Earnings (Loss) Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net Income (Loss)	$ 76,097	$ 16,209	$ 128,311	$ 17,215
Noncontrolling interests	(13,130)	(4,930)	(28,756)	(10,221)
Net Income (Loss) Attributable to Virtus Investment Partners, Inc.	$ 62,967	$ 11,279	$ 99,555	$ 6,994
Shares:
Basic: Weighted-average number of common shares outstanding (in shares)	7,698	7,720	7,674	7,572
Plus: Incremental shares from assumed conversion of dilutive instruments (in shares)	309	175	364	364
Diluted: Weighted-average number of common shares outstanding (in shares)	8,007	7,895	8,038	7,936
Earnings (Loss) per share—Basic (in $ per share)	$ 8.18	$ 1.46	$ 12.97	$ 0.92
Earnings (Loss) per Share—Diluted (in $ per share)	$ 7.86	$ 1.43	$ 12.39	$ 0.88