Fair Value Measurements Input Hierarchy of Items Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	$ 810	$ 3,145	$ 398
Securitized beneficial interests	0	0	0
Total Assets	810	3,145	398
Guarantees	0	0	0
Derivative financial instruments	77	644	747
Total liabilities	77	644	747
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0	0
Securitized beneficial interests	35,304	31,992	20,989
Total Assets	35,304	31,992	20,989
Guarantees	6,023	6,367	9,489
Derivative financial instruments	0	0	0
Total liabilities	6,023	6,367	9,489
Total Assets / Liabilities, at Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	810	3,145	398
Securitized beneficial interests	35,304	31,992	20,989
Total Assets	36,114	35,137	21,387
Guarantees	6,023	6,367	9,489
Derivative financial instruments	77	644	747
Total liabilities	$ 6,100	$ 7,011	$ 10,236