Other Long-Term Liabilities - Summary of Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Asset retirement obligations	$ 7,543	$ 6,805
Dividends payable—2015 LTIP	160	0
Escheat liability	172	220
Capital lease payable	0	6
Lease incentive	500	426
Deferred rent	340	404
Royalty payable	257	270
Total other long-term liabilities	$ 8,972	$ 8,131