POSTRETIREMENT BENEFIT PLANS - Net Periodic Benefit Cost of Pension Plans and Other Employee Related Benefit Plans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.4	$ 1.5
Interest cost	4.6	4.8
Expected return on plan assets	(5.2)	(5.3)
Amortization of prior service cost (benefit)	(1.4)	(2.5)
Amortization of net actuarial loss	3.1	3.2
Total net periodic benefit cost	2.5	1.7
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.2	1.3
Interest cost	3.4	3.6
Expected return on plan assets	(5.0)	(5.1)
Amortization of prior service cost (benefit)	0.2	0.2
Amortization of net actuarial loss	1.9	2.1
Total net periodic benefit cost	1.7	2.1
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.2	0.2
Interest cost	1.2	1.2
Expected return on plan assets	(0.2)	(0.2)
Amortization of prior service cost (benefit)	(1.6)	(2.7)
Amortization of net actuarial loss	1.2	1.1
Total net periodic benefit cost	$ 0.8	$ (0.4)