Weighted Average Shares Outstanding - Summary of Weighted Average Number of Shares (Detail) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Basic shares outstanding	23,879	23,819	23,873	23,791
Plus: Dilutive effect of ISOs	346	105	346	105
Plus: Dilutive effect of Restricted grants	63	49	63	49
Diluted shares outstanding	24,288	23,973	24,282	23,945