Share Based Compensation - Components of Share-Based Compensation Expense (Income) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	$ 336	$ (15)	$ 1,716	$ 3,327
Compensation expense	76	38	240	154
Share based and Long Term Incentive Compensation	412	23	1,956	3,481
Cash Settled Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	(494)	(1,447)	125	(1,151)
Equity-settled awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	625	918	1,104	2,915
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	6	(20)	12	(3)
Employee Stock Option
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	199	534	475	1,566
General and Administrative Expense
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share based and Long Term Incentive Compensation	338	(276)	1,844	1,846
Other Operating Expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share based and Long Term Incentive Compensation	$ 74	$ 299	$ 112	$ 1,635