SUMMARY OF ACCOUNTING POLICIES - Intangible Assets (Details) - USD ($)	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Components of acquired intangible assets
Intangible assets residual value	$ 0
Gross carrying amount	614,000,000	$ 670,000,000
Accumulated Amortization	(369,000,000)	(355,000,000)
Total amortization expense	245,000,000	315,000,000
Intangible amortization	70,000,000	81,000,000	$ 60,000,000
Intangible assets fully amortized and removed	50,000,000
Estimated future annual amortization expense for acquired intangible assets
2025	63,000,000
2026	43,000,000
2027	35,000,000
2028	27,000,000
2029	24,000,000
Thereafter	53,000,000
Total amortization expense	$ 245,000,000	315,000,000
Customer-related intangibles
Components of acquired intangible assets
Intangible assets, weighted average useful life	6 years 2 months 12 days
Gross carrying amount	$ 316,000,000	373,000,000
Accumulated Amortization	(186,000,000)	(204,000,000)
Total amortization expense	130,000,000	169,000,000
Estimated future annual amortization expense for acquired intangible assets
Total amortization expense	$ 130,000,000	169,000,000
Customer-related intangibles | Maximum
Components of acquired intangible assets
Useful life	10 years
Licenses and other intangibles
Components of acquired intangible assets
Intangible assets, weighted average useful life	5 years 6 months
Gross carrying amount	$ 298,000,000	297,000,000
Accumulated Amortization	(183,000,000)	(151,000,000)
Total amortization expense	115,000,000	146,000,000
Estimated future annual amortization expense for acquired intangible assets
Total amortization expense	$ 115,000,000	$ 146,000,000