Retirement Plans and Other Post-Retirement Benefits - Schedule of Fair Value of Benefit Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 601.2	$ 545.7
Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	204.6	169.6
Small and Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68.1	65.7
Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.1
International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	114.3	100.3
Real Estate Investment Trusts (REIT) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25.9	25.4
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	171.6	164.9
Cash and Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.7	18.7
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	412.7	350.6
Level 1 [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	204.6	169.6
Level 1 [Member] | Small and Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68.1	65.7
Level 1 [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.8
Level 1 [Member] | International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	73.7	61.9
Level 1 [Member] | Real Estate Investment Trusts (REIT) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25.9	25.4
Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40.4	27.2
Level 1 [Member] | Cash and Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	188.5	195.1
Level 2 [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 [Member] | Small and Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.3
Level 2 [Member] | International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40.6	38.4
Level 2 [Member] | Real Estate Investment Trusts (REIT) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	131.2	137.7
Level 2 [Member] | Cash and Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.7	18.7
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Small and Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Real Estate Investment Trusts (REIT) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Cash and Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets