STOCK-BASED COMPENSATION - STOCK OPTIONS (Details) (Stock Options, USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options
Weighted-average fair values along with the assumptions incorporated into the valuation models
Weighted-average fair value per stock option (in dollars per share)	$ 6.70	$ 6.03	$ 6.30
Expected term	8 years	5 years	5 years
Risk-free interest rate minimum (as a percent)	0.12%	0.18%	0.17%
Risk-free interest rate maximum (as a percent)	2.88%	2.11%	2.18%
Expected dividend yield (as a percent)	5.28%	5.33%	5.28%
Expected volatility (as a percent)	18.00%	24.00%	25.00%
Stock Options
Outstanding at the beginning of the period (in shares)	49,993
Granted (in shares)	13,890
Exercised (in shares)	(58,169)
Outstanding at the end of the period (in shares)	5,714	49,993
Exercisable (in shares)	0
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 53.03
Granted (in dollars per share)	$ 55.23
Exercised (in dollars per share)	$ 53.44
Outstanding at the end of the period (in dollars per share)	$ 54.18	$ 53.03
Weighted-Average Remaining Contractual Life (in Years)
Outstanding at the end of the period	7 years 6 months
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	$ 0.1
Options exercised (in dollars)	$ 1.0