Borrowings (Interest Rates and Company Borrowings) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Interest and debt expense:
Weighted average interest rate during the quarter	1.66%	1.62%	1.65%	1.71%
Interest rate at quarter end	1.69%	1.66%	1.69%	1.66%
Maximum amount outstanding during the quarter	$ 265,000	$ 232,000	$ 265,000	$ 232,000
Average amount outstanding during the period	258,207	219,163	224,582	188,271
Facility fees	$ 25	$ 91	$ 169	$ 289