SHAREHOLDERS EQUITY - Summary of Dividend payments (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended														6 Months Ended	12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Record Date	Jun. 13, 2017	Mar. 27, 2017	Dec. 05, 2016	Sep. 12, 2016	Jun. 13, 2016	Mar. 21, 2016	Dec. 07, 2015	Sep. 14, 2015	Jun. 15, 2015	Mar. 20, 2015	Dec. 08, 2014	Sep. 15, 2014	Jun. 16, 2014	Mar. 17, 2014
Payment Date	Jun. 20, 2017	Apr. 03, 2017	Dec. 12, 2016	Sep. 19, 2016	Jun. 20, 2016	Mar. 28, 2016	Dec. 11, 2015	Sep. 21, 2015	Jun. 19, 2015	Mar. 23, 2015	Dec. 15, 2014	Sep. 22, 2014	Jun. 23, 2014	Mar. 24, 2014
Dividend (per share)	$ 0.18	$ 0.18	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.16	$ 0.16	$ 0.16	$ 0.16	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.36	$ 0.68	$ 0.64	$ 0.60
Dividend paid, amount	$ 2,048	$ 2,043	$ 1,929	$ 1,928	$ 1,929	$ 1,929	$ 1,815	$ 1,815	$ 1,814	$ 1,809	$ 1,695	$ 1,696	$ 1,695	$ 1,692	$ 4,091	$ 7,715	$ 7,253	$ 6,778