Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Aug. 18, 2015
Total debt
Long-term debt	$ 36,365	$ 36,365
Amounts payable within one year	1,078	0
Long-term debt, noncurrent	35,287	36,365
Revolving credit facility [Member]
Total debt
Long-term debt	35,287	35,287	$ 100,000
Secured debt of affiliate [Member]
Total debt
Long-term debt	$ 1,078	$ 1,078