Activity of Awarded Options (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Shares Under Options
Outstanding at beginning of year (in shares) | shares	3,094,016
Granted (in shares) | shares	459,087
Exercised (in shares) | shares	0
Forfeited (in shares) | shares	469,282
Outstanding at end of year (in shares) | shares	3,083,821
Exercisable at end of year (in shares) | shares	2,416,073
Weighted- Average Exercise Price
Outstanding at beginning of year (in dollars per share) | $ / shares	$ 16.89
Granted (in dollars per share) | $ / shares	6.03
Exercised (in dollars per share) | $ / shares	0.00
Forfeited (in dollars per share) | $ / shares	11.75
Outstanding at end of year (in dollars per share) | $ / shares	16.05
Exercisable at end of year (in dollars per share) | $ / shares	$ 18.28
Weighted- Average Remaining Contractual Term
Outstanding at end of year	5 years 4 months 24 days
Exercisable at end of year	4 years 7 months 6 days
Aggregate Intrinsic Value
Outstanding at end of year | $	$ 0
Exercisable at end of year | $	$ 0