Securities - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	12 Months Ended		1 Months Ended		12 Months Ended
	Oct. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Corporate Bonds	Dec. 31, 2012 Corporate Bonds	Dec. 31, 2012 Maximum
Schedule Of Available For Sale Securities [Line Items]
Bonds converted to common stock				$ 2,600,000
Fair value of bonds converted to common stock				1,900,000
Percentage of Investment							5.00%
Impairment of nonmarketable equity securities		600,000		600,000
Carrying value of corporate bonds sold					3,200,000	2,200,000
Proceeds from sale of investment securities, available for sale			3,227,000	2,580,000		2,500,000
Gain on sale of corporate bonds sold			379,000	347,000	400,000	300,000
Impairment of investment securities, available for sale			0	620,000
Proceeds from sale of common stock	$ 1,400,000