Retirement Benefits - Components of Retirement Benefit Expense (Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.2	$ 1.4	$ 4.4	$ 2.7
Interest cost on benefit obligation	16.7	15.2	33.5	30.4
Assumed return on plan assets	(23.2)	(24.1)	(46.4)	(48.2)
Amortization of prior service credits	0	0	0	0
Recognized net actuarial losses (gains)	13.5	23.7	26.9	47.3
Retirement benefit expense (income)	9.2	16.2	18.4	32.2
Postretirement Medical and Life Insurance Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0.1	0	0.1
Interest cost on benefit obligation	0.7	0.6	1.3	1.2
Assumed return on plan assets	0	0	0	0
Amortization of prior service credits	(0.2)	(0.2)	(0.4)	(0.4)
Recognized net actuarial losses (gains)	(0.8)	(0.6)	(1.5)	(1.1)
Retirement benefit expense (income)	$ (0.3)	$ (0.1)	$ (0.6)	$ (0.2)