Deferred Compensation Plan	9 Months Ended
Sep. 30, 2010
Deferred Compensation Plan [Abstract]
Compensation and Employee Benefit Plans [Text Block]	DEFERRED COMPENSATION PLAN The Company maintains the Duff & Phelps Deferred Compensation Plan (“Deferred Compensation Plan”) for key employees. This plan is detailed further in the Company's Annual Report on Form 10-K for the year ended December 31, 2010. Under the terms of the plan, the Company established a “rabbi trust” as a vehicle for accumulating assets to pay benefits under the plan. Payments under the plan may be paid from the general assets of the Company or from the assets of any such rabbi trust. Payment from any such source reduces the obligation owed to the participant or beneficiary. The rabbi trust invests in an investment vehicle structured as a corporate-owned life insurance (“COLI”) policy with a cash surrender value that mirrors the payable to the participants of the plan and tracks the value of the plan assets. Participants can earn a return on their deferred compensation that is based on hypothetical investment funds. The policy is redeemable on demand in an amount equal to the cash surrender value. The cash surrender value approximates fair value. The fair market value of the investments in the rabbi trust is included in “Investments related to the deferred compensation plan” with the corresponding deferred compensation obligation included in current and non-current portion of the liability related to the deferred compensation plan on the Condensed Consolidated Balance Sheets. Changes in the fair value of the investments are recognized as compensation expense (or credit). Changes in the fair value of the benefits payables to participants are recognized as a corresponding offset to compensation expense (or credit). The net impact of changes in fair value is not material.

DEFERRED COMPENSATION PLAN

The Company maintains the Duff & Phelps Deferred Compensation Plan (“Deferred Compensation Plan”) for key employees. This plan is detailed further in the Company's Annual Report on Form 10-K for the year ended December 31, 2010. Under the terms of the plan, the Company established a “rabbi trust” as a vehicle for accumulating assets to pay benefits under the plan. Payments under the plan may be paid from the general assets of the Company or from the assets of any such rabbi trust. Payment from any such source reduces the obligation owed to the participant or beneficiary. The rabbi trust invests in an investment vehicle structured as a corporate-owned life insurance (“COLI”) policy with a cash surrender value that mirrors the payable to the participants of the plan and tracks the value of the plan assets. Participants can earn a return on their deferred compensation that is based on hypothetical investment funds. The policy is redeemable on demand in an amount equal to the cash surrender value. The cash surrender value approximates fair value.

The fair market value of the investments in the rabbi trust is included in “Investments related to the deferred compensation plan” with the corresponding deferred compensation obligation included in current and non-current portion of the liability related to the deferred compensation plan on the Condensed Consolidated Balance Sheets. Changes in the fair value of the investments are recognized as compensation expense (or credit). Changes in the fair value of the benefits payables to participants are recognized as a corresponding offset to compensation expense (or credit). The net impact of changes in fair value is not material.