Subsequent Events - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended			1 Months Ended			1 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Common Stock	Jun. 30, 2013 Common Stock	Mar. 31, 2013 Common Stock	Nov. 04, 2013 Subsequent Event Common Stock Dividend Reinvestment and Stock Purchase 2012 Plan	Nov. 04, 2013 Subsequent Event Repurchase of Equity Common Stock	Oct. 11, 2013 Subsequent Event Dividend Paid	Oct. 11, 2013 Subsequent Event Dividend Paid Series B Preferred Stock	Sep. 30, 2013 Subsequent Event Dividend Paid Series B Preferred Stock	Sep. 30, 2013 Subsequent Event Dividend Paid Series B Preferred Stock Minimum
Subsequent Event [Line Items]
Dividend yield on preferred stock													6.25%
Conversion of preferred stocks to common stock, conversion rate											3.9702	3.9202
Average closing price of common stock										$ 4.77
Annualized common stock dividend yield										10.0692%
Consecutive trading day period to determine the average closing price of common stock										10 days
Stock issued during period					723,000	1,269,000	2,272,000	73,564
Common stock issued, weighted average price per share								$ 5.00
Proceeds from common stock issuance	$ (3,085)	$ 21,644	$ (2,560)	$ 47,432				$ 368
Number of common stock repurchased	1,472,710								730,700
Common stock repurchased, weighted average price	$ 4.53								$ 4.52