Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Compensation	$ 11,762	$ 13,732
Non-income taxes	5,881	7,383
Royalty tax withholdings	7,337	6,921
Other expenses	19,388	13,070
Total accrued expenses	$ 44,368	$ 41,106