Effects of New Accounting Pronouncements Effects of New Accounting Pronouncements (Details) - USD ($)	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2018	Mar. 31, 2018	Mar. 31, 2017
Cash and Cash Equivalents, at Carrying Value	$ 64,613,000	$ 57,131,000	$ 63,021,000
Restricted Cash and Investments, Current	587,000	294,000
Restricted Cash, Noncurrent	250,000	250,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	65,450,000	57,675,000	$ 63,565,000	$ 78,428,000
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Description of Prior-period Information Retrospectively Adjusted	420,000
Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 0	$ 888,000