Borrowings (Components of Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest expense, borrowings:
Interest expense	$ 44,743	$ 36,220	$ 88,074	$ 70,416
Capitalized interest	(6,669)	(2,227)	(12,168)	(2,646)
Amortization of transaction costs	1,047	881	2,100	1,842
Interest expense resulting from derivatives	$ 1	$ 156	$ 4	$ 672