Concentration of Credit Risk - Total Revenue (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Virtus Multi Sector Short Term Bond Fund Member
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	$ 39,475	$ 24,445	$ 14,506
Virtus Emerging Markets Opportunities Fund [Member]
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	29,818
Virtus Premium AlphaSector Fund [Member]
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	27,987
DNP Select Income Fund Member
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees			$ 14,959
Sales Revenue, Services, Net [Member] | Virtus Multi Sector Short Term Bond Fund Member
Concentration Risk [Line Items]
Percent of total revenue	17.00%	14.00%	10.00%
Sales Revenue, Services, Net [Member] | Virtus Emerging Markets Opportunities Fund [Member]
Concentration Risk [Line Items]
Percent of total revenue	12.00%
Sales Revenue, Services, Net [Member] | Virtus Premium AlphaSector Fund [Member]
Concentration Risk [Line Items]
Percent of total revenue	12.00%
Sales Revenue, Services, Net [Member] | DNP Select Income Fund Member
Concentration Risk [Line Items]
Percent of total revenue			10.00%