STOCK-BASED COMPENSATION PLANS - Stock Option Plan (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Service period	3 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Stock options granted at percentage of fair value	100.00%
Service period	3 years
Number Of Shares
Number of shares, options outstanding, beginning of year	39	82	88
Number of shares, exercised	13	43	6
Number of shares, options outstanding, end of year	26	39	82
Number of shares, options exercisable	26	39	82
Weighted Average Exercise Price Per Share
Weighted average exercise price per share, options outstanding, beginning of year	$ 22.43	$ 23.00	$ 22.95
Weighted average exercise price per share, exercised	22.30	23.52	22.07
Weighted average exercise price per share, options outstanding, end of year	22.50	22.43	23.00
Weighted average exercise price per share, options exercisable	$ 22.50	$ 22.43	$ 23.00
Exercise price range $22.07 to $22.93 | Stock Options
Weighted Average Exercise Price Per Share
Exercise price range, options outstanding	26
Options exercise price range, lower range limit	$ 22.07
Options exercise price range, upper range limit	$ 22.93