Borrowings (Components of Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Interest expense, borrowings:
Interest expense	$ 31,983	$ 27,220	$ 93,475	$ 77,184
Capitalized interest	(2,075)	(1,119)	(5,769)	(3,417)
Amortization of transaction costs	963	863	2,909	2,510
Interest expense resulting from derivatives	687	1,818	3,311	6,920
Total interest expense	31,558	28,782	93,926	83,197
Amortization on early extinguishment of debt		499		499
Total	$ 31,558	$ 29,281	$ 93,926	$ 83,696