Fair Value Measurements - Changes in level 3 inputs (Details) - Yaskawa Note - Yaskawa - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021	Mar. 31, 2022	Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value at beginning of period	$ 15,392	$ 16,128	$ 16,169
Interest expense accrued	37	77	150
Increase (decrease) in fair value	699	(605)	(927)
Conversion		(15,600)
Fair value at period end	$ 16,128	$ 0	$ 15,392

The value of the stock converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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