Shareholders' Equity - Additional Information (Detail) - Equity Component [Domain] - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
		May. 31, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Stockholders' Equity, Other	[1]				$ (1,529)	$ 1,059
Preferred Stock Conversions, Inducements			$ 0	$ 3,368	0	3,368
Proceeds from Issuance of Convertible Preferred Stock					0	313,646
Other Comprehensive loss, pension and postretirements obligations, before tax					(32)	75
Change in pension and postretirement obligations, net of tax			$ (5)	$ 13	$ (11)	$ 26
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			7,945		7,945			7,945
Preferred stock dividends (in dollars per share)					$ 300.00
Preferred stock dividend rate					6.00%
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)					$ 300.00
Preferred stock dividend rate					6.00%

[1] Includes equity-classified share-based compensation of $2,106 and $1,651 for the six months ended June 30, 2015 and 2014.