Share-Based Compensation - Unrecognized Share-Based Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	$ 801
Average Expected Recognition Period	2 years 4 months 24 days
Stock option awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	768
Average Expected Recognition Period	2 years 6 months
Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	$ 33
Average Expected Recognition Period	9 months 18 days