Environmental Compliance (Notes)	12 Months Ended
Dec. 31, 2013
Environmental Compliance [Abstract]
Environmental Compliance [Text Block]	ENVIRONMENTAL COMPLIANCE Environmental compliance costs include the handling, treatment and disposal of hazardous substances and wastes. Pursuant to the USEC Privatization Act, environmental liabilities associated with the Paducah GDP prior to July 28, 1998 are the responsibility of the U.S. government. Depleted Uranium USEC has historically accrued estimated costs for the future disposition of depleted uranium generated from enrichment operations at the Paducah GDP. DOE provided funding for the support of the RD&D Program in 2012 by accepting title to USEC’s balance of depleted uranium. As of December 31, 2013, a small remaining quantity of depleted uranium remains to be transferred to DOE under USEC’s agreement with DOE. The transfer of depleted uranium to DOE enabled USEC to release cash deposits that had been used as collateral for future depleted uranium disposition. Stored Wastes USEC's prior enrichment operations generated hazardous, low-level radioactive and mixed wastes. The storage, treatment, and disposal of wastes are regulated by federal and state laws. USEC utilizes offsite treatment and disposal facilities and stores wastes at the Paducah site pursuant to permits, orders and agreements with DOE and state agencies. Liabilities accrued for the treatment and disposal of stored wastes generated by USEC's operations, included in accounts payable and accrued liabilities, amounted to $1.8 million at December 31, 2013 and $2.1 million at December 31, 2012. GDP Lease Turnover Under the GDP lease agreement with DOE, ownership of capital improvements that USEC leaves behind as well as responsibility for D&D transfers to DOE. The turnover requirements of the lease require USEC to remove certain uranium and USEC-generated waste and place the property in a safe shutdown condition. Accrued liabilities for lease turnover costs related to the Paducah GDP, included in accounts payable and accrued liabilities, were $30.4 million at December 31, 2013 and $32.2 million at December 31, 2012. In addition, $10.3 million of accrued liabilities for lease turnover costs were included in other long-term liabilities at December 31, 2012. USEC ceased uranium enrichment at the Portsmouth GDP in 2001. During subsequent years, USEC maintained the Portsmouth site and performed services under contract with DOE. On September 30, 2011, USEC completed the transition of Portsmouth site facilities to DOE. As part of the transition, at USEC’s request, the NRC terminated USEC’s certificate of compliance for the Portsmouth site. In connection with the return of facilities, DOE agreed to accept ownership of all nuclear material at the site, some of which required processing for waste disposal. USEC agreed to pay DOE its cost of disposing of such wastes. The accrued disposal obligation, included in accounts payable and accrued liabilities, is $5.5 million at December 31, 2013 and $6.7 million at December 31, 2012. American Centrifuge Decontamination and Decommissioning Financial Assurance USEC leases facilities in Piketon, Ohio from DOE for the American Centrifuge Plant. At the conclusion of the lease, USEC is obligated to return these leased facilities to DOE in a condition that meets NRC requirements and in the same condition as the facilities were in when they were leased to USEC (other than due to normal wear and tear). USEC owns all capital improvements at the ACP and, unless otherwise consented to by DOE, must remove them by the conclusion of the lease term. USEC is required to provide financial assurance to the NRC incrementally based on facility construction progress, centrifuge installation and decommissioning cost projections. USEC is also required to provide financial assurance to DOE in an amount equal to its current estimate of costs to comply with lease turnover requirements, less the amount of financial assurance required of USEC by the NRC for D&D. As of December 31, 2013, USEC has provided financial assurance to the NRC and DOE in the form of surety bonds totaling $29.4 million, which is fully cash collateralized by USEC. Financial assurance provided for the ACP increased $6.4 million in 2013 related to construction of centrifuge machines, for which DOE takes title, as part of the RD&D Program. If construction of the ACP is resumed, the financial assurance requirements will increase each year commensurate with the status of facility construction and operations. As part of USEC’s license to operate the ACP, USEC provides the NRC with a projection of the total D&D cost. The total D&D cost related to the NRC and the incremental lease turnover cost related to DOE is uncertain at this time and is dependent on many factors including the size of the plant. Financial assurance will also be required for the disposition of depleted uranium generated from future commercial centrifuge operations. Asset Retirement Obligations D&D requirements for the ACP create asset retirement obligations ("ARO"). The capitalization of asset retirement obligations based on construction progress has been suspended since the third quarter of 2009, when USEC significantly reduced machine manufacturing and construction activities due to project funding uncertainty. In 2012, USEC expensed previously capitalized costs related to the American Centrifuge project, including previously capitalized asset retirement obligations of $19.3 million, and there is no ARO asset balance as of December 31, 2013. The ARO liability balance is $22.6 million as of December 31, 2013 and is unchanged since December 31, 2010. USEC has determined that the fair value of the obligation is accrued at a sufficient amount based on construction progress and no further increase would be made until additional commercial plant deployment resumes.

ENVIRONMENTAL COMPLIANCE

Environmental compliance costs include the handling, treatment and disposal of hazardous substances and wastes. Pursuant to the USEC Privatization Act, environmental liabilities associated with the Paducah GDP prior to July 28, 1998 are the responsibility of the U.S. government.

Depleted Uranium

USEC has historically accrued estimated costs for the future disposition of depleted uranium generated from enrichment operations at the Paducah GDP. DOE provided funding for the support of the RD&D Program in 2012 by accepting title to USEC’s balance of depleted uranium. As of December 31, 2013, a small remaining quantity of depleted uranium remains to be transferred to DOE under USEC’s agreement with DOE. The transfer of depleted uranium to DOE enabled USEC to release cash deposits that had been used as collateral for future depleted uranium disposition.

Stored Wastes

USEC's prior enrichment operations generated hazardous, low-level radioactive and mixed wastes. The storage, treatment, and disposal of wastes are regulated by federal and state laws. USEC utilizes offsite treatment and disposal facilities and stores wastes at the Paducah site pursuant to permits, orders and agreements with DOE and state agencies. Liabilities accrued for the treatment and disposal of stored wastes generated by USEC's operations, included in accounts payable and accrued liabilities, amounted to $1.8 million at December 31, 2013 and $2.1 million at December 31, 2012.

GDP Lease Turnover

Under the GDP lease agreement with DOE, ownership of capital improvements that USEC leaves behind as well as responsibility for D&D transfers to DOE. The turnover requirements of the lease require USEC to remove certain uranium and USEC-generated waste and place the property in a safe shutdown condition. Accrued liabilities for lease turnover costs related to the Paducah GDP, included in accounts payable and accrued liabilities, were $30.4 million at December 31, 2013 and $32.2 million at December 31, 2012. In addition, $10.3 million of accrued liabilities for lease turnover costs were included in other long-term liabilities at December 31, 2012.

USEC ceased uranium enrichment at the Portsmouth GDP in 2001. During subsequent years, USEC maintained the Portsmouth site and performed services under contract with DOE. On September 30, 2011, USEC completed the transition of Portsmouth site facilities to DOE. As part of the transition, at USEC’s request, the NRC terminated USEC’s certificate of compliance for the Portsmouth site. In connection with the return of facilities, DOE agreed to accept ownership of all nuclear material at the site, some of which required processing for waste disposal. USEC agreed to pay DOE its cost of disposing of such wastes. The accrued disposal obligation, included in accounts payable and accrued liabilities, is $5.5 million at December 31, 2013 and $6.7 million at December 31, 2012.

American Centrifuge Decontamination and Decommissioning

Financial Assurance

USEC leases facilities in Piketon, Ohio from DOE for the American Centrifuge Plant. At the conclusion of the lease, USEC is obligated to return these leased facilities to DOE in a condition that meets NRC requirements and in the same condition as the facilities were in when they were leased to USEC (other than due to normal wear and tear). USEC owns all capital improvements at the ACP and, unless otherwise consented to by DOE, must remove them by the conclusion of the lease term. USEC is required to provide financial assurance to the NRC incrementally based on facility construction progress, centrifuge installation and decommissioning cost projections. USEC is also required to provide financial assurance to DOE in an amount equal to its current estimate of costs to comply with lease turnover requirements, less the amount of financial assurance required of USEC by the NRC for D&D.

As of December 31, 2013, USEC has provided financial assurance to the NRC and DOE in the form of surety bonds totaling $29.4 million, which is fully cash collateralized by USEC. Financial assurance provided for the ACP increased $6.4 million in 2013 related to construction of centrifuge machines, for which DOE takes title, as part of the RD&D Program. If construction of the ACP is resumed, the financial assurance requirements will increase each year commensurate with the status of facility construction and operations. As part of USEC’s license to operate the ACP, USEC provides the NRC with a projection of the total D&D cost. The total D&D cost related to the NRC and the incremental lease turnover cost related to DOE is uncertain at this time and is dependent on many factors including the size of the plant. Financial assurance will also be required for the disposition of depleted uranium generated from future commercial centrifuge operations.

Asset Retirement Obligations

D&D requirements for the ACP create asset retirement obligations ("ARO"). The capitalization of asset retirement obligations based on construction progress has been suspended since the third quarter of 2009, when USEC significantly reduced machine manufacturing and construction activities due to project funding uncertainty. In 2012, USEC expensed previously capitalized costs related to the American Centrifuge project, including previously capitalized asset retirement obligations of $19.3 million, and there is no ARO asset balance as of December 31, 2013. The ARO liability balance is $22.6 million as of December 31, 2013 and is unchanged since December 31, 2010. USEC has determined that the fair value of the obligation is accrued at a sufficient amount based on construction progress and no further increase would be made until additional commercial plant deployment resumes.