Securities - Contractual Maturities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Securities Available-for-Sale, Amortized Cost
Due in one year or less	$ 8,229
Due after one year through five years	304,142
Due after five years through ten years	44,642
Due after ten years	183,292
Debt securities excluding securities not due at a single maturity date	540,305
Total	$ 1,824,225	$ 1,678,160
Securities Available-for-Sale, Weighted Average Yield
Due in one year or less (as a percent)	1.15%
Due after one year through five years (as a percent)	1.05%
Due after five years through ten years (as a percent)	2.52%
Due after ten years (as a percent)	3.00%
Debt securities (as a percent)	1.83%
Total (as a percent)	2.00%
Securities Available-for-Sale, Fair Value
Due in one year or less	$ 8,017
Due after one year through five years	291,151
Due after five years through ten years	41,310
Due after ten years	175,433
Debt securities	515,911
Debt Securities, Available-for-sale, Total	1,734,416	1,693,632
Collateralized mortgage obligations
Securities Available-for-Sale, Amortized Cost
Total	681,539	673,238
Securities Available-for-Sale, Fair Value
Debt Securities, Available-for-sale, Total	641,498	672,967
Asset-backed Securities
Securities Available-for-Sale, Amortized Cost
Securities not due at a single maturity date	268,682
Total	$ 268,682	236,293
Securities Available-for-Sale, Weighted Average Yield
Securities not due at a single maturity date, Weighted Average Yield (as a percent)	2.17%
Securities Available-for-Sale, Fair Value
Securities not due at a single maturity date	$ 259,622
Debt Securities, Available-for-sale, Total	259,622	236,877
Collateralized loan obligations.
Securities Available-for-Sale, Amortized Cost
Securities not due at a single maturity date	181,116
Total	$ 181,116	79,838
Securities Available-for-Sale, Weighted Average Yield
Securities not due at a single maturity date, Weighted Average Yield (as a percent)	3.10%
Securities Available-for-Sale, Fair Value
Securities not due at a single maturity date	$ 175,549
Debt Securities, Available-for-sale, Total	175,549	$ 79,763
Mortgage-backed and collateralized mortgage obligations
Securities Available-for-Sale, Amortized Cost
Securities not due at a single maturity date	$ 834,122
Securities Available-for-Sale, Weighted Average Yield
Securities not due at a single maturity date, Weighted Average Yield (as a percent)	1.81%
Securities Available-for-Sale, Fair Value
Securities not due at a single maturity date	$ 783,334