Income Taxes - Schedule of Reconciliation of Federal Statutory Rate to Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%	21.00%
State income taxes, net of federal tax benefit	2.00%	1.90%	2.70%
Change in liability for uncertain tax positions	0.70%	(0.20%)	0.40%
Tax benefit from settlements of employee equity awards	(1.20%)	(1.80%)	(1.30%)
Other items, net	0.80%	0.80%	1.10%
Effective income tax rate on income attributable to HCA Healthcare, Inc.	23.30%	21.70%	23.90%
Income attributable to noncontrolling interests from consolidated partnerships	(1.80%)	(2.50%)	(2.90%)
Effective income tax rate on income before income taxes	21.50%	19.20%	21.00%