Changes in Stockholders' Equity and Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 70,217
Net Income	4,973	4,755
Net change in unrealized loss on short term investments	8	(46)
Ending balance	72,139
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,578
Share based compensation	372
Dividends declared
Net Income
Net change in unrealized loss on short term investments
Ending balance	1,950
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	68,647
Share based compensation
Dividends declared	(3,431)
Net Income	4,973
Net change in unrealized loss on short term investments
Ending balance	70,189
Accumulated Other Comprehensive Gain (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(37)
Share based compensation
Dividends declared
Net Income
Net change in unrealized loss on short term investments	8
Ending balance	$ (29)