Stock Options - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013 Stock Option	Mar. 31, 2012 Stock Option	Jun. 30, 2013 Stock Option	Dec. 31, 2012 Stock Option
Disclosure Stock Options Additional Information [Line Items]
Percentage of options vested						50.00%
Options vesting date					Jan. 17, 2013
Percentage of options that will vest next year					50.00%
Stock based compensation expense	$ 88	$ 1,288	$ 88	$ 1,066