XML 115 R93.htm IDEA: XBRL DOCUMENT v3.3.1.900
Retirement Plans and Other Post-Retirement Benefits - Schedule of Net Periodic Benefit Cost of Pension and Other Benefits (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Pension Benefits [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 11.6 $ 10.4 $ 11.6
Interest cost 23.3 24.8 21.8
Expected return on plan assets (46.0) (43.9) (43.4)
Amortization of prior service cost/(credit) 3.1 3.3 3.1
Amortization of actuarial loss 17.1 12.1 21.1
Total net periodic benefit cost 9.1 6.7 14.2
Other Benefits [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 1.4 1.5 2.9
Interest cost 2.0 2.5 2.1
Amortization of prior service cost/(credit) (0.3) (0.3) (0.5)
Amortization of actuarial loss 0.2 0.4 0.6
Total net periodic benefit cost $ 3.3 $ 4.1 $ 5.1