STOCK COMPENSATION PLANS (Restricted Stock Units activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Performance Units and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested shares at beginning of year (in shares)	652,184	763,386	765,143
Shares granted (in shares)	1,380,621	890,252	753,612
Shares vested (in shares)	(1,126,932)	(958,750)	(666,856)
Shares forfeited (in shares)	(53,635)	(42,704)	(88,513)
Nonvested shares at end of year (in shares)	852,238	652,184	763,386
Nonvested shares at beginning of year, weighted average grant date value (in dollars per share)	$ 13.64	$ 11.47	$ 11.73
Shares granted, weighted average grant date value (in dollars per share)	$ 17.37	$ 15.18	$ 11.78
Shares vested, weighted average grant date value (in dollars per share)	$ 15.91	$ 13.40	$ 12.08
Shares forfeited, weighted average grant date value (in dollars per share)	$ 13.99	$ 12.51	$ 11.81
Nonvested shares at end of year, weighted average grant date value (in dollars per share)	$ 15.90	$ 13.64	$ 11.47
Fair value of shares issued	$ 16,793,342	$ 5,441,944	$ 0
Unrecognized compensation expense at end of year	15,459,606	10,663,208	10,725,573
Weighted average remaining vesting period (in years)	1 year 7 months 5 days	1 year 7 months 6 days	1 year 7 months 5 days
Weighted average grant date fair value	23,977,660	13,514,025	8,877,549
Closing trading price of company stock (in dollars per share)	$ 18.14
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested shares at beginning of year (in shares)	289,210	149,779	64,667
Shares granted (in shares)	169,000	267,750	169,000
Shares vested (in shares)	(175,009)	(123,413)	(75,708)
Shares forfeited (in shares)	(7,500)	(4,906)	(8,180)
Nonvested shares at end of year (in shares)	275,701	289,210	149,779
Nonvested shares at beginning of year, weighted average grant date value (in dollars per share)	$ 13.77	$ 11.54	$ 11.41
Shares granted, weighted average grant date value (in dollars per share)	$ 17.05	$ 14.51	$ 11.65
Shares vested, weighted average grant date value (in dollars per share)	$ 14.31	$ 12.76	$ 11.73
Shares forfeited, weighted average grant date value (in dollars per share)	$ 14.32	$ 11.58	$ 11.14
Nonvested shares at end of year, weighted average grant date value (in dollars per share)	$ 15.43	$ 13.77	$ 11.54
Fair value of shares issued	904,135	671,162	0
Unrecognized compensation expense at end of year	5,001,210	4,728,581	2,104,393
Weighted average remaining vesting period (in years)	1 year 11 months 15 days	2 years 6 months 6 days	2 years 1 month 7 days
Weighted average grant date fair value	$ 2,882,200	$ 3,885,053	$ 1,968,850
Closing trading price of company stock (in dollars per share)	$ 18.14
IncrementalCommonSharesAttributableToNonvestedSharesWithForfeitableDividends	125,000