Segment Information (Details) insurancePolicy in Millions, customer in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2022 USD ($) insurancePolicy customer	Jun. 30, 2021 USD ($)
Segment Reporting [Abstract]
Number of insurance policies administered | insurancePolicy	13
Number of annual customer interactions | customer	250
Segment Reporting Information [Line Items]
Revenues	$ 3,707	$ 4,141
Depreciation and amortization	285	313
Amortization of acquired intangible assets	104	109
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Subtotal	259	332
Interest income	20	20
Interest expense	(37)	(62)
Restructuring costs	(33)	(67)
Transaction, separation and integration-related costs	(2)	(9)
Amortization of acquired intangible assets	(104)	(109)
Merger related indemnification	(10)	0
Gains on dispositions	29	347
Debt extinguishment costs	0	(28)
Income before income taxes	122	424
Operating segments
Segment Reporting Information [Line Items]
Revenues	3,707	4,141
Depreciation and amortization	259	286
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Subtotal	337	403
All Other
Segment Reporting Information [Line Items]
Revenues	0	0
Depreciation and amortization	26	27
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Subtotal	(78)	(71)
GBS | Operating segments
Segment Reporting Information [Line Items]
Revenues	1,758	1,887
Depreciation and amortization	41	40
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Subtotal	210	272
GIS | Operating segments
Segment Reporting Information [Line Items]
Revenues	1,949	2,254
Depreciation and amortization	218	246
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Subtotal	$ 127	$ 131