Contract balances (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets	$ 125,742	$ 104,345	$ 109,078
Change in contract assets	21,397	(4,733)
Contract liabilities - current	(179,140)	(158,603)	(142,768)
Change in contract liabilities - current	(20,537)	(15,835)
Contract liabilities - noncurrent	(118)	(52)	(19)
Change in contract liabilities - noncurrent	(66)	(33)
Net contract liabilities	(53,516)	(54,310)	$ (33,709)
Change in net contract assets (liabilities)	794	(20,601)
Amounts included in contract liability at the beginning of the period	155,000	138,200
Amounts from performance obligations satisfied in prior periods	$ 66,300	$ 58,800