Share Based Compensation - Components of Share-Based Compensation Expense (Income) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	$ 3,342	$ 313
Compensation Expense	116	0
Share based and Long Term Incentive Compensation	3,458	313
Cash Settled Awards [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	296	(2,683)
Equity-settled awards [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	1,997	2,349
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	17	46
Employee Stock Option [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total share-based compensation	$ 1,032	$ 601