Shareholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Apr. 30, 2013 Subsequent Event
Class of Stock [Line Items]
Preferred stock dividends (in dollars per share)	$ 150
Preferred stock dividend rate	6.00%
Common stock dividends (in dollars per share)	$ 0.05625
Other Comprehensive loss, pension and postretirements obligations, before tax	$ 29	$ 36
Change in pension and postretirement obligations, tax	$ 10	$ 13
Net proceeds used to repurchase shares before effectiveness (up to 50%)			50.00%
Net proceeds used to repurchase shares after effectiveness			25.00%
Buyback obligation termination (less than 5%)			5.00%
Standstill agreement termination (less than 10%)			10.00%