Accrued Liabilities - Components of Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Asset retirement obligations		$ 296	$ 342
Accrued outside services		1,455	1,101
Accrued accounting and legal		458	275
Accrued recognition awards		370	345
Accrued other		47	696
Capital lease payable		6	17
Deferred rent		72	77
Lease incentive		40	147
Dividends payable for 2011 LTIP		0	637
Total accrued other		2,744	$ 3,637
Decrease in accounts payable and accrued liabilities		$ 900
2011 Long Term Incentive Plan
Restructuring Cost and Reserve [Line Items]
Decrease in accounts payable and accrued liabilities	$ 600