Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015	Dec. 31, 2015
Class of Stock [Line Items]
Stockholders' Equity, Other	[1]			$ 3,960		$ (1,529)
Share-based compensation (equity-classified)				$ (3,922)	[1]	$ 2,106
Stock Issued During Period, Shares, Conversion of Convertible Securities				85,982		6,879,222
Other Comprehensive loss, pension and postretirements obligations, before tax				$ (38)		$ (21)
Change in pension and postretirement obligations, net of tax		$ 0	$ (5)	0		$ (11)
Preferred Stock, Amount of Preferred Dividends in Arrears				$ 16,600
Common stock, shares authorized		228,000,000		228,000,000			228,000,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		3,864		3,864			3,915
Preferred stock dividends (in dollars per share)						$ 300.00
Preferred Stock, Amount of Preferred Dividends in Arrears				$ 2,800
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		14,933		14,933			27,551
Preferred stock dividends (in dollars per share)						$ 300.00
Preferred Stock, Amount of Preferred Dividends in Arrears				$ 13,800
Convertible Preferred Stock
Class of Stock [Line Items]
Conversion of Stock, Shares Converted				52		12,619
Depositary Shares
Class of Stock [Line Items]
Conversion of Stock, Shares Converted				5,159		1,261,850
Preferred Stock, Dividend Rate, Percentage				6.00%

[1] Includes equity-classified share-based compensation of $(3,922) and $2,106 for the six months ended June 30, 2016 and 2015, respectively.