STOCKHOLDERS' EQUITY (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Jul. 31, 2012	Dec. 31, 2011
STOCKHOLDERS' EQUITY
Cash dividend paid			$ 35,108	$ 30,890
Cash dividend per share (in dollars per share)	$ 0.08	$ 0.07	$ 0.24	$ 0.21
Number of shares repurchased (in shares)		598,986	781,781	1,388,282
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	$ 20.93	$ 18.63
Number of shares of common stock authorized for repurchase (in shares)					5,000,000
Additional shares that may be purchased under share repurchase program (in shares)	5,300,000		5,300,000
Common stock reserved for issuance upon exercise of stock options (in shares)	4,400,000		4,400,000