BENEFIT PLANS (Reconciliation of Beginning and Ending Balances for Plan Assets Valued using Significant Unobservable Inputs) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Private Equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance at December 31, 2014	$ 35.7
Return on plan assets:
Unrealized	2.9
Realized	1.6
Purchases	5.9
Sales	(4.2)
Balance at December 31, 2015	41.9
Hedge Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance at December 31, 2014	69.7
Return on plan assets:
Unrealized	0.7
Realized	0.2
Purchases	9.6
Sales	(26.2)
Balance at December 31, 2015	54.0
Real Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance at December 31, 2014	16.5
Return on plan assets:
Unrealized	0.0
Realized	1.7
Purchases	0.4
Sales	(1.2)
Balance at December 31, 2015	$ 17.4