Investment Securities - Debt Securities, Held-to-maturity, Credit Quality Indicator (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	$ 1,178,370	$ 840,259
Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	645,362	361,107
Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	7,077	7,189
Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	1,870	1,928
Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	191,469	204,495
Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	147,414	151,711
Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	185,178	$ 113,829
AAA
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	67,528
AAA \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	67,528
AA
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	18,234
AA \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	18,234
A
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	25,920
A \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
A \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
A \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
A \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
A \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
A \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	25,920
Not Rated
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	1,066,688
Not Rated \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	645,362
Not Rated \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	7,077
Not Rated \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	1,870
Not Rated \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	191,469
Not Rated \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	147,414
Not Rated \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	$ 73,496