LONG-TERM DEBT (Details) (USD $)	3 Months Ended				3 Months Ended									1 Months Ended		3 Months Ended				1 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2012 Minimum	Sep. 30, 2012 Maximum	Sep. 30, 2012 Interest rate swap agreement maturing on September 26, 2012	Sep. 30, 2012 Interest rate swap agreement maturing on May 13, 2016	Sep. 30, 2012 Revolving credit facility	Jun. 30, 2012 Revolving credit facility	Sep. 30, 2012 Term loan facility	Jun. 30, 2012 Term loan facility	Sep. 30, 2012 Other, generally unsecured	Jun. 30, 2012 Other, generally unsecured	Apr. 15, 2011 New Credit Facility	Apr. 30, 2011 New Credit Facility, term loan	Apr. 15, 2011 New Credit Facility, term loan	Sep. 30, 2012 New Credit Facility, term loan Quarterly principal reduction through March 2013	Sep. 30, 2012 New Credit Facility, term loan Quarterly principal reduction from June 2013 through March 2014	Sep. 30, 2012 New Credit Facility, term loan Quarterly principal reduction from June 2014 through May 2016	Sep. 30, 2012 New Credit Facility, term loan Principal reduction May 2016	Apr. 30, 2011 New Credit Facility, revolving credit	Sep. 30, 2012 New Credit Facility, revolving credit	Sep. 30, 2011 New Credit Facility, revolving credit	Apr. 15, 2011 New Credit Facility, revolving credit
Components of long-term debt
Long-term debt	$ 557,784,000	$ 511,466,000					$ 280,000,000	$ 230,000,000	$ 277,500,000	$ 281,250,000	$ 284,000	$ 216,000
Less current maturities	(19,034,000)	(17,091,000)
Long-term debt, net of current maturities	538,750,000	494,375,000
Total undrawn revolver capacity																					120,000,000	170,000,000
Overall capacity of senior secured credit facility													700,000,000		300,000,000
Maximum borrowing capacity																							400,000,000
Term of facility														5 years						5 years
Sublimit under the revolving credit facility related to standby letters of credit																							50,000,000
Sublimit under the revolving credit facility related to swingline loans																							10,000,000
Sublimit under the revolving credit facility related to multicurrency borrowings																							150,000,000
Variable rate basis	LIBOR
Debt, margin on LIBOR rate (as a percent)			1.00%	2.00%
Effective interest rate after giving effect to the floating-to-fixed interest rate swaps (as a percent)							1.72%	1.75%	3.59%	3.58%
Principal reduction amount																3,750,000	5,625,000	7,500,000	187,500,000
Variable interest rate description before hedging of debt	LIBOR				LIBOR	LIBOR
Notional amount of interest rate swap	277,500,000	281,300,000			218,800,000	165,000,000
Effective interest rate for hedged variable rate debt (as a percent)					1.89%	2.09%
Amounts expected to be reclassified from other comprehensive income to interest expense in the next twelve months	$ 5,100,000