STOCK-BASED COMPENSATION – STOCK-BASED COMPENSATION EXPENSE (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Information related to share based awards
Total stock-based compensation expense	$ 12.9	$ 4.2	$ 17.0	$ 9.9
Deferred income tax benefit	5.2	1.7	6.8	4.0
Stock-based compensation cost capitalized	0	0	0	0
Omnibus Incentive Compensation Plan 2014
Information related to share based awards
Number of shares authorized for grant	3,000,000		3,000,000
Number of highest paid officers of entity or its subsidiary that cannot be granted awards in excess of a set amount			3
Stock options
Information related to share based awards
Total stock-based compensation expense	0.5	0.5	0.8	0.9
Stock options | Omnibus Incentive Compensation Plan 2014
Information related to share based awards
Number of shares authorized for grant to single employee who is entity's chief executive officer, chief financial officer, or other three highest compensated officers of entity or its subsidiaries	1,000,000		1,000,000
Performance stock rights
Information related to share based awards
Total stock-based compensation expense	9.2	1.0	9.7	3.2
Performance stock rights | Omnibus Incentive Compensation Plan 2014
Information related to share based awards
Number of shares authorized for grant to single employee who is entity's chief executive officer, chief financial officer, or other three highest compensated officers of entity or its subsidiaries	250,000		250,000
Restricted Share Units
Information related to share based awards
Total stock-based compensation expense	3.0	2.5	6.1	5.3
Nonemployee director deferred stock units
Information related to share based awards
Total stock-based compensation expense	$ 0.2	$ 0.2	$ 0.4	$ 0.5