Acquisitions (Tables)

12 Months Ended

Dec. 31, 2012

Business Combinations [Abstract]

Business Acquisition, Pro Forma Information [Table Text Block]

The unaudited pro forma financial information was prepared for comparative purposes only and does not purport to be indicative of what would have occurred had the acquisition been made at that time or of results which may occur in the future.

	Year Ended
	December 31, 2011		December 31, 2010
Revenue	$	441,767	$	431,909
Reimbursable expenses	14,773		11,252
Total revenue	$	456,540	$	443,161
Net income attributable to Duff & Phelps Corporation	$	23,259	$	18,567
Net income per share attributable to stockholders of Class A common stock of Duff & Phelps Corporation
Basic	$	0.77	$	0.65
Diluted	$	0.74	$	0.63