LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details 3) (USD $)				6 Months Ended		6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Credit Agreement	Jun. 30, 2012 Term Loan	Jun. 15, 2012 Term Loan Y	Jun. 30, 2012 Accounts receivable securitization program	Jun. 30, 2012 Letter of Credit Agreements	Jun. 30, 2012 Surety bonds
Financing Arrangements
Face amount of term loan					$ 100,000,000
Maximum borrowing capacity			75,000,000			75,000,000	95,600,000
Debt, floating rate of interest basis				LIBOR		LIBOR
Borrowing capacity for issuance of letters of credit committed by financial institutions subject to the Company's compliance with the requirements of issuance							50,000,000
Available borrowing capacity for issuance of letters of credit committed by financial institutions subject to the Company's compliance with the requirements of issuance							49,000,000
Outstanding letters of credit						2,200,000	20,000,000
Outstanding surety bonds under collateralized bond program								13,800,000
Amounts collateralized by restricted funds	21,025,000	52,693,000					17,300,000	3,700,000
Reduction in amounts collateralized by restricted funds under letters of credit transferred to uncollateralized bond programs							26,100,000
Outstanding surety bonds under uncollateralized bond programs								36,600,000
Debt instrument, term (in months or years)					5
Remaining borrowing capacity						72,800,000
Outstanding letters of credit which released restricted funds under the collateralized letter of credit facility						$ 2,200,000