Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Statement of Comprehensive Income [Abstract]
Net income	$ 137,879	$ 143,151	$ 102,586	$ 125,044
Postretirement liability adjustment:
Amortization of postretirement liability losses included in net periodic benefit cost, net of tax of $41 and $21 for the three months ended and $123 and $61 for the nine months ended September 30, 2026 and 2025, respectively.	127	63	381	190
Postretirement liability adjustment	127	63	381	190
Other comprehensive income	127	63	381	190
Comprehensive income attributable to common stockholders	$ 138,006	$ 143,214	$ 102,967	$ 125,234

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details