COMMITMENTS, CONTINGENCIES AND LITIGATION (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Schedule of credit agreements

	December 31,
	2012			2011
Credit limit:
Revolving credit facility	$	70,000		$	60,000
Term loan		67,300			59,000
Outstanding balance on revolving credit facility, due August 2015		30,501			100
Outstanding principal balance on the term loan, less unamortized discount of $627 and $573, respectively, due August 2015		64,873			58,177
Letters of credit issued		13,578			11,130
Borrowing capacity		25,921			48,770
Interest rate – term loan		3.7	%		3.8	%
Interest rate – revolving credit facility		3.7	%		5.0	%

Schedule of maturities of long-term debt

Maturities of the term loan are as follows:
2013	$	3,500
2014		3,500
2015		58,500
	$	65,500

Schedule of future minimum capital lease payments and the present value of the minimum lease payments for all capital leases

2013	$	8,710
2014		8,933
2015		9,366
2016		8,357
2017		7,870
Thereafter		26,597
Remaining capital lease payments		69,833
Less: amounts representing imputed interest		(21,275	)
Present value of minimum lease payments		48,558
Less: current portion		(4,504	)
	$	44,054

Schedule of future minimum rental payments for operating leases

2013	$	29,030
2014		28,412
2015		20,731
2016		20,825
2017		15,352
Thereafter		35,126
	$	149,476

Schedule of future minimum payments under service and purchase commitments

2013	$	6,304
2014		4,107
2015		2,928
2016		1,552
2017		390
Thereafter		429
	$	15,710