COMMON STOCK AND EARNINGS PER SHARE (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
COMMON STOCK AND EARNINGS PER SHARE
Weighted average shares of common stock outstanding - basic	46,620,897	46,245,776	46,558,520	46,203,498
Potentially dilutive shares resulting from stock plans	396,000	658,000	498,000	687,000
Weighted average shares of common stock outstanding - diluted	47,017,440	46,904,015	47,056,715	46,889,703
Antidilutive options not included in the weighted average	606,000		438,000
Earnings per share, other disclosures
Purchase of common stock for treasury			$ (2,622,000)	$ (13,669,000)
Repurchase of common stock, shares			164,862	677,670
Exercise of stock options			$ 400,000	$ 12,900,000
Exercise of stock options, shares			37,089	849,908
Vested (in shares)			388,677	48,305