GOODWILL AND INTANGIBLE ASSETS - NET (Narrative) (Details) - USD ($)	3 Months Ended									12 Months Ended
	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, 2011	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$ 115,930,000				$ 57,417,000					$ 115,930,000	$ 57,417,000	$ 22,268,000
Goodwill impairment loss	0	$ 0	$ 0	$ 0	(2,241,000)	$ 0	$ 0	$ 0		0	(2,241,000)	0
North America
Goodwill [Line Items]
Goodwill	81,464,000				31,078,000					81,464,000	31,078,000	16,438,000
Goodwill impairment loss											0
Accumulated impairment loss	0				0					0	0	0
Europe
Goodwill [Line Items]
Goodwill	34,466,000				26,339,000					34,466,000	26,339,000	2,864,000
Goodwill impairment loss											0
Accumulated impairment loss	0				0					0	0	0
Russia
Goodwill [Line Items]
Goodwill	0				0					0	0	2,966,000
Goodwill impairment loss											(2,241,000)
Accumulated impairment loss	2,241,000				2,241,000					2,241,000	2,241,000	0
Other
Goodwill [Line Items]
Goodwill	0				0					0	0	0
Goodwill impairment loss									$ (1,697,000)
Accumulated impairment loss	$ 1,697,000				$ 1,697,000					$ 1,697,000	$ 1,697,000	$ 1,697,000