DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Cumulative Adjustment to Retained earnings due to prospective adoption of new revenue guidance

Transition adjustment	Benefit to / (reduction of) January 1, 2018 Retained Earnings	Corresponding Balance Sheet Line Item
Recognition of MA deferred revenue / increase in MA unbilled receivables (1)	$108 million	Deferred revenue, Non-current portion of deferred revenue, Accounts receivable, Other assets
Increase to capitalized MA sales commissions (2)	$78 million	Other current assets, Other assets, Accounts payable and accrued liabilities
Capitalization of work-in-process for in-progress ratings	$9 million	Other current assets
Net impact of all other adjustments	$4 million	Various
Net increase in tax liability on the above	($43 million)	Deferred tax liabilities, net
Total post-tax adjustment	$156 million
(1) Represents deferred revenue as of December 31, 2017 as well as amounts then unbilled that would have been recognized as revenue in 2017 or earlier if the New Revenue Accounting Standard was then in effect. These amounts will not be recognized as revenue in future statements of operations. Conversely, revenue will be recorded to the Company's statement of operations in 2018 under the New Revenue Accounting Standard, which otherwise would have been recognized in periods subsequent to 2018 if accounted for under ASC Topic 605.
(2) Represents sales commissions that would have been capitalized as of December 31, 2017 if the New Revenue Accounting Standard was then in effect, but had previously been expensed by the Company under the previous accounting guidance. These sales commissions, as well as sales commissions incurred in 2018 related to new sales and renewals, will be amortized to expense in the statements of operations beginning in 2018 over an extended period generally based upon the average economic life of the products sold or over the period in which implementation and advisory services will be provided.

New Revenue Accounting Standard [Member] | Balance Sheets [Member]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

	As Reported June 30, 2018		Under previous accounting guidance June 30, 2018		Effect of Change Higher/(Lower)
ASSETS
Current assets:
Cash and cash equivalents	$	1,314.5	$	1,314.5	$	-
Short-term investments		101.2		101.2		-
Accounts receivable, net of allowances		1,137.1		1,122.9		14.2
Other current assets		286.9		264.2		22.7
Total current assets:		2,839.7		2,802.8		36.9
Property and equipment, net		312.2		312.2		-
Goodwill		3,662.7		3,662.7		-
Intangible assets, net		1,541.4		1,541.4		-
Deferred tax assets, net		136.6		136.5		0.1
Other assets		259.0		189.0		70.0
Total assets	$	8,751.6	$	8,644.6	$	107.0
LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' EQUITY
Accounts payable and accrued liabilities	$	593.6	$	593.4	$	0.2
Commercial paper		89.9		89.9		-
Current portion of long-term debt		299.9		299.9		-
Deferred revenue		860.5		930.8		(70.3)
Total current liabilities		1,843.9		1,914.0		(70.1)
Non-current portion of deferred revenue		126.0		133.6		(7.6)
Long-term debt		4,934.2		4,934.2		-
Deferred tax liabilities, net		363.2		335.1		28.1
Unrecognized tax benefits		398.3		398.3		-
Other liabilities		625.9		625.6		0.3
Total liabilities		8,291.5		8,340.8		(49.3)
Shareholders' equity:
Common stock		3.4		3.4		-
Capital surplus		538.6		538.6		-
Retained earnings		8,204.6		8,048.3		156.3
Treasury stock		(8,198.9)		(8,198.9)		-
Accumulated other comprehensive loss		(304.8)		(304.8)		-
Total Moody's shareholders' equity		242.9		86.6		156.3
Noncontrolling interests		217.2		217.2		-
Total shareholders' equity		460.1		303.8		156.3
Total liabilities, noncontrolling interests and shareholders' equity	$	8,751.6	$	8,644.6	$	107.0

New Revenue Accounting Standard [Member] | Income Statement [Member]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

			For the Three Months Ended June 30, 2018
			As Reported		Under previous accounting guidance		Effect ofChangeHigher/(Lower)
Revenue			$	1,175.1	$	1,169.9	$	5.2
Expenses
	Operating			320.2		320.7		(0.5)
	Selling, general and administrative			270.5		272.5		(2.0)
	Depreciation and amortization			48.4		48.4		-
	Acquisition-related expenses			2.0		2.0		-
		Total expenses		641.1		643.6		(2.5)
Operating income				534.0		526.3		7.7
Non-operating (expense) income, net
	Interest expense, net			(53.4)		(53.4)		-
	Other non-operating income, net			14.9		14.9		-
		Total non-operating (expense) income, net		(38.5)		(38.5)		-
Income before provision for income taxes				495.5		487.8		7.7
	Provision for income taxes			117.6		115.7		1.9
Net income				377.9		372.1		5.8
	Less: Net income attributable to noncontrolling interests			1.7		1.7		-
Net income attributable to Moody's			$	376.2	$	370.4	$	5.8
Earnings per share
	Basic		$	1.96	$	1.93	$	0.03
	Diluted		$	1.94	$	1.91	$	0.03
Weighted average shares outstanding
	Basic			191.9		191.9
	Diluted			194.4		194.4
			For the Six Months Ended June 30, 2018
			As Reported		Under previous accounting guidance		Effect ofChangeHigher/(Lower)
Revenue			$	2,301.8	$	2,296.3	$	5.5
Expenses
	Operating			635.1		636.2		(1.1)
	Selling, general and administrative			541.6		544.0		(2.4)
	Depreciation and amortization			97.5		97.5		-
	Acquisition-related expenses			2.8		2.8		-
		Total expenses		1,277.0		1,280.5		(3.5)
Operating income				1,024.8		1,015.8		9.0
Non-operating (expense) income, net
	Interest expense, net			(104.1)		(104.1)		-
	Other non-operating income, net			15.9		15.9		-
		Total non-operating (expense) income, net		(88.2)		(88.2)		-
Income before provision for income taxes				936.6		927.6		9.0
	Provision for income taxes			181.9		179.2		2.7
Net income				754.7		748.4		6.3
	Less: Net income attributable to noncontrolling interests			5.6		5.6		-
Net income attributable to Moody's			$	749.1	$	742.8	$	6.3
Earnings per share
	Basic		$	3.91	$	3.88	$	0.03
	Diluted		$	3.85	$	3.82	$	0.03
Weighted average shares outstanding
	Basic			191.6		191.6
	Diluted			194.5		194.5

New Revenue Accounting Standard [Member] | Cash Flow [Member]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

				For the Six Months Ended June 30, 2018
				As Reported		Under previous accounting guidance		Effect of Change
Cash flows from operating activities
	Net income			$	754.7	$	748.4	$	6.3
	Reconciliation of net income to net cash provided by operating activities:
		Depreciation and amortization			97.5		97.5		-
		Stock-based compensation			69.5		69.5		-
		Deferred income taxes			(12.1)		2.0		(14.1)
		Changes in assets and liabilities:
			Accounts receivable		17.8		15.2		2.6
			Other current assets		(10.2)		(20.4)		10.2
			Other assets		(14.3)		(21.0)		6.7
			Accounts payable and accrued liabilities		(163.2)		(158.1)		(5.1)
			Deferred revenue		55.3		55.9		(0.6)
			Unrecognized tax benefits and other non-current tax liabilities		(33.6)		(33.6)		-
			Other liabilities		15.9		21.9		(6.0)
	Net cash provided by operating activities			$	777.3	$	777.3	$	-

Cumulative Effect on Start Period [Member] | New Revenue Accounting Standard [Member] | Balance Sheets [Member]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

			As Reported December 31, 2017		Adjustment Due to New Revenue Accounting Standard		Balance at January 1, 2018
ASSETS
Current assets:
	Cash and cash equivalents		$	1,071.5	$	-	$	1,071.5
	Short-term investments			111.8		-		111.8
	Accounts receivable, net of allowances			1,147.2		16.8		1,164.0
	Other current assets			250.1		32.9		283.0
		Total current assets		2,580.6		49.7		2,630.3
Property and equipment, net				325.1		-		325.1
Goodwill				3,753.2		-		3,753.2
Intangible assets, net				1,631.6		-		1,631.6
Deferred tax assets, net				143.8		-		143.8
Other assets				159.9		71.3		231.2
		Total assets	$	8,594.2	$	121.0	$	8,715.2
LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' (DEFICIT)/EQUITY
Current liabilities:
	Accounts payable and accrued liabilities		$	750.3	$	(0.8)	$	749.5
	Commercial paper			129.9		-		129.9
	Current portion of long-term debt			299.5		-		299.5
	Deferred revenue			883.6		(69.3)		814.3
		Total current liabilities		2,063.3		(70.1)		1,993.2
Non-current portion of deferred revenue				140.0		(8.0)		132.0
Long-term debt				5,111.1		-		5,111.1
Deferred tax liabilities, net				341.6		42.7		384.3
Unrecognized tax benefits				389.1		-		389.1
Other liabilities				664.0		0.3		664.3
		Total liabilities		8,709.1		(35.1)		8,674.0
Shareholders' (deficit) equity:
	Common stock			3.4		-		3.4
	Capital surplus			528.6		-		528.6
	Retained earnings			7,465.4		156.1		7,621.5
	Treasury stock			(8,152.9)		-		(8,152.9)
	Accumulated other comprehensive loss			(172.2)		-		(172.2)
		Total Moody's shareholders' (deficit) equity		(327.7)		156.1		(171.6)
	Noncontrolling interests			212.8		-		212.8
		Total shareholders' (deficit) equity		(114.9)		156.1		41.2
		Total liabilities, noncontrolling interests and shareholders' (deficit) equity	$	8,594.2	$	121.0	$	8,715.2

Cumulative Effect on Start Period [Member] | Compensation-Retirement Benefits Accounting Standard [Member] | Income Statement [Member]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

	For the Three Months Ended June 30, 2018						For the Three Months Ended June 30, 2017
	As Reported		Under previous accounting guidance		Effect of ChangeHigher/(Lower)		As Adjusted		Under previous accounting guidance		Effect of ChangeHigher/(Lower)
Operating expenses	$	320.2	$	321.0	$	(0.8)	$	284.8	$	285.8	$	(1.0)
Selling, general and administrative expenses		270.5		271.7		(1.2)		216.1		217.7		(1.6)
Operating income		534.0		532.0		2.0		460.1		457.5		2.6
Interest expense, net		(53.4)		(48.5)		(4.9)		(49.7)		(45.0)		(4.7)
Other non-operating income (expense), net		14.9		12.0		2.9		10.4		8.3		2.1
	For the Six Months Ended June 30, 2018						For the Six Months Ended June 30, 2017
	As Reported		Under previous accounting guidance		Effect of ChangeHigher/(Lower)		As Adjusted		Under previous accounting guidance		Effect of ChangeHigher/(Lower)
Operating expenses	$	635.1	$	637.4	$	(2.3)	$	560.1	$	563.2	$	(3.1)
Selling, general and administrative expenses		541.6		543.7		(2.1)		436.8		439.6		(2.8)
Operating income		1,024.8		1,020.4		4.4		906.8		900.9		5.9
Interest expense, net		(104.1)		(94.5)		(9.6)		(97.1)		(87.4)		(9.7)
Other non-operating income (expense), net		15.9		10.7		5.2		2.7		(1.1)		3.8