XML 147 R152.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Employee Benefits - Postretirement Amounts Included in Accumulated Other Comprehensive Income (Detail) - Other Postretirement Plan - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Net Actuarial (Gain) Loss $ (5.4) $ (6.5)
Prior Service Cost 0.0 0.0
Gross Amount in Accumulated Other Comprehensive Income (5.4) (6.5)
Income Tax Effect (1.4) (2.2)
Net Amount in Accumulated Other Comprehensive Income $ (4.0) $ (4.3)