Employee Benefits - Plan Assets and Investment Policy (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Return Seeking Assets | Minimum
Employee Benefits
Weighted-average asset allocations (as a percent)	50.00%
Return Seeking Assets | Maximum
Employee Benefits
Weighted-average asset allocations (as a percent)	70.00%
Liability Hedging Assets | Minimum
Employee Benefits
Weighted-average asset allocations (as a percent)	30.00%
Liability Hedging Assets | Maximum
Employee Benefits
Weighted-average asset allocations (as a percent)	50.00%
DB Plan
Employee Benefits
Total investments at fair value	$ 65.6	$ 63.8	$ 56.7
DB Plan | Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member]
Employee Benefits
Fair value of plan assets	2.0
DB Plan | Level 1
Employee Benefits
Total investments at fair value	2.0	51.7
DB Plan | Level 2
Employee Benefits
Total investments at fair value		12.1
DB Plan | Fair Value Measured at Net Asset Value Per Share [Member]
Employee Benefits
Fair value of plan assets	63.6
DB Plan | Common stock.
Employee Benefits
Fair value of plan assets		37.8
DB Plan | Common stock. | Level 1
Employee Benefits
Fair value of plan assets		37.8
DB Plan | U.S. government, state, and agency
Employee Benefits
Fair value of plan assets		8.3
DB Plan | U.S. government, state, and agency | Level 2
Employee Benefits
Fair value of plan assets		8.3
DB Plan | Corporate debt securities
Employee Benefits
Fair value of plan assets		3.8
DB Plan | Corporate debt securities | Level 2
Employee Benefits
Fair value of plan assets		3.8
DB Plan | Mutual funds
Employee Benefits
Fair value of plan assets	1.9	13.4
DB Plan | Mutual funds | Level 1
Employee Benefits
Fair value of plan assets	1.9	13.4
DB Plan | Interest bearing cash
Employee Benefits
Fair value of plan assets	0.1	0.5
DB Plan | Interest bearing cash | Level 1
Employee Benefits
Fair value of plan assets	$ 0.1	$ 0.5