INTANGIBLE ASSETS - Summary of intangible assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,816	$ 21,971
Accum Amort	15,796	12,512
Net Book Value	11,020	9,459
Weighted Average Life (in years)	8 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,672	16,268
Accum Amort	12,734	10,019
Net Book Value	7,938	6,249
Weighted Average Life (in years)	7 years
Tradenames
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,240	3,240
Accum Amort	1,296	972
Net Book Value	1,944	2,268
Weighted Average Life (in years)	10 years
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,316	943
Accum Amort	898	644
Net Book Value	418	299
Weighted Average Life (in years)	5 years
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,367	1,260
Accum Amort	835	691
Net Book Value	532	569
Weighted Average Life (in years)	11 years
Loan fees and other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	221	260
Accum Amort	33	186
Net Book Value	$ 188	$ 74
Weighted Average Life (in years)	5 years