Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Revenues	$ 92,028	$ 84,427	$ 264,960	$ 262,333
Reimbursable expenses	2,395	2,403	7,361	7,163
Total revenues	94,423	86,830	272,321	269,496
Direct client service costs
Compensation and benefits (includes $4,316 and $3,430 of equity-based compensation for the three months ended September 30, 2011 and 2010, respectively, and $13,381 and $11,362 for the nine months ended September 30, 2011 and 2010, respectively)	50,705	48,369	146,672	147,382
Other direct client service costs	2,050	1,342	4,959	5,211
Acquisition retention expenses (includes $211 and $600 of equity-based compensation for the three and nine months ended September 30, 2011, respectively)	221	0	600	0
Reimbursable expenses	2,415	2,330	7,484	7,223
Direct client service costs	55,391	52,041	159,715	159,816
Operating expenses
Selling, general and administrative (includes $819 and $1,004 of equity-based compensation for the three months ended September 30, 2011 and 2010, respectively, and $3,111 and $4,462 for the nine months ended September 30, 2011 and 2010, respectively)	23,611	22,945	72,915	73,333
Depreciation and amortization	2,878	2,567	7,934	7,410
Restructuring charges (Note 10)	3,091	0	3,995	0
Merger and acquisition costs	335	76	801	397
Charge from impairment of certain intangible assets	0	0	0	674
Operating expenses	29,915	25,588	85,645	81,814
Operating income	9,117	9,201	26,961	27,866
Other expense/(income), net
Interest income	(14)	(29)	(69)	(106)
Interest expense	30	66	178	234
Other expense/(income)	10	(43)	3	189
Nonoperating expense/(income) including interest expense/income	26	(6)	112	317
Income before income taxes	9,091	9,207	26,849	27,549
Provision for income taxes	2,655	2,010	8,275	8,166
Net income	6,436	7,197	18,574	19,383
Less: Net income attributable to noncontrolling interest	2,404	3,088	7,005	8,494
Net income attributable to Duff & Phelps Corporation	$ 4,032	$ 4,109	$ 11,569	$ 10,889
Common Stock Class A
Weighted average shares of Class A common stock outstanding
Basic	26,945	24,873	27,050	24,972
Diluted	27,060	24,954	27,834	25,741
Net income per share attributable to stockholders of Class A common stock of Duff & Phelps Corporation (Note 4)
Basic	$ 0.14	$ 0.15	$ 0.41	$ 0.41
Diluted	$ 0.14	$ 0.15	$ 0.40	$ 0.40
Cash dividends declared per common share	$ 0.08	$ 0.06	$ 0.24	$ 0.17