CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 6,218	$ 5,371	$ 4,829
Expenses
Operating	1,637	1,475	1,387
Selling, general and administrative	1,480	1,229	1,167
Restructuring	0	50	60
Depreciation and amortization	257	220	200
Acquisition-Related Expenses	0	0	3
Loss pursuant to the divestiture of MAKS	0	9	14
Total expenses	3,374	2,983	2,831
Operating income	2,844	2,388	1,998
Non-operating (expense) income, net
Interest expense, net	(171)	(205)	(208)
Other non-operating income, net	82	46	20
Non-operating (expense) income, net	(89)	(159)	(188)
Income before provision for income taxes	2,755	2,229	1,810
Provision for income taxes	541	452	381
Net income	2,214	1,777	1,429
Less: Net (loss) income attributable to noncontrolling interests	0	(1)	7
Net income attributable to Moody’s	$ 2,214	$ 1,778	$ 1,422
Earnings per share
Basic (in USD per share)	$ 11.88	$ 9.48	$ 7.51
Diluted (in USD per share)	$ 11.78	$ 9.39	$ 7.42
Weighted average shares outstanding
Basic (in shares)	186.4	187.6	189.3
Diluted (in shares)	187.9	189.3	191.6