RETIREMENT FUND AND PROFIT SHARING PLAN (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Employees Savings Plan [Member] | UNITED STATES
Defined Contribution Plan Disclosure [Line Items]
Compensation expense	$ 300	$ 300	$ 900	$ 800
Employees Savings Plan [Member] | Class A Common Stock [Member] | UNITED STATES
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	46,504		46,504
Employees Savings Plan [Member] | Class B Common Stock [Member] | UNITED STATES
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	144,362		144,362
Retirement Fund [Member] | HONG KONG
Defined Contribution Plan Disclosure [Line Items]
Compensation expense	$ 100	100	$ 300	200
Retirement Fund [Member] | Class A Common Stock [Member] | HONG KONG
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	3,323		3,323
Retirement Fund [Member] | Class B Common Stock [Member] | HONG KONG
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	17,342		17,342
SERP [Member]
Components of SERP expense [Abstract]
Service cost	$ 175	148	$ 525	445
Interest cost	168	165	505	494
Net amortization	94	98	281	293
Net periodic benefit cost	437	$ 411	1,311	$ 1,232
Amounts recognized in accumulated other comprehensive loss, pretax [Abstract]
Prior service cost	996		996		$ 1,172
Net loss	2,865		2,865		2,970
Total amounts recognized in accumulated other comprehensive loss	$ 3,861		$ 3,861		$ 4,142