Investment Securities - Securities Held-to-Maturity Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2023		Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period	$ 1,500		$ 0	$ 1,500	[1]	$ 0
Provision for Credit Losses	0		1,500	0		1,500
Charge-offs	0		0	0		0
Recoveries	0		0	0		0
Allowance for Credit Losses, End of Period	1,500	[2]	1,500	1,500	[2]	1,500
Debt Securities, Held-to-maturity, Fair Value	2,120,812	[2]		2,120,812	[2]		$ 2,110,472	[1]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	173	[2]		173	[2]		8	[1]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(157,563)	[2]		(157,563)	[2]		(158,671)	[1]
U.S. Treasury securities
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period				0
Allowance for Credit Losses, End of Period	0			0
Debt Securities, Held-to-maturity, Fair Value	172,594			172,594			171,700
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0			0			0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(12,987)			(12,987)			(12,462)
Municipal securities
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period				140
Allowance for Credit Losses, End of Period	140			140
Debt Securities, Held-to-maturity, Fair Value	1,191,684			1,191,684			1,165,785
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	173			173			8
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(53,811)			(53,811)			(77,526)
Agency commercial MBS
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period				0
Allowance for Credit Losses, End of Period	0			0
Debt Securities, Held-to-maturity, Fair Value	395,400			395,400			393,124
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0			0			0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(35,178)			(35,178)			(34,287)
Private label commercial MBS
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period				0
Allowance for Credit Losses, End of Period	0			0
Debt Securities, Held-to-maturity, Fair Value	313,511			313,511			319,798
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0			0			0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(34,612)			(34,612)			(26,027)
Corporate Debt Securities
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period				1,360
Allowance for Credit Losses, End of Period	1,360			1,360
Debt Securities, Held-to-maturity, Fair Value	47,623			47,623			60,065
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0			0			0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(20,975)			(20,975)			$ (8,369)
Municipal securities
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period	140		0	140		0
Provision for Credit Losses	0		140	0		140
Charge-offs	0		0	0		0
Recoveries	0		0	0		0
Allowance for Credit Losses, End of Period	140		140	140		140
Corporate Debt Securities
Schedule of Held-to-maturity Securities [Line Items]
Allowance for Credit Losses, Beginning of Period	1,360		0	1,360		0
Provision for Credit Losses	0		1,360	0		1,360
Charge-offs	0		0	0		0
Recoveries	0		0	0		0
Allowance for Credit Losses, End of Period	$ 1,360		$ 1,360	$ 1,360		$ 1,360

[1] Excludes accrued interest receivable of $13.5 million at December 31, 2022 which is recorded in "Other assets" on the condensed consolidated balance sheets

[2] Excludes accrued interest receivable of $13.4 million at June 30, 2023 which is recorded in "Other assets" on the condensed consolidated balance sheets