Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income tax provision on fair market value adjustment on cash flow hedges	$ 1	$ 2	$ 1	$ 0
Income tax provision on unrealized gain on defined benefit plans			0
Cost of Services
Income tax provision (benefit) on reclassification adjustment for net realized (gains) losses on cash flow hedges	(1)	0	(2)	0
Interest Expense
Income tax provision (benefit) on reclassification adjustment for net realized (gains) losses on cash flow hedges	$ 2	$ 1	$ 4	$ 4

Amount, before reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, before reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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