SHARE-BASED COMPENSATION - Stock Option Exercises (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Exercises of Stock Options
Intrinsic value of stock options exercised	$ 877	$ 3,759	$ 8,658
Cash received from option exercises	3,886	12,503	3,005
Tax benefit realized from options exercised during the annual period	$ 364	$ 1,590	$ 6,689