STOCKHOLDERS' EQUITY AND EARNINGS PER SHARE (Details 1) - shares	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	200,000,000	200,000,000
Common Stock, shares issued	18,079,522	17,552,139
Redeemable Convertible Preferred Stock, shares authorized	1,000,000,000	1,000,000,000
Redeemable Convertible Preferred Stock, shares issued	8,200,000	8,200,000
Total shares authorized	300,000,000
Total shares issued	26,279,522	25,752,139
Less: Treasury Stock	(1,826,096)	(1,629,818)
Total issued and outstanding	24,453,426	24,122,321
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	150,208,500
Common Stock, shares issued	1,255,642	728,259
Common Class B1 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	4,023,400
Common Stock, shares issued	3,811,342	3,811,342
Common Class B2 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	4,023,400
Common Stock, shares issued	3,811,342	3,811,342
Common Class B3 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	8,165,700
Common Stock, shares issued	7,735,169	7,735,169
Common Class B4 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	781,644
Common Stock, shares issued	627,579	627,579
Common Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	16,994,144
Common Stock, shares issued	15,985,432	15,985,432
Common Class C [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	15,803,212
Common Stock, shares issued	838,448	838,448
Common Class D [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	16,994,144
Common Stock, shares issued	0	0
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, shares authorized	200,000,000
Common Stock, shares issued	18,079,522	17,552,139
Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Redeemable Convertible Preferred Stock, shares authorized	100,000,000
Redeemable Convertible Preferred Stock, shares issued	8,200,000	8,200,000