Effect of Interest Rate Contracts on the Statement of Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
The effect of interest rate contracts on the statement of operations:
Loss recognized in income on interest rate contracts	$ 4,348	$ 4,628	$ 9,153	$ 11,465
(Gain) loss recognized in AOCI on interest rate contracts (effective portion)			(12,142)	(253)
Loss reclassified from AOCI into income (effective portion)			8,685	10,225
(Gain) loss recognized in income on interest rate contracts (ineffective portion and amount excluded from effectiveness testing)			$ 468	$ 1,240

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Paragraph 4C

-Subparagraph (d)

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Amount of decrease in the fair value of derivatives recognized in the income statement.

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-Publisher FASB

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