavioral Health Services | Pennsylvania
Minority Interest [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners		20.00%
Behavioral Health Services | Ohio
Minority Interest [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners		30.00%
Acute Care Hospital Services | Las Vegas, Nevada
Minority Interest [Line Items]
Number of hospital facilities | Hospital	6
Payments to purchase minority ownership interests	$ 445
Purchase price of minority ownership interests	418
Return of reserve capital to purchase of minority ownership interests	$ 27
Acute Care Hospital Services | Las Vegas, Nevada | Minimum
Minority Interest [Line Items]
Ownership interests purchased	26.10%
Acute Care Hospital Services | Las Vegas, Nevada | Maximum
Minority Interest [Line Items]
Ownership interests purchased	27.50%