Stock-Based Compensation Plans - Summary of Transactions Involving Stock Options Awarded (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Aggregate Intrinsic Value	$ 56	$ 1,076	$ 18	$ 46
Stock options vested and exercisable, Aggregate Intrinsic Value	56
Stock options vested and expected to vest, Aggregate Intrinsic Value	56
Number of Shares Outstanding, Beginning Balance	4,150,410	3,168,630	3,165,866
Number of Shares, Granted	505,000	2,736,750	309,000
Number of Shares, Exercised	0	0	(10,000)
Number of Shares, Expired	(88,000)	(1,709,020)	(110,266)
Number of Shares, Forfeited	(226,660)	(45,950)	(185,970)
Number of Shares Outstanding, Ending Balance	4,340,750	4,150,410	3,168,630	3,165,866
Weighted Average Exercise Price, Beginning Balance	$ 1.07	$ 3.03	$ 3.51
Stock options vested and exercisable	2,161,392
Weighted Average Exercise Price, Granted	$ 0.20	$ 0.43	$ 1.24
Number of stock options vested and expected to vest	3,900,155
Weighted Average Exercise Price, Exercised			$ 0.62
Weighted Average Exercise price, Expired	$ 3.03	$ 3.67	$ 13.92
Weighted Average Exercise Price, Forfeited	$ 1.61	$ 1.30	$ 1.82
Weighted Average Exercise Price, Ending Balance	$ 0.90	$ 1.07	$ 3.03	$ 3.51
Stock options vested and exercisable, Weighted Average Exercise Price	$ 1.24
Stock options vested and expected to vest, Weighted Average Exercise Price	$ 0.93
Weighted Average Remaining Contractual Term in Years	7 years 9 months 18 days	8 years 4 months 24 days	3 years 4 months 24 days	6 years 10 months 24 days
Stock options vested and exercisable, Weighted Average Remaining Contractual Term in Years	7 years
Stock options vested and expected to vest, Weighted Average Remaining Contractual Term in Years	7 years 9 months 18 days
Director Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vested and exercisable, Aggregate Intrinsic Value
Number of Shares Outstanding, Beginning Balance	42,000	79,000	100,000
Number of Shares, Expired	(21,000)	(37,000)	(21,000)
Number of Shares Outstanding, Ending Balance	21,000	42,000	79,000	100,000
Weighted Average Exercise Price, Beginning Balance	$ 5.93	$ 9.27	$ 10.24
Stock options vested and exercisable	21,000
Weighted Average Exercise price, Expired	$ 2.89	$ 13.06	$ 13.88
Weighted Average Exercise Price, Ending Balance	$ 8.97	$ 5.93	$ 9.27	$ 10.24
Stock options vested and exercisable, Weighted Average Exercise Price	$ 8.97
Weighted Average Remaining Contractual Term in Years	2 years 8 months 12 days	1 year 10 months 24 days	1 year 8 months 12 days	2 years 2 months 12 days
Stock options vested and exercisable, Weighted Average Remaining Contractual Term in Years	2 years 8 months 12 days
Non-Plan Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vested and exercisable, Aggregate Intrinsic Value
Number of Shares Outstanding, Beginning Balance	5,000	10,000	10,000
Number of Shares, Expired	(5,000)	(5,000)
Number of Shares Outstanding, Ending Balance		5,000	10,000	10,000
Weighted Average Exercise Price, Beginning Balance	$ 4.12	$ 3.64	$ 3.64
Stock options vested and exercisable
Weighted Average Exercise price, Expired	$ 4.12	$ 3.15
Weighted Average Exercise Price, Ending Balance		$ 4.12	$ 3.64	$ 3.64
Stock options vested and exercisable, Weighted Average Exercise Price
Weighted Average Remaining Contractual Term in Years	0 years	6 months	2 years	2 years
Stock options vested and exercisable, Weighted Average Remaining Contractual Term in Years	0 years