Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2018	May 25, 2018	Sep. 23, 2017
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Entity Registrant Name	CIRRUS LOGIC INC
Entity Central Index Key	0000772406
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--03-31
Entity Common Stock, Shares Outstanding		60,978,789
Entity Public Float			$ 2,433,893,534