Net Periodic Benefit Expenses Recognized for Post-Retirement Plans (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Amortization of net prior service costs from earlier periods			$ 0
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	(19.8)	(18.9)	15.1
Interest cost	(13.5)	(13.1)	13.1
Expected return on plan assets	(12.9)	(12.5)	(11.9)
Amortization of net actuarial loss from earlier periods	10.8	9.1	5.0
Amortization of net prior service costs from earlier periods	0.6	0.7	0.6
Settlement charges	0	0	1.6
Net periodic expense	31.8	29.3	23.5
Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	(1.7)	(1.5)	1.1
Interest cost	(0.8)	(0.7)	0.8
Expected return on plan assets	0	0	0
Amortization of net actuarial loss from earlier periods	0.3	0.3	0.3
Amortization of net prior service costs from earlier periods	0	0
Settlement charges	0	0	0
Net periodic expense	$ 2.8	$ 2.5	$ 2.2