Fair value measurement (Tables)

9 Months Ended

Sep. 30, 2020

Fair value measurement

Fair Value Assets Recurring and Nonrecurring

		September 30, 2020				December 31, 2019
		Carrying				Carrying
	Category	amount		Fair value		amount		Fair value
Fair values disclosed:
Cash and cash equivalents	Level 1	$	470,285	$	470,285	$	359,671	$	359,671
Restricted cash	Level 1		120,014		120,014		60,585		60,585
Short-term debt	Level 2		20,285		20,285		4,705		4,705
Long-term debt
Senior unsecured notes	Level 1		492,281		515,000		490,933		520,625
Term loan	Level 2		96,330		96,782		154,548		155,355
Long-term revolver loan	Level 2		43,950		44,251		—		—