v3.26.1
Benefit Plans - Schedule of Net Periodic Benefit Costs (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Feb. 28, 2026
Feb. 28, 2025
Feb. 28, 2026
Feb. 28, 2025
Pension Benefits | Qualified        
Components of net periodic benefit costs:        
Service cost $ 11,348 $ 10,932 $ 22,695 $ 21,864
Interest cost 9,027 8,725 18,053 17,449
Expected return on assets (12,579) (11,744) (25,158) (23,488)
Prior service (credit) cost amortization (149) 50 (298) 100
Actuarial loss (gain) amortization 4,125 3,204 8,249 6,408
Net periodic benefit cost 11,772 11,167 23,541 22,333
Pension Benefits | Nonqualified        
Components of net periodic benefit costs:        
Service cost 831 757 1,663 1,514
Interest cost 335 289 670 577
Expected return on assets 0 0 0 0
Prior service (credit) cost amortization (8) (12) (15) (24)
Actuarial loss (gain) amortization 246 200 491 400
Net periodic benefit cost 1,404 1,234 2,809 2,467
Other Benefits        
Components of net periodic benefit costs:        
Service cost 210 211 420 422
Interest cost 281 285 563 570
Expected return on assets 0 0 0 0
Prior service (credit) cost amortization (111) (111) (223) (223)
Actuarial loss (gain) amortization (299) (309) (599) (617)
Net periodic benefit cost $ 81 $ 76 $ 161 $ 152