Postretirement Benefit Plans - Fair Value of Plan Assets Held by Our Postretirement Benefits Plans (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	$ 278.0	$ 257.0
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	268.8	249.1	184.3
Pension [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	268.8	249.1
Pension [Member] | Level 2 [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	98.2	86.9
Pension [Member] | Level 2 [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	56.6	46.0
Pension [Member] | Level 2 [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	25.5	26.2
Pension [Member] | Level 2 [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	85.0	86.1
Pension [Member] | Level 2 [Member] | Cash and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	3.5	3.9
Pension [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	268.8	249.1
Pension [Member] | Total [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	98.2	86.9
Pension [Member] | Total [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	56.6	46.0
Pension [Member] | Total [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	25.5	26.2
Pension [Member] | Total [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	85.0	86.1
Pension [Member] | Total [Member] | Cash and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	3.5	3.9
Others Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	9.2	7.9	7.5
Others Benefits [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	9.2	7.9
Others Benefits [Member] | Level 3 [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Level 3 [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Level 3 [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Level 3 [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	9.2	7.9
Others Benefits [Member] | Level 3 [Member] | Cash and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	9.2	7.9
Others Benefits [Member] | Total [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Total [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Total [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	0	0
Others Benefits [Member] | Total [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	9.2	7.9
Others Benefits [Member] | Total [Member] | Cash and other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan asset	$ 0	$ 0