Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission. In the opinion of management, such unaudited information includes all adjustments, consisting of normal recurring adjustments necessary for a fair presentation of our financial position and results of operations. The results of operations for the three months ended June 30, 2018 are not necessarily indicative of results that may be achieved for the entire year. The financial statements and related notes do not include all information and footnotes required by U.S. GAAP for annual reports. This quarterly report should be read in conjunction with the consolidated financial statements included in our annual report on Form 10 -K for the year ended March 31, 2018.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016 - 02, Leases (Topic 842 ) . The pronouncement requires lessees to recognize a liability for lease obligations, which represents the discounted obligation to make future minimum lease payments, and a corresponding right-of-use asset on the balance sheet for all leases with terms greater than 12 months. The guidance also requires qualitative and quantitative disclosures designed to present financial statement users with the ability to assess the amount, timing, and uncertainty of cash flows arising from leases. We have initiated our plan for the adoption and implementation of this new accounting standard, including assessing our lease arrangements, evaluating practical expedients, and making necessary changes to our accounting policies, processes, and internal controls over financial reporting. We expect to adopt the requirements of ASU 2016 - 02 beginning April 1, 2019 using the modified retrospective method. We are still assessing the expected impact of the standard on our consolidated balance sheets but it will not significantly impact our consolidated statements of income and cash flows. Recently Adopted Accounting Pronouncements Effective April 1, 2018, we adopted ASU 2014 - 09 Revenue from Contracts with Customers (Topic 606 ) and all related amendments (referred to collectively hereinafter as “ASU 606” ) on a modified retrospective basis. ASU 606 requires an entity to recognize revenue for the transfer of goods or services equal to the amount it expects to be entitled to receive for the goods and services. The adoption did not have a material impact on our condensed consolidated balance sheets, statements of income, or cash flows. The primary impact of adoption was the enhancement of disclosures to provide additional clarity regarding how revenue is earned and recognized, and to show revenues at a more disaggregated level, included in Note 2. In March 2018, the FASB issued ASU 2018 - 05, Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118. The amendments in this update provide guidance on when to record and disclose provisional amounts for certain income tax effects of the Tax Cuts and Jobs Act ("TCJA"). The amendments also require any provisional amounts or subsequent adjustments to be included in net income from continuing operations. Additionally, this ASU discusses required disclosures that an entity must make with regard to the TCJA. This ASU is effective immediately as new information is available to adjust provisional amounts that were previously recorded. We have adopted this standard and will continue to evaluate indicators that may give rise to a change in our tax provision as a result of the TCJA. Refer to Note 7 for additional information on the TCJA.