STOCK-BASED COMPENSATION (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock-based compensation
Number of shares that may be issued under plans approved by shareowners	9,500,000
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	3,021,189
Weighted-average exercise price of outstanding options, warrants and rights (in dollars per share)	$ 22.15
Number of remaining securities available for future issuance under equity compensation plans, excluding securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	4,530,673
Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	2,702,768
Weighted-average exercise price of outstanding options, warrants and rights (in dollars per share)	$ 22.15
Number of remaining securities available for future issuance under equity compensation plans, excluding securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	4,530,673
Equity compensation plans not approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	318,421
Performance awards
Stock-based compensation
Minimum percentage of Company's ROE to earn awards under performance awards	10.00%	9.00%
Minimum percentage of Company's ROE to earn maximum awards under performance awards	11.20%	10.00%
Period over which average return on average equity is calculated	3 years	3 years
Performance shares issued	306,100	191,100
Estimated fair value of performance shares awarded	$ 8,608	$ 5,433
Number of shares of common stock which are multiplied by award earned percentage payout to calculate number of awards	1
No. of Awards
Awards granted (in shares)	306,100	191,100
Performance awards | Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	602,160
SARs
Stock-based compensation
Performance shares issued			344,400
Estimated fair value of performance shares awarded			3,300
Expiration period from date of grant	10 years
Exercisable period of grants from grant date	5 years
Beginning of annual installments from date of grant	1 year
Weighted-Average Base Price per share
Balance at the beginning of the period (in dollars per share)	$ 22.27	$ 21.97	$ 22.28
SARs granted (in dollars per share)			$ 18.34
SARs exercised/forfeited/expired (in dollars per share)	$ 22.60	$ 8.31	$ 20.98
Balance at the end of the period (in dollars per share)	$ 22.15	$ 22.27	$ 21.97
No. of Awards
Balance at the beginning of the period (in shares)	2,274,229	2,324,837	2,469,202
Awards granted (in shares)			344,400
Awards exercised / forfeited / expired (in shares)	(633,062)	(50,608)	(488,765)
Balance at the end of the period (in shares)	1,641,167	2,274,229	2,324,837
SARs | Minimum
Stock-based compensation
Number of annual installments to exercise stock appreciation rights	3
SARs | Maximum
Stock-based compensation
Number of annual installments to exercise stock appreciation rights	4
SARs | Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	1,066,759
Number of shares of common stock assumed to be payable with respect to each outstanding award	1
Restricted stock units
Stock-based compensation
Performance shares issued	190,800	175,500
Estimated fair value of performance shares awarded	$ 5,400	$ 5,000
No. of Awards
Awards granted (in shares)	190,800	175,500
Restricted stock units | Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	646,632
P-SARs
Stock-based compensation
Number of stock appreciation rights which are multiplied by award percentage payout to calculate number of awards (in shares)	1
Deferred compensation plan for officers | Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	319,555
Deferred compensation plan for officers | Equity compensation plans not approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	102,318
Deferred compensation plan for directors who are not employees | Equity compensation plans approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	67,662
Deferred compensation plan for directors who are not employees | Equity compensation plans not approved by shareowners
Additional equity compensation plan information
Number of securities to be issued upon exercise of outstanding options, warrants and rights (in shares)	216,103