Leases - Lease cost and other information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Lease Cost Components:
Amortization of ROU assets - finance leases	$ 117	$ 117	$ 233	$ 233
Interest on lease liabilities - finance leases	8	10	18	21
Operating lease cost (cost resulting from lease payments)	4,356	4,278	8,633	8,518
Short-term lease cost	184	109	323	215
Variable lease cost (cost excluded from lease payments)	956	840	1,753	1,475
Total lease cost	5,621	5,354	10,960	10,462
Supplemental Cash Flow and Other Information Related to Leases:
Finance lease - operating cash flows	8	10	18	21
Finance lease - financing cash flows	119	110	238	220
Operating lease - operating cash flows (fixed payments)	4,220	4,154	8,413	8,250
Operating lease - operating cash flows (net change asset/liability)	(3,300)	(3,321)	(6,667)	(6,608)
New ROU assets - operating leases	$ 6,550	$ 701	$ 9,093	$ 701
Weighted - average remaining lease term (years) - finance leases	3 years 11 months 4 days	4 years 11 months 4 days	3 years 11 months 4 days	4 years 11 months 4 days
Weighted - average remaining lease term (years) - operating leases	8 years 10 months 9 days	9 years 7 months 17 days	8 years 10 months 9 days	9 years 7 months 17 days
Weighted - average discount rate - finance leases	1.70%	1.70%	1.70%	1.70%
Weighted - average discount rate - operating leases	3.30%	3.00%	3.30%	3.00%
Maturity Analysis of Lease Liabilities:
2024 (excluding 6 months ended June 30, 2024)	$ 8,613		$ 8,613
2025	16,374		16,374
2026	15,866		15,866
2027	14,693		14,693
2028	14,030		14,030
Thereafter	61,212		61,212
Total undiscounted cash flows	130,788		130,788
Discount on cash flows	(18,947)		(18,947)
Total operating lease liabilities	$ 111,841		$ 111,841		$ 108,300
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities.		Other Liabilities.		Other Liabilities.