Long-Term Debt	12 Months Ended
Dec. 31, 2012
Long-term Debt, Unclassified [Abstract]
Long-term Debt [Text Block]	Long-Term Debt On July 15, 2009, Duff & Phelps, LLC entered into a credit agreement with Bank of America, N.A., as administrative agent and the lenders from time to time party thereto, as amended by (i) the first amendment to the credit agreement dated as of November 8, 2010, (ii) the second amendment to credit agreement dated as of February 23, 2011, (iii) the third amendment to credit agreement dated as of August 15, 2011, (iv) the fourth amendment to credit agreement dated as of October 13, 2011 and (v) the fifth amendment to credit agreement dated August 10, 2012 (collectively, the “Credit Agreement”). The Credit Agreement provides for a $75,000 senior secured revolving credit facility ("Credit Facility"), including a $10,000 sub-limit for the issuance of letters of credit. The proceeds of the facility are permitted to be used for working capital, permitted acquisitions and general corporate purposes. The maturity date is October 13, 2016. Amounts borrowed may be voluntarily prepaid at any time without penalty or premium, subject to customary breakage costs. There was $22,500 outstanding under the Credit Facility as of December 31, 2012. As of December 31, 2012, the Company had $2,397 of outstanding letters of credit issued against the Credit Facility. These letters of credit were issued in connection with real estate leases. Loans under the Credit Facility will, at the Company's option, bear interest on the principal amount outstanding at either (a) a rate equal to LIBOR, plus an applicable margin or (b) a base rate, plus an applicable margin. The applicable margin rate is based on the Company's most recent consolidated leverage ratio and ranges from 1.25% to 2.25% per annum for the LIBOR rate or 0.25% to 1.25% per annum for the base rate. In addition, the Company is required to pay an unused commitment fee on the actual daily amount of the unutilized portion of the commitments of the lenders at a rate ranging from 0.30% to 0.50% per annum, based on the Company's most recent consolidated leverage ratio. Based on the Company's consolidated leverage ratio at December 31, 2012, the Company qualifies for the 1.25% applicable margin for the LIBOR rate or 0.25% applicable margin for the base rate, and 0.30% for the unused commitment fee. The Credit Agreement contains customary representations and warranties and customary affirmative and negative covenants, including, among others, limitations on (a) the incurrence of liens, (b) the incurrence of indebtedness, (c) the ability to make dividends and distributions, as well as redeem and repurchase equity interests and (d) acquisitions, mergers, consolidations and sales of assets. In addition, the Credit Agreement contains financial covenants that do not permit (i) a total leverage ratio of greater than 3.00 to 1.00 until the quarter ending March 31, 2013; and 2.75 to 1.00 thereafter and (ii) a consolidated fixed charge coverage ratio of less than 1.15 to 1.00 beginning July 1, 2011 through and including June 30, 2012; 1.20 to 1.00 beginning July 1, 2012 through and including September 30, 2013; and 1.25 to 1.00 thereafter. The financial covenants are tested on the last day of each fiscal quarter based on the last four fiscal quarter periods. Management believes that the Company was in compliance with all of its covenants as of December 31, 2012. The obligation of the Company to pay amounts outstanding under the Credit Facility may be accelerated upon the occurrence of an "Event of Default" as defined in the Credit Agreement. The Company's obligations under the Credit Agreement are guaranteed by D&P Acquisitions, and certain domestic subsidiaries of the Company (collectively, the "Guarantors"). The Credit Agreement is secured by a lien on substantially all of the personal property of the Company and each of the Guarantors.

Long-Term Debt

On July 15, 2009, Duff & Phelps, LLC entered into a credit agreement with Bank of America, N.A., as administrative agent and the lenders from time to time party thereto, as amended by (i) the first amendment to the credit agreement dated as of November 8, 2010, (ii) the second amendment to credit agreement dated as of February 23, 2011, (iii) the third amendment to credit agreement dated as of August 15, 2011, (iv) the fourth amendment to credit agreement dated as of October 13, 2011 and (v) the fifth amendment to credit agreement dated August 10, 2012 (collectively, the “Credit Agreement”). The Credit Agreement provides for a $75,000 senior secured revolving credit facility ("Credit Facility"), including a $10,000 sub-limit for the issuance of letters of credit.

The proceeds of the facility are permitted to be used for working capital, permitted acquisitions and general corporate purposes. The maturity date is October 13, 2016. Amounts borrowed may be voluntarily prepaid at any time without penalty or premium, subject to customary breakage costs. There was $22,500 outstanding under the Credit Facility as of December 31, 2012. As of December 31, 2012, the Company had $2,397 of outstanding letters of credit issued against the Credit Facility. These letters of credit were issued in connection with real estate leases.

Loans under the Credit Facility will, at the Company's option, bear interest on the principal amount outstanding at either (a) a rate equal to LIBOR, plus an applicable margin or (b) a base rate, plus an applicable margin. The applicable margin rate is based on the Company's most recent consolidated leverage ratio and ranges from 1.25% to 2.25% per annum for the LIBOR rate or 0.25% to 1.25% per annum for the base rate. In addition, the Company is required to pay an unused commitment fee on the actual daily amount of the unutilized portion of the commitments of the lenders at a rate ranging from 0.30% to 0.50% per annum, based on the Company's most recent consolidated leverage ratio. Based on the Company's consolidated leverage ratio at December 31, 2012, the Company qualifies for the 1.25% applicable margin for the LIBOR rate or 0.25% applicable margin for the base rate, and 0.30% for the unused commitment fee.

The Credit Agreement contains customary representations and warranties and customary affirmative and negative covenants, including, among others, limitations on (a) the incurrence of liens, (b) the incurrence of indebtedness, (c) the ability to make dividends and distributions, as well as redeem and repurchase equity interests and (d) acquisitions, mergers, consolidations and sales of assets. In addition, the Credit Agreement contains financial covenants that do not permit (i) a total leverage ratio of greater than 3.00 to 1.00 until the quarter ending March 31, 2013; and 2.75 to 1.00 thereafter and (ii) a consolidated fixed charge coverage ratio of less than 1.15 to 1.00 beginning July 1, 2011 through and including June 30, 2012; 1.20 to 1.00 beginning July 1, 2012 through and including September 30, 2013; and 1.25 to 1.00 thereafter. The financial covenants are tested on the last day of each fiscal quarter based on the last four fiscal quarter periods. Management believes that the Company was in compliance with all of its covenants as of December 31, 2012.

The obligation of the Company to pay amounts outstanding under the Credit Facility may be accelerated upon the occurrence of an "Event of Default" as defined in the Credit Agreement. The Company's obligations under the Credit Agreement are guaranteed by D&P Acquisitions, and certain domestic subsidiaries of the Company (collectively, the "Guarantors"). The Credit Agreement is secured by a lien on substantially all of the personal property of the Company and each of the Guarantors.