Condensed Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 69,475	$ 113,328
Accounts receivable (net of allowance for doubtful accounts of $1,750 and $1,347 at June 30, 2011 and December 31, 2010, respectively)	60,243	60,358
Unbilled services	41,418	23,101
Prepaid expenses and other current assets	11,634	7,479
Net deferred income taxes, current	485	2,555
Total current assets	183,255	206,821
Property and equipment (net of accumulated depreciation of $29,511 and $26,375 at June 30, 2011 and December 31, 2010, respectively)	31,071	29,250
Goodwill	147,150	139,170
Intangible assets (net of accumulated amortization of $22,705 and $20,656 at June 30, 2011 and December 31, 2010, respectively)	30,786	30,407
Other assets	4,453	2,638
Investments related to deferred compensation plan (Note 9)	25,124	23,151
Net deferred income taxes, non-current	114,464	116,789
Total non-current assets	353,048	341,405
Total assets	536,303	548,226
Current liabilities
Accounts payable	2,866	2,397
Accrued expenses	8,208	11,254
Accrued compensation and benefits	12,746	39,875
Liability related to deferred compensation plan, current portion (Note 9)	540	1,314
Deferred revenues	3,949	2,427
Other current liabilities	0	430
Due to noncontrolling unitholders, current portion	5,640	5,640
Total current liabilities	33,949	63,337
Liability related to deferred compensation plan, less current portion (Note 9)	24,986	21,764
Other long-term liabilities	18,720	16,676
Due to noncontrolling unitholders, less current portion	105,638	103,885
Total non-current liabilities	149,344	142,325
Total liabilities	183,293	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	240,782	232,644
Accumulated other comprehensive income	3,049	1,400
Retained earnings	19,491	16,923
Total stockholders' equity of Duff & Phelps Corporation	263,639	251,270
Noncontrolling interest	89,371	91,294
Total stockholders' equity	353,010	342,564
Total liabilities and stockholders' equity	536,303	548,226
Common Stock Class A
Stockholders' equity
Common stock value	316	302
Common Stock Class B
Stockholders' equity
Common stock value	$ 1	$ 1