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Stock-Based Compensation and Employee Benefit Plans - Weighted-Average Assumptions for Fair Value for Stock Options (Detail) - Non Performance-Based Stock Options [Member]
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Vicor [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Risk-free interest rate 1.50% 2.00% 2.20%
Expected dividend yield 0.00% 0.00% 0.00%
Expected volatility 45.00% 51.00% 52.00%
Expected lives (years) 7 years 2 months 12 days 7 years 2 months 12 days 6 years 7 months 6 days
VI Chip [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Risk-free interest rate 1.70% 2.10% 2.30%
Expected dividend yield 0.00% 0.00% 0.00%
Expected volatility 34.00% 37.00% 41.00%
Expected lives (years) 6 years 6 months 6 years 6 months 6 years 6 months
Picor [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Risk-free interest rate 1.50% 1.90% 2.20%
Expected dividend yield 0.00% 0.00% 0.00%
Expected volatility 42.00% 41.00% 42.00%
Expected lives (years) 6 years 6 months 6 years 6 months 6 years 6 months