Shareholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			9 Months Ended					9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013		Jun. 10, 2014	Sep. 30, 2014 Depositary Shares	Sep. 30, 2014 Series A Preferred Stock	Dec. 31, 2013 Series A Preferred Stock	Sep. 30, 2014 Series B Preferred Stock	Sep. 30, 2014 Series B Preferred Stock	Sep. 30, 2014 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued										7,945	11,500	32,500	32,500
Stockholders' Equity, Other				$ 488	[1]	$ (46,563)	[1]
Preferred Stock Conversions, Inducements	888		0	4,256		0				4,300
Conversion of Stock, Shares Converted for Inducement Consideration										3,527
Preferred stock dividends (in dollars per share)										$ 450			$ 198
Preferred stock dividend rate										6.00%			6.00%
Proceeds from Issuance of Convertible Preferred Stock	313,000			313,330		0
Conversion of Stock, Shares Converted									355,482					3,555
Other Comprehensive loss, pension and postretirements obligations, before tax				114		86
Change in pension and postretirement obligations, net of tax	$ 14		$ 10	$ 40		$ 30
Depositary Shares Issued During Period, New Issues		3,250,000
Depositary Share Interest in a Share of 6.00% Convertible Perpetual Preferred Stock, Series B	0.01
Stock Issued During Period, Shares, New Issues												32,500
Preferred Stock, Liquidation Preference Per Share	$ 10,000			$ 10,000
Conversion Price per Share	$ 18.34			$ 18.34
Convertible Preferred Stock, Shares Issued upon Conversion	545.17
Premium, Conversion Price to Common Share Closing Price Prior to Series B Preferred Stock Offering								30.00%
Common Share Price, Last Reported Prior to Series B Preferred Stock Offering								$ 14.11
Premium, Conversion Ratio into Common Stock if Closing Sale Price Exceed Prior Period Conversion Price	130.00%			130.00%

[1] Includes equity-classified share-based compensation of $2,638 and $4,781 for the nine months ended September 30, 2014 and 2013.