XML 75 R64.htm IDEA: XBRL DOCUMENT v3.20.2
Other Comprehensive Income and Accumulated Other Comprehensive Income - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income by Component (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Realized gain/(loss) on sale of securities $ 20.0 $ (5.0) $ (39.3) $ 50.2
Tax (expense) benefit (3.2) (1.2) 18.9 (12.0)
Total reclassifications for the period (1.9) 0.3 (2.4) 0.3
Unrealized Gains and Losses on Available-for-Sale Securities [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Total reclassifications for the period (0.2) 0.9 2.5 2.2
Benefit Plan Items [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Total reclassifications for the period (1.7) (0.6) (4.9) (1.9)
Reclassification Out of Accumulated Other Comprehensive Income [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Total reclassifications for the period (1.9) 0.3 (2.4) 0.3
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Realized gain/(loss) on sale of securities (0.2) 1.2 3.2 2.8
Total before tax (0.2) 1.2 3.2 2.8
Tax (expense) benefit 0.0 (0.3) (0.7) (0.6)
Net of tax (0.2) 0.9 2.5 2.2
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Benefit Plan Items [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Accumulated other comprehensive income components/Negative prior-service costs 1.6 1.6 4.8 4.8
Accumulated other comprehensive income components/Net actuarial loss (3.7) (2.4) (11.0) (7.2)
Total before tax (2.1) (0.8) (6.2) (2.4)
Tax (expense) benefit 0.4 0.2 1.3 0.5
Net of tax $ (1.7) $ (0.6) $ (4.9) $ (1.9)