Long-Term Debt Foreign Seasonal Lines of Credit (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	593,696
Unsued lines of credit	600,438
Foreign Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	374,532
Line of credit facility, current borrowing capacity	655,154
Unsued lines of credit	13,981
Line of credit facility, amount issued but unfunded	7,239
Foreign Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of credit facility, borrowing period	180 days
Foreign Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of credit facility, borrowing period	270 days
Long-Term Foreign Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	88,226
Line of credit facility, current borrowing capacity	125,000
Secured Debt [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	290,000
Secured Debt [Member] | Long-Term Foreign Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	38,596