LEASE COMMITMENTS - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Future minimum payments under operating leases
Period of disclosure of future minimum lease payments	5 years
2017	$ 1,072
2018	1,072
2019	1,072
2020	1,072
2021	1,072
Total minimum lease payments	5,360
Rental expense for operating leases	$ 1,500	$ 1,000	$ 900