Significant Customers and Concentrations of Credit Risk (Notes)	3 Months Ended
Jun. 30, 2018
Significant Customers and Concentrations of Credit Risk [Abstract]
Concentration Risk Disclosure [Text Block]	Significant Customers and Concentrations of Credit Risk Avnet, Inc. (Avnet), one of the Company’s distributors, distributes the Company’s products worldwide. As of June 30, 2018 and March 31, 2018, Avnet accounted for 70% and 61% of the Company’s total net accounts receivable, respectively. Net revenues from Avnet accounted for 51% and 41% of the Company’s worldwide net revenues in the first quarter of fiscal 2019 and 2018, respectively. The Company expects its accounts receivable to be relatively higher than normal on a temporary basis as the Company partners with its distributors to manage their inventory requirements. Xilinx is subject to concentrations of credit risk primarily in its trade accounts receivable and investments in debt securities to the extent of the amounts recorded on the condensed consolidated balance sheet. The Company attempts to mitigate the concentration of credit risk in its trade receivables through its credit evaluation process, collection terms, distributor sales to diverse end customers and through geographical dispersion of sales. Xilinx generally does not require collateral for receivables from its end customers or distributors. No end customer accounted for more than 10% of the Company’s worldwide net revenues for the first quarter of fiscal 2019 and 2018. The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 91% of its portfolio in AA (or its equivalent) or higher grade securities as rated by Standard & Poor’s or Moody’s Investors Service. The Company’s methods to arrive at investment decisions are not solely based on the rating agencies’ credit ratings. Xilinx also performs additional credit due diligence and conducts regular portfolio credit reviews, including a review of counterparty credit risk related to the Company’s forward currency exchange and interest rate swap contracts. Additionally, Xilinx limits its investments in the debt securities of a single issuer based upon the issuer’s credit rating and attempts to further mitigate credit risk by diversifying risk across geographies and type of issuer. As of June 30, 2018, approximately 24% of the portfolio consisted of mortgage-backed securities. All of the mortgage-backed securities in the investment portfolio were issued by U.S. government-sponsored enterprises and agencies and are rated AA+ by Standard & Poor’s and Aaa by Moody’s Investors Service.

Significant Customers and Concentrations of Credit Risk

Avnet, Inc. (Avnet), one of the Company’s distributors, distributes the Company’s products worldwide. As of June 30, 2018 and March 31, 2018, Avnet accounted for 70% and 61% of the Company’s total net accounts receivable, respectively. Net revenues from Avnet accounted for 51% and 41% of the Company’s worldwide net revenues in the first quarter of fiscal 2019 and 2018, respectively. The Company expects its accounts receivable to be relatively higher than normal on a temporary basis as the Company partners with its distributors to manage their inventory requirements.

Xilinx is subject to concentrations of credit risk primarily in its trade accounts receivable and investments in debt securities to the extent of the amounts recorded on the condensed consolidated balance sheet. The Company attempts to mitigate the concentration of credit risk in its trade receivables through its credit evaluation process, collection terms, distributor sales to diverse end customers and through geographical dispersion of sales. Xilinx generally does not require collateral for receivables from its end customers or distributors.

No end customer accounted for more than 10% of the Company’s worldwide net revenues for the first quarter of fiscal 2019 and 2018.

The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 91% of its portfolio in AA (or its equivalent) or higher grade securities as rated by Standard & Poor’s or Moody’s Investors Service. The Company’s methods to arrive at investment decisions are not solely based on the rating agencies’ credit ratings. Xilinx also performs additional credit due diligence and conducts regular portfolio credit reviews, including a review of counterparty credit risk related to the Company’s forward currency exchange and interest rate swap contracts. Additionally, Xilinx limits its investments in the debt securities of a single issuer based upon the issuer’s credit rating and attempts to further mitigate credit risk by diversifying risk across geographies and type of issuer.

As of June 30, 2018, approximately 24% of the portfolio consisted of mortgage-backed securities. All of the mortgage-backed securities in the investment portfolio were issued by U.S. government-sponsored enterprises and agencies and are rated AA+ by Standard & Poor’s and Aaa by Moody’s Investors Service.