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Summary of Significant Accounting Policies - Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Line Items]
Net Loss From Continuing Operations	$ (36,641)	$ (24,034)	$ (21,531)	$ (24,517)	$ (57,111)	$ (106,723)	$ (103,079)
Net Income From Discontinued Operations	(857)		151,236	(2,627)		147,752	3,019
Basic Net Income (Loss) Attributable to Common Stock, Shares					46,547	46,553	46,422
Diluted Net Income (Loss) Attributable to Common Stock, Shares					46,547	46,553	46,422
Basic Net Loss From Continuing Operations Attributable to Common Stock, Per Share	$ (0.80)	$ (0.52)	$ (0.45)	$ (0.52)	$ (1.24)	$ (2.22)	$ (2.22)
Diluted Net Loss From Continuing Operations Attributable to Common Stock, Per Share	$ (0.80)	$ (0.52)	$ (0.45)	$ (0.52)	$ (1.24)	$ (2.22)	$ (2.22)
Basic Net Income From Discontinued Operations Attributable to Common Stock, Per Share	$ (0.02)		$ 3.13	$ (0.06)		$ 3.07	$ 0.06
Diluted Net Income From Discontinued Operations Attributable to Common Stock, Per Share	$ (0.02)		$ 3.13	$ (0.06)		$ 3.07	$ 0.06
Continuing Operations
Earnings Per Share [Line Items]
Net Loss From Continuing Operations					(57,111)	(106,723)	(103,079)
Loss (Income) Allocable to Unvested Stock Grants					(595)	3,424	0
Basic Net Income (Loss) Attributable to Common Stock					(57,706)	(103,299)	(103,079)
Diluted Net Income (Loss) Attributable to Common Stock					(62,226)	(103,299)	(103,079)
Basic Net Income (Loss) Attributable to Common Stock, Shares					46,547	46,553	46,422
Diluted Net Income (Loss) Attributable to Common Stock, Shares					46,547	46,553	46,422
Basic Net Loss From Continuing Operations Attributable to Common Stock, Per Share					$ (1.24)	$ (2.22)	$ (2.22)
Diluted Net Loss From Continuing Operations Attributable to Common Stock, Per Share					$ (1.24)	$ (2.22)	$ (2.22)
Discontinued Operations
Earnings Per Share [Line Items]
Net Income From Discontinued Operations						147,752	3,019
Loss (Income) Allocable to Unvested Stock Grants					0	(4,742)	0
Basic Net Income (Loss) Attributable to Common Stock						143,010	3,019
Diluted Net Income (Loss) Attributable to Common Stock						$ 143,010	$ 3,019
Basic Net Income (Loss) Attributable to Common Stock, Shares						46,553	46,422
Diluted Net Income (Loss) Attributable to Common Stock, Shares						46,553	46,422
Basic Net Income From Discontinued Operations Attributable to Common Stock, Per Share						$ 3.07	$ 0.06
Diluted Net Income From Discontinued Operations Attributable to Common Stock, Per Share						$ 3.07	$ 0.06