Revenue - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Trade receivables	$ 7,563	$ 14,261
Unbilled receivables	1,589	5,540
Insurance proceeds receivable (Note 14)	1,991	0
Other short-term receivables	156	9
Allowance for doubtful accounts	(1,175)	(1,411)
Total accounts receivable	$ 10,124	$ 18,399