Consolidated Statement of Shareholders' Equity (Deficit) (USD $) In Millions	Total	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total Moody's Shareholders' Equity (Deficit)	Non-Controlling Interests
Beginning Balance at Dec. 31, 2010	$ (298.4)	$ 3.4	$ 391.5	$ 3,736.2	$ (4,407.3)	$ (33.4)	$ (309.6)	$ 11.2
Beginning Balance (in shares) at Dec. 31, 2010		342.9			(112.1)
Net income	577.0			571.4			571.4	5.6
Dividends	136.6			131.5			131.5	5.1
Stock-based compensation	56.9		56.9				56.9
Shares issued for stock-based compensation plans, net	46.4		(59.2)		105.6		46.4
Shares issued for stock-based compensation plans, net (in shares)					2.6
Net excess tax benefit upon settlement of stock-based compensation awards	7.2		7.2				7.2
Excess of consideration paid over carrying value of additional investment in KIS Pricing	1.9		1.9				1.9
Purchase of KIS Pricing shares from noncontrolling interest	1.0							1.0
Treasury shares repurchased, shares					11.0
Treasury shares repurchased	333.8				333.8		333.8
Currency translation adjustment	(47.0)					(46.9)	(46.9)	(0.1)
Net actuarial losses and prior service cost	(34.2)					(34.2)	(34.2)
Amortization of actuarial losses and prior service costs included in net income	(4.4)					(4.4)	(4.4)
Net unrealized gain on cash flow hedges	2.6					2.6	2.6
Ending Balance at Dec. 31, 2011	(158.4)	3.4	394.5	4,176.1	(4,635.5)	(107.5)	(169.0)	10.6
Ending Balance (in shares) at Dec. 31, 2011		342.9			(120.5)
Net income	696.1			690.0			690.0	6.1
Dividends	157.5			152.8			152.8	4.7
Stock-based compensation	64.6		64.6				64.6
Shares issued for stock-based compensation plans, net	116.6		(100.9)		217.5		116.6
Shares issued for stock-based compensation plans, net (in shares)					5.6
Net excess tax benefit upon settlement of stock-based compensation awards	10.3		10.3				10.3
Adjustment to redemption value of redeemable noncontrolling interest	(3.4)		(3.4)				(3.4)
Treasury shares repurchased, shares					4.8
Treasury shares repurchased	196.5				196.5		196.5
Currency translation adjustment	33.6					34.2	34.2	(0.6)
Net actuarial losses and prior service cost	(14.8)					(14.8)	(14.8)
Amortization of actuarial losses and prior service costs included in net income	(5.9)					(5.9)	(5.9)
Net unrealized gain on cash flow hedges	0.1					0.1	0.1
Ending Balance at Dec. 31, 2012	396.6	3.4	365.1	4,713.3	(4,614.5)	(82.1)	385.2	11.4
Ending Balance (in shares) at Dec. 31, 2012		342.9			(119.7)
Net income	810.2			804.5			804.5	5.7
Dividends	221.9			215.7			215.7	6.2
Stock-based compensation	67.2		67.2				67.2
Shares issued for stock-based compensation plans, net	136.0		(51.9)		187.9		136.0
Shares issued for stock-based compensation plans, net (in shares)					5.0
Net excess tax benefit upon settlement of stock-based compensation awards	33.3		33.3				33.3
Adjustment to redemption value of redeemable noncontrolling interest	(7.9)		(7.9)				(7.9)
Treasury shares repurchased, shares					14.2
Treasury shares repurchased	893.1				893.1		893.1
Currency translation adjustment	(13.8)					(13.8)	(13.8)	0
Net actuarial losses and prior service cost	29.9					29.9	29.9
Amortization of actuarial losses and prior service costs included in net income	(7.0)					(7.0)	(7.0)
Net unrealized gain on cash flow hedges	4.4					4.4	4.4
Ending Balance at Dec. 31, 2013	$ 347.9	$ 3.4	$ 405.8	$ 5,302.1	$ (5,319.7)	$ (54.6)	$ 337.0	$ 10.9
Ending Balance (in shares) at Dec. 31, 2013		342.9			(128.9)