LONG TERM DEBT (Details) (USD $)				3 Months Ended											1 Months Ended	3 Months Ended					3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Mar. 31, 2012 On or prior to November 15, 2013	Mar. 31, 2012 On or after November 15, 2014 D	Mar. 31, 2012 Twelve month period beginning November 15, 2014	Mar. 31, 2012 Twelve month period beginning November 15, 2015	Mar. 31, 2012 Period beginning November 15, 2016 and thereafter through November 15, 2018	Mar. 31, 2012 October 1, 2011 to September 30, 2012 Denominator Numerator	Mar. 31, 2012 October 1, 2012 and thereafter until maturity Numerator Denominator	Mar. 31, 2012 Prior to December 31, 2011 Denominator Numerator	Mar. 31, 2012 January 1, 2012 to September 30, 2012 Numerator Denominator	Mar. 31, 2012 Revolving Credit Facility	Mar. 31, 2012 Standby letters of credit	Mar. 31, 2011 Term Loan	Mar. 31, 2012 Term Loan	Dec. 31, 2011 Term Loan	Mar. 11, 2011 Term Loan	Mar. 31, 2012 7.125% Senior Notes due 2018	Dec. 31, 2011 7.125% Senior Notes due 2018	Mar. 31, 2012 Subordinated seller notes, non-collateralized, net of unamortized discounts with principal and interest payable in either monthly, quarterly or annual installments, maturing through November, 2016	Dec. 31, 2011 Subordinated seller notes, non-collateralized, net of unamortized discounts with principal and interest payable in either monthly, quarterly or annual installments, maturing through November, 2016
Long-Term Debt
Long-term debt	$ 506,095,000	$ 508,033,000														$ 295,550,000	$ 297,000,000		$ 200,000,000	$ 200,000,000	$ 10,545,000	$ 11,033,000
Less current portion	(7,927,000)	(8,065,000)
Long-term debt, less current portion	498,168,000	499,968,000
Interest rate stated percentage (as a percent)			7.125%
Interest rate, minimum (as a percent)																					3.00%
Interest rate, maximum (as a percent)																					7.00%
Maximum borrowing capacity													100,000,000
Fees related to the amendment of the credit agreement															4,100,000
Reduction in the interest rate margin applicable to the Term Loan (as a percent)																		0.75%
Interest, base rate													LIBOR		LIBOR	LIBOR
Interest rate margin (as a percent)													3.75%			3.00%		3.00%
LIBOR floor applicable to term loans under Credit Agreement, prior to amendment (as a percent)																		1.50%
LIBOR floor applicable to term loans under Credit Agreement (as a percent)																1.00%
Numerator for consolidated interest coverage ratio, minimum									3.25	3.50
Denominator for consolidated interest coverage ratio, minimum									1.00	1.00
Numerator for total leverage ratio, maximum										4.00	5.00	4.50
Denominator for total leverage ratio, maximum										1.00	1.00	1.00
Interest rate (as a percent)																4.00%
Maximum annual capital expenditure as a percentage of consolidated net revenue of preceding fiscal year													7.50%
Maximum percentage of the aggregate principal amount up to which the notes may be redeemed				35.00%
Minimum notice period that the entity must provide for the redemption of the debt instrument (in days)					30
Additional maximum rollover from prior year's capital expenditure allowance													15,000,000
Maximum notice period that the entity must provide for the redemption of the debt instrument (in days)					60
Balance available under the credit facility													$ 99,500,000	$ 500,000
Percentage of the aggregate principal amount at which the notes may be redeemed				107.125%		103.563%	101.781%	100.00%