Shareholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Depositary shares issued during period, (in shares)	11,500
Preferred stock dividend rate	6.00%	6.00%
Proceeds from the issuance of preferred stock, net	$ 110,300,000	$ 0	$ 110,337,000	$ 0
Preferred stock dividends declared per share			$ 146.67
Preferred stock liquidation preference (in dollars per share)		$ 10,000
Quarterly dividends per share (in dollars per share)		$ 150
Conversion price (in dollars per share)		$ 6.00
Conversion rate, convertible preferred stock into common		1,666.67
Premium for conversion price to concurrent common stock offering price		20.00%
Common stock offering price, new issue (in dollars per share)		$ 5.00
Conversion ratio into common stock if closing sale price exceed prior period conversion price		130.00%
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Issuance of common stock (in shares)	9,200,000.0
Proceeds from issuance of common stock	43,500,000
Common stock, shares authorized		128,000,000	128,000,000
Accumulated other comprehensive losses attributable to pension and postretirement benefit obligations, net of tax		$ 300,000	$ (1,000,000)	$ (1,100,000)
Treasury stock (in shares)		233,063	218,320