Revenue - Contract liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Revenue
Deferred revenue	$ 243,131	$ 234,352
Accrued loss provision	7,094	6,060
Contract liabilities	250,225	$ 240,412
Increase in contract liabilities	9,800
Revenue recognized included in contract liability at beginning of period	$ 211,300