Summary of significant accounting policies - Goodwill and other intangible assets, net, Advertising (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill
Impairment losses on intangible assets	$ 0	$ 0
Maximum
Goodwill
Finite useful life of intangible assets	10 years