Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Income Taxes Unrecognized Tax Benefits Details
Balance at beginning of year	$ 3,331	$ 2,881	$ 2,420
Gross increases - tax position in prior period	0	0	82
Gross increases - tax positions related to the current year	649	450	379
Balance at end of year	$ 3,980	$ 3,331	$ 2,881