v3.25.2
Capitalization and Short-Term Borrowings (Summary of Changes in Common Stock Equity) (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance (in shares)     91,005,993  
Beginning balance     $ 2,848,343  
Net income (loss) available for common stock $ 149,818 $ (54,158) 411,162 $ 245,134
Dividends Declared on Common Stock (48,340) (47,195) (141,566) (138,354)
Other Comprehensive Income (Loss), Net of Tax $ 107,168 $ (70,290) $ (100,331) $ 60,110
Share Repurchases (in shares)     (650,037)  
Ending balance (in shares) 90,355,956   90,355,956  
Ending balance $ 2,975,488   $ 2,975,488  
Dividends per share (in dollars per share) $ 0.535 $ 0.515 $ 1.565 $ 1.505
Share Repurchase Plan        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Share Repurchases (in shares)     (828,720)  
Share Repurchases     $ (53,800)  
Common Stock        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance (in shares) 90,398,000 92,032,000 91,006,000 91,819,000
Beginning balance $ 90,398 $ 92,032 $ 91,006 $ 91,819
Common stock issued under stock and benefit plans (in shares) 12,000 11,000 179,000 320,000
Common Stock Issued Under Stock and Benefit Plans $ 12 $ 11 $ 179 $ 320
Ending balance (in shares) 90,356,000 91,612,000 90,356,000 91,612,000
Ending balance $ 90,356 $ 91,612 $ 90,356 $ 91,612
Common Stock | Share Repurchase Plan        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Share Repurchases (in shares) (54,000) (431,000) (829,000) (527,000)
Share Repurchases $ (54) $ (431) $ (829) $ (527)
Paid In Capital        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance 1,042,822 1,045,929 1,045,487 1,040,761
Share-Based Payment Expense [1] 4,685 4,905 13,911 14,262
Common Stock Issued Under Stock and Benefit Plans 529 587    
Ending balance 1,047,406 1,046,479 1,047,406 1,046,479
Paid In Capital | Stock and Benefit Plans        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Share Repurchases     (2,377) (2,514)
Paid In Capital | Share Repurchase Plan        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Share Repurchases (630) (4,942) (9,615) (6,030)
Earnings Reinvested in the Business        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance 1,855,366 2,090,172 1,727,326 1,885,856
Net income (loss) available for common stock 149,818 (54,158) 411,162 245,134
Dividends Declared on Common Stock (48,340) (47,195) (141,566) (138,354)
Share Repurchases (3,311) (18,435) (43,389) (22,252)
Ending balance 1,953,533 1,970,384 1,953,533 1,970,384
Earnings Reinvested in the Business | Share Repurchase Plan        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Share Repurchases (3,311) (18,435) (43,389) (22,252)
Accumulated Other Comprehensive Income (Loss)        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance (222,975) 75,340 (15,476) (55,060)
Other Comprehensive Income (Loss), Net of Tax 107,168 (70,290) (100,331) 60,110
Ending balance $ (115,807) $ 5,050 $ (115,807) $ 5,050
[1] Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.