XML 13 R3.htm IDEA: XBRL DOCUMENT v3.23.3
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2023
Sep. 30, 2022
Statement of Comprehensive Income [Abstract]        
Net income $ 241.9 $ 262.8 $ 368.6 $ 615.4
Pension Plan and Restoration of Retirement Income Plan:        
Amortization of prior service cost, net of tax of $0.0, $0.1, $0.0 and $0.1, respectively 0.1 0.0 0.2 0.1
Amortization of deferred net loss, net of tax of $0.1, $0.0, $0.2 and $0.3, respectively 0.1 0.4 0.6 0.9
Settlement cost, net of tax of $0.0, $0.5, $0.3 and $2.9, respectively 0.0 1.4 1.1 9.5
Postretirement benefit plans:        
Amortization of prior service credit, net of tax ($0.0), ($0.1), ($0.0) and ($0.1) 0.0 (0.1) 0.0 (0.1)
Amortization of deferred net gain, net of tax of $010, $0.0, $0.1 and $0.0, respectively 0.0 0.0 (0.1) 0.0
Other comprehensive income, net of tax 0.2 1.7 1.8 10.4
Comprehensive income $ 242.1 $ 264.5 $ 370.4 $ 625.8