STOCK-BASED COMPENSATION - Stock Options (Details) $ in Millions		3 Months Ended				12 Months Ended
	Jun. 04, 2009	Dec. 31, 2015 shares	Sep. 30, 2015 shares	Jun. 30, 2015 shares	Mar. 31, 2015 shares	Dec. 31, 2015 USD ($) item shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Stock-based compensation
Stock-based compensation plans | item						2
Compensation expense on share-based plans | $						$ 32.7	$ 28.6	$ 28.8
Stock options
Stock-based compensation
Common stock granted, net of cancellations (in shares)		6,000	56,000	33,000	903,000
Excess tax benefit realized for tax deductions from non-qualified stock option exercises and disqualifying dispositions of incentive stock options | $						$ 314.7	$ 11.9	$ 30.3
2011 Omnibus Incentive Plan
Stock-based compensation
Aggregate amount of common stock authorized (in shares)		14,500,000				14,500,000
Reduction in number of shares for each share granted		2.16				2.16
Common stock granted, net of cancellations (in shares)						4,595,021
Shares available for grant		8,809,885				8,809,885
2011 Omnibus Incentive Plan | Stock options
Stock-based compensation
Vesting period						5 years
2011 Omnibus Incentive Plan | Stock options | Maximum
Stock-based compensation
Tenure of award						10 years
2009 Directors Plan
Stock-based compensation
Aggregate amount of common stock authorized (in shares)		1,600,000				1,600,000
Percentage of award vesting on the last business day prior to the date of the annual meeting						100.00%
2009 Directors Plan | Minimum
Stock-based compensation
Percentage of closing price of the company's common stock on the date an option is granted to determine the exercise price						100.00%
2009 Directors Plan | Stock options, non-employee directors
Stock-based compensation
Common stock granted, net of cancellations (in shares)						87,964
Shares available for grant		1,512,036				1,512,036
The period during which awards can be granted, effective June 4, 2009	10 years