Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 68,732	$ 38,986
Accounts receivable (net of allowance for doubtful accounts of $2,037 and $1,753 at December 31, 2012 and 2011, respectively)	79,360	77,795
Unbilled services	54,159	51,427
Prepaid expenses and other current assets	10,980	8,257
Net deferred income taxes, current	1,819	2,545
Total current assets	215,050	179,010
Property and equipment (net of accumulated depreciation of $39,534 and $32,516 at December 31, 2012 and 2011, respectively)	49,926	33,632
Goodwill	205,653	192,970
Intangible assets (net of accumulated amortization of $35,144 and $25,626 at December 31, 2012 and 2011, respectively)	38,201	40,977
Other assets	16,969	13,942
Investments related to deferred compensation plan	28,775	23,542
Net deferred income taxes, less current portion	161,339	115,826
Total non-current assets	500,863	420,889
Total assets	715,913	599,899
Current liabilities
Accounts payable	5,131	4,148
Accrued expenses	23,939	22,612
Accrued compensation and benefits	54,315	41,518
Liability related to deferred compensation plan, current portion	506	646
Deferred revenues	6,388	4,185
Due to noncontrolling unitholders, current portion	7,623	6,209
Total current liabilities	97,902	79,318
Long-term debt	22,500	0
Liability related to deferred compensation plan, less current portion	28,361	23,083
Other long-term liabilities	36,511	32,248
Due to noncontrolling unitholders, less current portion	140,458	101,557
Total non-current liabilities	227,830	156,888
Total liabilities	325,732	236,206
Commitments and contingencies
Stockholders' equity
Preferred stock (50,000 shares authorized; zero issued and outstanding)	0	0
Additional paid-in capital	352,858	252,572
Accumulated other comprehensive income	2,620	287
Retained earnings	34,279	25,631
Total stockholders' equity of Duff & Phelps Corporation	390,181	278,807
Noncontrolling interest	0	84,886
Total stockholders' equity	390,181	363,693
Total liabilities and stockholders' equity	715,913	599,899
Common Stock Class A [Member]
Stockholders' equity
Common stock value	424	316
Common Stock Class B [Member]
Stockholders' equity
Common stock value	$ 0	$ 1