DEBT - Line of credit (Details) - USD ($)			3 Months Ended		27 Months Ended
	Jan. 20, 2017	Mar. 04, 2016	Mar. 31, 2017	Apr. 01, 2016	Mar. 31, 2017	Dec. 30, 2016	Jan. 15, 2015
Line of Credit
Payment on note			$ 1,272,000	$ 939,000
Total debt obligations, excluding capital lease obligations			4,775,000		$ 4,775,000	$ 6,046,000
Genesys | Braun
Line of Credit
Deferred payments		$ 2,300,000
Deferred payments outstanding			1,100,000
Genesys | Mineo
Line of Credit
Deferred payments		2,300,000
Deferred payments outstanding			$ 1,100,000
Genesys | Bruan and Mineo
Line of Credit
Number of monthly installments			24 months
Amount of each installment		$ 95,834
Interest rate on deferred payment (as a percent)		0.65%
Interest and principal payments			$ 1,200,000
Federal Funds Effective Swap Rate [Member] | BMO
Line of Credit
Spread on floating interest rate (as a percent)			0.50%
Abacus Notes
Line of Credit
Interest rate (as a percent)							4.00%
Kinzer Note
Line of Credit
Amount borrowed to finance acquisition							$ 600,000
Payment on note					600,000
Outstanding balance			$ 0		0
Rubbert Note
Line of Credit
Amount borrowed to finance acquisition							600,000
Payment on note					600,000
Outstanding balance			0		0
360 Energy Note
Line of Credit
Amount borrowed to finance acquisition							$ 3,000,000
Interest rate (as a percent)							4.00%
Payment on note			2,200,000
Outstanding balance			800,000		800,000
Revolving Credit Facility | BMO
Line of Credit
Maximum borrowing capacity	$ 35,000,000
Revolving Credit Facility | Abacus and 360 Energy | BMO
Line of Credit
Amount borrowed to finance acquisition							$ 1,500,000
Revolving line of credit
Line of Credit
Total debt obligations, excluding capital lease obligations			$ 1,500,000		$ 1,500,000
Revolving line of credit | BMO
Line of Credit
Repurchase of common stock	8,000,000
Standby letter of credit sub-facility | BMO
Line of Credit
Maximum borrowing capacity	10,000,000
Credit Agreement | BMO
Line of Credit
The aggregate amount under the revolving line of credit	25,000,000
The aggregate amount under the revolving line of credit for a total facility	60,000,000
Earn-out obligations	20,000,000
Total consideration for all permitted acquisitions	$ 10,000,000
Percentage of increased interest rate in case of default	2.00%
Credit Agreement | Maximum | BMO
Line of Credit
Fee on unused commitments (as a percent)	0.35%
Commitment fee (as a percent)	1.50%
Credit Agreement | Minimum | BMO
Line of Credit
Fee on unused commitments (as a percent)	0.20%
Commitment fee (as a percent)	0.94%
Unrestricted cash or undrawn availability under the revolving line of credit	$ 5,000,000
Credit Agreement | Federal Funds Effective Swap Rate [Member] | Base rate | BMO
Line of Credit
Spread on floating interest rate (as a percent)			0.50%
Credit Agreement | Base rate | LIBOR | Maximum | BMO
Line of Credit
Spread on floating interest rate (as a percent)			2.00%
Credit Agreement | Base rate | LIBOR | Minimum | BMO
Line of Credit
Spread on floating interest rate (as a percent)			1.25%
Credit Agreement | LIBOR | Base rate | BMO
Line of Credit
Spread on floating interest rate (as a percent)			1.00%
Credit Agreement | LIBOR | Base rate | Maximum | BMO
Line of Credit
Spread on floating interest rate (as a percent)			1.00%
Credit Agreement | LIBOR | Base rate | Minimum | BMO
Line of Credit
Spread on floating interest rate (as a percent)			0.25%
Term Note
Line of Credit
Total debt obligations, excluding capital lease obligations						1,500,000
Term Note | Abacus and 360 Energy | BMO
Line of Credit
Amount borrowed to finance acquisition	$ 1,500,000						$ 2,000,000
Notes payable for insurance
Line of Credit
Interest rate (as a percent)			2.98%		2.98%
Total debt obligations, excluding capital lease obligations			$ 400,000		$ 400,000	$ 599,000