Consolidated Balance Sheets Consolidated Balance Sheets Parenthetical (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Nuclear fuel; fuel in process	$ 61,123	$ 49,545
Allowance for Doubtful Accounts Receivable, Current	$ 2,712	$ 3,015
Common Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	65,424,153	65,295,888
Common stock, restricted shares	109,369	156,185
Treasury Stock, Shares	25,492,919	25,492,919