Restructuring, Impairment and Related Charges - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and related charges recognized	$ 155	$ 136	$ 271	$ 204
Net restructuring, impairment and related charges recognized	40	42	156	110
Restructuring liabilities	132		132		$ 157
Impairment of long-lived and intangible assets			236	113
International
Restructuring Cost and Reserve [Line Items]
Net restructuring, impairment and related charges recognized	131		189
Impairment of long-lived and intangible assets	115	94	115	94
Strategic Growth Initiative Plan - Relocation of Corporate Headquarters
Restructuring Cost and Reserve [Line Items]
Pre-tax charges recorded to-date	104		104
Strategic Growth Initiative Plan - Relocation of Corporate Headquarters | Employee Retention Expenses, Severance, Accelerated Depreciation and Asset Impairments
Restructuring Cost and Reserve [Line Items]
Net restructuring, impairment and related charges recognized	14	14	27	34
Strategic Growth Initiative Plan - Relocation of Corporate Headquarters | Minimum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	105		105
Strategic Growth Initiative Plan - Relocation of Corporate Headquarters | Maximum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	125		125
Operating Model and Cost Optimization Programs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges recorded to-date	288		288
Operating Model and Cost Optimization Programs | Minimum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	310		310
Operating Model and Cost Optimization Programs | Maximum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	320		320
Strategic Growth Initiative Plan - Other | Employee Severance, Accelerated Depreciation, and Project Consulting
Restructuring Cost and Reserve [Line Items]
Net restructuring, impairment and related charges recognized	17	$ 20	53	$ 59
Strategic Growth Initiative Plan | International
Restructuring Cost and Reserve [Line Items]
Net restructuring, impairment and related charges recognized	9		50
Strategic Growth Initiative Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	100		100
Strategic Growth Initiative Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected total pre-tax charges	$ 120		$ 120