Shareholder Report, Line Graph (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class IA
Account Value [Line Items]
Line Graph and Table Measure Name	Class IA
Account Value	$ 25,734	$ 20,809	$ 16,855	$ 23,447	$ 20,535	$ 13,809	$ 10,026	$ 11,610	$ 10,724	$ 9,263	$ 10,000
Class IB
Account Value [Line Items]
Line Graph and Table Measure Name	Class IB
Account Value	$ 25,097	20,349	16,525	23,047	20,231	13,642	9,925	11,519	10,673	9,239	10,000
Russell 3000 Index [Member]
Account Value [Line Items]
Line Graph and Table Measure Name	Russell 3000 Index
Account Value	$ 32,604	26,334	20,907	25,877	20,593	17,035	13,002	13,721	11,327	10,048	10,000
Russell 3000 Index [Member]
Account Value [Line Items]
Line Graph and Table Measure Name	Russell 3000 Index
Account Value	$ 32,604	26,334	20,907	25,877	20,593	17,035	13,002	13,721	11,327	10,048	10,000
Russell 2000 Growth Index [Member]
Account Value [Line Items]
Line Graph and Table Measure Name	Russell 2000 Growth Index
Account Value	$ 21,772	18,906	15,933	21,636	21,040	15,628	12,163	13,411	10,978	9,862	10,000
Russell 2000 Growth Index [Member]
Account Value [Line Items]
Line Graph and Table Measure Name	Russell 2000 Growth Index
Account Value	$ 21,772	$ 18,906	$ 15,933	$ 21,636	$ 21,040	$ 15,628	$ 12,163	$ 13,411	$ 10,978	$ 9,862	$ 10,000