NET INCOME PER SHARE (DILUTED SHARES TABLE) (DETAILS) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Shares used in basic earnings per share calculation	54,093	56,476	55,233	56,790
Effect of dilutive securities:
Stock options	377	673	378	817
Restricted stock units	435	599	380	566
Performance-based restricted stock units	0	0	0	0
Total effects of dilutive securities	812	1,272	758	1,383
Shares used in dilutive earnings per share calculation	54,905	57,748	55,991	58,173