GOODWILL AND OTHER INTANGIBLE ASSETS - Other Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Intangible Assets [Line Items]
Gross carrying value	$ 73,750	$ 73,693
Accumulated amortization	(60,833)	(59,193)
Net carrying value	12,917	14,500
Noncompete agreements
Intangible Assets [Line Items]
Gross carrying value	2,269	2,269
Accumulated amortization	(1,860)	(1,710)
Net carrying value	409	559
Patents, trademarks and tradename
Intangible Assets [Line Items]
Gross carrying value	3,129	3,106
Accumulated amortization	(283)	(263)
Net carrying value	2,846	2,843
Customer relationships and contracts
Intangible Assets [Line Items]
Gross carrying value	59,079	59,045
Accumulated amortization	(53,571)	(52,303)
Net carrying value	5,508	6,742
Developed technology
Intangible Assets [Line Items]
Gross carrying value	8,494	8,494
Accumulated amortization	(4,340)	(4,138)
Net carrying value	4,154	4,356
Customer backlog
Intangible Assets [Line Items]
Gross carrying value	779	779
Accumulated amortization	(779)	(779)
Net carrying value	$ 0	$ 0