Regulated Subsidiaries (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Duff & Phelps Securities, LLC [Member]
Regulated Subsidiaries [Line Items]
Net Capital	$ 4,369	$ 5,868
Excess Capital	4,320	5,761
Minimum Net Capital Required	49	107
Aggregate Indebtedness	741	1,716
Duff & Phelps Securities, Limited [Member]
Regulated Subsidiaries [Line Items]
Net Capital	1,923	443
Excess Capital	1,880	399
Minimum Net Capital Required	43	44
GCP Securities, LLC [Member]
Regulated Subsidiaries [Line Items]
Net Capital	141	141
Excess Capital	136	109
Minimum Net Capital Required	5	32
Aggregate Indebtedness	0	473
Pagemill Partners, LLC [Member]
Regulated Subsidiaries [Line Items]
Net Capital	3,556	159
Excess Capital	3,534	149
Minimum Net Capital Required	22	10
Aggregate Indebtedness	$ 329	$ 151