DEBT (Details) (USD $)	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013
Debt Instrument [Line Items]
Total debt	$ 889,773,000		$ 787,269,000
Total debt	889,773,000		787,269,000
Less short-term borrowings and current maturities of long-term debt	(6,950,000)		(22,323,000)
Long-term debt, less current maturities	882,823,000		764,946,000
Letters of Credit Outstanding, Amount	600,000
Long Term Convertible Debt Current And Noncurrent [Abstract]
Debt Instrument, Convertible, Effective Interest Rate	6.90%	6.90%
Amortization of debt discount	921,000	870,000
Term Loan [Member]
Debt Instrument [Line Items]
Total debt	229,472,000		230,625,000
Repayment of debt	1,200,000
Balances Of Debt And Equity Components [Abstract]
Debt Instrument, Face Amount	250,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	102,000,000		0
Proceeds from borrowings	102,000,000
Revolving Credit Facility [Member] | Second Amendment [Member]
Balances Of Debt And Equity Components [Abstract]
Debt Instrument, Face Amount			200,000,000
Revolving Credit Facility [Member] | Third Amendment [Member]
Balances Of Debt And Equity Components [Abstract]
Debt Instrument, Face Amount	350,000,000
Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Total debt	107,117,000		106,196,000
Total debt	107,117,000		106,196,000
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Balances Of Debt And Equity Components [Abstract]
Equity component- net carrying value	14,905,000		14,905,000
Debt Instrument, Face Amount	115,000,000		115,000,000
Debt component- unamortized discount	(7,883,000)		(8,804,000)
Long Term Convertible Debt Current And Noncurrent [Abstract]
Contractual coupon interest	863,000	863,000
Amortization of debt discount	921,000	870,000
Total interest expense	1,784,000	1,733,000
Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Total debt	450,000,000		450,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Other debt [Member]
Debt Instrument [Line Items]
Total debt	$ 1,184,000		$ 448,000