Revenue recognition - Deferred Contracts Costs Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Deferred contract costs [Roll Forward]
Balance at Beginning of Period	$ 44,545	$ 25,838
Additions	13,038	7,956
Amortization Expense	(6,582)	(3,481)
Balance at End of Period	$ 51,001	$ 30,313