Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2020

Fair value measurement

Fair Value Assets Recurring and Nonrecurring

		December 31, 2020				December 31, 2019
		Carrying				Carrying
	Category	amount		Fair value		amount		Fair value
Fair values disclosed:
Cash and cash equivalents	Level 1	$	278,766	$	278,766	$	359,671	$	359,671
Restricted cash	Level 1		28,129		28,129		60,585		60,585
Loan receivables	Level 2		5,798		6,438		—		—
Short-term debt	Level 2		29,145		29,145		4,705		4,705
Long-term debt
Senior unsecured notes	Level 1		492,734		514,219		490,933		520,625
Term loan	Level 2		97,812		98,420		154,548		155,355
Long-term revolver loan	Level 2		46,102		46,184		—		—