XML 85 R68.htm IDEA: XBRL DOCUMENT v3.8.0.1
Employee Benefit Plans (Net Periodic Pension Costs Included in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Before-Tax Amount      
Accumulated other comprehensive loss, before tax, beginning of period $ 404.8 $ 336.6  
Prior service cost arising during the year, before tax   (3.3)  
Net loss recognized due to settlement, before tax 0.3 0.5  
Net gain recognized due to curtailment, before tax   (0.1)  
Net actuarial (loss) gain arising during the year, before tax 9.0 (76.5)  
Amortization of prior service cost, before tax 1.4 1.2  
Amortization of net actuarial losses 13.5 10.0  
Accumulated other comprehensive loss, before tax, end of period (380.6) (404.8) $ (336.6)
Income Tax      
Accumulated other comprehensive loss, tax, beginning of period (100.3) (87.6)  
Prior service cost arising during the year, tax   (0.7)  
Net loss recognized due to settlement, tax 0.1 0.1  
Net gain recognized due to curtailment, tax   0.0  
Net actuarial (loss) gain arising during the year, tax 2.4 (13.6)  
Amortization of prior service costs, tax 0.1 0.1  
Amortization of net actuarial losses, tax 2.2 1.4  
Accumulated other comprehensive loss, tax, end of period (95.5) (100.3) (87.6)
After-Tax Amount      
Accumulated other comprehensive loss, after tax, beginning of period (304.5) (249.0)  
Prior service cost arising during the year 0.0 (2.6) (4.7)
Net loss recognized due to settlement 0.2 0.4 0.2
Net gain recognized due to curtailment 0.0 (0.1) 0.0
Net actuarial (loss) gain arising during the year, after tax 6.6 (62.9) 2.1
Amortization of prior service costs, after tax 1.3 1.1 0.4
Amortization of net actuarial losses included in net periodic pension cost 11.3 8.6 6.3
Accumulated other comprehensive loss, after tax, end of period $ (285.1) $ (304.5) $ (249.0)