Equity Compensation - Stock Options Granted, Forfeited, Exercised and Expired (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Number of shares
Number of Shares, Outstanding at beginning of period				1,153,273
Number of Shares, Granted		0	0	121,208	168,500
Number of Shares, Forfeited				(38,334)
Number of Shares, Exercised		0	0	0	0
Number of Shares, Expired				(138,773)
Number of Shares, Outstanding at end of period		1,097,374		1,097,374
Number of Shares, Exercisable at end of period		845,397		845,397
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding at beginning of period				$ 76.92
Weighted Average Exercise Price, Granted				4.91
Weighted Average Exercise Price, Forfeited				19.96
Weighted Average Exercise Price, Exercised				0
Weighted Average Exercise Price, Expired				86.40
Weighted Average Exercise Price, Outstanding at end of period		$ 69.76		69.76
Weighted Average Exercise Price, Exercisable at end of period		$ 85.68		$ 85.68
Aggregate Exercise Price
Aggregate Exercise Price, Outstanding at beginning of period				$ 88,711
Aggregate Exercise Price, Granted				595
Aggregate Exercise Price, Forfeited				(765)
Aggregate Exercise Price, Exercised				0
Aggregate Exercise Price, Expired				(11,990)
Aggregate Exercise Price, Outstanding at end of period		$ 76,551		76,551
Aggregate Exercise Price, Exercisable at end of period		72,434		$ 72,434
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term, Outstanding at end of period, years				1 year 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable at end of period, years				1 year 7 months 6 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding at end of period	[1]	0		$ 0
Aggregate Intrinsic Value, Exercisable at end of period	[1]	$ 0		$ 0

[1] The aggregate intrinsic value of the stock options was calculated by identifying those stock options that had a lower exercise price than the closing market price of our common stock on September 30, 2015 and multiplying the difference between the closing market price of our common stock and the exercise price of each of those stock options by the number of shares subject to those stock options that were outstanding or exercisable, as applicable. Since the closing market price of our common stock on September 30, 2015 was lower than the exercise price of all outstanding stock options and exercisable stock options, the aggregate intrinsic value of the stock options was zero.