OPERATING SEGMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Revenue, Property and Equipment and Intangible Assets Outside of the United States
Total revenue	$ 45,739	$ 39,670	$ 118,732	$ 113,350
Total long- lived assets	152,352		152,352		139,213
United States
Revenue, Property and Equipment and Intangible Assets Outside of the United States
Total revenue	36,100	30,248	91,658	85,100
Total long- lived assets	81,747		81,747		71,456
Canada
Revenue, Property and Equipment and Intangible Assets Outside of the United States
Total revenue	9,639	9,422	27,074	28,250
Total long- lived assets	$ 70,605		$ 70,605		$ 67,757