BORROWINGS (Details) (USD $)	3 Months Ended		12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Equipment under capital leases	Mar. 31, 2013 Equipment under capital leases	Dec. 31, 2012 Equipment under capital leases	Dec. 31, 2012 Credit Agreement	Mar. 31, 2013 Credit Agreement	Dec. 31, 2012 Financing Agreement	Mar. 31, 2013 Purchasing Card	Dec. 31, 2012 Purchasing Card
Borrowings
Maximum borrowing capacity									$ 3,000,000	$ 3,000,000	$ 20,000,000
Variable rate basis									one-month LIBOR	one-month LIBOR	one-month LIBOR
Interest rate margin on variable rate basis (as a percent)									1.00%	1.00%	2.50%
Cap for variable rate base (as a percent)											0.50%
Amounts outstanding									0	0	0
Letters of credit, outstanding amount	1,800,000		1,800,000		1,800,000
Outstanding balance												4,800,000	3,900,000
Unused borrowing capacity												200,000	1,100,000
Fixed assets under capital leases						4,200,000	4,200,000	1,700,000
Accumulated depreciation						1,700,000	1,700,000	1,700,000
Depreciation and amortization	3,863,000	4,034,000	15,838,000	16,385,000			1,000	129,000
Computer equipment acquired under capital lease obligations	2,563,000		2,563,000			2,563,000
Payment of capital lease obligation	2,563,000	77,000	2,598,000	735,000		2,563,000
Future payment obligations under capital leases	$ 0		$ 0