Convertible Preferred Stock and Common Stock Warrants	12 Months Ended
Dec. 31, 2012
Features of Convertible Preferred Stock [Abstract]
Convertible Preferred Stock and Common Stock Warrants	10. CONVERTIBLE PREFERRED STOCK AND COMMON STOCK WARRANTS In May 2010, Toshiba and B&W signed a securities purchase agreement to make a $200 million investment in USEC. Under the terms of the agreement, Toshiba and B&W each agreed to invest $100 million in USEC over three phases, each of which is subject to specific closing conditions. Closing for the first phase occurred in September 2010 and USEC received $75 million. Closing on the second phase of $50 million is subject to closing conditions, including obtaining a conditional commitment for a $2 billion loan guarantee from DOE. Closing on the third phase of $75 million is subject to additional closing conditions, including closing on a $2 billion loan guarantee. At the first closing, Toshiba and B&W purchased 75,000 shares of Series B-1 12.75% convertible preferred stock, and warrants to purchase 6.25 million shares of common stock at an exercise price of $7.50 per share, which will be exercisable in the future. As of December 31, 2012, the convertible preferred stock balance of $100.5 million includes additional shares of convertible preferred stock totaling $25.5 million representing dividends paid-in-kind either issued or payable. The convertible preferred stock balance of $100.5 million equates to 189.6 million shares of common stock based on the arithmetic average of the daily volume-weighted average share price for USEC common stock as of December 31, 2012 for the preceding 20 trading days, or $0.53 per share. The effect of dilutive securities on net income per share is provided in Note 16. Currently, USEC and the investors (as to such investor's obligations) have the right to terminate the securities purchase agreement. USEC continues to have discussions with Toshiba and B&W regarding their investment. As of December 31, 2012, the convertible preferred stock can be converted or sold at the holder's option and is classified as a current liability at the redemption value. Prior to obtaining shareholder approval, the preferred stock may not be converted into an aggregate number of shares of common stock in excess of 19.99% of the shares of USEC's common stock outstanding on May 25, 2010 (approximately 22.8 million shares), in compliance with the rules of the New York Stock Exchange. If a share issuance limitation were to exist at the time of share conversion, any preferred stock shares subject to the share issuance limitation would be subject to optional or mandatory redemption for, at USEC's option, cash or SWU consideration. However, USEC's ability to redeem may be limited by Delaware law, and if not limited may result in mandatory payment of USEC's credit facility.

10. CONVERTIBLE PREFERRED STOCK AND COMMON STOCK WARRANTS

In May 2010, Toshiba and B&W signed a securities purchase agreement to make a $200 million investment in USEC. Under the terms of the agreement, Toshiba and B&W each agreed to invest $100 million in USEC over three phases, each of which is subject to specific closing conditions. Closing for the first phase occurred in September 2010 and USEC received $75 million. Closing on the second phase of $50 million is subject to closing conditions, including obtaining a conditional commitment for a $2 billion loan guarantee from DOE. Closing on the third phase of $75 million is subject to additional closing conditions, including closing on a $2 billion loan guarantee.

At the first closing, Toshiba and B&W purchased 75,000 shares of Series B-1 12.75% convertible preferred stock, and warrants to purchase 6.25 million shares of common stock at an exercise price of $7.50 per share, which will be exercisable in the future. As of December 31, 2012, the convertible preferred stock balance of $100.5 million includes additional shares of convertible preferred stock totaling $25.5 million representing dividends paid-in-kind either issued or payable. The convertible preferred stock balance of $100.5 million equates to 189.6 million shares of common stock based on the arithmetic average of the daily volume-weighted average share price for USEC common stock as of December 31, 2012 for the preceding 20 trading days, or $0.53 per share. The effect of dilutive securities on net income per share is provided in Note 16.

Currently, USEC and the investors (as to such investor's obligations) have the right to terminate the securities purchase agreement. USEC continues to have discussions with Toshiba and B&W regarding their investment. As of December 31, 2012, the convertible preferred stock can be converted or sold at the holder's option and is classified as a current liability at the redemption value.

Prior to obtaining shareholder approval, the preferred stock may not be converted into an aggregate number of shares of common stock in excess of 19.99% of the shares of USEC's common stock outstanding on May 25, 2010 (approximately 22.8 million shares), in compliance with the rules of the New York Stock Exchange. If a share issuance limitation were to exist at the time of share conversion, any preferred stock shares subject to the share issuance limitation would be subject to optional or mandatory redemption for, at USEC's option, cash or SWU consideration. However, USEC's ability to redeem may be limited by Delaware law, and if not limited may result in mandatory payment of USEC's credit facility.