Compensation Expense Expected to be Recognized in Respect of Nov-Vested Stock Options Outstanding (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Estimated Stock Based Compensation Expense for year 2013	$ 237
Estimated Stock Based Compensation Expense for year 2014	458
Estimated Stock Based Compensation Expense for year 2015	247
Estimated Stock Based Compensation Expense for year 2016	32
Estimated Stock Based Compensation Expense for year 2017	12
Estimated Stock Based Compensation Expense	$ 986