Fair Value Measurements - Input Hierarchy of Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018
Total Assets / Liabilities at Fair Value
Financial Assets:
Derivative financial instruments	$ 0	$ 186	$ 0
Securitized beneficial interests	25,579	40,332	17,512
Total assets	25,579	40,518	17,512
Financial Liabilities:
Long-term debt	689,046	830,785	897,970
Guarantees	1,026	3,714	1,861
Total liabilities	690,072	834,499	899,831
Level 2
Financial Assets:
Derivative financial instruments	0	186	0
Securitized beneficial interests	0	0	0
Total assets	0	186	0
Financial Liabilities:
Long-term debt	688,431	830,082	897,264
Guarantees	0	0	0
Total liabilities	688,431	830,082	897,264
Level 3
Financial Assets:
Derivative financial instruments	0	0	0
Securitized beneficial interests	25,579	40,332	17,512
Total assets	25,579	40,332	17,512
Financial Liabilities:
Long-term debt	615	703	706
Guarantees	1,026	3,714	1,861
Total liabilities	$ 1,641	$ 4,417	$ 2,567