SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance at beginning of year	$ 7,236	$ 5,153	$ 4,286
Additions Charged to Costs and Expenses	9,589	9,396	7,252
Write-offs	9,299	7,313	6,385
Balance at end of year	7,526	7,236	5,153
Restricted Cash
Restricted cash to serve as collateral for the Workers' Compensation program	3,120
Previously reported
Balance at beginning of year	22,028	16,686	10,526
Additions Charged to Costs and Expenses	19,773	22,101	20,276
Write-offs	20,422	16,759	14,116
Balance at end of year	$ 21,379	$ 22,028	$ 16,686