STOCK COMPENSATION PLANS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangements by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value	$ 30.39	$ 34.40	$ 39.85	$ 44.37
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	6 years	6 years	6 years	6 years
Summary of Changes in Options Outstanding Under the Stock Incentive Plans [Rollforward]
Shares authorized for issuance under the 2008 and 2000 Stock Incentive Plans	9.8		9.8
Shares available for grant under the Company's stock option plans	6.3		6.3
Award vesting period (in years)			3 years	3 years
Stock Options Vested and Expected to Vest at December 31, 2011
Aggregate intrinsic value, vested and expected to vest options	$ 24.5		$ 24.5
Stock Options Exercised, Impact Disclosures
Cash received by the Company			27.6	$ 37.5	$ 43.9
Share-based Payment Arrangement, Exercise of Option, Tax Benefit			6.9	9.4	13.4
Aggregate intrinsic value			$ 24.5	$ 44.1	$ 34.8
Assumptions the Company Used to Develop Fair Value Estimates
Fair value of the employee's purchase right			$ 31.84	$ 34.43	$ 31.54
Risk free interest rate	1.60%	2.50%	1.60%	2.70%
Expected volatility	20.80%	20.00%	20.80%	18.90%
Fair Values of Options Granted and the Employee's Purchase Right in the Stock Purchase Plan
Stock option plan expense			$ 5.9	$ 3.5	$ 0.9
Restricted Stock and Performance Shares
Restricted stock, vesting increment			one third increments beginning on the first anniversary of the grant
Performance share awards, vesting conditions			Performance share awards are subject to certain earnings per share, revenue and total shareholder return targets
Restricted stock and performance share compensation expense			$ 91.2	80.1	100.8
Unrecognized compensation cost related to nonvested restricted stock and performance share-based compensation arrangements	$ 112.2		$ 112.2
Unrecognized compensation cost weighted average expected future recognition period (in years)			2 years 2 months 12 days
Employee Stock Purchase Plan Disclosure
Shares of common stock authorized for issuance under the employee stock purchase plan	1.8		1.8
The employee stock purchase plan permits employees to purchase shares of common stock at a certain percentage of the market price (in hundredths)			85.00%
Number of shares purchased by eligible employees			0.2
Expense related to the Company's employee stock purchase plan			$ 9.9	$ 8.0	$ 8.0
Employee Stock Purchase Plan [Member]
Assumptions the Company Used to Develop Fair Value Estimates
Risk free interest rate			1.90%	2.30%	1.30%
Expected volatility			20.00%	20.00%	20.00%
Expected dividend yield			0.00%	0.00%	0.00%
Restricted Stock and Performance Shares [Member]
Summary of Nonvested Shares
Nonvested, beginning of period		1.3	1.3
Number of options granted			0.9
Number of options vested			(0.8)
Nonvested, end of period	1.3		1.3	1.3
Weighted-average grant date fair value, nonvested, beginning of period		$ 140.58	$ 140.58
Weighted-average grant date fair value, granted			150.29
Weighted-average grant date fair value, vested			$ 120.22
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period			0.1
Weighted-average grant date fair value, nonvested, end of period	$ 152.70		$ 152.70	$ 140.58
Employee Stock Purchase Plan Disclosure
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 153.10
Stock Options [Member]
Changes in Options Outstanding Under the Stock Incentive Plans, Additional Disclosures
Number of options outstanding, beginning balance		0.8	0.8
Number of options granted			0.2
Number of options exercised			(0.3)
Number of options cancelled			(0.1)
Number of options outstanding, ending balance	0.6		0.6	0.8
Weighted-average exercise price per option, outstanding, beginning balance		$ 100.30	$ 100.30
Weighted-average exercise price per option granted			163.80
Weighted-average exercise price per option exercised			85.74
Weighted-average exercise price per option cancelled			151.21
Weighted-average exercise price per option, outstanding, ending balance	$ 125.26		$ 125.26	$ 100.30
Weighted-average remaining contractual term of options outstanding (in years)			5 years 4 months 24 days
Aggregate intrinsic value of options outstanding	$ 27.3		$ 27.3
Stock Options Vested and Expected to Vest at December 31, 2011
Number of options vested and expected to vest	0.6		0.6
Weighted-average exercise price per option, vested and expected to vest options	$ 125.26		$ 125.26
Weighted-average exercise price per exercisable option	$ 99.86		$ 99.86
Weighted-average remaining contractual term, vested and expected to vest options (in years)			2 years 10 months 24 days
Number of options exercisable	0.4		0.4
Weighted-average remaining contractual term, exercisable options (in years)			2 years 10 months 24 days
Aggregate intrinsic value, exercisable options	$ 24.5		$ 24.5