SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Revenue from External Customer
Date of issuance period	2 years
Decrease in revenue due to change in estimate of variable consideration for performance obligations	$ (9)
Minimum
Revenue from External Customer
Number of years for payments to commence under financing contracts after closing	10 years
Number of days for payments to commence under financing contracts after closing	30 days
Package expiration period	6 months
Maximum
Revenue from External Customer
Number of years for payments to commence under financing contracts after closing	15 years
Number of days for payments to commence under financing contracts after closing	60 days
Package expiration period	24 months