Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
		May. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Mar. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Stockholders' Equity, Other	[1]				$ (2,782)	$ 488
Preferred Stock Conversions, Inducements			$ 0	$ 888	0	4,256
Share-based compensation (equity-classified)					3,369	2,638
Proceeds from Issuance of Convertible Preferred Stock					$ 0	$ 313,330
Stock Issued During Period, Shares, Conversion of Convertible Securities					1,458,336	5,924,706
Other Comprehensive loss, pension and postretirements obligations, before tax					$ (49)	$ 114
Change in pension and postretirement obligations, net of tax			(6)	$ 14	$ (17)	40
Preferred Stock, Amount of Preferred Dividends in Arrears			$ 5,900
Common Stock, Shares Authorized, Increase During Period		100,000,000
Common stock, shares authorized			228,000,000		228,000,000		128,000,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued			7,070		7,070			7,945
Preferred Stock Conversions, Inducements						$ 4,300
Conversion of Stock, Shares Converted for Inducement Consideration						3,527
Preferred stock dividends (in dollars per share)			$ 150.00		$ 300.00	$ 450.00
Preferred Stock, Amount of Preferred Dividends in Arrears			$ 1,000
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued			32,500		32,500			32,500
Preferred stock dividends (in dollars per share)			$ 150.00		$ 300.00	$ 198.33
Preferred Stock, Amount of Preferred Dividends in Arrears			$ 4,900
Convertible Preferred Stock
Class of Stock [Line Items]
Conversion of Stock, Shares Converted					875	3,555
Depositary Shares
Class of Stock [Line Items]
Conversion of Stock, Shares Converted					87,500	355,482

[1] Includes equity-classified share-based compensation of $3,369 and $2,638 for the nine months ended September 30, 2015 and 2014, respectively.