ACCOUNTS RECEIVABLE

12 Months Ended

Dec. 31, 2018

Accounts Receivable, Net [Abstract]

ACCOUNTS RECEIVABLE

7.    ACCOUNTS RECEIVABLE

Accounts receivable comprised the following at December 31, 2018 and December 31, 2017:

	December 31, 2018			December 31, 2017
Third-party customers	$	203,068		$	194,606
Less: allowance for bad debts and credit notes	(9,697		)	(10,436		)
Total accounts receivable	$	193,371		$	184,170

Bad debt expense for the years ended December 31, 2018, 2017 and 2016 was US$ 0.8 million, US$ 1.9 million, and US$ 3.8 million, respectively.