Shareholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Class of Stock [Line Items]
Stockholders' Equity, Other	$ (979)	[1]	$ (1,936)	[1]
Other Comprehensive loss, pension and postretirements obligations, before tax	(17)		38
Change in pension and postretirement obligations, net of tax	$ (6)		$ 13
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued	7,945				7,945
Preferred stock dividends (in dollars per share)	$ 150
Preferred stock dividend rate	6.00%
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued	32,500				32,500
Preferred stock dividends (in dollars per share)	$ 150
Preferred stock dividend rate	6.00%

[1] Includes equity-classified share-based compensation of $990 and $825 for the three months ended March 31, 2015 and 2014.