SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - SELLING, MARKETING AND ADMINISTRATIVE EXPENSE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Research and development costs	$ 47,268	$ 49,281	$ 47,554
Advertising expense	521,479	561,644	$ 570,223
Prepaid advertising expense	$ 651	$ 3,924