STOCKHOLDERS' EQUITY (Details) (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Oct. 31, 2008
STOCKHOLDERS' EQUITY
Cash dividend paid			$ 30,890	$ 26,712
Cash dividend per share (in dollars per share)	$ 0.07	$ 0.06	$ 0.21	$ 0.18
Number of shares repurchased (in shares)	598,986	558,749	1,388,282	1,889,141
Par value of common stock (in dollars per share)	$ 1		$ 1		$ 1
Weighted average stock price of shares repurchased (in dollars per share)	$ 17.85	$ 13.95	$ 18.63	$ 13.95
Number of shares of common stock authorized for repurchase (in shares)						7,500,000
Additional shares that may be purchased under share repurchase program (in shares)	1,100,000		1,100,000
Common stock issued upon exercise of stock options by employees (in shares)	3,000	180,000	56,000	418,000
Common stock reserved for issuance upon exercise of stock options (in shares)	5,200,000		5,200,000