Summary of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Earning per share reconciliation
Net income	$ 9,765		$ 9,069
Weighted-average common shares outstanding	76,298	[1]	75,894	[1]
Earnings (loss) per share, basic	$ 0.13	[1]	$ 0.12	[1]
Net income	$ 9,765		$ 9,069
Weighted-average common shares outstanding, basic	76,298	[1]	75,894	[1]
Effect of assumed exercise of stock options, warrants and RSUs	2,363	[1]	1,682	[1]
Weighted-average common shares outstanding, diluted	78,661	[1]	77,576	[1]
Earnings (loss) per share, diluted	$ 0.12	[1]	$ 0.12	[1]
Outstanding options and RSUs excluded as impact would be antidilutive	57		592
Stock Options
Earning per share reconciliation
Weighted-average effect of dilutive securities	1,926	[1]	1,308	[1]
RSUs
Earning per share reconciliation
Weighted-average effect of dilutive securities	437	[1]	374	[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