Summary of Significant Accounting Policies, Concentration of Credit Risk (Details) (Net Receivables [Member])	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Slovenske elektrarne, a.s. [Member]
Receivable by major customers [Abstract]
Percentage of receivables contributed by major customers (in hundredths)	17.40%	24.20%
Shandong Nuclear Power Co Ltd [Member]
Receivable by major customers [Abstract]
Percentage of receivables contributed by major customers (in hundredths)	13.80%	5.00%