Summary of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Earning per share reconciliation
Net income	$ 1,504		$ 4,703		$ 11,269		$ 13,772
Weighted-average common shares outstanding	76,286	[1]	75,898	[1]	76,385	[1]	75,896	[1]
Earnings per share, basic	$ 0.02	[1]	$ 0.06	[1]	$ 0.15	[1]	$ 0.18	[1]
Net income	$ 1,504		$ 4,703		$ 11,269		$ 13,772
Weighted-average common shares outstanding, basic	76,286	[1]	75,898	[1]	76,385	[1]	75,896	[1]
Effect of assumed exercise of stock options, warrants and RSUs	1,994	[1]	1,600	[1]	2,178	[1]	1,642	[1]
Weighted-average common shares outstanding, diluted	78,280	[1]	77,498	[1]	78,563	[1]	77,538	[1]
Earnings per share, diluted	$ 0.02	[1]	$ 0.06	[1]	$ 0.14	[1]	$ 0.18	[1]
Outstanding options and RSUs excluded as impact would be antidilutive	166		216		112		404
Stock Options
Earning per share reconciliation
Weighted-average effect of dilutive securities	1,607	[1]	1,234	[1]	1,766	[1]	1,272	[1]
RSUs
Earning per share reconciliation
Weighted-average effect of dilutive securities	387	[1]	366	[1]	412	[1]	370	[1]

[1] The number of common shares and per share amounts have been retroactively restated for all prior periods presented to reflect the Company's two-for-one common stock split effected in the form of a common stock dividend distributed on April 1, 2014.