Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015	Dec. 31, 2015
Class of Stock [Line Items]
Stockholders' Equity, Other	[1]	$ 628		$ (979)
Share-based compensation (equity-classified)		$ (602)	[1]	$ 990
Stock Issued During Period, Shares, Conversion of Convertible Securities		85,982		5,009,017
Other Comprehensive loss, pension and postretirements obligations, before tax		$ (27)		$ (17)
Change in pension and postretirement obligations, net of tax		0		$ (6)
Preferred Stock, Amount of Preferred Dividends in Arrears		$ 13,800
Common stock, shares authorized		228,000,000			228,000,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		3,864			3,915
Preferred stock dividends (in dollars per share)				$ 150.00
Preferred Stock, Amount of Preferred Dividends in Arrears		$ 2,200
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		17,152			27,551
Preferred stock dividends (in dollars per share)				$ 150.00
Preferred Stock, Amount of Preferred Dividends in Arrears		$ 11,600
Convertible Preferred Stock
Class of Stock [Line Items]
Conversion of Stock, Shares Converted		52		9,188
Depositary Shares
Class of Stock [Line Items]
Conversion of Stock, Shares Converted		5,159		918,800

[1] Includes equity-classified share-based compensation of $(602) and $990 for the three months ended March 31, 2016 and 2015, respectively.