SEGMENT REPORTING - Depreciation Expense Included in Operating Performance (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Segment reporting information
Total depreciation expense	$ 431	$ 414	$ 409
Operating segments
Segment reporting information
Total depreciation expense	412	394	388
Operating segments | Flex Agility Solutions
Segment reporting information
Total depreciation expense	171	177	184
Operating segments | Flex Reliability Solutions
Segment reporting information
Total depreciation expense	$ 241	$ 217	$ 204