Summary of changes in outstanding options (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable	5 years 1 month 4 days
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding | shares	120,089
Oustanding | $ / shares	$ 35.33
Outstanding remaining term	5 years 4 months 24 days	5 years 3 months 18 days
Outstanding | $	$ 1,531
Exercised | shares	(15,334)
Exercises | $ / shares	$ 17.54
Exercised | $	$ (115)
Options outstanding | shares	104,755	120,089
Outstanding | $ / shares	$ 37.93	$ 35.33
Outstanding | $	$ 1,416	$ 1,531
Exercisable | shares	92,407
Exercisable | $ / shares	$ 36.87
Exercisable | $	$ 1,212
Vested | shares	0
Vested | $	$ 0