Leases - Lease cost and other information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Lease Cost Components:
Amortization of ROU assets - finance leases	$ 117	$ 117	$ 350	$ 350
Interest on lease liabilities - finance leases	12	14	37	43
Operating lease cost (cost resulting from lease payments)	4,550	4,292	13,419	12,977
Short-term lease cost	218	116	592	327
Variable lease cost (cost excluded from lease payments)	615	783	1,813	2,073
Total lease cost	5,512	5,322	16,211	15,770
Supplemental Cash Flow and Other Information Related to Leases:
Finance lease - operating cash flows	12	14	37	43
Finance lease - financing cash flows	109	107	325	320
Operating lease - operating cash flows (fixed payments)	4,356	4,127	12,982	12,440
Operating lease - operating cash flows (net change asset/liability)	$ (3,466)	(3,215)	(10,313)	(9,691)
New ROU assets - operating leases		$ 4,196	$ 12,616	$ 5,494
Weighted - average remaining lease term (years) - finance leases	5 years 8 months 1 day	6 years 7 months 28 days	5 years 8 months 1 day	6 years 7 months 28 days
Weighted - average remaining lease term (years) - Operating leases	10 years 1 month 17 days	10 years 11 months 15 days	10 years 1 month 17 days	10 years 11 months 15 days
Weighted - average discount rate - finance leases	1.70%	1.70%	1.70%	1.70%
Weighted - average discount rate - Operating leases	3.00%	3.30%	3.00%	3.30%
Maturity Analysis of Lease Liabilities:
2022 (excluding the nine months ended September 30, 2022)	$ 4,303		$ 4,303
2023	16,727		16,727
2024	15,343		15,343
2025	13,902		13,902
2026	13,246		13,246
Thereafter	79,764		79,764
Total undiscounted cash flows	143,285		143,285
Discount on cash flows	(22,174)		(22,174)
Total operating lease liabilities	$ 121,111		$ 121,111		$ 115,900
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities.		Other Liabilities.		Other Liabilities.