Financial Instruments - Summary of Bond Activity (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available for Sale [Roll Forward]
Fair value at beginning of period	$ 25,708	$ 60,659
Purchases	26,980	3,447
Redemptions	(6,530)	(22,078)
Maturities	(8,347)	(15,409)
Change in bond premium	1,517	(857)
Fair market value adjustment	(658)	(54)
Fair value at end of period	$ 38,670	$ 25,708

Available For Sale Securities Debt Securities Fair Market Value Adjustment

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Amount of cash outflow to acquire investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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