XML 112 R98.htm IDEA: XBRL DOCUMENT v3.3.1.900
Defined Benefit Plans - Reconciliation of Level Three Measurements (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]    
Beginning balance $ 68.5 $ 64.5
Actual return on assets related to assets still held 4.7 4.0
Ending balance 73.2 68.5
Group annuity/insurance contracts    
Defined Benefit Plan Disclosure [Line Items]    
Beginning balance 21.8 21.2
Actual return on assets related to assets still held 0.5 0.6
Ending balance 22.3 21.8
Commingled Funds | Multi-strategy hedge funds    
Defined Benefit Plan Disclosure [Line Items]    
Beginning balance 21.6 20.5
Actual return on assets related to assets still held 0.7 1.1
Ending balance 22.3 21.6
Commingled Funds | Real estate    
Defined Benefit Plan Disclosure [Line Items]    
Beginning balance 25.1 22.8
Actual return on assets related to assets still held 3.5 2.3
Ending balance $ 28.6 $ 25.1