Balance Sheets Parenthetical - USD ($) $ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Nuclear fuel; fuel in process | $ 64,292 | $ 51,854 |
| Allowance for Doubtful Accounts Receivable, Current | $ 2,260 | $ 2,046 |
| Common Stock, Par or Stated Value Per Share | $ 1 | $ 1 |
| Common Stock, Shares Authorized | 100,000,000 | 100,000,000 |
| Common Stock, Shares, Issued | 65,671,235 | 65,709,819 |
| Common stock, restricted shares | 156,976 | 118,834 |
| Treasury Stock, Shares | 25,305,965 | 25,384,834 |