EQUITY METHOD INVESTMENT - Summarized Balance Sheets and Statements of Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance sheet
Current assets	$ 24,893	$ 23,641
Current liabilities	15,331	13,394
Income Statement Related Disclosures [Abstract]
Revenues	83,064	77,155	$ 64,888
Net income attributable to Humana	$ 2,933	3,367	2,707
Kindred at Home
Balance sheet
Current assets		844
Non-current assets		4,858
Current liabilities		556
Non-current liabilities		2,445
Shareholders' equity		2,700
Income Statement Related Disclosures [Abstract]
Revenues		2,972	3,100
Expenses		2,552	2,835
Net income attributable to Humana		$ 207	$ 54