Condensed Consolidated Balance Sheets (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 77,594	$ 113,328
Accounts receivable (net of allowance for doubtful accounts of $1,745 and $1,347 at September 30, 2011 and December 31, 2010, respectively)	63,760	60,358
Unbilled services	38,462	23,101
Prepaid expenses and other current assets	6,716	7,479
Net deferred income taxes, current	2,467	2,555
Total current assets	188,999	206,821
Property and equipment (net of accumulated depreciation of $30,969 and $26,375 at September 30, 2011 and December 31, 2010, respectively)	32,276	29,250
Goodwill	146,650	139,170
Intangible assets (net of accumulated amortization of $23,959 and $20,656 at September 30, 2011 and December 31, 2010, respectively)	29,112	30,407
Other assets	4,360	2,638
Investments related to deferred compensation plan (Note 9)	22,598	23,151
Net deferred income taxes, non-current	113,087	116,789
Total non-current assets	348,083	341,405
Total assets	537,082	548,226
Current liabilities
Accounts payable	2,470	2,397
Accrued expenses	8,463	11,254
Accrued compensation and benefits	20,641	39,875
Liability related to deferred compensation plan, current portion (Note 9)	503	1,314
Deferred revenues	4,424	2,427
Other current liabilities	0	430
Due to noncontrolling unitholders, current portion	5,642	5,640
Total current liabilities	42,143	63,337
Liability related to deferred compensation plan, less current portion (Note 9)	21,851	21,764
Other long-term liabilities	19,714	16,676
Due to noncontrolling unitholders, less current portion	106,008	103,885
Total non-current liabilities	147,573	142,325
Total liabilities	189,716	205,662
Commitments and contingencies (Note 11)
Stockholders' equity
Preferred stock (50,000 shares authorized; zero issued and outstanding)	0	0
Additional paid-in capital	234,185	232,644
Accumulated other comprehensive income	1,130	1,400
Retained earnings	21,053	16,923
Total stockholders' equity of Duff & Phelps Corporation	256,674	251,270
Noncontrolling interest	90,692	91,294
Total stockholders' equity	347,366	342,564
Total liabilities and stockholders' equity	537,082	548,226
Common Stock Class A
Stockholders' equity
Common stock value	305	302
Common Stock Class B
Stockholders' equity
Common stock value	$ 1	$ 1