Balance Sheets Parenthetical (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Nuclear fuel; fuel in process	$ 46,404	$ 48,492
Allowance for Doubtful Accounts Receivable, Current	$ 1,738	$ 2,261
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	65,706,047	65,639,091
Common stock, restricted shares	138,896	120,534
Treasury Stock, Shares	25,492,919	25,492,919