Leases - Lease cost and other information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Lease Cost Components:
Amortization of ROU assets - finance leases	$ 117	$ 117
Interest on lease liabilities - finance leases	11	13
Operating lease cost (cost resulting from lease payments)	4,240	4,333
Short-term lease cost	109	143
Variable lease cost (cost excluded from lease payments)	634	437
Total lease cost	5,111	5,043
Supplemental Cash Flow and Other Information Related to Leases:
Finance lease - operating cash flows	11	13
Finance lease - financing cash flows	110	108
Operating lease - operating cash flows (fixed payments)	4,097	4,181
Operating lease - operating cash flows (net change asset/liability)	$ (3,287)	(3,303)
New ROU assets - operating leases		$ 12,428
Weighted - average remaining lease term (years) - finance leases	5 years 2 months 4 days	6 years 2 months 1 day
Weighted - average remaining lease term (years) - operating leases	9 years 10 months 17 days	10 years 5 months 19 days
Weighted - average discount rate - finance leases	1.70%	1.70%
Weighted - average discount rate - operating leases	3.00%	3.00%
Maturity Analysis of Lease Liabilities:
2023 (excluding the quarter ended March 31, 2023)	$ 12,226
2024	15,011
2025	13,548
2026	13,135
2027	12,172
Thereafter	66,550
Total undiscounted cash flows	132,642
Discount on cash flows	(20,233)
Total operating lease liabilities	$ 112,409		$ 115,600
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities.		Other Liabilities.