SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 segment	Dec. 31, 2012
SEGMENT INFORMATION
Number of operating segments									1
Segment information
Revenues	$ 50,131	$ 24,876	$ 25,352	$ 25,143	$ 23,969	$ 24,316	$ 26,836	$ 26,847	$ 125,502	$ 101,968
Identifiable assets	170,977				60,967				170,977	60,967
Outside the United States
Segment information
Revenues									53,988	44,761
Wholly owned foreign subsidiaries
Segment information
Revenues									51,199	42,172
Identifiable assets	$ 55,627				$ 26,525				$ 55,627	$ 26,525