Revenue from contracts with customers - Contract balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Construction contractor, contract cost, subject to uncertainty, amount	$ 31,000
Contract assets	165,924		$ 158,861
Change in contract assets	7,063
Contract liabilities - current	(187,741)		(202,144)
Change in contract liabilities - current	14,403
Contract liabilities - noncurrent	(2,161)		(291)
Change in contract liabilities - noncurrent	(1,870)
Net contract liabilities	(23,978)		$ (43,574)
Change in net contract assets (liabilities)	19,596
Contract with customer, liability, revenue recognized	97,600	$ 134,600
Amounts from performance obligations satisfied in prior periods	$ 33,400	$ 17,700