LONG-TERM DEBT (Details) (USD $)	3 Months Ended	12 Months Ended											1 Months Ended	3 Months Ended	12 Months Ended			3 Months Ended			12 Months Ended		3 Months Ended
	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 On or prior to November 15, 2013	Dec. 31, 2012 On or after November 15, 2014 D	Dec. 31, 2012 Twelve month period beginning November 15, 2014	Dec. 31, 2012 Twelve month period beginning November 15, 2015	Dec. 31, 2012 Period beginning November 15, 2016 and thereafter through November 15, 2018	Dec. 31, 2012 Revolving Credit Facility	Dec. 31, 2010 Revolving Credit Facility	Dec. 31, 2012 Standby letters of credit	Mar. 31, 2011 Term Loan	Dec. 31, 2010 Term Loan	Dec. 31, 2012 Term Loan	Dec. 31, 2011 Term Loan	Mar. 11, 2011 Term Loan	Dec. 31, 2010 7.125% Senior Notes due 2018	Dec. 31, 2012 7.125% Senior Notes due 2018	Dec. 31, 2011 7.125% Senior Notes due 2018	Dec. 31, 2012 Subordinated seller notes, non-collateralized, net of unamortized discount with principal and interest payable in either monthly, quarterly or annual installments at effective interest rates ranging from 2.00% to 6.5%, maturing through November 2018	Dec. 31, 2011 Subordinated seller notes, non-collateralized, net of unamortized discount with principal and interest payable in either monthly, quarterly or annual installments at effective interest rates ranging from 2.00% to 6.5%, maturing through November 2018	Dec. 31, 2010 Prior Term Loan Facility	Dec. 31, 2010 10.25% Senior Notes due 2014	Dec. 31, 2012 10.25% Senior Notes due 2014
Long-Term Debt
Long-term debt		$ 520,646,000	$ 508,033,000												$ 293,300,000	$ 297,000,000			$ 200,000,000	$ 200,000,000	$ 27,346,000	$ 11,033,000
Issuance of debt														300,000,000	300,000,000			200,000,000
Less current portion		(11,082,000)	(8,065,000)
Long-term debt, less current portion		509,564,000	499,968,000
Interest rate stated percentage																			7.125%						10.25%
Interest rate, minimum (as a percent)																					2.00%
Interest rate, maximum (as a percent)																					6.50%
Maximum borrowing capacity										100,000,000	100,000,000
Charge related to the early extinguishment of senior debt	14,000,000			13,985,000
Premium paid to debt holders	9,800,000
Write-off of debt issuance cost	4,200,000
Mandatory prepayment															700,000
Interest, base rate										LIBOR			LIBOR		LIBOR
Interest rate margin (as a percent)										3.25%					3.00%		3.00%
LIBOR floor applicable to term loans under Credit Agreement, prior to amendment (as a percent)																	1.50%
Amount paid back under the facility		3,700,000	3,000,000	221,956,000																			220,300,000
LIBOR floor applicable to term loans under Credit Agreement (as a percent)															1.00%		1.00%
Fees related to the amendment of the credit agreement	16,976,000												4,100,000
Reduction in the interest rate margin applicable to the Term Loan prior to amendment (as a percent)																	0.75%
Consolidated interest coverage ratio, minimum										3.50
Consolidated interest coverage ratio, maximum										4.00
Proceeds from debt issuance allocated to partially funding an acquisition	78,200,000
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
Maximum notice period that the entity must provide for the redemption of the debt instrument (in days)						60
Additional maximum rollover from prior year's capital expenditure allowance										15,000,000
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%
Retirement of debt				184,831,000																				184,800,000
Maturities of long-term debt
2013		11,082,000
2014		10,942,000
2015		10,473,000
2016		287,574,000
2017		200,575,000
Total		$ 520,646,000	$ 508,033,000												$ 293,300,000	$ 297,000,000			$ 200,000,000	$ 200,000,000	$ 27,346,000	$ 11,033,000