Recent Accounting Pronouncements Adjustments due to adoption of ASC 606 Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
Item Effected [Line Items]
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	$ 43,637	$ 43,506	$ 43,518
Assets	396,703	372,976	372,988
Deferred Revenue, Current	9,026	9,766	9,818
Liabilities, Current	73,835	81,653	81,705
Liabilities	99,453	106,578	106,630
Retained earnings	86,000	54,856	54,816
Stockholders' Equity Attributable to Parent	297,250	266,398	266,358
Liabilities and Equity	$ 396,703	372,976	372,988
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Item Effected [Line Items]
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent			43,518
Assets			372,988
Deferred Revenue, Current			9,818
Liabilities, Current			81,705
Liabilities			106,630
Retained earnings			54,816
Stockholders' Equity Attributable to Parent			266,358
Liabilities and Equity			$ 372,988
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Item Effected [Line Items]
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent		(12)
Assets		(12)
Deferred Revenue, Current		(52)
Liabilities, Current		(52)
Liabilities		(52)
Retained earnings		40
Stockholders' Equity Attributable to Parent		40
Liabilities and Equity		$ (12)