Securities Available for Sale - Amortized cost/fair value (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 579,704	$ 399,668
Gross Unrealized Gains	6,496	9,424
Gross Unrealized Losses	(62,621)	(63,390)
Fair Value	523,579	345,702
Assets pledged as collateral
Debt Securities, Available-for-sale [Line Items]
Fair Value	352,100	319,000
U.S. agency residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	254,999	255,675
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(40,483)	(41,248)
Fair Value	214,516	214,427
Senior asset-backed securities related to Structured Program transactions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	144,529
Gross Unrealized Gains	0
Gross Unrealized Losses	(605)
Fair Value	143,924
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	93,449	90,447
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(14,409)	(16,053)
Fair Value	79,040	74,394
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	43,723	26,988
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(5,580)	(4,470)
Fair Value	38,143	22,518
Other asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,187	14,959
Gross Unrealized Gains	44	29
Gross Unrealized Losses	(765)	(785)
Fair Value	28,466	14,203
Other asset-backed securities related to Structured Program transactions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,550
Gross Unrealized Gains	6,452
Gross Unrealized Losses	(22)
Fair Value	16,980
Restricted investments	8,500
Asset-backed securities related to Structured Program transactions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		8,322
Gross Unrealized Gains		9,395
Gross Unrealized Losses		0
Fair Value		17,717
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,267	3,277
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(757)	(834)
Fair Value	$ 2,510	$ 2,443

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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Amortized cost excluding accrued interest, after allowance for credit loss, of 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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