Fair Value Measurements Input Hierarchy of Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securitized beneficial interests	$ 0	$ 0	$ 0
Total Assets	0	0	0
Guarantees	0	0	0
Total liabilities	0	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securitized beneficial interests	29,371	40,368	21,792
Total Assets	29,371	40,368	21,792
Guarantees	4,467	7,350	4,865
Total liabilities	4,467	7,350	4,865
Total Assets / Liabilities, at Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securitized beneficial interests	29,371	40,368	21,792
Total Assets	29,371	40,368	21,792
Guarantees	4,467	7,350	4,865
Total liabilities	$ 4,467	$ 7,350	$ 4,865