STOCKHOLDERS' EQUITY/MEMBERS' DEFICIT - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended	12 Months Ended
	Apr. 27, 2020	Aug. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Limited Liability Company Llc Members Equity [Line Items]
Number of units converted			3,456,634
Conversion of redeemable preferred stock into common stock			38,111,001
Conversion of common stock shares issued upon conversion (in shares)			12,472,242		12,472,242
Reclassification of members capital			$ 7.0
Purchase price of eligible units			$ 20.0
Issuance of common stock upon exercise of options					$ 19.4
Members’ Capital
Limited Liability Company Llc Members Equity [Line Items]
Issuance of common stock upon exercise of options					$ 5.9
OAK Street Health Inc and Affiliates
Limited Liability Company Llc Members Equity [Line Items]
Business acquisition, equity interest issued or issuable, number of shares (in shares)		268,817
Purchase price of eligible units	$ 20.0			$ 20.0
Purchase price per unit (in dollars per share)	$ 156.29
Threshold percentage on transfer of common units	10.00%
Additional unit based compensation expense				0.6
OAK Street Health Inc and Affiliates | Accumulated Deficit
Limited Liability Company Llc Members Equity [Line Items]
Issuance of common stock upon exercise of options				13.5
OAK Street Health Inc and Affiliates | Members’ Capital
Limited Liability Company Llc Members Equity [Line Items]
Issuance of common stock upon exercise of options				$ 5.9
Common Stock | Oak Street Health Inc
Limited Liability Company Llc Members Equity [Line Items]
Business acquisition, equity interest issued or issuable, number of shares (in shares)			226,940
Common Stock | OAK Street Health Inc and Affiliates
Limited Liability Company Llc Members Equity [Line Items]
Business acquisition, equity interest issued or issuable, number of shares (in shares)		58,240,199	37,884,061
Common Stock Subject To Service-Based Vesting
Limited Liability Company Llc Members Equity [Line Items]
Conversion of common stock shares issued upon conversion (in shares)			22,612,472
Common Stock Subject To Service-Based Vesting | OAK Street Health Inc and Affiliates
Limited Liability Company Llc Members Equity [Line Items]
Business acquisition, equity interest issued or issuable, number of shares (in shares)			22,612,472
Common Stock Option To Purchase | OAK Street Health Inc and Affiliates
Limited Liability Company Llc Members Equity [Line Items]
Business acquisition, equity interest issued or issuable, number of shares (in shares)			14,313,416