FAIR VALUE MEASUREMENTS - Narrative (Details) ₨ / shares in Units, shares in Millions, $ in Millions, ₨ in Billions						3 Months Ended		6 Months Ended
	Jun. 05, 2024 USD ($)	Jun. 05, 2024 INR (₨)	Apr. 29, 2024 USD ($) shares	Apr. 29, 2024 INR (₨) ₨ / shares shares	Mar. 23, 2024 USD ($) shares	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 05, 2024 INR (₨)	Mar. 23, 2024 INR (₨)	Dec. 31, 2023 USD ($)	Feb. 28, 2023 USD ($)	Feb. 28, 2023 INR (₨)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset impairments						$ 0.0	$ 0.0	$ 0.0	$ 0.0
Long-term obligations						38,968.4		38,968.4				$ 38,921.5
Estimate of Fair Value Measurement
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, fair value						36,400.0		36,400.0				36,700.0
Estimate of Fair Value Measurement | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, fair value						29,700.0		29,700.0				30,000.0
Estimate of Fair Value Measurement | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, fair value						6,700.0		6,700.0				$ 6,700.0
VIL
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Number of converted shares | shares					1,440
Equity shares sold (in shares) | shares			1,440	1,440
Price per share (in INR per share) | ₨ / shares				₨ 12.78
Net proceeds			$ 216.0	₨ 18.0
Debt and equity securities, realized gain						46.4		46.4
Equity securities						0.0		0.0
OCDs | VIL
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities	$ 19.2				$ 172.7	$ 0.0		$ 0.0		₨ 1.6	₨ 14.4
Not proceeds from sale of debt securities	$ 22.0	₨ 1.8
OCDs | VIL
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
VIL OCDs, face value													$ 193.2	₨ 16.0
Debt securities													$ 116.5
Debt securities, interest rate (as a percent)													11.20%	11.20%
OCDs | VIL | Maturing on August 27, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
VIL OCDs, face value													$ 96.6	₨ 8.0
OCDs | VIL | Maturing on August 27, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
VIL OCDs, face value													$ 96.6	₨ 8.0