Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Measurement

Fair Value Assets Recurring and Nonrecurring

		December 31,2019				December 31,2018
		Carrying				Carrying
	Category	amount		Fair value		amount		Fair value
Fair values disclosed:
Cash and cash equivalents	Level 1	$	359,671	$	359,671	$	237,744	$	237,744
Restricted cash	Level 1		60,585		60,585		67,823		67,823
Short-term debt	Level 2		4,705		4,705		19,896		19,896
Long-term debt
Senior unsecured notes	Level 1		490,933		520,625		489,136		487,813
Term loans	Level 2		154,548		155,355		222,162		224,582