CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Income	$ 501	$ 498
Other Comprehensive Income (Loss):
Foreign currency translation adjustments - Pre Tax	109	(108)
Foreign currency translation adjustments - Tax	(2)	1
Foreign currency translation adjustments - Net of Tax	107	(107)
Net gains on net investment hedges - Pre Tax	(76)	64
Net gains on net investment hedges - Tax	19	(17)
Net gains on net investment hedges - Net of Tax	(57)	47
Cash Flow Hedges:
Reclassification of losses included in net income - Pre Tax	1	1
Reclassification of losses included in net income - Tax	0	0
Reclassification of losses included in net income - Net of Tax	1	1
Pension and Other Retirement Benefits:
Net actuarial (losses) and prior service costs - Pre Tax	0	(3)
Net actuarial (losses) and prior service costs - Tax	0	1
Net actuarial (losses) and prior service costs - Net of Tax	0	(2)
Total other comprehensive (loss) income - Pre Tax	34	(46)
Total other comprehensive income (loss) - Tax	17	(15)
Total other comprehensive income (loss) - Net of Tax	51	(61)
Comprehensive income	552	437
Less: comprehensive (loss) income attributable to noncontrolling interests	(3)	0
Comprehensive Income Attributable to Moody's	$ 555	$ 437