Stock-Based Compensation - Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Options
Outstanding at beginning of year (in shares)	1,191,125	1,546,500	1,688,500
Granted (in shares)	81,000	126,000	94,500
Exercised (in shares)	0	0	(60,000)
Expired or forfeited (in shares)	(232,375)	(481,375)	(176,500)
Outstanding at end of year (in shares)	1,039,750	1,191,125	1,546,500
Exercisable at end of year (in shares)	1,039,750	1,191,125	1,546,500
Weighted- Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 10.48	$ 11.62	$ 11.88
Granted (in dollars per share)	1.58	2.44	5.22
Exercised (in dollars per share)	0.00	0.00	4.96
Expired or forfeited (in dollars per share)	16.72	12.04	13.01
Outstanding at end of year (in dollars per share)	8.39	10.48	11.62
Exercisable at end of year (in dollars per share)	8.39	10.48	11.62
Weighted-average fair value of options granted during the year (in dollars per share)	$ 1.11	$ 1.54	$ 2.20