EARNINGS PER SHARE (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Computation of Basic Income per Share [Abstract]
Net income	$ 24.7	$ 69.7	$ 43.7	$ 40.5	$ 34.6	$ 28.7	$ 47.6	$ 38.7	$ 178.6	$ 149.6	$ 241.7
Basic shares									79.9	80.1	80.0
Basic net income per share (in dollars per share)	$ 0.31	$ 0.87	$ 0.54	$ 0.50	$ 0.43	$ 0.36	$ 0.59	$ 0.48	$ 2.24	$ 1.87	$ 3.02
Computation of Diluted Income per Share [Abstract]
Basic shares									79.9	80.1	80.0
Stock-based compensation (in shares)									1.0	0.9	0.8
Diluted									80.9	81.0	80.8
Diluted net income per share (in dollars per share)	$ 0.31	$ 0.86	$ 0.54	$ 0.50	$ 0.43	$ 0.35	$ 0.59	$ 0.48	$ 2.21	$ 1.85	$ 2.99
Antidilutive shares excluded from the computation of earnings per share (in shares)									0.6	1.0	0.9