Significant Accounting Policies - Accrued Expenses and Other Payables (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
Accounting Policies [Abstract]
Accrued compensation and benefits	$ 16,539	$ 40,517
Excise and other tax liabilities	55,451	59,455
Derivative liabilities	40,813	28,612
Accrued interest	27,767	20,543
Product exchange liabilities	9,355	5,843
Deferred gain on sale of general partner interest in TLP	30,113	30,113
Other	15,995	29,343
Total	$ 196,033	$ 214,426