Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Mar. 31, 2018	[1]	Dec. 30, 2017	[1]	Sep. 30, 2017	[1]	Jul. 01, 2017	[1]	Apr. 01, 2017	[2]	Dec. 31, 2016	[2]	Oct. 01, 2016	[2]	Jul. 02, 2016	[2]	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Earnings Per Share [Abstract]
Net income	$ 165,659		$ 11,945		$ 167,532		$ 167,245		$ 153,425		$ 141,846		$ 164,192		$ 163,049		$ 512,381	$ 622,512	$ 550,867
Weighted Average Number of Shares Outstanding, Basic	254,559		254,089		248,094		247,911		249,014		250,982		253,466		252,901		249,595	252,301	257,184
Dilutive effect of employee equity incentive plans																	2,754	2,284	2,260
Dilutive effect of 2017 Convertible Notes and warrants																	5,611	14,228	9,223
Weighted average common shares outstanding-diluted	257,916		258,108		258,217		265,797		267,157		270,781		270,373		266,206		257,960	268,813	268,667
Basic (in dollars per share)	$ 0.65	[3]	$ 0.05	[3]	$ 0.68	[3]	$ 0.67	[3]	$ 0.62	[3]	$ 0.57	[3]	$ 0.65	[3]	$ 0.64	[3]	$ 2.05	$ 2.47	$ 2.14
Diluted (in dollars per share)	$ 0.64	[3]	$ 0.05	[3]	$ 0.65	[3]	$ 0.63	[3]	$ 0.57	[3]	$ 0.52	[3]	$ 0.61	[3]	$ 0.61	[3]	$ 1.99	$ 2.32	$ 2.05

[1] Xilinx uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal 2018 was a 52-week year and each quarter was a 13-week quarter.

[2] Xilinx uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal 2017 was a 53-week year and each quarter was a 13-week quarter except the third quarter, which was a 14-week quarter.

[3] Net income per common share is computed independently for each of the quarters presented. Therefore, the sum of the quarterly per common share information may not equal the annual net income per common share.