Computation of Basic and Diluted Net (Loss) Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income (loss)	$ 1,172	$ (3,262)
Income (loss) per share:
Basic	$ 0.05	$ (0.14)
Diluted	$ 0.05	$ (0.14)
Weighted average number of shares of common stock outstanding during the period used to compute basic net income (loss) per share (in thousands)	21,897	22,550
Incremental shares attributable to exercise of outstanding options, stock appreciation rights and restricted share units (assuming proceeds would be used to purchase treasury stock) (in thousands)	349
Weighted average number of shares of common stock used to compute diluted net income (loss) per share (in thousands)	22,246	22,550