Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Measurement [Abstract]

Fair Value Assets Recurring and Nonrecurring

		March 31, 2017					December 31, 2016
	Category		Carrying amount		Fair value		Carrying amount		Fair value
Fair values disclosed, recurring:
Cash and cash equivalents	Level 1	$	236,894	$	236,894	$	207,867	$	207,867
Restricted cash	Level 1		637,986		637,986		550,222		550,222
Short-term debt (note 18)	Level 2		24,616		24,616		23,912		23,912
Long-term debt (note 18)
Senior unsecured notes	Level 1		495,863		508,750		495,780		509,500
Revolving loans	Level 2		100,575		100,575		99,926		99,926