LONG-TERM DEBT, BY TYPE (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Long-term debt
Long-term debt	$ 1,174,905	$ 1,158,862
Less current portion	133,951	142,237
Long-term debt, Net	1,040,954	1,016,625
Revolving credit facility
Long-term debt
Long-term debt	317,571	320,000
Receivable securitization facility
Long-term debt
Long-term debt	145,000	120,000
Equipment leasing facility and other capital leases
Long-term debt
Long-term debt	64,597	61,301
Senior subordinated notes due 2017
Long-term debt
Long-term debt	173,271	173,061
Senior notes due 2018
Long-term debt
Long-term debt	348,064	347,867
Convertible senior subordinated notes
Long-term debt
Long-term debt	109,738	128,655
Secured Promissory Notes [Member]
Long-term debt
Long-term debt	8,686	0
Other debt
Long-term debt
Long-term debt	$ 7,978	$ 7,978