Shareholder Rights Plan	12 Months Ended
Mar. 31, 2018
Text Block [Abstract]
Shareholder Rights Plan	Note 11 — Shareholder Rights Plan During fiscal 1997, the Company’s Board of Directors approved the adoption of its Shareholder Rights Plan. The Shareholder Rights Plan provides for a dividend distribution to the Company’s shareholders of one preferred stock purchase right for each outstanding share of the Company’s common stock held by such shareholder (as used in this Note 11, the “right” or the “rights”), only in the event of certain takeover-related events. In April 2002, the Company’s Board of Directors approved an amendment to the Shareholder Rights Plan to extend the expiration date of the rights to February 10, 2012, set the exercise price of each right at $118, and enable Fidelity Management & Research Company and its affiliates to purchase up to 18% of the shares of common stock of the Company without triggering the rights, with the limitations under the Shareholder Rights Plan remaining in effect for all other stockholders of the Company. In November 2008, the Company’s Board of Directors approved an amendment to the Shareholder Rights Plan to extend the expiration date of the rights to February 10, 2022, remove the ability of Fidelity Management & Research Company and its affiliates to purchase up to 18% of the shares of common stock of the Company without triggering the rights, substitute Computershare Trust Company, N.A. as the rights agent and effect certain technical changes to the Shareholder Rights Plan. Generally, the Shareholder Rights Plan provides that if a person or group acquires 15% or more of the Company’s common stock without the approval of the Company’s Board of Directors, subject to certain exceptions, the holders of the rights, other than the acquiring person or group, would, under certain circumstances, have the right to purchase additional shares of the Company’s common stock having a market value equal to two times the then-current exercise price of the right. In addition, if the Company is thereafter merged into another entity, or if 50% or more of the Company’s consolidated assets or earning power are sold, then the right would entitle its holder to buy common shares of the acquiring entity having a market value equal to two times the then-current exercise price of the right. The Company’s Board of Directors may exchange or redeem the rights under certain conditions.

Note 11 — Shareholder Rights Plan

During fiscal 1997, the Company’s Board of Directors approved the adoption of its Shareholder Rights Plan. The Shareholder Rights Plan provides for a dividend distribution to the Company’s shareholders of one preferred stock purchase right for each outstanding share of the Company’s common stock held by such shareholder (as used in this Note 11, the “right” or the “rights”), only in the event of certain takeover-related events. In April 2002, the Company’s Board of Directors approved an amendment to the Shareholder Rights Plan to extend the expiration date of the rights to February 10, 2012, set the exercise price of each right at $118, and enable Fidelity Management & Research Company and its affiliates to purchase up to 18% of the shares of common stock of the Company without triggering the rights, with the limitations under the Shareholder Rights Plan remaining in effect for all other stockholders of the Company. In November 2008, the Company’s Board of Directors approved an amendment to the Shareholder Rights Plan to extend the expiration date of the rights to February 10, 2022, remove the ability of Fidelity Management & Research Company and its affiliates to purchase up to 18% of the shares of common stock of the Company without triggering the rights, substitute Computershare Trust Company, N.A. as the rights agent and effect certain technical changes to the Shareholder Rights Plan.

Generally, the Shareholder Rights Plan provides that if a person or group acquires 15% or more of the Company’s common stock without the approval of the Company’s Board of Directors, subject to certain exceptions, the holders of the rights, other than the acquiring person or group, would, under certain circumstances, have the right to purchase additional shares of the Company’s common stock having a market value equal to two times the then-current exercise price of the right.

In addition, if the Company is thereafter merged into another entity, or if 50% or more of the Company’s consolidated assets or earning power are sold, then the right would entitle its holder to buy common shares of the acquiring entity having a market value equal to two times the then-current exercise price of the right. The Company’s Board of Directors may exchange or redeem the rights under certain conditions.