Debt Securities Available for Sale - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($) security	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) security	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Mortgage-backed securities and collateralized mortgage obligations	$ 1,054,116,000		$ 1,054,116,000
Mortgage-backed securities and collateralized mortgage obligations	896,819,000		896,819,000
Proceeds from sales of debt securities available for sale	234,400,000	$ 126,800,000	277,022,000	$ 126,772,000
Gross gains on sale of available-for-sale securities	0	210,000	0	210,000
Gross losses on sale of available-for-sale securities	9,600,000	0	10,800,000	0
Proceeds from maturities and calls of debt securities, available-for-sale	0	$ 0	0	$ 0
Debt securities, available-for-sale, restricted	$ 768,700,000		$ 768,700,000		$ 724,000,000
Number of securities in unrealized loss position | security	333		333		455
Accrued interest receivable on debt securities available for sale	$ 2,400,000		$ 2,400,000		$ 3,200,000
Subsidiaries
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, restricted	$ 67,400,000		$ 67,400,000		$ 28,300,000