Stockholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended				12 Months Ended		12 Months Ended				1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Director Plan	Dec. 31, 2013 Purchase Plan	Aug. 31, 2013 Current Program	Dec. 31, 2013 Repurchase Program	Dec. 31, 2012 Repurchase Program	Dec. 31, 2011 Repurchase Program	Aug. 31, 2013 Repurchase Program	Feb. 23, 2011 Fixed Rate Cumulative Perpetual Preferred Stock Series A	Mar. 31, 2011 Fixed Rate Cumulative Perpetual Preferred Stock Series A	Dec. 31, 2013 Fixed Rate Cumulative Perpetual Preferred Stock Series A
Stockholders Equity Note [Line Items]
Repurchase of outstanding shares of common stock						5.00%				3.00%
Repurchase of outstanding shares of common stock under Stock Repurchase Program						1,260,000				730,000
Common stock shares authorized	50,000,000	50,000,000
Common stock, par value	$ 1.00	$ 1.00
Shares authorized but unissued				45,000	300,000
Shares available for issuance				26,386	229,909
Share exercise price description					Shares are purchased at 85% of the fair market value on the exercise date through monthly payroll deductions of not less than 1% or more than 10% of cash compensation paid in the month
Average price repurchased shares of common stock									$ 14.16
Repurchase Of Common Stock Shares			23,592				0	0	23,592
Additional dividend payable	$ 67,200,000
Long term borrowings	35,000,000	0	0
Number of securities called by warrants													651,547
Exercise price of warrants													19.13
Proceeds from Issuance of Warrants													83,100,000
Value of warrant													3,700,000
Redemption Of Warrant Issued											4,500,000
Net reduction of additional paid-in capital												$ 800,000
Warrant exercisable term													10 years
Stock repurchased during period, shares	0	0