Investments - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2022 USD ($) security	Jun. 30, 2021 USD ($)	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($)	Mar. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Vertical risk retention interest			5.00%	5.00%
Increase in trading investments			$ 0	$ 5,117	$ 0
Trading investments	$ 55,903		$ 54,481	$ 55,903
Number of government sponsored securities with unrealized losses | security	191		213	191
Number of mortgage-backed securities | security	194		248	194
Par value of mortgage-backed securities pledged to FRB	$ 547,000		$ 612,000	$ 547,000
Gain (loss) on non-marketable securities investment	(60,000)	$ 35,000
Non-marketable securities investment	8,000		14,000	8,000
Low income housing tax credit investments			11,000	9,000	7,000
Amount of amortization reported in income tax expense			9,000	7,000	$ 6,000
Total carrying value of LIHTC investments	80,000		72,000	80,000
Liability for unfunded commitments	$ 46,000		$ 30,000	$ 46,000
Equity Securities
Debt Securities, Available-for-sale [Line Items]
Non-marketable securities investment						$ 5,000