Investment in Aizu Fujitsu Semiconductor Wafer Solution Limited ("AFSW") - Narrative (Details) - USD ($)	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Unfunded commitment	$ 2,200,000
Forecast
Variable Interest Entity [Line Items]
Expected exercise price under certain conditions		$ 1
Minimum number of days before closing		60 days
Estimated Time Of Regulatory Approval, Minimum		6 months
Estimated Time Of Regulatory Approval, Maximum		12 months
Forecast | Subsequent Event
Variable Interest Entity [Line Items]
Agreement To Maintain And Continue AFSW, Term		1 year
Aizu Fajitsu Semiconductor Wafer Solution Limited
Variable Interest Entity [Line Items]
Ownership percentage in entity	49.00%
Additional financial support provided to investment	$ 3,427,000		$ 2,698,000
Unfunded commitment	$ 1,500,000		$ 1,700,000
Fujitsu Semiconductor Limited | Forecast
Variable Interest Entity [Line Items]
Purchase of additional interest		51.00%
Fujitsu Semiconductor Limited | Aizu Fajitsu Semiconductor Wafer Solution Limited
Variable Interest Entity [Line Items]
Ownership percentage in entity	51.00%