Fair Value of Derivative and Other Financial Instruments - Investments in NDT and Gross Realized Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Equity securities:
Net gains (losses) from equity securities sold	$ (2,210)	$ (309)	$ 1,735	$ 5,931
Net gains (losses) from equity securities still held	(4,061)	(3,153)	(52,320)	2,388
Total net gains (losses) on equity securities	(6,271)	(3,462)	(50,585)	8,319
Available-for-sale debt securities:
Net gains (losses) on debt securities	(9,465)	5,410	(33,519)	7,789
Net gains (losses) on investment securities	$ (15,736)	$ 1,948	$ (84,104)	$ 16,108

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Amount of unrealized and realized gain (loss) on investment in debt and equity securities.

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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