Activity of Awarded Options (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Shares Under Options
Outstanding at beginning of year (in shares)	2,475,074
Granted (in shares)	224,501
Exercised (in shares)	0
Forfeited (in shares)	(412,841)
Outstanding at end of year (in shares)	2,286,734
Exercisable at end of year (in shares)	1,711,098
Weighted- Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 22.84
Granted (in dollars per share)	$ 5.59
Exercised (in dollars per share)	$ 0.00
Forfeited (in dollars per share)	$ 22.99
Outstanding at end of year (in dollars per share)	$ 21.14
Exercisable at end of year (in dollars per share)	$ 23.21
Weighted- Average Remaining Contractual Term
Outstanding at end of year	6 years 7 months 6 days
Exercisable at end of year	6 years 1 month 6 days
Aggregate Intrinsic Value
Outstanding at end of year	$ 7
Exercisable at end of year	$ 0