Capital Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Total Shares Authorized	210,000,000
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Par Value	$ 0.01	$ 0.01
Phantom Stock Value Per Share	$ 3.33
SERP units	0	0	16,023
Share Repurchase Program, Remaining Authorized, Amount	$ 925.0
Common Stock, Voting Rights	one vote per share
Stock Repurchased and Retired During Period, Shares	0
Proceeds from Issuance of Common Stock	$ 0.0	$ 220.7	$ 0.0
Company recognized total stock compensation expense, net of forfeitures	$ 38.1	$ 29.2	$ 36.6
Union ratification stock awards
Class Of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	0	22,594
Share-based Payment Arrangement, Expense	$ 0.0	$ 0.6
Restricted Stock Units (RSUs) [Member] | LTIP
Class Of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	816,238	1,229,552	553,578
Share-based Payment Arrangement | LTIP
Class Of Stock [Line Items]
Fair Value Of Shares Granted	$ 25.2	$ 29.6	$ 24.0
Performance Shares | LTIP
Class Of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	388,386	463,939	284,653
Fair Value Of Shares Granted	$ 14.9	$ 20.1	$ 22.0
Class A [Member]
Class Of Stock [Line Items]
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Par Value	$ 0.01	$ 0.01
Class B [Member]
Class Of Stock [Line Items]
Common Stock, Shares Authorized	0	0
Common Stock, Par Value	$ 0	$ 0