Concentration of Credit Risk - Summary of Funds Provided Ten Percent or More of Total Revenues (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Virtus Emerging Markets Opportunities Fund [Member]
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	$ 53,202	$ 29,818
Virtus Premium AlphaSector Fund [Member]
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	41,921	27,987
Virtus Multi-Sector Short Term Bond Fund [Member]
Concentration Risk [Line Items]
Investment management, administration and transfer agent fees	$ 52,568	$ 39,475	$ 24,445
Sales Revenue, Services, Net [Member] | Virtus Emerging Markets Opportunities Fund [Member]
Concentration Risk [Line Items]
Percent of total revenues	14.00%	12.00%
Sales Revenue, Services, Net [Member] | Virtus Premium AlphaSector Fund [Member]
Concentration Risk [Line Items]
Percent of total revenues	11.00%	12.00%
Sales Revenue, Services, Net [Member] | Virtus Multi-Sector Short Term Bond Fund [Member]
Concentration Risk [Line Items]
Percent of total revenues	14.00%	17.00%	14.00%