STOCK-BASED COMPENSATION PLANS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Non-vested Stock Awards Outstanding, Weighted-Average Grant Date Fair Value
Granted (in dollars per share)	$ 23.76	$ 20.88	$ 16.76
Stock-based compensation plans, additional disclosures
Weighted average fair value of stock awards granted (in dollars per share)	$ 23.76	$ 20.88	$ 16.76
Non-vested Stock Awards
Non-vested Stock Awards Outstanding, Number of Shares
Balance at the beginning of the period (in shares)	216,000
Granted (in shares)	108,000
Stock awards vested (in shares)	(72,000)
Forfeited (in shares)	(8,000)
Balance at the end of the period (in shares)	244,000	216,000
Non-vested Stock Awards Outstanding, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 19.88
Granted (in dollars per share)	$ 23.76
Stock awards vested (in dollars per share)	$ 19.41
Forfeited (in dollars per share)	$ 21.38
Balance at the end of the period (in dollars per share)	$ 21.69	$ 19.88
Stock-based compensation plans, additional disclosures
Total compensation cost	$ 2,000,000	$ 1,500,000	$ 1,600,000
Total recognized tax benefit	800,000	600,000	600,000
Weighted average fair value of stock awards granted (in dollars per share)	$ 23.76
Total fair value of awards vested	1,400,000	1,300,000	913,000
Unrecognized stock-based compensation expense	3,100,000
Non-vested Stock Awards | Maximum
Stock-based compensation plans, additional disclosures
Vesting period	5 years
Expected weighted-average period for recognition of unrecognized compensation	2 years
Stock Options
Stock Options Outstanding, Number of Shares
Balance at the beginning of the period (in shares)	409,000
Acquired (in shares)	552,000
Stock options exercised (in shares)	(254,000)
Expired (in shares)	(19,000)
Balance at the end of the period (in shares)	688,000	409,000
Exercisable options at the end of the period (in shares)	570,000
Stock Options Outstanding, Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 25.39
Stock options exercised (in dollars per share)	$ 10.26
Acquired (in dollars per share)	$ 11.97
Expired (in dollars per share)	$ 22.83
Balance at the end of the period (in dollars per share)	$ 18.13	$ 25.39
Exercisable options at the end of the period (in dollars per share)	$ 19.31
Stock-based compensation plans, additional disclosures
Total compensation cost	240,000	0	53,000
Unrecognized stock-based compensation expense	909,000
Expected weighted-average period for recognition of unrecognized compensation	1 year
Contractual life	10 years
Weighted average remaining contractual term for options outstanding	4 years 11 months 16 days
Total intrinsic value	$ 2,700,000	$ 98,000	$ 198,000
Stock Options | Maximum
Stock-based compensation plans, additional disclosures
Vesting period	5 years
2011 Equity Compensation Plan
Stock-based compensation plans
Number of shares authorized under the plan	1,400,000
Number of shares available for grant under the plan	908,000
2011 Equity Compensation Plan | Non-vested Stock Awards
Stock-based compensation plans
Number of shares counted against the share limit for each restricted stock granted	3
2011 Equity Compensation Plan | Stock Options
Stock-based compensation plans
Number of shares counted against the share limit for each restricted stock granted	1