CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net Income	$ 303	$ 474	$ 1,128	$ 1,787
Other Comprehensive Income (Loss):
Foreign currency translation adjustments - Pre Tax	(358)	(124)	(806)	(234)
Foreign currency translation adjustments - Tax	6	5	10	9
Foreign currency translation adjustments - Net of Tax	(352)	(119)	(796)	(225)
Foreign currency translation adjustments - reclassification of losses included in net income - Pre tax			20	0
Foreign currency translation adjustments - reclassification of losses included in net income, Tax			0	0
Foreign currency translation adjustments - reclassification of losses included in net income - Net of Tax			20	0
Net gains on net investment hedges - Pre Tax	256	99	561	233
Net gains on net investment hedges - Tax	(63)	(26)	(140)	(56)
Net gains on net investment hedges - Net of Tax	193	73	421	177
Net investment hedges - reclassification of gains included in net income - Pre Tax			0	(2)
Net investment hedges - reclassification of gains included in net income - Tax			0	1
Net investment hedges - reclassification of gains included in net income - Net of Tax			0	(1)
Cash Flow Hedges:
Reclassification of losses included in net income - Pre Tax	1	1	2	2
Reclassification of losses included in net income - Tax	(1)	0	(1)	0
Reclassification of losses included in net income - Net of Tax	0	1	1	2
Pension and Other Retirement Benefits:
Amortization of actuarial losses/prior service costs and settlement charge included in net income - Pre Tax	1	3	2	16
Amortization of actuarial losses/prior service costs and settlement charge included in net income - Tax	0	(1)	0	(4)
Amortization of actuarial losses/prior service costs and settlement charge included in net income - Net of Tax	1	2	2	12
Net actuarial gains and prior service costs - Pre Tax	0	4	3	4
Net actuarial gains and prior service costs - Tax	0	(1)	(1)	(1)
Net actuarial gains and prior service costs - Net of Tax	0	3	2	3
Total other comprehensive (loss) income - Pre Tax	(100)	(17)	(218)	19
Total other comprehensive (loss) income - Tax	(58)	(23)	(132)	(51)
Total other comprehensive (loss) income - Net of Tax	(158)	(40)	(350)	(32)
Comprehensive income	145	434	778	1,755
Less: comprehensive (loss) income attributable to noncontrolling interests	(9)	(3)	(12)	(2)
Comprehensive Income Attributable to Moody's	$ 154	$ 437	$ 790	$ 1,757