XML 86 R69.htm IDEA: XBRL DOCUMENT v3.8.0.1
Pension and Postretirement Plans - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Jun. 30, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Defined contribution plan, cost   $ 8.2 $ 8.4 $ 7.0
Capitalized portion of defined benefit contribution percent   13.00% 13.00% 12.00%
Allocation percentage in united states based investments   60.00%    
Equity Securities        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Target allocation, plan assets percentage   65.00%    
Fixed Income Securities        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Target allocation, plan assets percentage   35.00%    
Pension Plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Settlements   $ 11.0 $ 0.0  
Settlements   11.3 0.0  
Pension settlement charges   4.0 0.0 $ 0.0
Curtailment loss $ 0.3 0.0 0.0 0.3
Pension benefits $ 1.7      
Transfer of special death benefit   14.0 0.0  
Pension Plan | Qualified Plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Payment for pension and other postretirement benefits   2.3 3.1 10.3
Expected future employer contributions, next fiscal year   4.0    
Pension Plan | Nonqualified Plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Payment for pension and other postretirement benefits   2.3 2.3 2.2
Expected future employer contributions, next fiscal year   3.0    
Other Postretirement Benefits Plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Settlements   0.0 0.0  
Settlements   0.0 0.0  
Pension settlement charges   0.0 0.0 0.0
Curtailment loss   0.0 0.0 $ 0.0
Transfer of special death benefit   (14.0) $ 0.0  
Expected future employer contributions, next fiscal year   $ 9.0