Share Based Compensation - Share Based Compensation Expense (Income) Included in Operating Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based and Long Term Incentive Compensation	$ 412	$ 23	$ 1,956	$ 3,481
General and administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based and Long Term Incentive Compensation	338	(276)	1,844	1,846
Other Operating Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based and Long Term Incentive Compensation	$ 74	$ 299	$ 112	$ 1,635