Borrowings (Components of Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Interest expense, borrowings:
Interest expense	$ 38,825	$ 31,983	$ 109,241	$ 93,475
Capitalized interest	(5,055)	(2,075)	(7,701)	(5,769)
Amortization of transaction costs	909	963	2,751	2,909
Interest expense resulting from derivatives	148	687	820	3,311
Total interest expense	$ 34,827	$ 31,558	$ 105,111	$ 93,926