Selected Balance Sheet Data, Accounts Receivable (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Accounts Receivable, Net
Accounts receivable		$ 61,506	$ 66,217
Less allowance for bad debts		(5,128)	(5,821)
Accounts receivable, net	[1]	$ 56,378	$ 60,396

[1] Accounts receivable, net includes an immaterial amount due from affiliates for 2015 and 2014, respectively.