SHAREHOLDERS' EQUITY (NARRATIVE) (Details) - USD ($)	1 Months Ended	4 Months Ended		8 Months Ended		12 Months Ended			24 Months Ended	36 Months Ended	46 Months Ended	60 Months Ended
	Sep. 30, 2014	Apr. 30, 2016	Apr. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2009	Nov. 30, 2015	Dec. 31, 2014	May 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, increase in authorized amount											$ 1,600,000,000
Payments for repurchase of common stock						$ 203,000,000	$ 365,200,000	$ 319,100,000
Payments for repurchase of stock warrants	$ 57,400,000
Stock repurchase program, remaining repurchase authorized amount				$ 252,700,000		252,700,000			$ 252,700,000
Common stock dividends paid						$ 54,800,000	$ 52,000,000	$ 51,000,000
Dividends (in dollars per share)		$ 0.07	$ 0.06	$ 0.08	$ 0.07	$ 0.31	$ 0.27	$ 0.24
Available for future grant (in shares)				4,620,000	6,882,000	4,620,000	6,882,000	8,571,000	4,620,000			8,571,000
Proceeds from stock options exercised						$ 8,400,000	$ 6,300,000	$ 5,000,000
Price of junior preferred stock (per 1/1000 of a share)				$ 70.00		$ 70.00			$ 70.00
Junior preferred stock right becomes exercisable when a person or group becomes owner of stated percentage (more than)						4.99%
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Series B junior participating preferred stock par value (in dollars per share)				$ 0.01		$ 0.01			$ 0.01
Junior preferred stock, purchase right to purchase fractional share (in shares)						0.001
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period						10 years
Allocated share-based compensation expense						$ 12,200,000	9,600,000	7,900,000
Allocated share-based compensation expense, net of tax						$ 7,900,000	$ 6,200,000	$ 5,100,000
Compensation expense related to stock options reduced both basic and diluted earnings per share (in dollars per share)						$ (0.04)	$ (0.03)	$ (0.02)
Unrecognized compensation expense				$ 6,900,000		$ 6,900,000			$ 6,900,000
Weighted average recognition period						1 year 4 months 24 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period									3 years
Allocated share-based compensation expense						$ 3,100,000	$ 2,200,000	$ 3,000,000
Unrecognized compensation expense				5,000,000	$ 900,000	$ 5,000,000	$ 900,000		$ 5,000,000
Weighted average recognition period						2 years 3 months 24 days
Granted (in shares)						401,000
Granted (in dollars per share)						$ 18.17	$ 17.59	$ 17.15
Grant date fair value of performance shares awarded				7,300,000	1,700,000	$ 7,300,000	$ 1,700,000	$ 1,900,000	7,300,000			$ 1,900,000
Fair value of vested shares						$ 2,100,000	$ 2,700,000	$ 3,700,000
Restricted Stock [Member] | Directors, Officers, and Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)						400,000	100,000	100,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense						$ 7,700,000	$ 5,300,000	$ 4,700,000
Granted (in shares)						507,976	516,660	283,630
Grant date fair value of performance shares awarded				$ 10,300,000	$ 9,400,000	$ 10,300,000	$ 9,400,000		$ 10,300,000
Performance period						3 years
Performance unit payout						200.00%	150.00%
Years 2007 Through 2009 [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period										3 years
Expiration period										5 years
Years 2010 and Thereafter [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period												3 years
Expiration period												7 years
2015 [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period									3 years
Expiration period									10 years
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock purchased and retired (in shares)						11,688,000	20,582,000	18,489,000
Common Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount													$ 100,000,000.0