Share-Based Compensation - Summary of Data Related to RSUs and PSUs Award Activity (Details) - RSUs and PSUs - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of shares vested	$ 143	$ 200	$ 144
Total compensation cost, net of estimated forfeitures, related to nonvested restricted stock unit awards not yet recognized, pre-tax	$ 205	$ 192	$ 165
Weighted-average period in years over which restricted stock unit award cost is expected to be recognized	2 years	2 years	2 years