Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial	$ 312	$ 2,543
Securitized beneficial interests	0	0
Total Assets	312	2,543
Guarantees	0	0
Derivative Liabilities	16	0
Liabilities, Fair Value Disclosure	16	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial	0	0
Securitized beneficial interests	25,864	15,797
Total Assets	25,864	15,797
Guarantees	5,265	4,575
Derivative Liabilities	0	0
Liabilities, Fair Value Disclosure	5,265	4,575
Total Assets / Liabilities, at Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial	312	2,543
Securitized beneficial interests	25,864	15,797
Total Assets	26,176	18,340
Guarantees	5,265	4,575
Derivative Liabilities	16	0
Liabilities, Fair Value Disclosure	$ 5,281	$ 4,575