EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Basic earnings per share:
Net income	$ 7,461		$ 9,854
Weighted Average Common Shares	28,227,000		28,628,000
Basic earnings per share	$ 0.26		$ 0.34
Diluted earnings per share:
Net income	$ 7,461		$ 9,854
Weighted Average Common Shares	28,227,000		28,628,000
Effect of dilutive securities:
Employee stock plans	1,208,000	[1]	1,559,000	[1]
Diluted weighted average common shares	29,435,000	[1]	30,187,000	[1]
Diluted earnings per share	$ 0.25	[1]	$ 0.33	[1]
Antidilutive shares attributable to stock-based awards outstanding excluded from computation of diluted earnings per share	297,531		210,044

[1] The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share when they become contingently issuable per ASC 260-10, Earnings per Share and excludes such shares when they are not contingently issuable. The Company has excluded all performance-based awards underlying the fiscal 2012 and 2011 awards as those shares were not contingently issuable as of the end of the period.